Patent Publication Number: US-2022223760-A1

Title: Display device

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a national entry of International Application No. PCT/KR2020/006568, filed on May 20, 2020, which claims under 35 U.S.C. §§ 119(a) and 365(b) priority to and benefits of Korean Patent Application No. 10-2019-0063375, filed on May 29, 2019, in the Korean Intellectual Property Office (KIPO), the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Technical Field 
     The disclosure relates to a display device, and more particularly, to a display device including electrodes having different widths. 
     2. Description of Related Art 
     Display devices are becoming increasingly important with the development of multimedia. Accordingly, various types of display devices such as organic light emitting displays and liquid crystal displays are being used. 
     A display device includes a display panel such as an organic light emitting display panel or a liquid crystal display panel as a device for displaying an image of the display device. Among them, a light emitting display panel may include light-emitting elements such as light emitting diodes (LEDs). For example, the LEDs may be organic light emitting diodes (OLEDs) using an organic material as a fluorescent material or may be inorganic LEDs using an inorganic material as a fluorescent material. 
     Inorganic LEDs using an inorganic semiconductor as a fluorescent material are durable even in a high-temperature environment and have higher blue light efficiency than OLEDs. In addition, a transfer method using dielectrophoresis (DEP) has been developed for a manufacturing process which has been pointed out as a limitation of conventional inorganic LEDs. Therefore, research is being continuously conducted on inorganic LEDs having better durability and efficiency than OLEDs. 
     SUMMARY 
     Aspects of the disclosure provide a display device including a plurality of electrodes having different widths and light-emitting elements disposed between the electrodes. 
     Aspects of the disclosure also provide a display device in which light-emitting elements disposed between electrodes have a uniform distribution. 
     It should be noted that aspects of the disclosure are not limited thereto and other aspects, which are not mentioned herein, will be apparent to those of ordinary skill in the art from the following description. 
     According to an embodiment of the disclosure, a display device may include at least one pixel, at least one electrode spaced apart from each other in each of the at least one pixel, and at least one light-emitting element disposed between the at least one electrode. The at least one electrode may include at least one inner electrode disposed adjacent to a central portion of the at least one pixel, and at least one outer electrode spaced apart from each of the at least one inner electrode. A distance between the central portion of the at least one pixel and the at least one outer electrode may be greater than a distance between the central portion of the at least one pixel and the at least one inner electrode, and a width of the at least one inner electrode may be different from a width of the at least one outer electrode. 
     The display device may further comprise a bank disposed between the at least one pixel and surrounding the inner electrode and the at least one outer electrode, a plurality of alignment regions between a central portion of the at least one inner electrode and a central portion of the at least one outer electrode and in which the at least one light-emitting element is disposed, and a non-alignment region between the bank and the central portion of the at least one outer electrode. A width of each of the plurality of alignment regions may be greater than a width of the non-alignment region. 
     A distance between the bank and the at least one outer electrode may be less than a distance between the outer electrode and the central portion of the at least one pixel. 
     The at least one light-emitting element may have a shape extending in a direction, and a distance between the at least one inner electrode and the at least one outer electrode may be less than a length of the at least one light-emitting element measured in the direction. 
     A distance between the at least one inner electrode may be equal to the distance between the at least one inner electrode and the at least one outer electrode, and the at least one light-emitting element may be also disposed between the at least one inner electrode. 
     The width of the at least one inner electrode may be greater than the width of the at least one outer electrode. 
     The at least one inner electrode may include a first inner electrode, and a second inner electrode spaced apart from the first inner electrode, and the first inner electrode and the second inner electrode may be spaced apart from each other based on the central portion of the at least one pixel. 
     The first inner electrode and the second inner electrode may have a same width. 
     The at least one inner electrode may include a third inner electrode having a central portion colinear with the central portion of a corresponding one of the at least one pixel and a plurality of fourth inner electrodes spaced apart from sides of the third inner electrode, and a width of the third inner electrode and a width of each of the plurality of fourth inner electrodes may be different from each other. 
     The width of each of the plurality of fourth inner electrodes may be greater than the width of the at least one outer electrode and may be less than the width of the third inner electrode. 
     According to an embodiment of the disclosure, a display device comprises a first bank and a second bank that are disposed on a substrate and spaced apart from a center of the substrate, at least one first electrode and at least one second electrode spaced apart from each other between the first and second banks, and at least one light-emitting element disposed between the at least one first electrode and the at least one second electrode. A width of the at least one first electrode and a width of the at least one second electrode may be different from each other. 
     The at least one first electrode and the at least one second electrode may be disposed between the first bank and the center of the substrate, the at least one first electrode may be disposed between the at least one second electrode and the bank, and the width of the at least one second electrode may be greater than the width of the at least one first electrode. 
     A distance between a central portion of the at least one first electrode and the bank may be less than a distance between the central portion of the at least one first electrode and a central portion of the at least one second electrode. 
     A first separation distance (WD) between the at least one first electrode and the bank, and a second separation distance (WA) between the at least one first electrode and the at least one second electrode may be defined as Equation 1 below, 
     
       
         
           
             
               
                 
                   WD 
                   &lt; 
                   
                     WA 
                     + 
                     
                       WE 
                       / 
                       2 
                     
                   
                 
               
               
                 
                   [ 
                   
                     Equation 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     1 
                   
                   ] 
                 
               
             
           
         
       
     
     where, WD is the first separation distance between the at least one first electrode and the bank, WA is the second separation distance between the at least one first electrode and the at least one second electrode, and WE is the width of the at least one first electrode or the at least one second electrode). 
     The display device may further comprise a third electrode spaced apart from the at least one second electrode with respect to the center of the substrate, the at least one second electrode and the third electrode having a same width, and a fourth electrode disposed between the third electrode and the second bank and spaced apart from the third electrode, the at least one first electrode and the fourth electrode having a same width. 
     A central portion of the at least one second electrode may be colinear with the center of the substrate, the at least one first electrode may be disposed between the at least one second electrode and the first bank, and the width of the at least one second electrode may be greater than the width of the at least one first electrode. 
     A distance between the first bank and a central portion of the at least one first electrode may be less than a distance between the central portion of the at least one first electrode and the central portion of the at least one second electrode. 
     According to an embodiment of the disclosure, a display device may comprise a plurality of banks each extending in a first direction and spaced apart from each other in a second direction different from the first direction, at least one first electrode extending in the first direction between the banks, at least one second electrode spaced apart from the at least one first electrode in the second direction, and at least one light-emitting element disposed between the at least one first electrode and the at least one second electrode. A width of the at least one first electrode and a width of the at least one second electrode are different from each other, and a distance between a central portion of the at least one first electrode and a central portion of the at least one second electrode may be greater than a distance between the at least one first electrode and a corresponding one of the plurality of banks. 
     The at least one first electrode may be spaced apart from sides of the at least one second electrode, and the width of the at least one second electrode is greater than the width of the at least one first electrode. 
     A distance between the at least one first electrode and sides of the at least one second electrode may be less than a length of the at least one light-emitting element. 
     The details of other embodiments are included in the detailed description and the accompanying drawings. 
     A display device according to an embodiment can include electrodes having different widths. Accordingly, the number of light-emitting elements disposed in a region other than a space between the electrodes can be minimized, and light-emitting elements disposed between the plurality of electrodes can have a uniform distribution. 
     The effects according to the embodiments are not limited by the contents exemplified above, and more various effects are included in this disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An additional appreciation according to the embodiments of the disclosure will become more apparent by describing in detail the embodiments thereof with reference to the accompanying drawings, wherein: 
         FIG. 1  is a schematic plan view of a display device according to an embodiment. 
         FIG. 2  is a schematic plan view of a pixel of the display device according to an embodiment. 
         FIG. 3  is a schematic cross-sectional view taken along lines Xa-Xa′, Xb-Xb′, and Xc-Xc′ of  FIG. 2 . 
         FIG. 4  is a schematic cross-sectional view illustrating a portion of a display device according to another embodiment. 
         FIG. 5  is a schematic view of a light-emitting element according to an embodiment. 
         FIG. 6  is a schematic cross-sectional view taken across a sub-pixel of the display device according to an embodiment. 
         FIGS. 7 and 8  are schematic views illustrating a state in which ink including light-emitting elements dispersed therein is sprayed onto the sub-pixel of the display device according to an embodiment. 
         FIG. 9  is a plan view illustrating a sub-pixel of a display device according to still another embodiment. 
         FIG. 10  is a schematic cross-sectional view taken across the sub-pixel of the display device of  FIG. 9 . 
         FIG. 11  is a plan view illustrating a sub-pixel of a display device according to yet another embodiment. 
         FIG. 12  is a schematic cross-sectional view taken across the sub-pixel of the display device of  FIG. 11 . 
         FIG. 13  is a schematic cross-sectional view taken across a sub-pixel according to another embodiment of the display device of  FIG. 11 . 
         FIG. 14  is a plan view illustrating a sub-pixel of a display device according to yet another embodiment. 
         FIG. 15  is a schematic cross-sectional view taken across the sub-pixel of the display device of  FIG. 14 . 
         FIG. 16  is a schematic cross-sectional view taken across a sub-pixel according to another embodiment of the display device of  FIG. 14 . 
         FIGS. 17 and 18  are schematic plan views each illustrating a sub-pixel of a display device according to yet another embodiment. 
         FIG. 19  is a schematic view of a light-emitting element according to another embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the disclosure are shown. This disclosure may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will convey the scope of the disclosure to those skilled in the art. 
     It will also be understood that when a layer is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be. The same reference numbers indicate the same components throughout the specification. 
     It will be understood that, although the terms “first,” “second,” and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For instance, a first element discussed below could be termed a second element without departing from the teachings of the disclosure. Similarly, the second element could also be termed the first element. 
     The terms “about” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” may mean within one or more standard deviations, or within ±30%, 20%, 10%, 5% of the stated value. 
     It will be understood that the terms “contact,” “connected to,” and “coupled to” may include a physical and/or electrical contact, connection, or coupling. 
     The phrase “at least one of” is intended to include the meaning of “at least one selected from the group of” for the purpose of its meaning and interpretation. For example, “at least one of A and B” may be understood to mean “A, B, or A and B.” 
     Unless otherwise defined or implied herein, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the disclosure, and should not be interpreted in an ideal or excessively formal sense unless clearly so defined herein. 
     Hereinafter, embodiments will be described with reference to the accompanying drawings. 
       FIG. 1  is a schematic plan view of a display device according to an embodiment. 
     Referring to  FIG. 1 , a display device  10  displays a video or a still image. The display device  10  may refer to all electronic devices that provide display screens. For example, the display device  10  may include a television, a laptop, a monitor, an advertising board, an Internet of Things (IoT) device, a mobile phone, a smartphone, a tablet personal computer (PC), an electronic watch, a smartwatch, a watch phone, a head-mounted display, a mobile communication terminal, an electronic organizer, an electronic book reader, a portable multimedia player (PMP), a navigation device, a game machine, a digital camera, a camcorder, and the like, which provide display screens. 
     The display device  10  includes a display panel that provides a display screen. Examples of the display panel may include a light-emitting diode (LED) display panel, an organic light-emitting display panel, a quantum dot light-emitting display panel, a plasma display panel, a field emission display panel, and the like. Hereinafter, although an example in which the LED display panel is applied as an example of the display panel is described, the disclosure is not limited thereto, and when the same technical spirit is applicable, it may be applied to other display panels. 
     A shape of the display device  10  may be variously modified. For example, the display device  10  may have shapes such as a rectangular shape of which lateral sides are long, a rectangular shape of which longitudinal sides are long, a square shape, a quadrangular shape of which corner portions (vertexes) are round, other polygonal shapes, a circular shape, and the like. A shape of a display region DA of the display device  10  may also be similar to an overall shape of the display device  10 . In  FIG. 1 , the display device  10  and the display region DA, which have the rectangular shape of which lateral sides are long, are illustrated. 
     The display device  10  may include the display region DA and a non-display region NDA. The display region DA is a region in which an image may be displayed, and the non-display region NDA is a region in which an image is not displayed. The display region DA may also be referred to as an active region, and the non-display region NDA may also be referred to as an inactive region. 
     The display region DA may generally occupy a center of the display device  10 . The display region DA may include pixels PX. The pixels PX may be arranged in a matrix form. A shape of each of the pixels PX may be a rectangular shape or a square shape in a plan view, but is not limited thereto, and may be a rhombic shape of which sides are inclined with respect to a first direction DR 1 . Each of the pixels PX may include one or more light-emitting elements  300 , which emit light in a specific wavelength band, to display a specific color. 
       FIG. 2  is a schematic plan view of a pixel of the display device according to an embodiment. 
     Referring to  FIG. 2 , each of the pixels PX may include a first sub-pixel PX 1 , a second sub-pixel PX 2 , and a third sub-pixel PX 3 . The first sub-pixel PX 1  may emit light of a first color, the second sub-pixel PX 2  may emit light of a second color, and the third sub-pixel PX 3  may emit light of a third color. The first color may be a blue color, the second color may be a green color, and the third color may be a red color, but the disclosure is not limited thereto, and each of the sub-pixels PXn may emit light of a same color, where n is a natural number. in  FIG. 2 , the pixel PX is illustrated as including three sub-pixels PXn, but the disclosure is not limited thereto, and the pixel PX may include a greater number of sub-pixels PXn. 
     Each of the sub-pixels PXn of the display device  10  may include a region that is defined as a light-emitting region EMA. The first sub-pixel PX 1  may include a first light-emitting region EMA 1 , the second sub-pixel PX 2  may include a second light-emitting region EMA 2 , and the third sub-pixel PX 3  may include a third light-emitting region EMA 3 . The light-emitting region EMA may be defined as a region in which the light-emitting elements  300  included in the display device  10  are disposed to emit light in a specific wavelength band. Each of the light-emitting elements  300  includes an active layer  330 , and the active layer  330  may emit light in a specific wavelength band without directivity. For example, the light emitted from the active layer  330  of the light-emitting element  300  may also be emitted in directions toward side surfaces of the light-emitting element  300  including both end portions thereof. The light-emitting region EMA of each sub-pixel PXn may include a region in which the light-emitting element  300  is disposed and a region in which the light emitted from the light-emitting element  300  is emitted to a region adjacent to the light-emitting element  300 . However, the disclosure is not limited thereto, and the light-emitting region EMA may also include a region in which the light emitted from the light-emitting element  300  is reflected or refracted by another member to be emitted. Light-emitting elements  300  may be disposed in each sub-pixel PXn, and the region in which the light-emitting elements  300  are disposed and a region adjacent to the region form the light-emitting region EMA. 
     Although not shown in the drawings, each of the sub-pixels PXn of the display device  10  may include a non-light-emitting region that is defined as a region other than the light-emitting region EMA. The non-light-emitting region may be defined as a region in which the light-emitting elements  300  are not disposed and which the light emitted by the light-emitting elements  300  does not reach so that light is not emitted. 
     Each sub-pixel PXn of the display device  10  may include electrodes  210  and  220 , the light-emitting elements  300 , banks  410 ,  420 , and  430  (shown in  FIG. 3 ), and at least one insulating layer  510 ,  520 , or  550  (shown in  FIG. 3 ). 
     The electrodes  210  and  220  may be electrically connected to the light-emitting elements  300  and may receive a predetermined voltage so as to allow the light-emitting elements  300  to emit light in a specific wavelength band. Further, at least a portion of each of the electrodes  210  and  220  may be utilized to form an electric field in the sub-pixel PXn, thereby aligning the light-emitting elements  300 . 
     The electrodes  210  and  220  may include a first electrode  210  and a second electrode  220 . In an embodiment, the first electrode  210  may be a pixel electrode separated for each sub-pixel PXn, and the second electrode  220  may be a common electrode electrically connected in common along each sub-pixel PXn. One of the first electrode  210  and the second electrode  220  may be an anode of the light-emitting element  300 , and the other thereof may be a cathode of the light-emitting element  300 . However, the disclosure is not limited thereto, and the reverse of the above description may be possible. 
     The first electrode  210  and the second electrode  220  may respectively include electrode stem portions  210 S and  220 S extending in the first direction DR 1  and one or more electrode branch portions  210 B and  220 B that extend and branch from the electrode stem portions  210 S and  220 S in a second direction DR 2  that is a direction intersecting (or crossing) the first direction DR 1 . 
     The first electrode  210  may include a first electrode stem portion  210 S extending in the first direction DR 1 , and at least one first electrode branch portion  210 B branching from the first electrode stem portion  210 S to extend in the second direction DR 2 . 
     The first electrode stem portion  210 S of an arbitrary pixel may have both ends that are spaced apart and terminated between the sub-pixels PXn and may be substantially collinear with the first electrode stem portion  210 S of an adjacent sub-pixel in the same row (e.g., adjacent in the first direction DR 1 ). Both ends of the first electrode stem portions  210 S disposed in each sub-pixel PXn may be spaced apart from each other so that different electrical signals may be applied to the first electrode branch portions  210 B, and the first electrode branch portions  210 B may be individually driven. 
     The first electrode branch portion  210 B may branch from at least a portion of the first electrode stem portion  210 S, may extend in the second direction DR 2 , and may be terminated in a state of being spaced apart from a second electrode stem portion  220 S that is disposed to face the first electrode stem portion  210 S. 
     The second electrode  220  may include the second electrode stem portion  220 S that extends in the first direction DR 1  and is spaced apart from the first electrode stem portion  210 S in the second direction DR 2  to face the first electrode stem portion  210 S, and a second electrode branch portion  220 B that branches from the second electrode stem portion  220 S and extends in the second direction DR 2 . The other end portion of the second electrode stem portion  220 S may be connected to a second electrode stem portion  220 S of another sub-pixel PXn that is adjacent in the first direction DR 1 . For example, unlike the first electrode stem portion  210 S, the second electrode stem portion  220 S may extend in the first direction DR 1  to cross each sub-pixel PXn. The second electrode stem portion  220 S intersecting each sub-pixel PXn may be connected to an outer portion of the display region DA, in which each pixel PX or each sub-pixel PXn is disposed, or connected to a portion extending from the non-display region NDA in a direction. 
     The second electrode branch portion  220 B may be spaced apart from and face the first electrode branch portion  210 B and may be terminated in a state of being spaced apart from the first electrode stem portion  210 S. The second electrode branch portion  220 B may be connected to the second electrode stem portion  220 S, and an end portion of the second electrode branch portion  220 B in an extending direction may be disposed in the sub-pixel PXn in a state of being spaced apart from the first electrode stem portion  210 S. 
     According to an embodiment, the first electrode  210  and the second electrode  220  may have different widths. The first electrode  210  and the second electrode  220  are disposed in a sub-pixel, and the light-emitting elements  300  are disposed between the first and second electrodes  210  and  220 . Each sub-pixel PXn of the display device  10  may have a constant width, and a region in which the light-emitting elements  300  are disposed and a region in which the light-emitting elements  300  are not disposed may be defined in each sub-pixel PXn. The light-emitting elements  300  are disposed between a first electrode  210  or a first electrode branch portion  210 B and a second electrode  220  or a second electrode branch portion  220 B, and may not be disposed in the other regions, which are between each of the electrodes  210  and  220  and an outer bank  430 . 
     During the process of manufacturing the display device  10 , the light-emitting elements  300  may be sprayed onto the electrodes  210  and  220  in a state of being dispersed in ink S (shown in  FIG. 7 ). The light-emitting elements  300  have a uniform distribution in the ink S, and thus the number of the light-emitting elements  300  to be disposed may be determined according to an area or volume of the region defined in the sub-pixel PXn. Here, in case that a distance (or separation distance) between each of the electrodes  210  and  220  and the outer bank  430 , which is the region in which the light-emitting elements  300  are not disposed, is greater than a region between the electrodes  210  and  220 , which is the region in which the light-emitting elements  300  are disposed, a great number of light-emitting elements  300  may be located between the electrodes  210  and  220  and the outer bank  430 . Furthermore, in case that a greater number of electrodes  210  and  220  are disposed in each sub-pixel PXn, the light-emitting elements  300  may be non-uniformly distributed in each region between the electrodes  210  and  220 . In order to prevent this, the display device  10  according to an embodiment includes the first electrode  210  and the second electrode  220  having different widths and may induce so that a great number of light-emitting elements  300  may be disposed between the first and second electrodes  210  and  220 . A more detailed description thereof will be made below with reference to other drawings. 
     The first electrode  210  and the second electrode  220  may each be electrically connected to a circuit element layer PAL (shown in  FIG. 3 ) of the display device  10  through contact holes, e.g., a first electrode contact hole CNTD and a second electrode contact hole CNTS. In the drawing, the first electrode contact hole CNTD is illustrated as being formed in the first electrode stem portion  210 S of each of the sub-pixels PXn, and only a second electrode contact hole CNTS is illustrated as being formed in a second electrode stem portion  220 S intersecting each sub-pixel PXn. However, the disclosure is not limited thereto, and in some cases (or in some embodiments), the second electrode contact hole CNTS may be formed in each sub-pixel PXn. 
     In the drawing, two first electrode branch portions  210 B are illustrated as being disposed in each sub-pixel PXn, and a second electrode branch portion  220 B is illustrated as being disposed between the two first electrode branch portions  210 B, but the disclosure is not limited thereto. Further, the first electrode  210  and the second electrode  220  do not necessarily have a shape extending in a direction and may be disposed in various structures (without extending in a direction). For example, the first electrode  210  and the second electrode  220  may each have a partially curved or bent shape, and one of the first electrode  210  and the second electrode  220  may be disposed to surround the other electrode. The structure or shape of the first electrode  210  and the second electrode  220  may not be particularly limited as long as at least some regions of the first electrode  210  and the second electrode  220  are spaced to face each other to form a space in which the light-emitting element  300  will be disposed therebetween. 
     Further, in some embodiments, the electrode stem portions  210 S and  220 S may be respectively omitted from the first electrode  210  and the second electrode  220 . The first electrode  210  and the second electrode  220  may have only a shape extending in a direction and may disposed to be spaced apart from each other in each sub-pixel PXn. This will be described below with reference to other embodiments. 
     The banks  410 ,  420 , and  430  may include the outer bank  430  disposed at a boundary between the sub-pixels PXn, and inner banks  410  and  420  disposed below the electrodes  210  and  220  adjacent to a central portion of each sub-pixel PXn. Although inner banks  410  and  420  are not illustrated in the drawings, a first inner bank  410  and a second inner bank  420  may be respectively disposed below the first electrode branch portion  210 B and the second electrode branch portion  220 B. A description thereof will be made below with reference to other drawings. 
     The outer bank  430  may be disposed at the boundary between the sub-pixels PXn. End portions of first electrode stem portions  210 S may be spaced apart from each other and terminated based on the outer bank  430 . The outer bank  430  may extend in the second direction DR 2  and may be disposed at the boundary between the sub-pixels PXn arranged in the first direction DR 1 . However, the disclosure is not limited thereto, and the outer bank  430  may extend in the first direction DR 1  and may also be disposed at the boundary between the sub-pixels PXn arranged in the second direction DR 2 . The outer bank  430  and the inner banks  410  and  420  may include the same material and may be simultaneously formed by a process. 
     The light-emitting elements  300  may be disposed between the first electrode  210  and the second electrode  220 . As shown in the drawings, the light-emitting elements  300  may be disposed between the first electrode branch portion  210 B and the second electrode branch portion  220 B. One end portion (or first end portion) of each of at least some of the light-emitting elements  300  may be electrically connected to the first electrode  210 , and another end portions (or second portion) of each of at least some of the light-emitting elements  300  may be electrically connected to the second electrode  220 . Both end portions of the light-emitting element  300  may be respectively placed on the first electrode branch portion  210 B and the second electrode branch portion  220 B, but the disclosure is not limited thereto. In some cases, the light-emitting element  300  may be disposed between the first electrode  210  and the second electrode  220  such that both end portions thereof do not overlap the first electrode  210  and the second electrode  220 . 
     The light-emitting elements  300  are disposed to be spaced apart from each other between the electrodes  210  and  220  and may be aligned substantially parallel to each other. A separation distance between the light-emitting elements  300  is not particularly limited. In some cases, the light-emitting elements  300  may be disposed adjacent to each other to form a group, and other light-emitting elements  300  may form a group in a state of being spaced apart therefrom at predetermined intervals, may have a non-uniform density, and may be oriented and aligned in a direction. Further, in an embodiment, the light-emitting element  300  may have a shape extending in a direction, and a direction in which each electrode, e.g., each of the first electrode branch portion  210 B and the second electrode branch portion  220 B, extends may be substantially perpendicular to a direction in which the light-emitting element  300  extend. However, the disclosure is not limited thereto, and the light-emitting element  300  may be obliquely disposed without being perpendicular to the direction in which the first electrode branch portion  210 B and the second electrode branch portion  220 B extend. 
     The light-emitting elements  300  according to an embodiment may include active layers  330  having different materials to emit light in different wavelength bands to the outside. The display device  10  according to an embodiment may include the light-emitting elements  300  emitting light in different wavelength bands. The display device  10  may include a first light-emitting element  301  disposed in the first sub-pixel PX 1 , a second light-emitting element  302  disposed in the second sub-pixel PX 2 , and a third light-emitting element  303  disposed in the third sub-pixel PX 3 . 
     The first light-emitting element  301 , the second light-emitting element  302 , and the third light-emitting element  303  and the light-emitting element  300  of  FIG. 1  may have a same structure, and may include different active layers  330 . The first light-emitting element  301  may include the active layer  330  emitting first light having a central wavelength band of a first wavelength, and the second light-emitting element  302  may include the active layer  330  emitting second light having a central wavelength band of a second wavelength, and the third light-emitting element  303  may include the active layer  330  emitting third light having a central wavelength band of a third wavelength. 
     Thus, the first light may be emitted from the first sub-pixel PX 1 , the second light may be emitted from the second sub-pixel PX 2 , and the third light may be emitted from the third sub-pixel PX 3 . In some embodiments, the display device  10  may include light-emitting elements including active layers  330  emitting light of different colors, for example, a first light-emitting element  301 , a second light-emitting element  302 , and a third light-emitting element  303 . The first light-emitting element  301 , the second light-emitting element  302 , and the third light-emitting element  303  may include active layers  330  emitting first light, second light, and third light, respectively. 
     In some embodiments, the first light may be blue light having a central wavelength band ranging from about 450 nm to about 495 nm, the second light may be green light having a central wavelength band ranging from about 495 nm to about 570 nm, and the third light may be red light having a central wavelength band ranging from about 620 nm to about 752 nm. However, the disclosure is not limited thereto. The first light, the second light, and the third light may be light of different colors or light of the same color, but the central wavelength bands may be different from the above ranges. Therefore, the detailed descriptions thereof will be omitted. 
     Further, although not shown in  FIG. 2 , the display device  10  may include a first insulating layer  510  that covers (or overlaps) at least some portions of the first electrode  210  and the second electrode  220 . 
     The first insulating layer  510  may be disposed in each sub-pixel PXn of the display device  10 . The first insulating layer  510  may be disposed to substantially cover the entirety of each sub-pixel PXn and extend even to other adjacent sub-pixels PXn. The first insulating layer  510  may be disposed to cover at least some portions of the first electrode  210  and the second electrode  220 . Although not shown in  FIG. 2 , the first insulating layer  510  may be disposed to expose some portions of the first electrode  210  and the second electrode  220 , specifically, some regions of the first electrode branch portion  210 B and the second electrode branch portion  220 B. 
     In addition to the first insulating layer  510 , the display device  10  may include the circuit element layer PAL located below each of the electrodes  210  and  220 , a second insulating layer  520  (shown in  FIG. 3 ) disposed to cover at least a portion of each of the electrodes  210  and  220  and the light-emitting element  300 , and a passivation layer  550  (shown in  FIG. 3 ). Hereinafter, the structure of the display device  10  will be described in detail with reference to  FIG. 3 . 
       FIG. 3  is a schematic cross-sectional view taken along lines Xa-Xa′, Xb-Xb′, and Xc-Xc′ of  FIG. 2 . 
       FIG. 3  illustrates only a cross section of the first sub-pixel PX 1 , but the cross section may be identically applied to other pixels PX or sub-pixels PXn.  FIG. 3  illustrates a cross section intersecting an end portion and the other end portion of an arbitrary light-emitting element  300 . 
     Referring to  FIGS. 2 and 3 , the display device  10  may include a circuit element layer PAL and a light-emitting layer EML. The circuit element layer PAL may include a substrate  110 , a buffer layer  115 , a light-blocking layer BML, first and second transistors  120  and  140 , and the like, and the light-emitting layer EML may include the electrodes  210  and  220 , the light-emitting element  300 , the insulating layers  510 ,  520 , and  550 , and the like that are disposed on the first and second transistors  120  and  140 . 
     The substrate  110  may be an insulating substrate. The substrate  110  may be made of an insulating material such as glass, quartz, a polymer resin, or the like. The substrate  110  may be a rigid substrate but may also be a flexible substrate that is bendable, foldable, rollable, or the like. 
     The light-blocking layer BML may be disposed on the substrate  110 . The light-blocking layer BML may include a first light-blocking layer BML 1  and a second light-blocking layer BML 2 . The first light-blocking layer BML 1  may be electrically connected to a first drain electrode  123  of the first transistor  120 , which will be described below. The second light-blocking layer BML 2  may be electrically connected to a second drain electrode  143  of the second transistor  140 . 
     The first light-blocking layer BML 1  and the second light-blocking layer BML 2  are respectively disposed to overlap a first active material layer (or first active layer)  126  of the first transistor  120  and a second active material layer (or second active material layer)  146  of the second transistor  140 . The first and second light-blocking layers BML 1  and BML 2  may include light-blocking materials to prevent light from being incident on the first and second active material layers  126  and  146 . As an example, the first and second light-blocking layers BML 1  and BML 2  may be formed of opaque metal materials that block light transmission. However, the disclosure is not limited thereto, and in some cases, the light-blocking layer BML may be omitted. 
     The buffer layer  115  is disposed on the light-blocking layer BML and the substrate  110 . The buffer layer  115  may be disposed to cover (or overlap) the entirety of the substrate  110 , including the light-blocking layer BML. The buffer layer  115  may prevent diffusion of impurity ions, prevent permeation of moisture or external air, and perform a surface planarization function. The buffer layer  115  may insulate the light-blocking layer BML from the first and second active material layers  126  and  146 . 
     A semiconductor layer is disposed on the buffer layer  115 . The semiconductor layer may include the first active material layer  126  of the first transistor  120 , the second active material layer  146  of the second transistor  140 , and an auxiliary layer  163 . The semiconductor layer may include polycrystalline silicon, monocrystalline silicon, an oxide semiconductor, or the like. 
     The first active layer  126  may include a first doped region  126   a , a second doped region  126   b , and a first channel region  126   c . The first channel region  126   c  may be disposed between the first doped region  126   a  and the second doped region  126   b . The second active layer  146  may include a third doped region  146   a , a fourth doped region  146   b , and a second channel region  146   c . The second channel region  146   c  may be disposed between the third doped region  146   a  and the fourth doped region  146   b . The first active layer  126  and the second active layer  146  may include polycrystalline silicon. The polycrystalline silicon may be formed by crystallizing amorphous silicon. Examples of the crystallization method may include a rapid thermal annealing (RTA) method, a solid phase crystallization (SPC) method, an excimer laser annealing (ELA) method, a metal-induced crystallization (MILC) method, and a sequential lateral solidification (SLS) method, and the like, but the disclosure is not limited thereto. As another example, the first active material layer  126  and the second active material layer  146  may include monocrystalline silicon, low-temperature polycrystalline silicon, amorphous silicon, or the like. The first doped region  126   a , the second doped region  126   b , the third doped region  146   a , and the fourth doped region  146   b  may be regions in which some regions of the first active material layer  126  and the second active material layer  146  are doped with impurities. However, the disclosure is not limited thereto. 
     However, the first active material layer  126  and the second active material layer  146  are not necessarily limited to the above description. In an embodiment, the first active material layer  126  and the second active material layer  146  may include an oxide semiconductor. In this case, the first doped region  126   a  and the third doped region  146   a  may be first conductorized regions, and the second doped region  126   b  and the fourth doped region  146   b  may be second conductorized regions. In case that the first active material layer  126  and the second active material layer  146  include an oxide semiconductor, the oxide semiconductor may be an oxide semiconductor containing indium (In). In some embodiments, the oxide semiconductor may include indium-tin oxide (ITO), indium-zinc oxide (IZO), indium-gallium oxide (IGO), indium-zinc-tin oxide (IZTO), indium-gallium-tin oxide (IGTO), indium-gallium-zinc oxide (IGZO), indium-gallium-zinc-tin oxide (IGZTO), or the like. However, the disclosure is not limited thereto. 
     A first gate insulating film  150  is disposed on the semiconductor layer. The first gate insulating film  150  may be disposed to cover (or overlap) the entirety of the buffer layer  115  and the semiconductor layer. The first gate insulating film  150  may serve as gate insulating films of the first and second transistors  120  and  140 . 
     A first conductive layer is disposed on the first gate insulating film  150 . On the first gate insulating film  150 , the first conductive layer may include a first gate electrode  121  disposed on the first active material layer  126  of the first transistor  120 , a second gate electrode  141  disposed on the second active material layer  146  of the second transistor  140 , and a power line  161  disposed on the auxiliary layer  163 . The first gate electrode  121  may overlap the first channel region  126   c  of the first active material layer  126 , and the second gate electrode  141  may overlap the second channel region  146   c  of the second active material layer  146 . 
     An interlayer insulating film  170  is disposed on the first conductive layer. The interlayer insulating film  170  may perform a function of an insulating film between layers. The interlayer insulating film  170  may include an organic insulating material and perform a surface planarization function. 
     A second conductive layer is disposed on the interlayer insulating film  170 . The second conductive layer includes the first drain electrode  123  and a first source electrode  124  of the first transistor  120 , the second drain electrode  143  and a second source electrode  144  of the second transistor  140 , and a power electrode  162  disposed on the power line  161 . 
     The first drain electrode  123  and the first source electrode  124  may respectively contact the first doped region  126   a  and the second doped region  126   b  of the first active material layer  126  through contact holes passing through the interlayer insulating film  170  and the first gate insulating film  150 . The second drain electrode  143  and the second source electrode  144  may respectively contact the third doped region  146   a  and the fourth doped region  146   b  of the second active material layer  146  through contact holes passing through the interlayer insulating film  170  and the first gate insulating film  150 . The first drain electrode  123  and the second drain electrode  143  may be electrically connected to the first light-blocking layer BML 1  and the second light-blocking layer BML 2 , respectively, through other contact holes. 
     A via layer  200  is disposed on the second conductive layer. The via layer  200  may include an organic insulating material and perform a surface planarization function. 
     The banks  410 ,  420 , and  430 , the electrodes  210  and  220 , and the light-emitting element  300  may be disposed on the via layer  200 . 
     The banks  410 ,  420 , and  430  may include inner banks  410  and  420  disposed to be spaced apart from each other in each sub-pixel PXn, and an outer bank  430  disposed on a boundary of an adjacent sub-pixel PXn. 
     The outer bank  430  may extend in the second direction DR 2  and may be disposed at the boundary between the sub-pixels PXn that are arranged in the first direction DR 1 . However, the disclosure is not limited thereto, and the outer bank  430  may extend in the first direction DR 1  and may be disposed at the boundary between the sub-pixels PXn arranged in the second direction DR 2 . For example, the outer bank  430  may divide the boundary of each sub-pixel PXn. 
     During the manufacture of the display device  10 , in case that ink in which the light-emitting elements  300  are dispersed is sprayed using an inkjet printing device, the outer bank  430  may perform a function of preventing the ink from crossing the boundary of the sub-pixel PXn. The outer bank  430  may separate inks, in which different light-emitting elements  300  are dispersed, from each other in different sub-pixels PXn so as to prevent the inks from being mixed with each other. However, the disclosure is not limited thereto. 
     The inner banks  410  and  420  may include a first inner bank  410  and a second inner bank  420  that are disposed adjacent to the central portion of each sub-pixel PXn. 
     The first inner bank  410  and the second inner bank  420  are disposed to be spaced apart from and face each other. The first electrode  210  may be disposed on the first inner bank  410 , and the second electrode  220  may be disposed on the second inner bank  420 . Referring to  FIGS. 2 and 3 , it can be understood that the first electrode branch portion  210 B is disposed on the first inner bank  410 , and the second electrode branch portion  220 B is disposed on the second inner bank  420 . 
     The first inner bank  410  and the second inner bank  420  may extend in the second direction DR 2  in each sub-pixel PXn. Although not shown in the drawing, since the first inner bank  410  and the second inner bank  420  extend in the second direction DR 2 , the first inner bank  410  and the second inner bank  420  may extend toward a sub-pixel PXn that is adjacent in the second direction DR 2 . However, the disclosure is not limited thereto, and the first inner bank  410  and the second inner bank  420  may be disposed in each sub-pixel PXn to form a pattern on the entire surface of the display device  10 . The banks  410 ,  420 , and  430  may include polyimide (PI), but the disclosure is not limited thereto. 
     The first inner bank  410  and the second inner bank  420  may have a structure in which at least some portions thereof partially protrude from the via layer  200 . The first inner bank  410  and the second inner bank  420  may protrude upward from a plane on which the light-emitting element  300  is disposed, and at least some portions of the protruding portions may have an inclination. The protruding shapes of the first inner bank  410  and the second inner bank  420  are not particularly limited. Since the inner banks  410  and  420  protrude from the via layer  200  and have inclined side surfaces, light emitted from the light-emitting element  300  may be reflected at the inclined side surfaces of the inner banks  410  and  420 . As will be described below, in case that the electrodes  210  and  220  disposed on the inner banks  410  and  420  include a material having high reflectance, the light emitted from the light-emitting element  300  may be reflected at the electrodes  210  and  220 , which are located on the inclined side surfaces of the inner banks  410  and  420 , to travel in an upward direction with respect to the via layer  200 . 
     As described above, the banks  410 ,  420 , and  430  may include the same material and may be formed by the same process. However, the outer bank  430  is disposed at the boundary of each sub-pixel PXn to form a grid-shaped pattern, but the inner banks  410  and  420  have a shape that is disposed in each sub-pixel PXn and extends in a direction. The outer bank  430  may divide adjacent sub-pixels PXn and, simultaneously, perform a function of preventing ink from overflowing to the adjacent sub-pixel PXn in an inkjet process, but the inner banks  410  and  420  may have a protruding structure in each sub-pixel PXn to perform a function of a reflective partition wall which reflects the light emitted from the light-emitting element  300  in the upward direction with respect to the via layer  200 . However, the disclosure is not limited thereto. 
     The electrodes  210  and  220  may be disposed on the via layer  200  and the inner banks  410  and  420 . As described above, the electrodes  210  and  220  include electrode stem portions  210 S and  220 S and electrode branch portions  210 B and  220 B. In  FIG. 2 , line Xa-Xa′ is a line intersecting the first electrode stem portion  210 S, line Xb-Xb′ is a line intersecting the first electrode branch portion  210 B and the second electrode branch portion  220 B, and line Xc-Xc′ is a line intersecting the second electrode stem portion  220 S. For example, it can be understood that, in  FIG. 3 , the first electrode  210  disposed in region Xa-Xa′ is the first electrode stem portion  210 S, the first electrode  210  and the second electrode  220  disposed in region Xb-Xb′ are the first electrode branch portion  210 B and the second electrode branch portion  220 B, respectively, and the second electrode  220  disposed in region Xc-Xc′ is the second electrode stem portion  220 S. Each of the electrode stem portions  210 S and  220 S and each of the electrode branch portions  210 B and  220 B may form the first electrode  210  and the second electrode  220 , respectively. 
     Some regions of the first electrode  210  and the second electrode  220  may be disposed on the via layer  200 , and some regions thereof may be disposed on the first inner bank  410  and the second inner bank  420 . As described above, the first electrode stem portion  210 S of the first electrode  210  and the second electrode stem portion  220 S of the second electrode  220  extend in the first direction DR 1 , and the first inner bank  410  and the second inner bank  420  may extend in the second direction DR 2  and may also be disposed in the adjacent sub-pixel PXn in the second direction DR 2 . Although not shown in the drawing, the first electrode stem portion  210 S and the second electrode stem portion  220 S of the first electrode  210  and the second electrode  220 , which extend in the first direction DR 1 , may partially overlap the first inner bank  410  and the second inner bank  420 , respectively. However, the disclosure is not limited thereto, and the first electrode stem portion  210 S and the second electrode stem portion  220 S may not overlap the first inner bank  410  and the second inner bank  420 . 
     A first electrode contact hole CNTD may be formed in the first electrode stem portion  210 S of the first electrode  210  to partially expose the first drain electrode  123  of the first transistor  120  by passing through the via layer  200 . The first electrode  210  may contact the first drain electrode  123  through the first electrode contact hole CNTD. The first electrode  210  may be electrically connected to the first drain electrode  123  of the first transistor  120  to receive an electrical signal therefrom. 
     The second electrode stem portion  220 S of the second electrode  220  may extend in a direction and may also be disposed in the non-light-emitting region in which the light-emitting elements  300  are not disposed. A second electrode contact hole CNTS may be formed in the second electrode stem portion  220 S to partially expose the power electrode  162  by passing through the via layer  200 . The second electrode  220  may contact the power electrode  162  through the second electrode contact hole CNTS. The second electrode  220  may be electrically connected to the power electrode  162  to receive an electrical signal therefrom. 
     Some regions of the first electrode  210  and the second electrode  220 , e.g., the first electrode branch portion  210 B and the second electrode branch portion  220 B may be respectively disposed on the first inner bank  410  and the second inner bank  420 . The first electrode branch portion  210 B of the first electrode  210  may be disposed to cover (or overlap) the first inner bank  410 , and the second electrode branch portion  220 B of the second electrode  220  may be disposed to cover the second inner bank  420 . Since the first inner bank  410  and the second inner bank  420  are disposed to be spaced apart from each other at the central portion of each sub-pixel PXn, the first electrode branch portion  210 B and the second electrode branch portion  220 B may be disposed to be spaced apart from each other. The light-emitting elements  300  may be disposed in a region between the first electrode  210  and the second electrode  220 , for example, a space in which the first electrode branch portion  210 B and the second electrode branch portion  220 B are spaced apart from and face each other. 
     Each of the electrodes  210  and  220  may include a transparent conductive material. As an example, each of the electrodes  210  and  220  may include materials such as indium tin oxide (ITO), indium zinc oxide (IZO), indium tin-zinc oxide (ITZO), and the like, but the disclosure is not limited thereto. In some embodiments, each of the electrodes  210  and  220  may include a conductive material having high reflectance. For example, each of the electrodes  210  and  220  may include a metal such as silver (Ag), copper (Cu), aluminum (Al), or the like as a material having high reflectance. In this case, light incident on each of the electrodes  210  and  220  may be reflected and emitted in an upward direction with respect to each sub-pixel PXn. 
     Further, each of the electrodes  210  and  220  may be formed in a structure, in which one or more layers of a transparent conductive material and a metal layer having high reflectance are stacked, or formed as a single layer including the transparent conductive material and the metal layer. In an embodiment, each of the electrodes  210  and  220  may have a stacked structure of ITO/Ag/ITO/IZO or may be formed of an alloy including aluminum (Al), nickel (Ni), lanthanum (La), and the like. However, the disclosure is not limited thereto. 
     The first insulating layer  510  is disposed on the via layer  200 , the first electrode  210 , and the second electrode  220 . The first insulating layer  510  is disposed to partially cover (or overlap) the first electrode  210  and the second electrode  220 . The first insulating layer  510  may be disposed to cover most of an upper surface of each of the first electrode  210  and the second electrode  220  and may partially expose the first electrode  210  and the second electrode  220 . The first insulating layer  510  may be disposed to partially expose the upper surface of the first electrode  210  and the upper surface of the second electrode  220 , e.g., an upper surface of the first electrode branch portion  210 B disposed on the first inner bank  410  and an upper surface of the second electrode branch portion  220 B disposed on the second inner bank  420 . For example, the first insulating layer  510  may be formed substantially entirely on the via layer  200  and may include openings that partially expose the first electrode  210  and the second electrode  220 . The openings of the first insulating layer  510  may be located to expose relatively flat upper surfaces of the first electrode  210  and the second electrode  220 . 
     In an embodiment, a step may be formed in the first insulating layer  510  between the first electrode  210  and the second electrode  220  so that a portion of an upper surface of the first insulating layer  510  is recessed. In some embodiments, the first insulating layer  510  may include an inorganic insulating material, and the portion of the upper surface of the first insulating layer  510 , which is disposed to cover the first electrode  210  and the second electrode  220 , may be recessed due to a step of a member disposed below the first insulating layer  510 . The light-emitting element  300  disposed on the first insulating layer  510  between the first electrode  210  and the second electrode  220  may form an empty space between itself and the recessed upper surface of the first insulating layer  510 . The light-emitting element  300  may be disposed in a state of being partially spaced apart from the upper surface of the first insulating layer  510 , and the empty space may be filled with a material forming the second insulating layer  520 , which will be described below. 
     However, the disclosure is not limited thereto. The upper surface of the first insulating layer  510  may be formed to be flat so that the light-emitting element  300  is disposed thereon. The upper surface may extend in a direction toward the first electrode  210  and the second electrode  220  to be terminated at the inclined side surfaces of the first electrode  210  and the second electrode  220 . For example, the first insulating layer  510  may be disposed in a region in which the electrodes  210  and  220  overlap the inclined side surfaces of the first inner bank  410  and the second inner bank  420 . Contact electrodes  261  and  262 , which will be described below, may contact the exposed regions of the first electrode  210  and the second electrode  220  and may smoothly contact an end portion of the light-emitting element  300  on the flat upper surface of the first insulating layer  510 . 
     The first insulating layer  510  may protect the first electrode  210  and the second electrode  220  and, simultaneously, insulate the first electrode  210  and the second electrode  220  from each other. The light-emitting element  300  disposed on the first insulating layer  510  may be prevented from being damaged by directly contacting other members. However, the shape and structure of the first insulating layer  510  are not limited thereto. 
     The light-emitting element  300  may be disposed on the first insulating layer  510  between the electrodes  210  and  220 . As an example, at least one light-emitting element  300  may be disposed on the first insulating layer  510  that is disposed between the electrode branch portions  210 B and  220 B. However, the disclosure is not limited thereto, and, although not shown in the drawing, at least some portions of the light-emitting elements  300 , which are disposed in each sub-pixel PXn, may be disposed in a region other than the region between the electrode branch portions  210 B and  220 B. The light-emitting element  300  may be disposed at a position at which a partial region thereof overlaps the electrodes  210  and  220 . The light-emitting element  300  may be disposed on an end portion of each of the first electrode branch portion  210 B and the second electrode branch portion  220 B facing each other and electrically connected to the electrodes  210  and  220  through the contact electrodes  261  and  262 . 
     As described above, the light-emitting elements  300 , which emit the light, and having different wavelengths, may be disposed in each sub-pixel PXn. Although only the first sub-pixel PX 1  in which the first light-emitting elements  301  are disposed is shown in the drawing, it is apparent that the same may be applied to the case of the second sub-pixel PX 2  and the third sub-pixel PX 3 . 
     Further, in the light-emitting element  300 , layers may be disposed in a direction horizontal to the via layer  200 . The light-emitting element  300  of the display device  10  according to an embodiment may have a shape extending in a direction and have a structure in which semiconductor layers are sequentially disposed in one direction. As will be described below, in the light-emitting element  300 , a first semiconductor layer  310 , an active layer  330 , a second semiconductor layer  320 , and an electrode layer  370  may be sequentially disposed in a direction, and an insulating film  380  may surround outer surfaces of the first semiconductor layer  310 , the active layer  330 , the second semiconductor layer  320 , and the electrode layer  370 . The light-emitting element  300  disposed in the display device  10  may be disposed such that an extending one direction thereof is parallel to the via layer  200 , and the semiconductor layers included in the light-emitting element  300  may be sequentially disposed in a direction parallel to an upper surface of the via layer  200 . However, the disclosure is not limited thereto. In some cases, in case that the light-emitting element  300  has a different structure, the layers may be disposed in a direction perpendicular to the via layer  200 . 
     Further, one end portion (or first end portion) of the light-emitting element  300  may contact a first contact electrode  261 , and the other end portion (or second end portion) thereof may contact a second contact electrode  262 . According to an embodiment, since the insulating film  380  is not formed on the end surfaces of the light-emitting element  300  in one direction, in which the light-emitting element  300  extends, and the end surfaces thereof are exposed, the exposed end surfaces may contact the first contact electrode  261  and the second contact electrode  262 , which will be described below. However, the disclosure is not limited thereto. In some cases, at least a partial region of the insulating film  380  is removed from the light-emitting element  300 , and as the insulating film  380  is removed, side surfaces of both end portions of the light-emitting element  300  may be partially exposed. In forming the second insulating layer  520  covering the outer surface of the light-emitting element  300  during the process of manufacturing the display device  10 , the insulating film  380  may be partially removed. The exposed side surfaces of the light-emitting element  300  may contact the first contact electrode  261  and the second contact electrode  262 . However, the disclosure is not limited thereto. 
     The second insulating layer  520  may be partially disposed on the light-emitting element  300 . The second insulating layer  520  may be disposed to partially surround the outer surface of the light-emitting element  300 . The second insulating layer  520  may serve to protect the light-emitting element  300  and, simultaneously, fix the light-emitting element  300  in the process of manufacturing the display device  10 . Further, in an embodiment, a portion of a material of the second insulating layer  520  may be disposed between the first insulating layer  510  and a lower surface of the light-emitting element  300 . As described above, the second insulating layer  520  may be formed to fill the space between the first insulating layer  510  and the light-emitting element  300 , which is formed during the process of manufacturing the display device  10 . Accordingly, the second insulating layer  520  may be formed to surround the outer surface of the light-emitting element  300 . However, the disclosure is not limited thereto. 
     The second insulating layer  520  may extend between the first electrode branch portion  210 B and the second electrode branch portion  220 B in the second direction DR 2  in a plan view. As an example, in a plan view, the second insulating layer  520  may have an island shape or a linear shape on the via layer  200 . 
     The contact electrodes  261  and  262  are disposed on each of the electrodes  210  and  220  and the second insulating layer  520 . The first contact electrode  261  and the second contact electrode  262  may be disposed to be spaced apart from each other on the second insulating layer  520 . The second insulating layer  520  may insulate the first contact electrode  261  and the second contact electrode  262  from each other so as not to directly contact each other. 
     Although not shown in the drawing, the contact electrodes  261  and  262  may extend in the second direction DR 2  in a plan view, and may be disposed to be spaced apart from each other in the first direction DR 1 . The contact electrodes  261  and  262  may contact at least one end portion of the light-emitting element  300 , and the contact electrodes  261  and  262  may be electrically connected to the first electrode  210  or the second electrode  220  to receive an electrical signal. The contact electrodes  261  and  262  may include the first contact electrode  261  and the second contact electrode  262 . The first contact electrode  261  may be disposed on the first electrode branch portion  210 B and may contact one end portion of the light-emitting element  300 , and the second contact electrode  262  may be disposed on the second electrode branch portion  220 B and may contact the other end portion of the light-emitting element  300 . 
     The first contact electrode  261  may contact the exposed partial region of the first electrode  210  on the first inner bank  410 , and the second contact electrode  262  may contact the exposed partial region of the second electrode  220  on the second inner bank  420 . The contact electrodes  261  and  262  may transmit electrical signals, which are transmitted from the electrodes  210  and  220 , to the light-emitting element  300 . 
     The contact electrodes  261  and  262  may include a conductive material. For example, the contact electrodes  261  and  262  may include ITO, IZO, ITZO, aluminum (Al), or the like. However, the disclosure is not limited thereto. 
     The passivation layer  550  may be disposed on the first contact electrode  261 , the second contact electrode  262 , and the second insulating layer  520 . The passivation layer  550  may serve to protect members disposed on the via layer  200  from an external environment. 
     Each of the first insulating layer  510 , the second insulating layer  520 , and the passivation layer  550 , which are described above, may include an inorganic insulating material or an organic insulating material. In an embodiment, each of the first insulating layer  510 , the second insulating layer  520 , and the passivation layer  550  may include an inorganic insulating material such as silicon oxide (SiO x ), silicon nitride (SiN x ), silicon oxynitride (SiO x N y ), aluminum oxide (Al 2 O 3 ), aluminum nitride (AlN), or the like. Further, each of the first insulating layer  510 , the second insulating layer  520 , and the passivation layer  550  may include acrylic resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene resin, polyphenylene sulfide resin, benzocyclobutene, cardo resin, siloxane resin, silsesquioxane resin, polymethylmethacrylate, polycarbonate, polymethylmethacrylate-polycarbonate synthetic resin, or the like as an organic insulating material. However, the disclosure is not limited thereto. 
     The display device  10  may include a greater number of insulating layers. According to an embodiment, the display device  10  may further include a third insulating layer  530  disposed to protect the first contact electrode  261 . 
       FIG. 4  is a schematic cross-sectional view illustrating a portion of a display device according to another embodiment. 
     Referring to  FIG. 4 , a display device  10  according to an embodiment may further include a third insulating layer  530  disposed on a first contact electrode  261 . The display device  10  is different from the display device  10  of  FIG. 3  at least in that the third insulating layer  530  is further included so that at least a portion of a second contact electrode  262  is disposed on the third insulating layer  530 . Hereinafter, repetitive descriptions will be omitted, and a description will be made to focus on differences. 
     The display device  10  of  FIG. 4  may include the third insulating layer  530  that is disposed on the first contact electrode  261  and configured to electrically insulate the first contact electrode  261  and the second contact electrode  262  from each other. The third insulating layer  530  may be disposed to cover (or overlap) the first contact electrode  261  and may be disposed not to overlap a partial region of a light-emitting element  300  so that the light-emitting element  300  may be electrically connected to the second contact electrode  262 . A portion of the third insulating layer  530  may contact the first contact electrode  261  and a second insulating layer  520  at an upper surface of the second insulating layer  520 . The third insulating layer  530  may be disposed to cover one end portion of the first contact electrode  261  on the second insulating layer  520 . Accordingly, the third insulating layer  530  may protect the first contact electrode  261  and electrically insulate the first contact electrode  261  from the second contact electrode  262 . 
     A side surface of the third insulating layer  530  in a direction in which the second contact electrode  262  is disposed may be aligned with a side surface of the second insulating layer  520 . However, the disclosure is not limited thereto. In some embodiments, similar to the first insulating layer  510 , the third insulating layer  530  may include an inorganic insulating material. 
     The first contact electrode  261  may be disposed between the first electrode  210  and the third insulating layer  530 , and the second contact electrode  262  may be disposed on the third insulating layer  530 . The second contact electrode  262  may partially contact the first insulating layer  510 , the second insulating layer  520 , the third insulating layer  530 , the second electrode  220 , and the light-emitting element  300 . An end portion of the second contact electrode  262  in a direction in which the first electrode  210  is disposed may be disposed on the third insulating layer  530 . 
     A passivation layer  550  may be disposed on the third insulating layer  530  and the second contact electrode  262  and protect the third insulating layer  530  and the second contact electrode  262 . Hereinafter, repetitive descriptions will be omitted. 
     The light-emitting element  300  may be a light-emitting diode, and specifically, may be an inorganic light-emitting diode having a size of a micrometer unit or a nanometer unit and made of an inorganic material. The inorganic light-emitting diode may be aligned between two electrodes in which polarity is formed by forming an electric field in a specific direction between the two electrodes facing each other. The light-emitting elements  300  may be aligned between two electrodes due to an electric field formed on the two electrodes. 
     The light-emitting element  300  may have a shape extending in a direction. The light-emitting element  300  may have a shape of a rod, a wire, a tube, or the like. In an embodiment, the light-emitting element  300  may have a cylindrical shape or a rod shape. However, the shape of the light-emitting element  300  is not limited thereto, and the light-emitting element  300  may have a shape of a cube, a rectangular parallelepiped, a polygonal pillar such as a hexagonal pillar or the like or have a shape that extends in a direction and have a partially inclined outer surface. Thus, the light-emitting element  300  may have various shapes. Semiconductors included in the light-emitting element  300 , which will be described below, may have a structure in which the semiconductors are sequentially disposed or stacked in the one direction. 
     The light-emitting element  300  may include a semiconductor layer doped with an arbitrary conductive-type (for example, p-type or n-type) impurity. The semiconductor layer may receive an electrical signal applied from an external power source and emit the received electrical signal as light in a specific wavelength band. 
       FIG. 5  is a schematic view of a light-emitting element according to an embodiment. 
     A light-emitting element  300  according to an embodiment may emit light in a specific wavelength band. In an embodiment, an active layer  330  may emit blue light having a central wavelength band ranging from about 450 nm to about 495 nm. However, the central wavelength band of the blue light is not limited to the above-described range, and it should be understood that the central wavelength band includes all wavelength bands that may be recognized as a blue color in the art. The light emitted from the active layer  330  of the light-emitting element  300  is not limited thereto, and the light may be green light having a central wavelength band ranging from about 495 nm to about 570 nm or red light having a central wavelength band ranging from about 620 nm to about 750 nm. Hereinafter, an example in which the light-emitting element  300  emits blue light will be described. 
     Referring to  FIG. 5 , the light-emitting element  300  may include a first semiconductor layer  310 , a second semiconductor layer  320 , the active layer  330 , an electrode layer  370 , and an insulating film  380 . 
     For example, the first semiconductor layer  310  may be an n-type semiconductor having a first conductive type. As an example, in case that the light-emitting element  300  emits light in a blue wavelength band, the first semiconductor layer  310  may include a semiconductor material having a chemical formula of Al x Ga y In 1-x-y N (0≤x≤1, 0≤y≤1, and 0≤x+y≤1). For example, the semiconductor material may be one or more among AlGaInN, GaN, AlGaN, InGaN, AlN, and InN that are doped with an n-type impurity. The first semiconductor layer  310  may be doped with a first conductive type dopant. As an example, the first conductive type dopant may be Si, Ge, Sn, or the like. In an embodiment, the first semiconductor layer  310  may be n-GaN doped with n-type Si. A length of the first semiconductor layer  310  may range from about 1.5 μm to about 5 μm, but the disclosure is not limited thereto. 
     The second semiconductor layer  320  is disposed on the active layer  330  that will be described below. For example, the second semiconductor layer  320  may be a p-type semiconductor having a second conductive type. As an example, in case that the light-emitting element  300  emits light in a blue or green wavelength band, the second semiconductor layer  320  may include a semiconductor material having a chemical formula of Al x Ga y In 1-x-y N (0≤x≤1, 0≤y≤1, and 0≤x+y≤1). For example, the semiconductor material may be one or more among AlGaInN, GaN, AlGaN, InGaN, AlN, and InN that are doped with a p-type impurity. The second semiconductor layer  320  may be doped with a second conductive type dopant. As an example, the second conductive type dopant may be Mg, Zn, Ca, Se, Ba, or the like. In an embodiment, the second semiconductor layer  320  may be p-GaN doped with p-type Mg. A length of the second semiconductor layer  320  may range from about 0.05 μm to about 0.10 μm, but the disclosure is not limited thereto. 
       FIG. 5  illustrates that the first semiconductor layer  310  and the second semiconductor layer  320  are formed of single layers, but the disclosure is not limited thereto. According to some embodiments, the first semiconductor layer  310  and the second semiconductor layer  320  may further include a greater number of layers, e.g., a clad layer or a tensile strain barrier reducing (TSBR) layer according to a material of the active layer  330 . A description thereof will be made below with reference to other drawings. 
     The active layer  330  is disposed between the first semiconductor layer  310  and the second semiconductor layer  320 . The active layer  330  may include a material having a single or multiple quantum well structure. In case that the active layer  330  includes a material having a multiple quantum well structure, the active layer  330  may have a structure in which quantum layers and well layers are alternately stacked. The active layer  330  may emit light by combination of electron-hole pairs in response to electrical signals applied through the first semiconductor layer  310  and the second semiconductor layer  320 . As an example, in case that the active layer  330  emits light in a blue wavelength band, the active layer  330  may include a material such as AlGaN, AlGaInN, or the like. In case that the active layer  330  has a multiple quantum well structure in which quantum layers and well layers are alternately stacked, the quantum layer may include a material such as AlGaN or AlGaInN, and the well layer may include a material such as GaN or AlInN. In an embodiment, the active layer  330  includes AlGaInN as a quantum layer and AlInN as a well layer. As described above, the active layer  330  may emit blue light having a central wavelength band ranging from about 450 nm to about 495 nm. 
     However, the disclosure is not limited thereto, and the active layer  330  may have a structure in which semiconductor materials having large bandgap energy and semiconductor materials having small bandgap energy are alternately stacked or include other group III to V semiconductor materials according to the wavelength band of emitted light. The light emitted from the active layer  330  is not limited to the light in a blue wavelength band, and the active layer  330  may also emit light in a red or green wavelength band in some cases. A length of the active layer  330  may range from about 0.05 μm to about 0.10 μm, but the disclosure is not limited thereto. 
     The light emitted from the active layer  330  may be emitted to not only an outer surface of the light-emitting element  300  in a lengthwise direction but also both side surfaces of the light-emitting element  300 . Directivity of the light emitted from the active layer  330  is not limited to a direction. 
     The electrode layer  370  may be an ohmic contact electrode. However, the disclosure is not limited thereto, and the electrode layer  370  may also be a Schottky contact electrode. The light-emitting element  300  may include at least one electrode layer  370 . Although  FIG. 5  illustrates that the light-emitting element  300  includes an electrode layer  370 , the disclosure is not limited thereto. In some cases, the light-emitting element  300  may include a greater number of electrode layers  370 , or the electrode layer  370  may be omitted. A description of the light-emitting element  300 , which will be made below, may be applied even in case that the number of electrode layers  370  is varied or another structure is further included. 
     In the display device  10  according to an embodiment, in case that the light-emitting element  300  is electrically connected to the electrode or the contact electrode, the electrode layer  370  may decrease the resistance between the light-emitting element  300  and the electrode or between the light-emitting element  300  and the contact electrode. The electrode layer  370  may include a conductive metal. For example, the electrode layer  370  may include at least one of aluminum (Al), titanium (Ti), indium (In), gold (Au), silver (Ag), indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin-zinc oxide (ITZO). Further, the electrode layer  370  may include a semiconductor material doped with an n-type or p-type impurity. The electrode layer  370  may include a same material or different materials, but the disclosure is not limited thereto. 
     The insulating film  380  is disposed to surround outer surfaces of the semiconductor layers and the electrode layers, which are described above. In an embodiment, the insulating film  380  may be disposed to surround at least the outer surface of the active layer  330  and may extend in a direction in which the light-emitting element  300  extends. The insulating film  380  may serve to protect the members. As an example, the insulating film  380  may be formed to surround side surfaces of the members and may be formed to expose both end portions of the light-emitting element  300  in a lengthwise direction. 
     In the drawing, the insulating film  380  is illustrated as being formed to extend in the lengthwise direction of the light-emitting element  300  to cover from the first semiconductor layer  310  to a side surface of the electrode layer  370 , but the disclosure is not limited thereto. Since the insulating film  380  covers only the outer surfaces of some semiconductor layers including the active layer  330  or covers only a portion of the outer surface of the electrode layer  370 , the outer surface of the electrode layer  370  may be partially exposed. An upper surface of the insulating film  380  may be formed to be rounded in a cross section in a region adjacent to at least one end portion of the light-emitting element  300 . 
     The insulating film  380  may have a thickness ranging from about 10 nm to about 1.0 μm, but the disclosure is not limited thereto. The thickness of the insulating film  380  may be about 40 nm. 
     The insulating film  380  may include materials having insulating properties such as silicon oxide (SiO x ), silicon nitride (SiN x ), silicon oxynitride (SiO x N y ), aluminum nitride (AlN), aluminum oxide (Al 2 O 3 ), or the like. Accordingly, it is possible to prevent an electrical short circuit that may occur in case that the active layer  330  directly contacts the electrode through which an electrical signal is transmitted to the light-emitting element  300 . Further, since the insulating film  380  protects the outer surface of the light-emitting element  300  including the active layer  330 , it is possible to prevent degradation in light emission efficiency. 
     Further, in some embodiments, an outer surface of the insulating film  380  may be surface treated. In the manufacture of the display device  10 , the light-emitting elements  300  may be aligned by being sprayed onto the electrodes in a state of being dispersed in ink. Here, in order to allow the light-emitting elements  300  to remain dispersed in the ink without being aggregated with other adjacent light-emitting elements  300 , the surface of the insulating film  380  may be hydrophobically or hydrophilically treated. 
     The light-emitting element  300  may have a length h ranging from about 1 μm to about 10 μm or from about 2 μm to about 6 μm, or from about 3 μm to about 5 μm. A diameter of the light-emitting element  300  may range from about 300 nm to about 700 nm, and an aspect ratio of the light-emitting element  300  may range from about 1.2 to about 100. However, the disclosure is not limited thereto, and the light-emitting elements  300  included in the display device  10  may have different diameters according to a composition difference of the active layer  330 . In an embodiment, each of the light-emitting elements  300  may have a diameter of about 500 nm. 
     As described above, the display device  10  may include the first electrode  210  and the second electrode  220  having different widths so that the light-emitting elements  300  disposed between the first electrode  210  and the second electrode  220  have a uniform distribution. Hereinafter, a structure of the first electrode  210  and the second electrode  220  of the display device  10  according to an embodiment will be described in detail with further reference to other drawings. 
       FIG. 6  is a schematic cross-sectional view taken across the sub-pixel of the display device according to an embodiment.  FIGS. 7 and 8  are schematic views illustrating a state in which ink, in which the light-emitting elements are dispersed, is sprayed onto the sub-pixel of the display device according to an embodiment. 
     In  FIGS. 6 to 8 , schematic cross sections each intersecting a sub-pixel PXn are illustrated. For convenience of description, only the outer bank  430 , the inner banks  410  and  420 , and the first electrode  210 , and the second electrode  220 , which are disposed in each sub-pixel PXn, are shown in  FIGS. 6 to 8 . However, even though other members, for example, the insulating layers  510  and  520 , the contact electrodes  261  and  262 , and the like are not shown in the drawings, descriptions made below may be applied to the embodiments including the insulating layers  510  and  520 , the contact electrodes  261  and  262 , and the like. 
     Referring to  FIGS. 6 to 8 , outer banks  430  and inner banks  410  and  420  are disposed in each sub-pixel PXn. The outer bank  430  may be disposed at the boundary between adjacent sub-pixels PXn. The outer bank  430  located at a side may be a first outer bank, and the outer bank  430  located at another side may be a second outer bank. The first outer bank and the second outer bank may each be disposed at the boundary between the sub-pixels PXn, and a pixel center line CPL of the sub-pixel PXn may be defined in a region where the first outer bank and the second outer bank are spaced apart from each other. The first outer bank and the second outer bank may be disposed to be spaced apart from the pixel center line CPL by the same separation distance. 
     The inner banks  410  and  420  may be disposed between the outer banks  430 , for example, between the first outer bank and the second outer bank. As described above, the first electrode  210  and the second electrode  220  are disposed on the inner banks  410  and  420 , respectively. Accordingly, the first electrode  210  and the second electrode  220  may be disposed between the outer banks  430 . A region in which the light-emitting elements  300  are disposed and a region in which the light-emitting elements  300  are not disposed may be defined in each sub-pixel PXn. In some embodiments, alignment regions AA 1  and AA 2  between the first electrode  210  and the second electrode  220  and a non-alignment region NAA between the first electrode  210  or the second electrode  220  and the outer bank  430  may be defined in each sub-pixel PXn. The alignment regions AA 1  and AA 2  and the non-alignment region NAA may be defined as regions including a portion of each of the electrodes  210  and  220 , including spaces between each of the electrodes  210  and  220  and the outer bank  430 . As shown in the drawings, the alignment regions AA 1  and AA 2  and the non-alignment region NAA may be defined based on a central portion of each of the first electrode  210  and the second electrode  220 . The light-emitting elements  300  may be disposed in the alignment regions AA 1  and AA 2  and electrically connected to the first electrode  210  and the second electrode  220 . In the non-alignment region NAA, the light-emitting elements  300  may not be disposed, or may not be electrically connected to the first electrode  210  or the second electrode  220  even though the light-emitting elements  300  are disposed. 
     In an embodiment, a central portion of the second inner bank  420  may be located on the same line with (or colinear with) the pixel center line CPL, and the central portion of the second electrode  220  may also be located collinear with the pixel center line CPL. First electrodes  210  may be disposed to be spaced apart from each of both sides of the second electrode  220 . As shown in the drawing, a second electrode  220  and two first electrodes  210  may be disposed in each sub-pixel PXn, and the second electrode  220  may be disposed between the first electrodes  210 . The central portion of the second electrode  220  is located collinear with the pixel center line CPL, and the first electrode  210  and the second electrode  220  may be disposed to be symmetrical with respect to the pixel center line CPL. Accordingly, a first alignment region AA 1  and a second alignment region AA 2 , in which the light-emitting elements  300  are disposed, may be respectively located between the central portion of the second electrode  220  and the central portion of each of the first electrodes  210 , and the non-alignment region NAA may be located between the central portion of the first electrode  210  and each of the outer banks  430 . 
     However, the disclosure is not limited thereto, and in some cases, the pixel center line CPL may be spaced apart from the first electrode  210  and the second electrode  220  without overlapping. This will be described below with reference to other embodiments. 
     During the process of manufacturing the display device  10 , the light-emitting elements  300  may be sprayed onto the electrodes  210  and  220  of each sub-pixel PXn in a state of being dispersed in ink S. As shown in  FIG. 7 , the ink S sprayed into each sub-pixel PXn is located in a region partitioned by the outer banks  430 . As the electrodes  210  and  220  and the outer banks  430  are disposed to be spaced from each other, regions formed by the electrodes  210  and  220  and the outer bank  430  being spaced apart from each other may be distinguished in each sub-pixel PXn. Since the light-emitting elements  300  may be distributed or dispersed in a uniform distribution in the ink S, the number of the light-emitting elements  300  located in each region may vary depending on an area or volume of each of the regions formed by the electrodes  210  and  220  and the outer banks  430  being separated apart from each other. 
     In case that the area or volume of the non-alignment region NAA is greater than the area or volume of each of the alignment regions AA 1  and AA 2 , among the light-emitting elements  300  dispersed in the ink S, the number of the light-emitting elements  300  located in the non-alignment region NAA may be greater than that located in each of the alignment regions AA 1  and AA 2 . In this case, among the light-emitting elements  300  sprayed in each sub-pixel PXn, the number of the light-emitting elements  300  that are disposed in the non-alignment region NAA and not electrically connected to the electrodes  210  and  220  may be greater than the number of the light-emitting elements  300  that are disposed in each of the alignment regions AA 1  and AA 2  and electrically connected to the first electrode  210  and the second electrode  220 . Further, in case that a greater number of electrodes  210  and  220  are disposed and a greater number of alignment regions AA 1  and AA 2  are defined, the number of the light-emitting elements  300  disposed in each of the alignment regions AA 1  and AA 2  may not be uniform. 
     The display device  10  according to an embodiment includes the first electrode  210  and the second electrode  220  having different widths, and thus the area or volume of each of the alignment regions AA 1  and AA 2  defined in each sub-pixel PXn may be greater than the area or volume of the non-alignment region NAA. 
     According to some embodiments, the display device  10  may include an inner electrode disposed between the outer banks  430  to be adjacent to the pixel center line CPL, and outer electrodes each spaced apart from the inner electrode and having a separation distance from the pixel center line CPL greater than that of the inner electrode. The outer electrode may be disposed closer to the outer bank  430  than the inner electrode. As illustrated in  FIG. 7 , the second electrode  220  may be the inner electrode, and each of the first electrodes  210  may be the outer electrode. The non-alignment region NAA may be a region between the outer electrode and the outer bank  430 , and the alignment regions AA 1  and AA 2  may be regions between each of the outer electrodes and the inner electrode. 
     Since the alignment regions AA 1  and AA 2  and the non-alignment region NAA are defined based on the central portion of each of the electrodes  210  and  220 , a width, area, or volume of the non-alignment region NAA may be adjusted by adjusting a width of each of the electrodes  210  and  220 . According to an embodiment, a width of the inner electrode may be different from a width of the outer electrode, and in some embodiments, the width of the inner electrode may be greater than the width of the outer electrode. For example, a width W 220  of the second electrode  220 , which is the inner electrode, may be greater than a width W 210  of the first electrode  210 , which is the outer electrode. In case that a width of the sub-pixel PXn is constant, as the width of the inner electrode increases, a width between the outer electrode and the outer bank  430  may become smaller. 
     In some embodiments, a separation distance between the outer bank  430  and the outer electrode may be less than a separation distance between the outer electrode and the pixel center line CPL. As another example, a separation distance between the central portion of the first electrode  210  and the outer bank  430  may be less than a separation distance between the central portion of the first electrode  210  and the central portion of the second electrode  220 . Accordingly, a width of each of the first alignment region AA 1  and the second alignment region AA 2 , which are regions between the first electrodes  210  and the second electrode  220 , may be greater than the width of the non-alignment region NAA, which is a region between the first electrode  210  and the outer bank  430 . 
     During the process of manufacturing the display device  10 , in case that the ink S in which the light-emitting elements  300  are dispersed is sprayed onto the electrodes  210  and  220 , the light-emitting elements  300  may be located in a uniform distribution on the electrodes  210  and  220  between the outer banks  430 . As the width of the second electrode  220 , which is the inner electrode, becomes greater in the sub-pixel PXn having a constant width, the width of the second electrode  220  may become greater than the width between the first electrode  210 , which is the outer electrode, and the outer bank  430 . Among the light-emitting elements  300  uniformly distributed in the ink S, a greater number of the light-emitting elements  300  may be located in the region between the inner electrode and the outer electrode than in the region between the outer electrode and the outer bank  430 . The number of the light-emitting elements  300  disposed between the inner electrode and the outer electrode may be greater than the number of the light-emitting elements  300  disposed between the outer electrode and the outer bank  430 . 
     Thereafter, as shown in  FIG. 8 , in case that an electrical signal is applied to each of the electrodes, for example, the first electrode  210 , which is the outer electrode, and the second electrode  220 , which is the inner electrode, an electric field is formed therebetween. The light-emitting elements  300  may receive a dielectrophoretic force by the electric field and may be aligned in the ink S between the first electrode  210  and the second electrode  220 . Most of the light-emitting elements  300  dispersed in the ink S may be disposed in the region between the first electrode  210  and the second electrode  220  occupying a greater area. In the display device  10  according to an embodiment, by increasing the number of the light-emitting elements  300  disposed between the electrodes and electrically connected thereto, the manufacturing efficiency of the display device  10  may be increased, and the light-emitting elements  300  may be disposed in a uniform distribution in case that electrodes are disposed. 
     In case that detailed descriptions are made for the electrodes  210  and  220  of each sub-pixel PXn, a first width W 210  of the first electrode  210 , a second width W 220  of the second electrode  220 , a first separation distance WD between the first electrode  210 , which is the outer electrode, and the outer bank  430 , and a second separation distance WA between the first electrode  210  and the second electrode  220  may be defined. The width of each of the electrodes  210  and  220  and the separation distance between the outer bank  430  and each of the electrodes  210  and  220  may satisfy Equation 1 below. In Equation 1, “WE” may be the first width W 210  of the first electrode  210  or the second width W 220  of the second electrode  220 . 
     
       
         
           
             
               
                 
                   WD 
                   &lt; 
                   
                     WA 
                     + 
                     
                       WE 
                       / 
                       2 
                     
                   
                 
               
               
                 
                   [ 
                   
                     Equation 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     1 
                   
                   ] 
                 
               
             
           
         
       
     
     (where “WD” is the first separation distance between the first electrode  210  and the outer bank  430 , “WA” is the second separation distance between the first electrode  210  and the second electrode  220 , and “WE” is the width of the first electrode or the second electrode). 
     As shown in  FIG. 6 , in case that a description is made based on the first outer bank, the first electrode  210 , and the second electrode  220  located on a side of the pixel center line CPL, the first alignment region AA 1  and the non-alignment region NAA may be located on a side of the pixel center line CPL. The width of the first alignment region AA 1  may be greater than that of the non-alignment region NAA such that more light-emitting elements  300  are disposed in the first alignment region AA 1 . According to an embodiment, based on the first electrode  210 , which is the outer electrode, the first separation distance WD between the first electrode  210  and the first outer bank  430  may be less than a sum of the second separation distance WA between the first electrode  210 , which is the outer electrode, and the second electrode  220 , which is the inner electrode, and a half of the second width W 220  of the second electrode  220 . 
     A side of the first electrode  210 , which is the outer electrode, facing the first outer bank  430  is the non-alignment region NAA, and another side thereof facing the second electrode  220  is the first alignment region AA 1 . The width of the second electrode  220 , which is the inner electrode, may be adjusted to increase the width of the first alignment region AA 1  to be greater than that of the non-alignment region NAA. In case that the first electrode  210  and the second electrode  220  satisfy Equation 1 described above, the region between the first outer bank and the first electrode  210 , which is the outer electrode, may be minimized so that the first alignment region AA 1  may have a greater area than the non-alignment region NAA. In Equation 1 described above, “WE” may be the width of the inner electrode. Only the case in which the inner electrode is the second electrode  220  is illustrated in  FIG. 6 , but in some cases, the first electrode  210  may be the inner electrode and the second electrode  220  may be the outer electrode. 
     The light-emitting element  300  has a shape extending in a direction, and may be disposed such that the one direction is parallel to the upper surface of the via layer  200  between the first electrode  210  and the second electrode  220 . According to an embodiment, the separation distance WA between the first electrode  210  and the second electrode  220  may be less than the length h of the light-emitting element  300 . The light-emitting elements  300  disposed in the alignment regions AA 1  and AA 2  may each have an end portion electrically connected to the first electrode  210  and the other end portion electrically connected to the second electrode  220 . In some embodiments, the separation distance WA between the first electrode  210  and the second electrode  220  is less than the length h of the light-emitting element  300 , and both end portions of the light-emitting element  300  may be located on the first electrode  210  and the second electrode  220 , respectively. 
     The relationship between the first width W 210  and the second width W 220  of the first electrode  210  and the second electrode  220 , or the inner electrode and the outer electrode may vary within a range satisfying Equation 1. As an example, the width of the inner electrode may be less than the width of the outer electrode. 
       FIG. 9  is a schematic plan view illustrating a sub-pixel of a display device according to still another embodiment.  FIG. 10  is a schematic cross-sectional view taken across the sub-pixel of the display device of  FIG. 9 . 
     Referring to  FIGS. 9 and 10 , a display device  10 _ 1  according to an embodiment may have an inner electrode having a width less than that of an outer electrode thereof. For example, a second width W 220 _ 1  of a second electrode  220 _ 1 , which is an inner electrode, may be less than a first width W 210 _ 1  of a first electrode  210 _ 1 , which is an outer electrode. The display device  10 _ 1  is different from the display device  10  of  FIG. 6  at least in that the width of the inner electrode is less than that of the outer electrode. Hereinafter, repetitive descriptions will be omitted and a description will be made to focus on differences. 
     Each sub-pixel PXn of the display device  10 _ 1  may have a constant width. For example, a separation distance between outer banks  430  is constant, and a first separation distance WD, which is a separation distance between the outer electrode and the outer bank  430 , may be adjusted by adjusting a width of each of the first electrode  210 _ 1  and the second electrode  220 _ 1 . The first electrode  210 _ 1  may include a first electrode stem portion  210 S and a first electrode branch portion  210 B_ 1 . As shown in the drawing, the first width W 210 _ 1  of the first electrode  210 _ 1 , which is the outer electrode, may be greater than the second width W 220 _ 1  of the second electrode  220 _ 1 , which is the inner electrode. However, the first electrode  210 _ 1  and the second electrode  220 _ 1  may satisfy Equation 1 as in  FIG. 6 . Here, “WE” may be the second width W 220 _ 1  of the second electrode  220 _ 1 , which is the inner electrode. The first and second inner banks  410 _ 1  and  420 _ 1  may be formed as shown in  FIG. 10 . 
     As described above, since each sub-pixel PXn of the display device  10 _ 1  has a constant width, by adjusting the width of the inner electrode or the outer electrode, the first separation distance WD between the outer electrode and the outer bank  430  may be adjusted, and furthermore, a width of each of a non-alignment region NAA and alignment regions AA 1  and AA 2  may be adjusted. The second separation distance WA, in which light-emitting elements  300  are disposed, between the first electrode  210  and the second electrode  220 , or between the inner electrode and the outer electrode is constant. The second separation distance WA may be less than a length h of the light-emitting element  300  so that both end portions of the light-emitting element  300  may be disposed on the first electrode  210  and the second electrode  220 , respectively. Accordingly, in the display device  10  according to an embodiment, a greater number of light-emitting elements  300  may be disposed in the alignment regions AA 1  and AA 2  by adjusting the width of the inner electrode or the outer electrode, or the width of the first electrode  210  or the second electrode  220 . 
     Hereinafter, a display device  10  according to various embodiments will be described with reference to other drawings. 
       FIG. 11  is a schematic plan view illustrating a sub-pixel of a display device according to yet another embodiment.  FIG. 12  is a schematic cross-sectional view taken across the sub-pixel of the display device of  FIG. 11 . 
     Referring to  FIGS. 11 and 12 , a display device  10 _ 2  according to an embodiment may include a greater number of first electrodes  210 _ 2  and a greater number of second electrodes  220 _ 2 . The display device  10 _ 2  of  FIGS. 11 and 12  includes three first electrodes  210 _ 2  and two second electrodes  220 _ 2  for each sub-pixel PXn, and the three first electrodes  210 _ 2  and the two second electrodes  220 _ 2  may be alternately disposed. As another example, the display device  10 _ 2  may include a first electrode stem portion  210 S_ 2 , three first electrode branch portions  210 B_ 2  branched from the first electrode stem portion  210 S_ 2 , a second electrode stem portion  220 S_ 2 , and two second electrode branch portions  220 B_ 2  branched from the second electrode stem portion  220 S_ 2 . The display device  10 _ 2  according to the embodiment is different from the display device  10  of  FIG. 6  at least in that the first electrode  210 _ 2  and the second electrode  220 _ 2  or the first electrode branch portion  210 B_ 2  and the second electrode branch portion  220 B_ 2  disposed in each sub-pixel PXn are different. The first and second banks  410 _ 2  and  420 _ 2  may be formed as shown in  FIG. 12 . Hereinafter, repetitive descriptions will be omitted, and a description will be made to focus on differences. 
     The display device  10 _ 2  of  FIGS. 11 and 12  includes a greater number of first electrodes  210 _ 2  and a greater number of second electrodes  220 _ 2 . Outer electrodes each facing an outer bank  430  may be the first electrodes  210 _ 2 , and inner electrodes may be two second electrodes  220 _ 2  and a first electrode  210 _ 2 . Even in the display device  10 _ 2  of  FIGS. 11 and 12 , a non-alignment region NAA may be located between the outer electrode and the outer bank  430  as in  FIG. 6 . However, a greater number of alignment regions AA 1  and AA 2  may be located between the outer electrodes and the inner electrodes. In an embodiment, light-emitting elements  300  may be disposed even between inner electrodes, and the alignment regions AA 1  and AA 2  may include a first alignment region AA 1  between the inner electrodes and a second alignment region AA 2  between the inner electrode and the outer electrode. A pixel center line CPL may be located collinear with a central portion of a first electrode  210 _ 2  among the inner electrodes. 
     The first alignment region AA 1 , the second alignment region AA 2 , and the non-alignment region NAA are sequentially located on a side of the pixel center line CPL, and may also be located on the other side of the pixel center line CPL. As described above, a width of the inner electrode may be greater than a width of the outer electrode, and Equation 1 above may be satisfied. Accordingly, a width of each of the alignment regions AA 1  and AA 2  may be greater than a width of the non-alignment region NAA. 
     According to an embodiment, the inner electrodes may have different widths. The inner electrodes may include a first inner electrode, for example, the first electrode  210 _ 2  whose central portion is located collinear with the pixel center line CPL, and second inner electrodes, for example, the second electrodes  220 _ 2  that are respectively spaced apart from both sides of the first electrode  210 _ 2 . The first electrode  210 _ 2  and the second electrode  220 _ 2  may have different widths. Here, a width W 220 _ 2  of the second electrode  220 _ 2 , which is the inner electrode, may be less than a width W 210 _ 2  of the first electrode  210 _ 2 , which is the inner electrode, but may be greater than the width of the outer electrode. For example, the width of each of the inner electrodes and the outer electrodes may decrease toward the outer bank  430  from the pixel center line CPL. 
     Accordingly, the width of the first alignment region AA 1  may be greater than the width of the second alignment region AA 2 . According to an embodiment, a separation distance between the outer bank  430  and the first electrode  210 _ 2 , which is the outer electrode, for example, a first separation distance WD may be less than a separation distance between the central portion of the first electrode  210 _ 2 , which is the outer electrode, and a central portion of the second electrode  220 _ 2 . The width of the second alignment region AA 2  may be less than that of the first alignment region AA 1 , but may be greater than that of the non-alignment region NAA. 
     In case that a greater number of electrodes are disposed in each sub-pixel PXn, the number of the alignment regions AA 1  and AA 2  in which the light-emitting elements  300  are disposed may be increased. As described above, in case that the non-alignment region NAA between the outer electrode and the outer bank  430  is wider than each of the alignment regions AA 1  and AA 2 , among the light-emitting elements  300  dispersed in ink S, the number of the light-emitting elements  300  located in the alignment regions AA 1  and AA 2  may be reduced. The distribution of the light-emitting elements  300  disposed for each of the alignment regions AA 1  and AA 2  may vary depending on the separation distance from the non-alignment region NAA. In the ink S, a greater number of the light-emitting elements  300  are located in the non-alignment region NAA, and thus a greater number of light-emitting elements  300  may be disposed in the second alignment region AA 2  adjacent to the non-alignment region NAA than in the first alignment region AA 1 . 
     In the display device  10 _ 2  according to an embodiment, the width of the non-alignment region NAA may be minimized by adjusting the width of each of the inner electrode and the outer electrode so that a greater number of light-emitting elements  300  may be disposed in the alignment regions AA 1  and AA 2 . Furthermore, the light-emitting element  300  may be uniformly disposed in the first alignment region AA 1  and the second alignment region AA 2 . 
     Further, as described above, the width of the inner electrode may be less than the width of the outer electrode. 
       FIG. 13  is a schematic cross-sectional view taken across a sub-pixel according to another embodiment of the display device of  FIG. 11 . 
     Referring to  FIG. 13 , the display device  10 _ 2  may have the inner electrode having a width less than that of the outer electrode thereof. A width of the display device  10 _ 2  including the inner electrodes may decrease from the outer electrode toward the inner electrode. The display device  10 _ 2  of  FIG. 13  is different from the display device  10 _ 2  of  FIG. 12  at least in that the width relationship between the inner electrode and the outer electrode is opposite to that in the display device  10 _ 2  of  FIG. 12 . The display device  10 _ 2  of  FIG. 13  is the same as the display device  10 _ 2  of  FIG. 12  to which the display device  10  of  FIG. 9  is added. Therefore, detailed descriptions thereof will be omitted. 
     In the display devices  10  and  10 _ 2  of  FIGS. 5 and 11 , each sub-pixel PXn may include odd numbers of electrodes  210  and  220 . However, the disclosure is not limited thereto, and in some cases, each sub-pixel PXn may include even numbers of electrodes. 
       FIG. 14  is a schematic plan view illustrating a sub-pixel of a display device according to yet another embodiment.  FIG. 15  is a schematic cross-sectional view taken across the sub-pixel of the display device of  FIG. 14 . 
     Referring to  FIGS. 14 and 15 , a display device  10 _ 3  according to an embodiment includes two first electrodes  210 _ 3  and two second electrodes  220 _ 3  for each sub-pixel PXn, and the two first electrodes  210 _ 3  and the two second electrodes  220 _ 3  may be alternately disposed. As another example, the display device  10 _ 3  may include a first electrode stem portion  210 S_ 3 , two first electrode branch portions  210 B_ 3  branched from the first electrode stem portion  210 S_ 3 , a second electrode stem portion  220 S_ 3 , and two second electrode branch portions  220 B_ 3  branched from the second electrode stem portion  220 S_ 3 . The display device  10 _ 3  according to the embodiment is different from the display device  10  of  FIG. 6  at least in that the first electrode  210 _ 3  and the second electrode  220 _ 3  or the first electrode branch portion  210 B_ 3  and the second electrode branch portion  220 B_ 3  that are disposed in each sub-pixel PXn are different. The first and second banks  410 _ 3  and  420 _ 3  may be formed as shown in  FIG. 15 . Hereinafter, repetitive descriptions will be omitted, and a description will be made to focus on differences. 
     The display device  10 _ 3  of  FIGS. 14 and 15  includes a greater number of first electrodes  210 _ 3  and a greater number of second electrodes  220 _ 3 . An outer electrode, which faces an outer bank  430 , and an inner electrode may be a first electrode  210 _ 3  and a second electrode  220 _ 3 , respectively. Even in the display device  10 _ 3  of  FIGS. 14 and 15 , a non-alignment region NAA may be located between the outer electrode and the outer bank  430  as in  FIG. 6 . However, a greater number of alignment regions AA 1  and AA 2  may be located between the outer electrodes and the inner electrodes. In an embodiment, light-emitting elements  300  may be disposed even between inner electrodes, and the alignment regions AA 1  and AA 2  may include a first alignment region AA 1  between the inner electrodes and a second alignment region AA 2  between the inner electrode and the outer electrode. 
     According to an embodiment, the inner electrodes include a first inner electrode and a second inner electrode, which may be spaced apart from each other based on a pixel center line CPL. For example, the inner electrodes may be a first electrode  210 _ 3  and a second electrode  220 _ 3  spaced apart from each other based on the pixel center line CPL. The outer electrodes may be the other first electrode  210 _ 3  and the other second electrode  220 _ 3 . The first electrode  210 _ 3  and the second electrode  220 _ 3 , which are the inner electrodes, may be the same and may have widths smaller than those of the other first electrode  210 _ 3  and the other second electrode  220 _ 3 , which are the outer electrodes. As shown in the drawing, based on the pixel center line CPL, the first electrode  210 _ 3 , which is the outer electrode, may be disposed on the second electrode  220 _ 3 , which is the inner electrode, and the outer bank  430 . A width of the first electrode  210 _ 3 , which is the outer electrode, may be less than that of the second electrode  220 _ 3 , which is the inner electrode. 
     The first alignment region AA 1  may be located to overlap the pixel center line CPL, and the second alignment regions AA 2  may be located at a side and the other side of the first alignment region AA 1 . A portion of the first alignment region AA 1 , the second alignment region AA 2 , and the non-alignment region NAA may be sequentially located on a side of the pixel center line CPL, and may also be located on the other side of the pixel center line CPL. As described above, a width of the inner electrode may be greater than a width of the outer electrode, and Equation 1 above may be satisfied. Accordingly, a width of each of the alignment regions AA 1  and AA 2  may be greater than a width of the non-alignment region NAA. 
     According to an embodiment, the inner electrodes may have different widths. The inner electrodes may include the first inner electrode, for example, the first electrode  210 _ 3  and the second inner electrode, for example, the second electrode  220 _ 3 , which are spaced apart from each other based on the pixel center line CPL, and the first electrode  210 _ 3  and the second electrode  220 _ 3  may have the same width. Here, a width W 210 _ 3  of the first electrode  210 _ 3 , which is the inner electrode, is the same as a width W 220 _ 3  of the second electrode  220 _ 2 , which is the inner electrode, and may be smaller than the width of the outer electrode. For example, the width of each of the inner electrodes and the outer electrodes may decrease toward the outer bank  430  from the pixel center line CPL. 
     Accordingly, the width of the first alignment region AA 1  may be greater than the width of the second alignment region AA 2 . According to an embodiment, a separation distance between the outer bank  430  and the first electrode  210 _ 3  or the second electrode  220 _ 3 , which is the outer electrode, for example, a first separation distance WD, may be less than a separation distance between a central portion of the first electrode  210 _ 3 , which is the outer electrode, and a central portion of the second electrode  220 _ 3 . The width of the second alignment region AA 2  may be less than that of the first alignment region AA 1 , but may be greater than that of the non-alignment region NAA. 
     The display device  10 _ 3  of  FIG. 15  may be different from the display device  10 _ 2  of  FIG. 12  at least in that the number of the electrodes  210 _ 3  and  220 _ 3  is an even number. In the display device  10 _ 3  of  FIG. 15 , the pixel center line CPL may not overlap the electrodes  210  and  220 , and the inner electrodes may be spaced from each other based on the pixel center line CPL. Descriptions of other structures and arrangements may be substantially identical or similar to those described above with reference to  FIG. 11 , and thus detailed descriptions thereof will be omitted. 
       FIG. 16  is a schematic cross-sectional view taken across a sub-pixel according to another embodiment of the display device of  FIG. 14 . Referring to  FIG. 16 , the display device  10 _ 3  may have the inner electrode having a width less than that of the outer electrode thereof. A width of the display device  10 _ 3  including the inner electrodes may decrease from the outer electrode toward the inner electrode. The display device  10 _ 3  of  FIG. 16  is different from the display device  10 _ 3  of  FIG. 15  at least in that the width relationship between the inner electrode and the outer electrode is opposite to that in the display device  10 _ 3  of  FIG. 15 . The display device  10 _ 3  of  FIG. 16  is the same as the display device  10 _ 3  of  FIG. 15  to which the display device  10  of  FIG. 9  is added. Therefore, detailed descriptions thereof will be omitted. 
     In the display device  10 , the electrode stem portions  210 S and  220 S of the first electrode  210  and the second electrode  220  may be omitted. 
       FIGS. 17 and 18  are schematic plan views each illustrating a sub-pixel of a display device according to yet another embodiment. 
     Referring to  FIGS. 17 and 18 , in a display device  10 , a first electrode  210  and a second electrode  220  may extend in a direction, for example, the second direction DR 2 . For example, in the first electrode  210  and the second electrode  220 , electrode stem portions  210 S and  220 S extending in the first direction DR 1  may be omitted. The display devices  10  according to the embodiments are different from the display device  10  of  FIG. 2  at least in that the electrode stem portions  210 S and  220 S are omitted. Cross sections taken along lines Xa-Xa′, Xb-Xb′, and Xc-Xc′ of  FIG. 17  may be substantially the same as those in  FIG. 3 . Hereinafter, repetitive descriptions will be omitted, and a description will be made to focus on differences. 
     First, as shown in  FIG. 17 , first electrodes  210  and second electrodes  220  may extend in the second direction DR 2  in each sub-pixel PXn. An outer bank  430  may also extend in the second direction DR 2 . The second electrode  220  and the outer bank  430  may extend to another sub-pixel PXn that is adjacent in the second direction DR 2 . Thus, each of the sub-pixels PXn that are adjacent in the second direction DR 2  may receive the a same electrical signal from the second electrode  220 . 
     Unlike the display device  10  of  FIG. 2 , in the display device  10  of  FIG. 17 , a second electrode contact hole CNTS may be disposed in each of the second electrodes  220 . The second electrode  220  may be electrically connected to a power electrode  162  of a circuit element layer PAL through the second electrode contact hole CNTS that is located in each sub-pixel PXn. 
     On the other hand, the first electrode  210  may extend in the second direction DR 2  and may be terminated at a boundary of each sub-pixel PXn. The sub-pixels PXn that are adjacent in the second direction DR 2  may include the first electrodes  210  spaced apart from each other, and the sub-pixels PXn may receive different electrical signals through first electrode contact holes CNTD. A shape of the first electrode  210  may be formed by extending in the second direction DR 2  and then disconnected at a boundary between adjacent sub-pixels PXn during the process of manufacturing the display device  10 . 
     The outer bank  430  may be disposed at the boundary between adjacent sub-pixels PXn in the first direction DR 1  and may extend in the second direction DR 2 . Although not shown in the drawing, the outer bank  430  may be disposed at the boundary between adjacent sub-pixels PXn in the second direction DR 2  and may extend in the first direction DR 1 . A description of the outer bank  430  is the same as that given above with reference to  FIG. 2 . 
     In the drawing, it is illustrated that three first electrodes  210  and two second electrodes  220  are alternately disposed and spaced apart from each other. However, the disclosure is not limited thereto, and in the display device  10 , some electrodes may be omitted, or a greater number of electrodes may be disposed. 
     Next, in the display device  10  of  FIG. 18 , two first electrodes  210  and two second electrodes  220  extending in the second direction DR 2  may be disposed in a sub-pixel PXn. The display device  10  according to the embodiment is different from the display device  10  of  FIG. 17  at least in that a first electrode  210  is omitted. In this case, each of an inner electrode and an outer electrode may include a first electrode  210  and a second electrode  220 . Each outer bank  430  may face a first electrode  210  and a second electrode  220 . Detailed descriptions of the display device  10  of  FIG. 18  may be substantially identical or similar to those described above with reference to  FIGS. 14 and 17 , and thus, a detailed description thereof will be omitted. 
     The structure of the light-emitting element  300  is not limited to that shown in  FIG. 5  and may have another structure. 
       FIG. 19  is a schematic view of a light-emitting element according to another embodiment. 
     Referring to  FIG. 19 , a light-emitting element  300 ′ may extend in a direction and have a partially inclined side surface. For example, the light-emitting element  300 ′ according to an embodiment may have a partially conical shape. 
     The light-emitting element  300 ′ may be formed such that layers are stacked not in a direction and each of the layers surrounds an outer surface of another layer. The light-emitting element  300 ′ of  FIG. 19  may be formed such that semiconductor layers surround at least a portion of an outer surface of another layer. The light-emitting element  300 ′ may include a semiconductor core of which at least a partial region extends in a direction and an insulating film  380 ′ formed to surround the semiconductor core. The semiconductor core may include a first semiconductor layer  310 ′, an active layer  330 ′, a second semiconductor layer  320 ′, and an electrode layer  370 ′. In an embodiment, the light-emitting element  300  may have a length h′ ranging from about 1 μm to about 10 μm. The light-emitting element  300 ′ of  FIG. 19  may be different from the light-emitting element  300  of  FIG. 5  at least in that the shape of each layer thereof is partially different. Hereinafter, repetitive descriptions thereof will be omitted, and differences will be described. 
     According to an embodiment, the first semiconductor layer  310 ′ may extend in a direction and have both end portions formed to be inclined toward a central portion. The first semiconductor layer  310 ′ of  FIG. 19  may have a shape in which a rod-shaped or cylindrical main body and end portions having inclined side surfaces on upper and lower portions of the main body are formed. An upper end portion of the main body may have a slope that is steeper than a slope of a lower end portion thereof. 
     The active layer  330 ′ is disposed to surround an outer surface of the main body of the first semiconductor layer  310 ′. The active layer  330 ′ may have an annular shape extending in a direction. The active layer  330 ′ may not be formed on upper and lower end portions of the first semiconductor layer  310 ′. The active layer  330 ′ may be formed only on a non-inclined side surface of the first semiconductor layer  310 ′. However, the disclosure is not limited thereto. Accordingly, light emitted from the active layer  330 ′ may be emitted to not only both end portions of the light-emitting element  300 ′ in a lengthwise direction but also both side surfaces thereof based on the lengthwise direction. When compared with the light-emitting element  300  of  FIG. 5 , the light-emitting element  300 ′ of  FIG. 19  may include the active layer  330 ′ having a larger area, thereby emitting a greater amount of light. 
     The second semiconductor layer  320 ′ is disposed to surround an outer surface of the active layer  330 ′ and the upper end portion of the first semiconductor layer  310 ′. The second semiconductor layer  320 ′ may include an annular main body extending in a direction and an upper end portion having a side surface formed to be inclined. For example, the second semiconductor layer  320 ′ may directly contact a parallel side surface of the active layer  330 ′ and the inclined upper end portion of the first semiconductor layer  310 ′. However, the second semiconductor layer  320 ′ is not formed on the lower end portion of the first semiconductor layer  310 ′. 
     The electrode layer  370 ′ is disposed to surround an outer surface of the second semiconductor layer  320 ′. For example, a shape of the electrode layer  370 ′ may be substantially the same as that of the second semiconductor layer  320 ′. For example, the electrode layer  370 ′ may fully contact the outer surface of the second semiconductor layer  320 ′. 
     The insulating film  380 ′ may be disposed to surround outer surfaces of the electrode layer  370 ′ and the first semiconductor layer  310 ′. The insulating film  380 ′ may directly contact the electrode layer  370 ′, the lower end portion of the first semiconductor layer  310 ′, and exposed lower end portions of the active layer  330 ′ and the second semiconductor layer  320 ′. 
     In concluding the detailed description, those skilled in the art will appreciate that many variations and modifications can be made to the embodiments without substantially departing from the principles of the disclosure. Therefore, the disclosed embodiments of the disclosure are used in a generic and descriptive sense only and not for purposes of limitation.