Patent ID: 12218176

DETAILED DESCRIPTION

Embodiments of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the present disclosure are shown. The subject matter of 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 fully convey the scope of the present 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 present. The same reference numbers indicate the same components throughout the specification.

It will be understood that, although the terms “first,” “second,” etc. 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 present disclosure. Similarly, the second element could also be termed the first element.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

FIG.1is a schematic diagram illustrating a light emitting element according to one embodiment.

A light emitting element300may be a light emitting diode (LED), for example, the light emitting element300may be an inorganic LED having a micrometer unit or nanometer unit size and made of an inorganic material. In the case of the light emitting element300being an inorganic LED, when an electric field is formed in a set or specific direction between two electrodes opposite to each other, the inorganic LED may be disposed between the two electrodes, each having a polarity (e.g., each having a polarity opposite to that of the other). The light emitting element300may receive a set or predetermined electrical signal from a connected electrode to emit light in a set or specific wavelength range.

The light emitting element300may include a semiconductor crystal doped with an arbitrary conductivity type (e.g., p-type or n-type) of impurity. The semiconductor crystal may receive an electrical signal applied from an external power source and emit light in a set or specific wavelength range.

Referring toFIG.1, the light emitting element300according to one embodiment may include a first conductivity type semiconductor310, a second conductivity type semiconductor320, an active layer330, and an insulation film380. In addition, the light emitting element300according to one embodiment may further include at least one conductive electrode layer370. Although the light emitting element300is illustrated as including one conductive electrode layer370inFIG.1, the present disclosure is not limited thereto. In some cases, the light emitting element300may include a greater number of conductive electrode layers370or the conductive electrode layer370may be omitted. A description of the light emitting element300, which will be made below, may be identically applied even when the number of conductive electrode layers370is varied or another structure is further included.

In this disclosure, terms “first,” “second,” and the like are used to refer to respective components, but these are used to simply distinguish the components from each other and do not necessarily refer to a corresponding component. That is, the components defined as first, second, and the like are not necessarily limited to a set or specific structure or location and, in some cases, other numbers may be assigned to the components. Therefore, the number assigned to each component may be described through the drawings and the following description, and a first component mentioned below may be a second component within the technical idea of the present disclosure.

The light emitting element300may have a shape extending in one direction. The light emitting element300may have a shape of nanorods, nanowires, nanotubes, and/or the like. In an embodiment, the light emitting element300may be a cylindrical shape or a rod shape. However, the shape of the light emitting element300is not limited thereto and may have various suitable shapes such as a regular hexahedral shape, a rectangular parallelepiped shape, a hexagonal column shape, and the like. A plurality of semiconductors included in the light emitting element300, which will be described below, may have a structure in which the semiconductors are sequentially arranged in the one direction or stacked.

The light emitting element300according to one embodiment may emit light in a set or specific wavelength range. In an example, the active layer330may emit blue light having a central wavelength range in a range from 450 nm to 495 nm. However, the central wavelength range of the blue light is not limited to the above range, and it should be understood that the central wavelength range includes all wavelength ranges which can be recognized as a blue color in the art. Further, the light emitted from the active layer330of the light emitting element300is not limited thereto, and the light may be green light having a central wavelength range in a range from 495 nm to 570 nm or red light having a central wavelength range in a range from 620 nm to 750 nm.

To describe the light emitting element300in more detail with reference toFIG.1, the first conductivity type semiconductor310may be an n-type semiconductor having, for example, a first conductivity type. For example, when the light emitting element300emits light in a blue wavelength range, the first conductivity type semiconductor310may include a semiconductor material having a chemical formula of InxAlyGa1-x-yN (0≤x≤1, 0≤y≤1, and 0≤x+y≤1). For example, the semiconductor material may be one or more selected from among InAIGaN, GaN, AlGaN, InGaN, AlN, and InN which are doped with an n-type. The first conductivity type semiconductor310′ may be doped with a first conductivity type dopant. For example, the first conductivity type dopant may be Si, Ge, Sn, and/or the like. In an example, the first conductivity type semiconductor310may be n-GaN doped with n-type Si. A length of the first conductivity type semiconductor310may be in a range from 1.5 μm to 5 μm, but the present disclosure is not limited thereto.

The second conductivity type semiconductor320is disposed on the active layer330which will be further described below. For example, the second conductivity type semiconductor320may be a p-type semiconductor having a second conductivity type. For example, when the light emitting element300emits light in a blue or green wavelength range, the second conductivity type semiconductor320may include a semiconductor material having a chemical formula of nxAlyGa1-x-yN(0≤x≤1, 0≤y≤1, and 0≤x+y+1). For example, the semiconductor material may be one or more selected from among InAlGaN, GaN, AlGaN, InGaN, AlN, and InN which are doped with a p-type. The second conductivity type semiconductor320may be doped with a second conductivity type dopant. For example, the second conductivity type dopant may be Mg, Zn, Ca, Se, Ba, and/or the like. In an example, the second conductivity type semiconductor320may be p-GaN doped with p-type Mg. A length of the second conductivity type semiconductor320may be in a range from 0.08 μm to 0.25 μm, but the present disclosure is not limited thereto.

In the drawings, although each of the first conductivity type semiconductor310and the second conductivity type semiconductor320is illustrated as being formed of one layer, the present disclosure is not limited thereto. In some cases, each of the first conductivity type semiconductor310and the second conductivity type semiconductor320may further include a greater number of layers, for example, a clad layer and/or a tensile strain barrier reducing (TSBR) layer according to a material of the active layer330.

The active layer330is disposed between the first conductivity type semiconductor310and the second conductivity type semiconductor320. The active layer330may include a material having a single or multiple quantum well structure. When the active layer330includes a material having a multiple quantum well structure, the active layer330may have a structure in which a plurality of quantum layers and a plurality of well layers are alternately stacked. The active layer330may emit light due to combination of electron-hole pairs in response to an electrical signal applied through the first conductivity type semiconductor310and the second conductivity type semiconductor320. An example, when the active layer330emits light in a blue wavelength range, the active layer330may include a material such as AlGaN, AlInGaN, and/or the like. In one or more embodiments, when the active layer330has a multi-quantum well structure in which quantum layers and well layers are alternately stacked, the quantum layer may include a material such as AlGaN and/or AlInGaN, and the well layer may include a material such as GaN and/or AlInN. In an example, the active layer330includes AlGaInN as the quantum layer and AlInN as the well layer. As described above, the active layer330may emit blue light having a central wavelength range in a range from 450 nm to 495 nm.

However, the present disclosure is not limited thereto, and the active layer330may have a structure in which a semiconductor material having large band gap energy and a semiconductor material having small band gap energy are alternately stacked or include different Group III to VI semiconductor materials according to a wavelength range of emitted light. The active layer330is not limited to emit light in the blue wavelength range, and in some cases, the active layer330may emit light in a red or green wavelength range. A length of the active layer330may be in a range from 0.05 μm to 0.25 μm, but the present disclosure is not limited thereto.

The light emitted from the active layer330may be emitted to an outer surface of the light emitting element300in a lengthwise direction and both side surfaces thereof. The directivity of the light emitted from the active layer330is not limited to any one direction.

The conductive electrode layer370may be an ohmic contact electrode. However, the present disclosure is not limited thereto, and the conductive electrode layer370may be a Schottky contact electrode. The conductive electrode layer370may include a conductive metal (e.g., an electrically conductive metal). For example, the conductive electrode layer370may include at least one selected from among aluminum (Al), titanium (Ti), indium (In), gold (Au), silver (Ag), indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin-zinc oxide (ITZO). In addition, the conductive electrode layer370may include a semiconductor material doped with an n-type or p-type. The conductive electrode layer370may include the same material or different materials, but the present disclosure is not limited thereto.

The insulation film380surrounds the outer surfaces of the plurality of semiconductors, which are described above. In an example, the insulation film380may surround at least the outer surface of the active layer330and may extend in one direction in which the light emitting element300extends. The insulation film380may serve to protect members of the light emitting element300. As an example, the insulation film380may be formed to surround side surfaces of the members and expose two end portions of the light emitting element300in the lengthwise direction.

In the drawing, the insulation film380is illustrated as being formed to extend in the lengthwise direction of the light emitting element300to cover from the first conductivity type semiconductor310to the conductive electrode layer370, but the present disclosure is not limited thereto. The insulation film380covers only the outer surfaces of some semiconductor layers including at least the active layer330or covers only a portion of the outer surface of the conductive electrode layer370so that a portion of the outer surface of the conductive electrode layer370may be exposed.

A thickness of the insulation film380may be in a range from 10 nm to 1.0 μm, but the present disclosure is not limited thereto. For example, the thickness of the insulation film380may be 40 nm.

According to one embodiment, in order to allow the light emitted from the active layer330of the light emitting element300to be transmitted without being reflected from the insulation film380, the insulation film380may include an insulation coating film381and light conversion particles385disposed on at least a portion of the insulation coating film381.

FIG.2is an enlarged view of Portion A ofFIG.1.FIG.3is a cross-sectional view illustrating the light emitting element according to one embodiment.

Referring toFIGS.1to3, the insulation coating film381is formed to surround the plurality of semiconductors. The insulation coating film381is disposed to surround the outer surface of the light emitting element300including the active layer330.

The insulation coating film381may include materials having insulation properties (e.g., electrically insulating properties), for example, silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum nitride (AlN), aluminum oxide (Al2O3), hafnium oxide (HfO2), yttrium oxide (Y2O3), titanium dioxide (TiO2), and/or the like. Thus, it is possible to prevent (or reduce an occurrence or likelihood of) an electrical short circuit which may occur when the active layer330is in direct contact with an electrode through which an electrical signal is transmitted to the light emitting element300, thereby preventing or reducing the degradation of light emission efficiency. In addition, the insulation coating film381includes a transparent material, and thus light emitted from the active layer330may pass through the insulation coating film381.

The light conversion particle385is disposed on the insulation coating film381. A plurality of light conversion particles385may be disposed to be spaced apart from each other, thereby forming one layer which partially covers the insulation coating film381. The light conversion particles385may be entirely disposed on the insulation coating film381, but the present disclosure is not limited thereto, and the light conversion particles385may be disposed on only a partial area. In an example, the light conversion particle385is disposed on the insulation coating film381, and an area in which the light conversion particle385is disposed may overlap at least the active layer330. A further detailed description thereof will be made below.

The light conversion particle385may be disposed to be attached, adsorbed, or bonded on the insulation coating film381. A physical bond or a chemical bond may be formed between the light conversion particle385and the insulation coating film381, and the type of bond is not particularly limited. As an example, the light conversion particle385may be physically adsorbed onto the insulation coating film381. A shape of the light conversion particle385may be a spherical shape or an elliptical shape. However, the shape of the light conversion particle385is not particularly limited, and although a spherical-shaped light conversion particle385is illustrated in the drawings, the present disclosure is not limited thereto.

As shown inFIG.3, in the light emitting element300, a semiconductor crystal, for example, the first conductivity type semiconductor310, the second conductivity type semiconductor320, and the active layer330may be disposed in one direction DL (hereinafter referred to as an “extension direction”) in which the light emitting element300extends, and the insulation coating film381may be formed to surround the first conductivity type semiconductor310, the second conductivity type semiconductor320, and the active layer330. When a set or predetermined electrical signal is transmitted from the two end portions of the light emitting element300, the active layer330may emit light in a set or specific wavelength range.

Light emitted from the active layer330may propagate in all directions (e.g., substantially all directions) without directivity. For example, light EL emitted from the active layer330may include second emitted light EL2parallel (e.g., substantially parallel) to the extension direction DL of the light emitting element300and first emitted light EL1not parallel to the extension direction DL. The first emitted light EL1is emitted from the active layer330to propagate toward a side surface SA of the light emitting element300, and the second emitted light EL2propagates toward the two end portions of the light emitting element300, for example, a first end portion EA1and a second end portion EA2, in the one direction DL.

In the drawing, the first emitted light EL1is illustrated as including light propagating in a direction perpendicular (e.g., substantially perpendicular) to the one direction DL and light propagating in a diagonal direction and the present disclosure is not limited thereto. In the following description, it can be understood that the second emitted light EL2includes light propagating toward the two end portions EA1and EA2of the light emitting element300in a direction that is substantially the same as the extension direction DL, and the first emitted light EL1is light, except for the second emitted light EL2, including light propagating toward the side surface SA of the emitting element300.

The light emitting element300may include an insulation coating film381surrounding at least the active layer330, and the first emitted light EL1emitted from the active layer330may propagate to the insulation coating film381of the light emitting element300. As described above, the insulation coating film381may include a transparent material and may include an insulating material to have a set or predetermined refractive index. The first emitted light EL1may be incident on the insulation coating film381, may not be emitted from an interface between the insulation coating film381and the outside and may be reflected again. Thus, a case in which the reflected first emitted light EL1may propagate toward an area in which the insulation coating film381is not formed, for example, the first and second end portions EA1and EA2, to be emitted in the same direction as the second emitted light EL2may occur.

As described below, the light emitting element300may be disposed on a target substrate, and the extension direction DL may be disposed parallel (e.g., substantially parallel) to one surface of the target substrate. That is, the light emitting element300may be disposed in a direction horizontal relative to the target substrate. Light emitted from the light emitting element300may be emitted from the side surface SA of the light emitting element300to propagate toward an upper portion of the one surface of the target substrate. However, as described above, when the first emitted light EL1propagating toward the side surface SA of the light emitting element300is reflected from the insulation coating film381to be emitted in the same direction as the second emitted light EL2, top emission efficiency of the light emitting element300disposed horizontally may be reduced.

According to one embodiment, the insulation film380of the light emitting element300may include the light conversion particles385disposed on the insulation coating film381, and the light conversion particles385may emit light, which is emitted from the active layer330to propagate toward the insulation coating film381, for example, the first emitted light EL1, to the outside of the light emitting element300. That is, the light conversion particles385may provide optical paths to allow light incident on the side surface SA of the light emitting element300to be emitted as it is without being reflected from the insulation coating film381.

FIG.4is a schematic diagram illustrating a propagation direction of light emitted from the light emitting element according to one embodiment.FIG.5is an enlarged view of Portion B ofFIG.4.

Referring toFIGS.2,4, and5, in an example, the light emitting element300may be disposed between electrodes21and22on a target substrate SUB. The first electrode21and the second electrode22may be disposed on the target substrate SUB. The first electrode21and the second electrode22are separated in a direction parallel (e.g., substantially parallel) to one surface of the target substrate SUB, and the light emitting element300is disposed such that the extension direction DL is parallel (e.g., substantially parallel) to the one surface of the target substrate SUB. The two end portions of the light emitting element300are disposed on the first electrode21and the second electrode22, respectively.

However, the present disclosure is not limited thereto, and an arrangement structure of the light emitting element300may be varied. The two end portions of the light emitting element300may be connected to at least one of the first electrode21and the second electrode22and may receive a set or predetermined electrical signal to emit light.

As shown inFIGS.4and5, the light emitted from the active layer330of the light emitting element300may be emitted toward the two end portions EA1and EA2of the light emitting element300or the insulation coating film381of the side surface SA. The second emitted light EL2emitted toward the two end portions EA1and EA2of the light emitting element300may be lost without propagating toward an upper portion of the target substrate SUB.

On the other hand, the first emitted light EL1propagating toward the side surface SA of the light emitting element300, that is, the insulation coating film381, may be emitted from the light emitting element300and may propagate toward an upper surface of the target substrate SUB to be displayed to the outside. When an amount of first emitted light EL1emitted from the light emitting element300to the side surface SA is increased, top emission efficiency of the light emitting element300disposed on the target substrate SUB may be increased.

To describe in further detail with reference toFIG.5, the active layer330emits the second emitted light EL2in the extension direction DL of the light emitting element300and emits the first emitted light EL1in a direction perpendicular (e.g., substantially perpendicular) to the extension direction DL or in a direction inclined thereto. The second emitted light EL2propagate in the extension direction DL to be emitted to the two end portions EA1and EA2of the light emitting element300.

Some of the first emitted light EL1is incident on the light conversion particles385through the insulation coating film381, and the remainder is reflected from the interface between the insulation coating film381and the outside. The light incident on the light conversion particle385is emitted from the light emitting element300through the light conversion particles385(EL1′ inFIG.5), and the light reflected from the insulation coating film381is emitted in the extension direction DL of the light emitting element300. (EL1″ inFIG.5).

The light emitted from the light emitting element300may be emitted to the two end portions EA1and EA2in the same direction as the extension direction DL (EL1″ and EL2inFIG.5) and emitted in a direction different from the extension direction DL, for example, emitted to the side surface SA in a direction perpendicular (e.g., substantially perpendicular) to the extension direction DL (EL1′ inFIG.5). As described above, in the light emitting element300, the extension direction DL is disposed in a direction parallel (e.g., substantially parallel) to the target substrate SUB, and the light emitted to the side surface SA of the light emitting element300may be visually recognized in a direction facing the target substrate SUB. That is, when an amount of light emitted to the side surface SA of the light emitting element300instead of the two end portions EA1and EA2among the light emitted from the active layer330is increased, top emission efficiency of the target substrate SUB may be increased.

The light emitting element300according to one embodiment includes the light conversion particles385disposed on the insulation coating film381, and thus the amount of light emitted to the side surface SA of the light emitting element300may be increased. In particular, among the light incident on the insulation coating film381, the amount of light reflected from the interface between the insulation coating film381and the outside (EL1″ inFIG.5) may be reduced, and the amount of light emitted through the light conversion particles385(EL1′ inFIG.5) may be increased. The amount of light emitted to the side surface SA of the light emitting element300may be increased, and the top emission efficiency of the light emitting element300disposed on the target substrate SUB may be improved.

As described above, the light conversion particles385providing a movement path for light emitted from the active layer330may scatter incident light, change a path thereof, or amplify the intensity thereof. In an example, the light conversion particles385may be first light conversion particles385acontaining dielectric materials or second light conversion particles385bcontaining noble metal particles.

Referring toFIGS.2and5, the light conversion particle385may include the first light conversion particle385ato provide an optical path for light emitted from the active layer330and, concurrently (e.g., simultaneously), scatter the light. The first light conversion particle385amay include a dielectric material to scatter light incident from the insulation coating film381. That is, the first light conversion particle385amay be a scattering particle including a dielectric material.

As shown in the drawings, the first emitted light EL1incident on the first light conversion particle385amay be scattered and emitted in all directions regardless of a propagation path (EL1′ inFIG.5). However, in order to increase the amount of light emitted to the side surface SA of the light emitting element300, that is, the amount of light emitted in a direction perpendicular (e.g., substantially perpendicular) to the extension direction DL, the first light conversion particle385amay scatter a larger amount of light in the same direction as the propagation direction of incident light. In other words, the first light conversion particle385amay include a material which causes Mie scattering.

In an example, the first light conversion particle385amay include a dielectric material having a refractive index of 1.5 or more. For example, the first light conversion particle385amay include at least any one selected from among silicon nitride (Si3N4), silicon dioxide (SiO2), aluminum oxide (Al2O3), hafnium oxide (HfO2), yttrium oxide (Y2O3), and titanium dioxide (TiO2). In addition, the first light conversion particle385amay have a diameter dp1in a range from 100 nm to 2000 nm. However, the present disclosure is not limited thereto.

Like the first light conversion particle385a, the light conversion particle385may scatter incident light to control a propagation direction of the emitted light. Unlike the first light conversion particle385a, the light conversion particle385may amplify the intensity of the incident light.

According to one embodiment, the light conversion particle385may include a second light conversion particle385bto provide an optical path of light emitted from the active layer330and, concurrently (e.g., simultaneously), amplify the intensity of the light.

FIG.6is an enlarged view illustrating an outer surface of a light emitting element according to another embodiment.FIG.7is a schematic diagram illustrating the propagation of light emitted from the light emitting element ofFIG.6.

Referring toFIGS.6and7, a light emitting element300includes the second light conversion particle385b, and a plurality of second light conversion particles385bmay be disposed on an insulation coating film381, Like the first light conversion particle385a, the second light conversion particle385bmay be physically or chemically bonded to the insulation coating film381. For example, the second light conversion particle385bmay be adsorbed and disposed on the insulation coating film381.

The second light conversion particle385bmay amplify the intensity of light incident through the insulation coating film381. For example, the second light conversion particle385bmay include a noble metal particle having a small particle size to generate surface plasmon resonance (SPR) with incident light. In a noble metal particle having a diameter that is smaller than a wavelength of the incident light, a plasmon electron may cause a resonance phenomenon with the incident light. The intensity of the light resonated with the plasmon electron may be amplified, and light efficiency may be increased. That is, the second light conversion particle385bmay be a plasmon particle.

As shown inFIG.7, the second light conversion particles385bdisposed on the insulation coating film381may amplify the intensity of first emitted light EL1incident from an active layer330. The intensity of light emitted through the second light conversion particles385b(EL1′ ofFIG.7) is amplified due to SPR. When the light emitting element300includes the second light conversion particles385b, the intensity of light emitted from the side surface SA may be increased.

In an example, the second light conversion particle385bmay include at least any one selected from among Au, Ag, copper (Cu), and Al, and a diameter dp2may be in a range of 10 nm to 300 nm. However, the present disclosure is not limited thereto.

The light emitting element300according to one embodiment may include at least any one selected from the first light conversion particle385aand the second light conversion particle385bto increase an amount and the intensity of light emitted to the side surface SA of the light emitting element300. Thus, the light emitting element300disposed parallel (e.g., substantially parallel) to the target substrate SUB is included in the extension direction DL so that top emission efficiency of the target substrate SUB may be increased.

The light conversion particle385may be disposed on at least a portion of the insulation coating film381to cover at least an area overlapping the active layer330. In the light emitting element300according to one embodiment, a particle area PA, which is an area in which the light conversion particle385is disposed on the insulation coating film381, may be disposed to partially cover the insulation coating film381and cover at least the active layer330.

Referring toFIG.3again, the particle area PA, which is an area in which the light conversion particle385is disposed, may be defined on the insulation coating film381of the light emitting element300. The light conversion particles385may entirely cover an outer surface of the insulation coating film381, but as shown in the drawing, the light conversion particle385is not disposed in some areas of the insulation coating film381so that the insulation coating film381may be exposed. In order to allow the first emitted light EL1emitted from the active layer330and propagating toward the insulation coating film381to be emitted through the light conversion particles385without being reflected, the particle area PA may be disposed adjacent to the active layer330. In an example, the particle area PA may be disposed to overlap at least the active layer330and may have a shape extending in the extension direction DL of the light emitting element300.

In addition, according to one embodiment, among the outer surface of the insulation coating film381, an area in which the particle area PA is disposed may be more than half of the outer surface. A ratio of the particle area PA to the outer surface of the insulation coating film381may be in a range from 0.5 to 0.6. The particle area PA is disposed to overlap at least the active layer330, and the area in which the particle area PA is disposed may occupy 50% or more, preferably, 50% or more and 60% or less, of the outer surface of the insulation coating film381.

Although the particle area PA is illustrated as being continuously formed on the insulation coating film381, the present disclosure is not limited thereto. A plurality of light conversion particles385may be disposed to be separated from each other on the insulation coating film381so that one or more particle areas PA may be defined to be separated from each other. However, the particle areas PA according to one embodiment overlap at least the active layer330, and the total sum of the areas occupied by the particle areas PA separated apart from each other may be 50% or more of the outer surface of the insulation coating film381.

A method of disposing the light conversion particles385on the insulation coating film381is not particularly limited. In an example, the light conversion particles385may be formed through a method of immersing a semiconductor crystal, on which the insulation coating film381is formed, in a solution in which the light conversion particles385are dispersed or in a solution in which precursors of the light conversion particles385are dissolved. For example, the light conversion particles385may be disposed on the insulation coating film381by immersing the insulation coating film381in a sol-gel solution containing precursors, an ink in which the precursors are dissolved, or a solution containing the light conversion particles385. However, the present disclosure is not limited thereto.

In some embodiments, the outer surface of the insulation coating film381of the insulation film380may be further surface-treated with other materials. In manufacturing the display device1, the light emitting element300may be injected onto an electrode in a state of being dispersed in a set or predetermined ink to be deposited. Here, in order to allow the light emitting element300to maintain the dispersed state without (or substantially without) being agglomerated with adjacent other light emitting element300in the ink, the outer surface of the insulation coating film381may be hydrophobically or hydrophilically treated.

The light emitting element300may have a length l in a range from 1 μm to 10 μm or from 2 μm to 5 μm, or, for example, a length l of about 4 μm. In addition, a diameter of the light emitting element300may be in a range from 300 nm to 700 nm, and an aspect ratio of the light emitting element300may be in a range from 1.2 to 100. However, the present disclosure is not limited thereto, and a plurality of light emitting elements300included in the display device1may have different diameters according to a difference in composition of the active layers330. In one or more embodiments, the diameter of the light emitting element300may be about 500 nm.

As described above, the light emitting element300includes the light conversion particles385disposed on the insulation coating film381. The light emitting element300has a shape extending in one direction, and the light emitted from the light emitting element300may propagate in a direction parallel (e.g., substantially parallel) to the extension direction DL and in directions different therefrom. Here, the light emitted from the active layer330is incident on in the light conversion particles385disposed on the insulation coating film381, and the light conversion particles385may emit the light to the side surface SA of the light emitting element300or amplify the intensity of light. In the light emitting element300according to one embodiment, an amount of light emitted in a direction different from or perpendicular (e.g., substantially perpendicular) to the extension direction DL may be increased.

In the light emitting element300according to one embodiment, the amount of light emitted to the side surface SA is increased so that top emission efficiency may be high even when the light emitting element300is disposed in a direction parallel (e.g., substantially parallel) to the target substrate SUB. Thus, unlikeFIG.5, an arrangement structure of the light emitting element300between the electrodes21and22on the target substrate SUB may be varied.

FIGS.8to10are schematic diagrams illustrating that a light emitting element is disposed on a substrate according to one embodiment.

The light emitting element300may be disposed on the target substrate SUB such that the extension direction DL is parallel (e.g., substantially parallel) to the target substrate SUB. However, unlikeFIG.4, the light emitting element300may not be necessarily disposed on the electrodes21and22and may be disposed therebetween. Hereinafter, a difference fromFIG.4will be mainly described.

Referring toFIG.8, according to one embodiment, the light emitting element300is disposed between the first electrode21and the second electrode22such that the first end portion EA1of the light emitting element300may be in contact with a side surface of the first electrode21, and the second end portion EA2thereof may be in contact with a side surface of the second electrode22. A distance between the first electrode21and the second electrode22may be the same as a length l of the light emitting element300, which is measured in the extension direction DL. InFIG.4, the side surfaces of the two end portions of the light emitting element300are in contact with upper surfaces of the first electrode21and the second electrode22, but inFIG.8, there is a difference in which the first end portion EA1and the second end portion EA2are in contact with the side surfaces of the first electrode21and the second electrode22.

As described above, since the light emitting element300includes the light conversion particles385, an amount of light emitted to the side surface SA may be greater than an amount of light emitted in the extension direction DL. That is, the light emitting element300disposed between the first electrode21and the second electrode22may emit light to the side surface SA so that the light may propagate toward an upper portion of the target substrate SUB. Even when the two end portions EA1and EA2of the light emitting element300are respectively in contact with the electrodes21and22to block, hinder, or reduce emission of light, the light emitting element300may emit a suitable or sufficient amount of light to the upper portion of the target substrate SUB through the side surface SA.

In one or more embodiments, the light emitting element300may be disposed as a plurality of light emitting elements300between the first electrode21and the second electrode22. Each light emitting element300may emit a suitable or sufficient amount of light to the side surface SA, and the plurality of light emitting elements300may be disposed between the first electrode21and the second electrode22in a direction perpendicular (e.g., substantially perpendicular) to one surface of the target substrate SUB.

Referring toFIG.9, the light emitting element300according to one embodiment includes a first light emitting element301and a second light emitting element302, and the first light emitting element301and the second light emitting element302may have different separation distances from one surface of a target substrate SUB. As inFIG.8, both end portions EA1and EA2of the first light emitting element301and the second light emitting element302may respectively be in contact with the side surfaces of the first electrode21and the second electrode22. However, unlikeFIG.8, there is a difference in which the light emitting element300ofFIG.9is disposed to be separated from the target substrate SUB between the first electrode21and the second electrode22. In addition, the first light emitting element301and the second light emitting element302may have different separation distances from the target substrate SUB.

The first light emitting element301and the second light emitting element302are disposed in a direction perpendicular (e.g., substantially perpendicular) from one surface of the target substrate SUB, for example, to be separated from the upper surface of the target substrate SUB. A distance h1between the first light emitting element301and the target substrate SUB may be smaller than a distance h2between the second light emitting element302and the target substrate SUB. That is, in the drawing, the first light emitting element301may be located below the second light emitting element302.

A large number of light emitting elements300is disposed in a narrow area between the first electrode21and the second electrode22so that an amount of light emitted from the side surfaces SA of the light emitting elements300may be further increased. That is, the first light emitting element301and the second light emitting element302, which constitute a plurality of layers, are disposed between the electrodes21and22so that an amount of light emitted per unit area of the target substrate SUB may be increased.

According to one or more embodiments, the light emitting element300may be disposed between the first electrode21and the second electrode22to be separated therefrom and contact electrodes26may be further disposed between the light emitting element300and the first and second electrodes21and22.

Referring toFIG.10, the light emitting element300may be disposed between the first electrode21and the second electrode22, and both end portions EA1and EA2may be respectively disposed to be separated from the electrodes21and22. The contact electrodes26are further disposed to be in contact with the light emitting element300and the electrodes21and22in an area in which the light emitting element300and the electrodes21and22are separated from each other.

In one or more embodiments, the contact electrodes26include a first contact electrode26ain contact with the first end portion EA1of the light emitting element300and the first electrode21, and a second contact electrode26bin contact with the second end portion EA2of the light emitting element300and the second electrode22. UnlikeFIGS.8and9, inFIG.10, the light emitting element300may not be in direct contact with the electrodes21and22but may be connected to the electrodes21and22through the contact electrodes26. Although not shown in the drawing, when a length of the light emitting element300measured in the extension direction DL is equal to a distance between the electrodes21and22, at least one end portion of the light emitting element300may not be connected to the electrode21or22. To prevent (or reduce a likelihood or occurrence of) this, the distance between the first electrode21and the second electrode22may be greater than the length l of the light emitting element300, and the light emitting element300may be connected to the electrodes21and22through the contact electrodes26.

In addition, in an example, each of the electrodes21and22may include a material having high reflectivity. As shown in the drawing, second emitted light EL2may be emitted from the two end portions EA1and EA2of the light emitting element300to propagate toward the electrodes21and22. When each of the electrodes21and22includes a material having high reflectivity, the second emitted light EL2emitted in the extension direction DL of the light emitting element300may be reflected in a direction upward from the target substrate SUB. Thus, top emission efficiency of the light emitting element300disposed on the target substrate SUB may further be improved.

The light emitting element300may emit light in a set or specific wavelength range, for example, blue light, and the display device1according to one embodiment may include at least one light emitting element300to display light of a set or specific color.

FIG.11is a plan view illustrating a display device including a light emitting element manufactured by a method according to one embodiment.

Referring toFIG.11, the display device1may include a plurality of pixels PX. Each of the pixels PX may include one or more light emitting elements300, which emit light in a set or specific wavelength range, to display a set or specific color.

Each of the plurality of pixels PX may include a first sub-pixel PX1, a second sub-pixel PX2, and a third sub-pixel PX3. The first sub-pixel PX1may emit light of a first color, the second sub-pixel PX2may emit light of a second color, and the third sub-pixel PX3may emit light of a third color. The first color may be red, the second color may be green, and the third color may be blue, but the present disclosure is not limited thereto, and each sub-pixel PXn may emit light of the same color. In addition, although each of the pixels PX is illustrated as including three sub-pixels inFIG.11, the present disclosure is not limited thereto, and each of the pixels PX may include a larger number of sub-pixels.

Each sub-pixel PXn of display device1may include areas defined as an emission area and a non-emission area. The emission area is defined as an area in which the light emitting elements300included in the display device1are disposed to emit light in a set or specific wavelength range. The non-emission area is an area other than the emission area and may be defined as an area in which the light emitting elements300are not disposed and light is not emitted therefrom.

The sub-pixel PXn of display device1may include a plurality of banks40, a plurality of electrodes21and22, and the light emitting elements300.

The plurality of electrodes21and22may be electrically connected to the light emitting elements300and may receive a set or predetermined voltage so as to allow the light emitting elements300to emit light. Further, at least a portion of each of the electrodes21and22may be utilized to form an electric field in the sub-pixel PXn so as to align the light emitting elements300.

In one or more embodiments, the plurality of electrodes21and22may include a first electrode21and a second electrode22. In an example, the first electrode21may be a pixel electrode separated for each sub-pixel PXn, and the second electrode22may be a common electrode commonly connected along each sub-pixel PXn. One of the first electrode21and the second electrode22may be an anode electrode of the light emitting element300, and the other may be a cathode electrode of the light emitting element300. However, the present disclosure is not limited thereto and the reverse of the above case may be possible.

The first electrode21and the second electrode22may include electrode stem portions21S and22S disposed to extend in a first direction D1and include electrode branch portions21B and22B branching and extending from the electrode stem portions21S and22S in a second direction D2intersecting the first direction D1, respectively.

The first electrode21may include a first electrode stem portion21S disposed to extend in the first direction D1, and at least one first electrode branch portion21B branching from the first electrode stem portion21S to extend in the second direction D2.

Both ends of the first electrode stem portion21S of any one pixel may be separated to be terminated between the sub-pixels PXn and disposed substantially collinear with a first electrode stem portion21S of an adjacent PXn in the same row (e.g., adjacent in the first direction D1). Thus, the first electrode stem portions21S disposed in respective sub-pixels PXn may apply different electrical signals to respective first electrode branch portions21B, and the first electrode branch portions21B may each be driven separately.

The first electrode branch portion21B branches from at least a portion of the first electrode stem portion21S and is disposed to extend in the second direction D2. The first electrode branch portion21B may be terminated in a state of being separated from the second electrode stem portion22S which is disposed opposite to the first electrode stem portion21S.

The second electrode22may include the second electrode stem portion22S which extends in the first direction D1and is disposed to be separated from and opposite to the first electrode stem portion21S, and the second electrode branch portion22B which branches from the second electrode stem portion22S and is disposed to extend in the second direction D2. However, both end portions of the second electrode stem portion22S may extend to a plurality of adjacent sub-pixels PXn in the first direction D1. Thus, both ends of the second electrode stem portion22S of a set or arbitrary pixel may be connected to a second electrode stem portion22S of an adjacent pixel PX between the pixels PX.

The second electrode branch portion22B may be separated from and opposite to the first electrode branch portion21B and terminated in a state of being separated from the first electrode stem portion21S. That is, one end portion of the second electrode branch portion22B may be connected to the second electrode stem portion22S, and the other end portion thereof may be disposed in the sub-pixel PXn in a state of being separated from the first electrode stem portion21S.

In the drawing, two first electrode branch portions21B are illustrated as being disposed and the second electrode branch portion22B is illustrated as being disposed between the two first electrode branch portions21B, but the present disclosure is not limited thereto.

The plurality of banks40may include a third bank43disposed at a boundary between the sub-pixels PXn, and a first bank41and a second bank42which are respectively disposed below the electrodes21and22. Although the first bank41and the second bank42are not illustrated in the drawing, the first bank41and the second bank42may be disposed below the first electrode branch portion21B and the second electrode branch portion22B, respectively.

The third bank43may be disposed at a boundary between the sub-pixels PXn. End portions of the plurality of first electrode stem portions21S may be separated from each other to be terminated based on the third bank43. The third bank43may extend in the second direction D2and may be disposed at the boundary between the sub-pixels PXn disposed in the first direction D1. However, the present disclosure is not limited thereto, and the third bank43may extend in the first direction D1and may be disposed at the boundary between the sub-pixel PXn disposed in the second direction D2. The third bank43may include the same material as the first bank41and the second bank42and may be formed in substantially the same process.

Although not shown in the drawing, a first insulating layer51may be disposed in each sub-pixel PXn to entirely cover each sub-pixel PXn including the first electrode branch portion21B and the second electrode branch portion22B. The first insulating layer51may protect each of the electrodes21and22and, concurrently (e.g., simultaneously), insulate the electrodes21and22from each other so as not to be in direct contact with each other.

The plurality of light emitting elements300may be disposed between the first electrode branch portion21B and the second electrode branch portion22B. One end portions of at least some of the plurality of light emitting elements300may be electrically connected to the first electrode branch portion21B and the other end portions thereof may be electrically connected to the second electrode branch portion22B.

The plurality of light emitting elements300may be separated from each other in the second direction D2and disposed substantially parallel to each other. A separation distance between the light emitting elements300is not particularly limited. In some cases, a plurality of light emitting elements300may be disposed adjacent to each other to form a group, and another plurality of light emitting elements300may be grouped in a state of being spaced apart at a certain interval, may have a nonuniform density, and may be oriented in one direction to be disposed.

As described above, the light emitting element300may include light conversion particles385disposed on the insulation coating film381and emit light toward an upper portion of the display device1. That is, display device1may include the light emitting element300ofFIG.1, and thus top emission efficiency may be improved.

The contact electrode26may be disposed on the first electrode branch portion21B and the second electrode branch portion22B. However, the contact electrode26may be substantially disposed on the first insulating layer51, and at least a portion of the contact electrode26may be in contact with or electrically connected to the first electrode branch portion21B and the second electrode branch portion22B.

A plurality of contact electrodes26may be disposed to extend in the second direction D2and disposed to be separated from each other in the first direction D1. The contact electrode26may be in contact with at least one end portion of the light emitting element300, and the contact electrode26may be in contact with the first electrode21or the second electrode22to receive an electrical signal. Thus, the contact electrode26may transmit an electrical signal, which is transmitted from each of the electrodes21and22, to the light emitting element300.

The contact electrode26may include a first contact electrode26aand a second contact electrode26b. The first contact electrode26amay be disposed on the first electrode branch portion21B to be in contact with one end portion of the light emitting element300, and the second contact electrode26bmay be disposed on the second electrode branch portion22B to be in contact with the other end portion thereof.

The first electrode stem portion21S and the second electrode stem portion22S may be electrically connected to a circuit element layer of the display device1through respective contact holes, for example, a first electrode contact hole CNTD and a second electrode contact hole CNTS. In the drawing, one second electrode contact hole CNTS is illustrated as being formed in the second electrode stem portion22S of each of the plurality of sub-pixels PXn. However, the present disclosure is not limited thereto, and in some cases, the second electrode contact hole CNTD may be formed in each sub-pixel PXn.

In addition, although not shown in the drawing, the display device1may include a second insulating layer52(seeFIG.12) and a passivation layer55(seeFIG.12) which are disposed to cover at least a portion of each of the electrodes21and22and the light emitting element300. An arrangement and a structure between the above components will be further described below with reference toFIG.12.

FIG.12is a partial cross-sectional view taken along line II-II′ ofFIG.11.

FIG.12illustrates a cross-sectional view of the first sub-pixel PX1and may be equally applied to another pixel PX or another sub-pixel PXn.FIG.22illustrates a cross section crossing one end portion and the other end portion of an arbitrary light emitting element300.

Meanwhile, although not shown inFIG.12, the display device1may further include circuit element layers located below the electrodes21and22. The circuit element layer may include a plurality of semiconductor layers and a plurality of conductive patterns and may include at least one transistor and a power line. However, a further detailed description thereof will not be provided below.

Referring toFIG.12, the display device1may include a via layer20, the electrodes21and22disposed on the via layer20, and the light emitting element300. A circuit element layer (not shown) may be further disposed below the via layer20. The via layer20may include an organic insulating material and perform a surface planarization function.

A plurality of banks41,42, and43are disposed on the via layer20. The plurality of banks41,42, and43may be disposed to be separated from each other in each sub-pixel PXn. The plurality of banks41,42, and43may include the first bank41and the second bank42which are disposed adjacent to a central portion of the sub-pixel PXn, and the third bank43disposed at a boundary between the sub-pixels PXn.

When the ink is sprayed using an inkjet printing device during the manufacturing of the display device1, the third bank43may perform a function of blocking the ink from crossing the boundary of the sub-pixel PXn. In addition, when the display device1further includes another member, the other member may be disposed on the third bank43and the third bank43may perform a function of supporting the other member. However, the present disclosure is not limited thereto.

The first bank41and the second bank42are disposed to be separated from and opposite to each other. The first electrode21may be disposed on the first bank41, and the second electrode22may be disposed on the second bank42. Referring toFIGS.11and12, it can be understood that the first electrode branch portion21B is disposed on the first bank41, and the second bank42is disposed on the second bank42.

As described above, the first bank41, the second bank42, and the third bank43may be formed in substantially the same process. Thus, the banks41,42, and43may constitute a single grid pattern. Each of the plurality of banks41,42, and43may include polyimide (PI).

Each of the plurality of banks41,42, and43may have a structure in which at least a portion protrudes from the via layer20. The banks41,42, and43may protrude upward based on a plane on which the light emitting element300is disposed, and at least a part of each of the protruding portions may have a slope. A shape of each of the banks41,42, and43having the protruding structures is not particularly limited. As shown in the drawing, the first bank41and the second bank42protrude to the same height, and the third bank43may have a shape protruding to a higher position.

Reflective layers21aand22amay be disposed on the first bank41and the second bank42, and electrode layers21band22bmay be disposed on the reflective layers21aand22a. The reflective layers21aand22aand the electrode layers21band22bmay constitute the electrodes21and22, respectively.

The reflective layers21aand22ainclude a first reflective layer21aand a second reflective layer22a. The first reflective layer21amay cover the first bank41, and the second reflective layer22amay cover the second bank42. Portions of the reflective layers21aand22aare electrically connected to the circuit element layer through a contact hole passing through the via layer20.

Each of the reflective layers21aand22amay include a material having high reflectivity to reflect light emitted from the light emitting element300. For example, each of the reflective layers21aand22amay include a material such as Ag, Cu, ITO, IZO, and/or ITZO, but the present disclosure is not limited thereto.

The electrode layers21band22binclude a first electrode layer21band a second electrode layer22b. The electrode layers21band22bmay have patterns substantially equal to patterns of the reflective layers21aand22a. The first reflective layer21aand the first electrode layer21bare disposed to be separated from the second reflective layer22aand the second electrode layer22b.

Each of the electrode layers21band22bincludes a transparent conductive material, and thus emission light EL emitted from the light emitting element300may be incident on the reflective layers21aand22a. For example, each of the electrode layers21band22bmay include a material such as ITO, IZO, and/or ITZO, but the present disclosure is not limited thereto.

In some embodiments, the reflective layers21aand22aand the electrode layers21band22bmay form a structure in which one or more transparent conductive layers such as ITO, IZO, and/or ITZO, and one or more metal layers such as Ag and/or Cu are stacked. For example, the reflective layers21aand22aand the electrode layers21band22bmay form a stacked structure of ITO/Ag/ITO/IZO.

In some embodiments, the first electrode21and the second electrode22may be formed as a single layer. That is, the reflective layers21aand22aand the electrode layers21band22bmay be formed as a single layer to transmit an electrical signal to the light emitting element300and, concurrently (e.g., simultaneously), reflect light. For example, each of the first electrode21and the second electrode22may include a conductive material (e.g., an electrically conductive material) having high reflectivity and may be an alloy containing Al, nickel (Ni), and/or lanthanum (La). However, the present disclosure is not limited thereto.

The first insulating layer51is disposed to partially cover the first electrode21and the second electrode22. The first insulating layer51may be disposed to cover most of the upper surfaces of the first electrode21and the second electrode22and may expose portions of the first electrode21and the second electrode22. The first insulating layer51may be disposed to partially cover an area in which the first electrode21is separated from the second electrode22and an area opposite to the area in which the first electrode21is separated from the second electrode22.

The first insulating layer51is disposed to expose relatively flat upper surfaces of the first electrode21and the second electrode22and disposed to allow the electrodes21and22to overlap inclined surfaces of the first bank41and the second bank42. The first insulating layer51forms a flat upper surface to allow the light emitting element300to be disposed, and the flat upper surface extend toward the first electrode21and the second electrode22in one direction. The extension portion of the first insulating layer51is terminated at inclined surfaces of the first electrode21and the second electrode22. Thus, the contact electrodes26may be in contact the exposed first electrode21and the exposed second electrode22and may be in smooth contact with the light emitting element300on the flat upper surface of the first insulating layer51.

The first insulating layer51may protect the first electrode21and the second electrode22and, concurrently (e.g., simultaneously), insulate the first electrode21from the second electrode22. In addition, the first insulating layer51may prevent the light emitting element300disposed thereon from being damaged by direct contact with other members (or may reduce a likelihood or degree of such damage).

The light emitting element300may be disposed on the first insulating layer51. At least one light emitting element300may be disposed on the first insulating layer51between the first electrode21and the second electrode22. The light emitting element300may include a plurality of layers disposed in a direction horizontal to the via layer20.

The light emitting element300of the display device1according to one embodiment may include the conductivity type semiconductors and the active layer, which are described above, and the conductivity type semiconductors and the active layer may be sequentially disposed on the via layer20in a horizontal direction. As shown in the drawing, in the light emitting element300, the first conductivity type semiconductor310, the active layer330, the second conductivity type semiconductor320, and the conductive electrode layer370may be sequentially disposed on the via layer20in the horizontal direction. However, the present disclosure is not limited thereto. The order of the plurality of layers disposed in the light emitting element300may be reversed. In some cases, when the light emitting element300has another structure, the plurality of layers may be disposed in a direction perpendicular (e.g., substantially perpendicular) to the via layer20.

The second insulating layer52may be partially disposed on the light emitting element300. The second insulating layer52may protect the light emitting element300and, concurrently (e.g., simultaneously), perform a function of fixing the light emitting element300during a process of manufacturing the display device1. The second insulating layer52may be disposed to surround an outer surface of the light emitting element300. That is, a portion of a material of the second insulating layer52may be disposed between a bottom surface of the light emitting element300and the first insulating layer51. The second insulating layer52may extend between the first electrode branch portion21B and the second electrode branch portion22B in the second direction D2to have an island shape or a linear shape when viewed in a plan view.

The contact electrodes26are disposed on the electrodes21and22and the second insulating layer52. The first contact electrode26aand the second contact electrode26bare disposed to be separated from each other on the second insulating layer52. Thus, the second insulating layer52may insulate the first contact electrode26afrom the second contact electrode26b.

The first contact electrode26amay be in contact with at least the first electrode21, which is exposed due to patterning of the first insulating layer51, and one end portion of the light emitting element300. The second contact electrode26bmay be in contact with at least the second electrode22, which is exposed due to the patterning of the first insulating layer51, and the other end portion of the light emitting element300. The first and second contact electrodes26aand26bmay be in contact with side surfaces of the two end portions of the light emitting element300, for example, the first conductivity type semiconductor310, the second conductivity type semiconductor320, or the conductive electrode layer370. As described above, the first insulating layer51forms the flat upper surface so that the contact electrodes26may be in smooth contact with the side surfaces of the light emitting element300.

The contact electrode26may include a conductive material. For example, the contact electrode260may include ITO, IZO, ITZO, Al, and/or the like. However, the present disclosure is not limited thereto.

The passivation layer55may be formed on the second insulating layer52and the contact electrodes26and may serve to perform a function of protecting members disposed on the via layer20from an external environment.

Each of the first insulating layer51, the second insulating layer52, and the passivation layer55, which are described above, may include an inorganic insulating material and/or an organic insulating material. In an example, each of the first insulating layer51, and the passivation layer55may include a material such as SiOx, SiOxNy, Al2O3, aluminum nitride (AlN), and/or the like. The second insulating layer52may be made of an organic insulating material including a photoresist and/or the like. However, the present disclosure is not limited thereto.

As described above, the display device1includes the plurality of banks40, particularly, the first bank41and the second bank42, and the electrodes21and22may be disposed on the inclined surfaces of the banks41and42. Among the light emitted from the light emitting element300, the second emitted light EL2emitted in the extension direction DL of the light emitting element300may propagate toward the electrodes21and22formed on the inclined surfaces of the banks41and42. The electrodes21and22including the reflective layers21aand22amay reflect the incident second emitted light EL2toward the upper portion of the light emitting element300, and top emission efficiency of the display device1may be increased.

However, the light emitting element300according to one embodiment may include the light conversion particles385disposed on the insulation coating film381to emit the first emitted light EL1in a direction perpendicular (e.g., substantially perpendicular) to the extension direction DL of the light emitting element300. When the display device1includes the light emitting element300ofFIG.1, even when the second emitted light EL2is not reflected to the upper portion of the light emitting element300through the inclined banks41and42, the display device1may emit a suitable or sufficient amount of emitted light through the light conversion particles385toward the upper portion of the light emitting element300. That is, in a display device1according to another embodiment, the banks, particularly, the first bank41and the second bank42, may be omitted.

FIG.13is a cross-sectional view illustrating a display device according to another embodiment.

Referring toFIG.13, in the display device1, the first bank41and the second bank42may be omitted, and a first electrode21and a second electrode22may be directly disposed on a via layer20. Although not shown inFIG.13, as shown inFIG.12, light conversion particles385may be disposed on an insulation coating film381of an outer surface of the light emitting element300, and light emitted from an active layer330of a light emitting element300may propagate toward an upper portion based on the via layer20.

Consequently, unlike the display device1ofFIG.12, there is an advantage in a process in which an operation of forming the banks41and42is omitted, and a step between members disposed on the via layer20may be reduced or omitted. In addition, since top emission efficiency may be suitably or sufficiently obtained even when the light emitted from the light emitting element300is not reflected, the reflective layers21aand22amay be omitted from the electrodes21and22. Descriptions of other members are the same as those described above with reference toFIG.12and thus will not be repeated here.

The display device1may further include a light emitting element300having a structure different from the structure of the light emitting element300ofFIG.1.

FIG.14is a schematic diagram of a light emitting element according to another embodiment.

Referring toFIG.14, a light emitting element300′ may be formed such that a plurality of layers are not stacked in one direction and each of the plurality of layers surrounds an outer surface of another layer. The light emitting element300′ ofFIG.13is the same as the light emitting element30ofFIG.1except that shapes of the layers are partially different from each other. Hereinafter, the same content will be omitted and a difference will be described.

According to one embodiment, a first conductivity type semiconductor310′ may extend in one direction and both end portions thereof may be formed to be inclined toward a central portion thereof. The first conductivity type semiconductor310′ ofFIG.13may have a shape in which a rod-shaped or cylindrical main body and conical-shaped end portions 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.

An active layer330′ is disposed to surround an outer surface of the main body of the first conductivity type semiconductor310′. The active layer330′ may have an annular shape extending in one direction. The active layer330′ may not be formed on upper and lower end portions of the first conductivity type semiconductor310′. That is, the active layer330, may be in contact with only a parallel side surface of the first conductivity type semiconductor310′.

A second conductivity type semiconductor320′ is disposed to surround an outer surface of the active layer330′ and the upper end portion of the first conductivity type semiconductor310′. The second conductivity type semiconductor320′ may include an annular-shaped main body extending in one direction and an upper end portion having a side surface formed to be inclined. That is, the second conductivity type semiconductor320′ may be in direct contact with a parallel side surface of the active layer330′ and an inclined upper end portion of the first conductivity type semiconductor310. However, the second conductivity type semiconductor320′ is not formed in the lower end portion of the first conductivity type semiconductor310′.

An electrode material layer370′ is disposed to surround an outer surface of the second conductivity type semiconductor320′. That is, a shape of the electrode material layer370′ may be substantially the same as a shape of the second conductivity type semiconductor320′. That is, the electrode material layer370′ may be entirely in contact with the outer surface of the second conductivity type semiconductor320′.

An insulation film380′ may be disposed to surround the electrode material layer370′ and the outer surface of the first conductivity type semiconductor310′. The insulation film380′ may be in direct contact with, in addition to the electrode material layer370′, the lower end portion of the first conductivity type semiconductor310′, and exposed lower end portions of the active layer330′ and the second conductivity type semiconductor320′.

Even in the light emitting element300′ ofFIG.14, the insulation film380′ includes an insulation coating film381′ and light conversion particles385′, and thus the light emitting element300′ may emit a suitable or sufficient amount of light in a direction perpendicular (e.g., substantially perpendicular) to a direction in which the light emitting element300′ extends. A detailed description thereof is the same as the above description and thus will not be repeated here.

In concluding the detailed description, those skilled in the art will appreciate that many variations and modifications can be made to the preferred embodiments without substantially departing from the principles of the present disclosure. Therefore, the disclosed preferred embodiments of the disclosure are used in a generic and descriptive sense only and not for purposes of limitation.