Patent ID: 12206045

DETAILED DESCRIPTION

Reference will now be made in detail to example embodiments of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the example embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the example embodiments are merely described below, by referring to the figures, to explain aspects. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, the expression, “at least one of a, b, and c,” should be understood as including only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

Hereinafter, example embodiments will be described in detail with reference to the accompanying drawings. The example embodiments described herein are merely examples, and various modifications may be made from these embodiments. In the following drawings, like reference numerals refer to like components, and the size of each component in the drawings may be exaggerated for clarity and convenience of description.

Hereinafter, when it is described that a certain component is “above” or “on” another component, the certain component may be directly above another component, or a third component may be interposed therebetween.

The singular expressions include plural expressions unless the context clearly dictates otherwise. When a part “includes” a component, it may indicate that the part does not exclude another component but may further include another component, unless otherwise stated.

The use of the terms “a” and “an” and “the” and similar referents may cover both the singular and the plural.

The meaning of “connection” may include a physical connection as well as an optical connection.

The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illustrate the inventive concept and does not pose a limitation on the scope of the inventive concept unless otherwise claimed.

Terms such as first, second, etc., may be used to describe various components, but the components should not be limited by these terms. The terms are used only for the purpose of distinguishing one component from another.

FIG.1is a cross-sectional view of a light emitting device10according to an example embodiment,FIG.2is a three-dimensional (3D) view of a buffer layer100and a scattering pattern400of the light emitting device10according to an example embodiment,FIG.3is a view illustrating that the scattering pattern400according to an example embodiment has a mesh structure including holes having a circular cross-section on the buffer layer100, andFIG.4is a view illustrating that the scattering pattern400according to an example embodiment has a mesh structure including holes having a hexagonal cross-section on the buffer layer100.

Referring toFIG.1, the light emitting device10according to an example embodiment may include the buffer layer100, a body200disposed on the buffer layer100and including a first semiconductor layer210, an active layer220, and a second semiconductor layer230, a reflective layer300disposed on the body200and configured to reflect light50incident from the active layer220, and the scattering pattern400embedded in the first semiconductor layer210on the buffer layer100and scattering the light50incident from the active layer220or the reflective layer300.

The buffer layer100may be positioned on a substrate, and after the buffer layer100is positioned, the substrate may be removed. The buffer layer100may be required to grow the body200or the first and second semiconductor layers210and230and the active layer220of the body200. For example, a material suitable for epitaxial growth of gallium nitride (GaN) having a hexagonal wurtzite structure may be selected as the buffer layer100, however, embodiments are not limited thereto. For example, the buffer layer100may include aluminum nitride (AlN) having a hexagonal wurtzite structure.

The scattering pattern400may be provided on an upper surface of the buffer layer100and may be provided in the first semiconductor layer210. For example, a surface of the scattering pattern400may contact the buffer layer100and the other surfaces of the scattering pattern400may contact and be embedded in the first semiconductor layer210. For example, the scattering pattern400may include a plurality of scattering elements protruding from the buffer layer100to the first semiconductor layer210, andFIG.1illustrates that the scattering elements have a stripe shape. However, embodiments are not limited thereto. For example, the scattering pattern400on the buffer layer100may have a structure having a plurality of holes, and a cross-section of the holes may have one of various shapes such as a circular, elliptical, or polygonal shape. The scattering pattern400and the first semiconductor layer210may appear to be alternately arranged on the cross-sectional view according to the former and the latter examples.

The scattering pattern400may have a period. For example, when the scattering pattern400includes the scattering elements, the period of the scattering pattern400may refer to the scattering elements being arranged on the buffer layer100at a constant period. In the case of the scattering pattern400having the mesh structure including holes, the period of the scattering pattern400may refer to the holes being arranged at a constant period. When the scattering pattern400includes the scattering elements, the buffer layer100may be exposed between adjacent scattering elements. In the case of the scattering pattern400having the mesh structure including holes, the entire upper surface of the buffer layer100may not be covered by the scattering pattern400due to the holes, and the buffer layer100may be exposed. The body200may be epitaxially grown on the buffer layer100not covered by the scattering pattern400and exposed.

Referring toFIGS.1and2, the scattering pattern400is arranged on the buffer layer100in the stripe shape, but embodiments are not limited thereto and the scattering pattern400may be arranged in various shapes. For example, the scattering pattern400may have a mesh structure including holes. Here, the cross-section of the holes may have various shapes such as a circular, elliptical, or polygonal shape. For example, the period between the scattering patterns400may be about 0.1 μm to about 10 μm. For example, a thickness of the scattering pattern400may be about 10 nm to about 1 μm. The thickness of the scattering pattern400may be less than a wavelength of the light50. The shape of the scattering pattern400, the period of the scattering pattern400, and the thickness of the scattering pattern400may be appropriately selected considering light extraction efficiency of an LED to be manufactured. For example, if gallium nitride (GaN) having a hexagonal wurtzite structure is grown on the buffer layer100, the scattering pattern400may have a mesh structure including holes having the hexagonal cross-section.

Referring toFIG.2, the scattering pattern400according to an example embodiment may have the stripe shape. A plurality of scattering patterns400in the form of stripes may be arranged to have a predetermined period, and the first semiconductor layer210of the body200may be alternately positioned thereon. A portion of the first semiconductor layer210may be in contact with the scattering patterns400, and the scattering patterns400may be embedded in the first semiconductor layer210.

Referring toFIG.3, the scattering pattern400according to an example embodiment may have a mesh structure including holes having a circular cross-section on the buffer layer100. The first semiconductor layer210of the body200may be positioned inside the holes having the circular cross-section of the scattering pattern400and on the scattering pattern400. A portion of the first semiconductor layer210may be in contact with the scattering pattern400, and the scattering pattern400may be embedded in the first semiconductor layer210.

Referring toFIG.4, the scattering pattern400according to an example embodiment may have a mesh structure including holes having a hexagonal cross-section on the buffer layer100. The first semiconductor layer210of the body200may be positioned inside the holes having the hexagonal cross-section of the scattering pattern400and on the scattering pattern400. A portion of the first semiconductor layer may be in contact with the scattering pattern400, and the scattering pattern400may be embedded in the first semiconductor layer210.

FIG.5is a view illustrating that a width of the holes having the hexagonal cross-section of the scattering pattern400changes in the thickness direction according to an example embodiment.

The holes of the scattering pattern400according to an example embodiment are illustrated to have a cross-section having a constant size according to the thickness on the buffer layer100, but embodiments are not limited thereto and a size of the cross-section of the hole of the scattering pattern400may change along a thickness direction toward the buffer layer100. Referring toFIG.5, the scattering pattern400according to an example embodiment may have a mesh structure having holes having a hexagonal cross-sectional area that changes along a thickness direction toward the buffer layer100. An angle between a side surface of the scattering pattern400and the buffer layer100may be appropriately selected so that the light50emitted from the active layer220may escape and be emitted external to the light emitting device10without total reflection. AlthoughFIG.5shows that the width of the cross-section of the holes increases in a direction away from the buffer layer100, embodiments are not limited thereto and the width of the cross-section of the holes may gradually decrease away from the buffer layer100or an increase and decrease of the width of the scattering pattern400may be repeated.

Without the scattering pattern400, when the light50emitted from the active layer220of the body200is incident on the air, where the refractive index of air nair=1, if an incident angle of the light is greater than a critical angle, the light50is totally reflected and only the light50having an incident angle less than the critical angle escapes from the light emitting device10. If both sides of the body200are parallel, the light50having an incident angle greater than the critical angle may continue to be totally reflected between both sides of the body200and may be trapped inside the body200or may be reabsorbed by the active layer220. Accordingly, the light extraction efficiency of the light emitting device10may be lowered.

The scattering pattern400may scatter the light50emitted from the active layer220. In particular, if the thickness of the scattering pattern400is not less or sufficiently greater than a wavelength of light, it may be difficult to ignore scattering such as Rayleigh scattering and Mie scattering. The scattering pattern400may have a refractive index lower than that of the first semiconductor layer210and may include a light-transmissive material. For example, the refractive index of the first semiconductor layer210may have a value of 2 or greater, and the refractive index of the scattering pattern400may have a value of about 2 or less. However, embodiments are not limited thereto. For example, a permittivity of the scattering pattern400may have a value of about 4 or less. The scattering pattern400may scatter the light50emitted from the active layer220, so that the light50, which may be totally reflected without the scattering pattern400, may be discharged out of the light emitting device10. Therefore, the light extraction efficiency of the light emitting device10may be improved using the scattering pattern400. The scattering pattern400may include, for example, at least one of dielectrics such as aluminum oxide (Al2O3), a silicon oxide film (SiO2), silicon nitride (Si3N4), titanium oxide (TiO2), magnesium oxide (MgO), magnesium fluoride (MgF2), stannic oxide (SnO2), tantalum dioxide (TaO2), zinc sulfide (ZnS), ceric oxide (CeO2), etc.

The body200may include the first semiconductor layer210, the active layer220, and the second semiconductor layer230, and may be grown on the buffer layer100in this order. A lower portion of the first semiconductor layer210may be in contact with a portion of the buffer layer100, and a portion thereof not in contact with the buffer layer100may be in contact with the scattering pattern400. Because the scattering pattern400is positioned on the buffer layer100and the body200is grown on the buffer layer100, the scattering pattern400may be embedded in the first semiconductor layer210of the body200. However, the body200is not limited to being grown on the buffer layer100, and may also be grown on the scattering pattern400that has undergone an annealing process.

The first semiconductor layer210and the second semiconductor layer230may include a group II-VI or group III-V compound semiconductor material. The first semiconductor layer210and the second semiconductor layer230may provide electrons and holes to the active layer220. To this end, the first semiconductor layer210may be doped n-type or p-type, and the second semiconductor layer230may be doped with a conductivity type electrically opposite to that of the first semiconductor layer210. For example, the first semiconductor layer210may be doped p-type and the second semiconductor layer230may be doped n-type, or the first semiconductor layer210may be doped n-type and the second semiconductor layer210may be doped n-type. In the case of doping the second semiconductor layer230n-type, for example, silicon (Si) may be used as a dopant, and in the case of doping the first semiconductor layer210as a p-type, for example, zinc (Zn) may be used as a dopant. Here, the second semiconductor layer230doped as an n-type may provide electrons to the active layer220, and the first semiconductor layer210doped as a p-type may provide holes to the active layer220.

The active layer220has a quantum well structure in which quantum wells are provided between barriers. As electrons and holes provided from the first semiconductor layer210and the second semiconductor layer230may recombine within the quantum well structure in the active layer220, and the light50may be emitted. A wavelength of light generated in the active layer220may be determined according to a band gap of a material constituting the quantum wells in the active layer220. The active layer220may have a single quantum well structure, or a multi-quantum well (MQW) structure in which multiple quantum wells and a plurality of barriers are alternately positioned. A thickness of the active layer220or the number of quantum wells in the active layer220may be appropriately selected considering a driving voltage and luminous efficiency of the light emitting device10to be manufactured.

The active layer220may include a quantum barrier layer and a quantum well layer. For example, the quantum barrier layer may include gallium nitride (GaN), and the quantum well layer may include indium gallium nitride (InxGa1-xN (0≤x≤1)). The quantum barrier layer or quantum well layer may include various materials, without being limited to the above example. The active layer220may have a structure in which the quantum barrier layers and the quantum well layers are alternately stacked N times, where, N is a natural number greater than or equal to 1.

The reflective layer300may reflect the light50emitted upward from the active layer220downward. Due to the reflective layer300, the light emitting device10may have a bottom emission structure. As the light50emitted upward is reflected downward by the reflective layer300, the light extraction efficiency of the bottom emission structure may be improved. In addition, the reflective layer300may serve as an upper electrode on the body200. The reflective layer300may include, for example, a metal such as gold (Au), silver (Ag), or aluminum (Al) or an alloy thereof, or a multilayer structure thereof, in a visible light range.

FIG.6is a cross-sectional view of the light emitting device10according to another example embodiment.

The light emitting device10according to the example embodiment ofFIG.1shows that the scattering pattern400is positioned on the buffer layer100and is in contact with the buffer layer100, and accordingly, apart from the one surface of the scattering pattern400being in contact with the buffer layer100the scattering pattern400is embedded in the first semiconductor layer210. However, embodiments are not limited thereto, and all of the surfaces of the scattering pattern400may be embedded in the first semiconductor layer210.

Referring toFIG.6, in the light emitting device10according to an example embodiment, the scattering pattern400may be completely embedded in the first semiconductor layer210so that all of the surfaces of the scattering pattern400are in contact with the first semiconductor layer210. Similarly, the example embodiments ofFIGS.2to5may not be limited to the configuration in which the scattering pattern400is positioned on the buffer layer100, and a portion of the first semiconductor layer210may be positioned on the buffer layer100, but the scattering pattern400may be included in the first semiconductor layer210, and the first semiconductor layer210may entirely cover the scattering pattern400.

FIG.7is a cross-sectional view of a light emitting device20according to another example embodiment.

Referring toFIG.7, the light emitting device20according to an example embodiment may include a plurality of cavities500between the scattering pattern400and the buffer layer100. The cavity500may contain, for example, air which has a refractive index of 1 and a permittivity of 1. Accordingly, a refractive index of the cavity500may be 1, and a permittivity of the cavity500may be approximately 1. Scattering of the light50emitted from the active layer220may take place more easily by the cavity500, thereby increasing light extraction efficiency.

Referring toFIG.7, the body200of the scattering pattern400according to an example embodiment may be grown on a surface of the scattering pattern400, without contacting a surface of the buffer layer100. In order for the body200to grow on the surface of the scattering pattern400, the scattering pattern400according to an example embodiment may have undergone an annealing process, and a lower portion of the first semiconductor layer210may be in contact with the scattering pattern400that has undergone the annealing process. The scattering pattern400that has undergone the annealing process may include a crystallized material. The body200may be grown on the scattering pattern400that has undergone the annealing process, and the scattering pattern400may be partially embedded in the first semiconductor layer210of the body200. For example, in the case of epitaxial growth of gallium nitride (GaN) having a hexagonal wurtzite crystal structure, the epitaxial growth may not be properly made on a scattering pattern400that has not been annealed. This is because a structure of the scattering pattern400that has not been annealed is not a hexagonal wurtzite crystal structure, but is in an amorphous state. Accordingly, the scattering pattern400including the crystallized material may be positioned by performing the annealing process to change a phase of the scattering pattern400in the amorphous state to a crystalline state. For example, when aluminum nitride (AlN) having the hexagonal wurtzite crystal structure is positioned under the scattering pattern400, the scattering pattern400may also have the hexagonal wurtzite crystal structure through the annealing process. Gallium nitride (GaN) may be epitaxially grown on the scattering pattern400including the crystallized material.

FIG.8is a cross-sectional view of a light emitting device30according to another example embodiment.

Referring toFIG.8, the light emitting device30may further include one or more voids600provided between the scattering pattern400and the first semiconductor layer210and containing air. The void600may be disposed between adjacent cavities500among the cavities500. The void600may or may not be formed according to conditions of epitaxial growth. The void600may also contain air similar to the cavity500, and accordingly, a refractive index of the void600may be 1, and a permittivity of the void600may be approximately 1. In the light emitting device30including the void600, scattering of the light50may take place more easily, and thus, light extraction efficiency may be increased. Conditions for epitaxial growth may be appropriately selected so that the voids600may be more easily formed. However, instead of epitaxially growing the body200on the scattering pattern400subjected to the annealing process as shown inFIGS.7and8, in the case of epitaxially growing the body200on the buffer layer100as shown inFIGS.1to6, if the void600is formed between the buffer layer100and the first semiconductor layer210, it may be difficult for the body200to epitaxially grow. Therefore, when the scattering pattern400is positioned so that the buffer layer100does not directly contact the first semiconductor layer210as shown inFIGS.7and8, the light emitting devices20and30may include the void600between the scattering pattern400and the first semiconductor layer210. That is, in the case of the light emitting device10according to the example embodiment ofFIGS.1to5, the conditions for epitaxial growth may be appropriately selected so that the void600may not be formed between the buffer layer100and the first semiconductor layer210.

FIGS.9A to9Dillustrate a method of manufacturing the light emitting device10according to an example embodiment through an etching process.

Referring toFIG.9A, the buffer layer100may be grown on a substrate110. The substrate110may include an organic material such as silicon (Si), glass, sapphire, or a polymer. The buffer layer100may include a material having the same crystal structure as that of a layer to be grown on the buffer layer100. For example, in order to epitaxially grow the body200including gallium nitride (GaN) having a hexagonal wurtzite crystal structure on the buffer layer100, the buffer layer100may include aluminum nitride (AlN) having the hexagonal wurtzite crystal structure. The buffer layer100may be grown in a flat shape over the entire upper region of the substrate110.

Referring toFIG.9B, a scattering material layer410is deposited on the buffer layer100, and a pattern is formed on the scattering material layer410using a photoresist. Here, the scattering material may be a material included in the scattering pattern400, and the scattering material layer410may be a layer formed by depositing the scattering material on the entire upper surface of the buffer layer100. For the deposition, various methods such as physical vapor deposition (PVD), chemical vapor deposition (CVD), and atomic layer deposition (ALD) may be used. A photoresist pattern430may be applied in a shape corresponding to a shape of the scattering pattern400to be formed. Forming the photoresist pattern430may include exposing and developing operation. After the photoresist is entirely applied to the scattering material layer410in the exposing and developing operation, light is radiated when a portion excluding a predetermined pattern shape is covered with a mask and the photoresist to which light is radiated is cured. Here, the portion not irradiated with light may melt. For example, a mask having a rectangular pattern may be used to form the scattering pattern400having a stripe shape. As another example, a plurality of circular masks may be used to form the scattering pattern400having a mesh structure including a plurality of circular cross-sectional holes. A structure, period, or thickness of the scattering pattern400may be appropriately selected considering light extraction efficiency and the like.

Referring toFIG.9C, a portion of the scattering material layer410not covered with the photoresist may be dry etched, and the photoresist pattern430may be removed using an organic solvent such as acetone to form the scattering pattern400having a certain shape on the buffer layer100.

Referring toFIG.9D, the body200is epitaxially grown on the buffer layer100on which the scattering pattern400is formed. Epitaxial growth conditions may be appropriately selected according to the structure, period, or thickness of the scattering pattern400. As a light emitting structure grows, the scattering pattern400may be embedded in the first semiconductor layer210.

After the above processes, the reflective layer300may be formed on the body200, and the substrate110may be removed. However, embodiments are not limited to removing the substrate110after the reflective layer300is formed, and the substrate110may be removed before the reflective layer300is formed. The substrate110may be removed using a potassium hydroxide (KOH) wet etching process.

The processes ofFIGS.9A to9Drepresent forming the scattering pattern400embedded in the first semiconductor layer210and positioned in contact with the buffer layer100on the buffer layer100, but embodiments are not limited thereto and the scattering pattern400may be formed such that all the surfaces thereof are embedded in the first semiconductor layer210. To this end, after the buffer layer100ofFIG.9Ais formed, a portion of the first semiconductor layer210may be epitaxially grown on the buffer layer100first. Thereafter, the processes corresponding toFIGS.9B and9Cmay be performed on a portion of the first semiconductor layer210, and the body200including the other portions of the first semiconductor layer210may be epitaxially grown on the first semiconductor layer210in which the scattering pattern400is formed in a process corresponding toFIG.9D. These processes have been described in detail above, and thus, repeated descriptions thereof are omitted.

FIGS.10A to10Dillustrate a method of manufacturing the light emitting device30according to another example embodiment.

The buffer layer100may be formed on the substrate110. This may be the same as the formation of the buffer layer100described above with reference toFIG.9A, and a detailed description thereof is omitted.

Referring toFIG.10A, the photoresist pattern430is formed on the buffer layer100. The photoresist pattern430may be surrounded by the scattering pattern400to form the cavity500in a follow-up process.

Referring toFIG.10B, the scattering pattern400is deposited on the buffer layer100on which the photoresist pattern430is formed. Here, low-temperature ALD may be used as a method of depositing the scattering pattern400. For example, for ALD of the scattering pattern400including aluminum oxide (Al2O3), Al2(CH3)3may be used as a precursor and H2O may be used as a reactant. Because a single atomic layer thin film is deposited through ALD, the scattering pattern400may be formed to be relatively thin. When the scattering pattern400is deposited as a single atomic layer thin film, the scattering pattern400may have the same pattern as the photoresist pattern430.

Referring toFIG.10C, the photoresist pattern430is removed. The photoresist may be sufficiently removed through an organic solvent such as acetone, thereby forming the cavity500containing air. Here, the removal of the photoresist may be performed by partially etching the scattering pattern400or may be performed without partial etching. When the photoresist is removed, a portion containing air between the scattering pattern400and the buffer layer100may form the cavity500. When the cavity500is formed, scattering may take place more easily, and thus, light extraction efficiency may be increased. After the photoresist is removed, annealing may be additionally performed. By increasing the crystallinity of the scattering pattern400through the annealing, the scattering pattern400may have the same lattice structure as the buffer layer100. For example, the scattering pattern400may include a crystallized material. When crystallinity is secured by changing the structure of the scattering pattern400from amorphous to crystalline, it may be easy to epitaxially grow the body200on a flat upper portion of the scattering pattern400. For example, to epitaxially grow gallium nitride (GaN) having a hexagonal wurtzite crystal structure, the scattering pattern400may be annealed on aluminum nitride (AlN) having the same crystal structure.

Referring toFIG.10D, the body200is epitaxially grown on the scattering pattern400that has undergone the annealing. The scattering pattern400may include a first surface formed on the cavity500and a second surface directly contacting the buffer layer100and formed on the buffer layer100. Here, although the first semiconductor layer210may be epitaxially grown on the first and second surfaces of the scattering pattern400, the void, which is an empty space where epitaxial growth has not occurred, may be formed on the second surface thereof. The void contains air and may function similar to the cavity500. When the void is formed, scattering may take place more easily, and thus, light extraction efficiency may be increased. Here, growth conditions may be appropriately selected so that the void is easily formed.

After the above steps, the reflective layer300may be formed on the body200, and the substrate110may be removed. This is the same as that described above with respect toFIG.9D, and thus, a detailed description thereof is omitted.

FIG.11Ais a view illustrating a display device1400including a plurality of light emitting devices1420according to an example embodiment, andFIG.11Bis a view illustrating that the display device1400including the light emitting device1420according to an example embodiment further includes a color conversion layer1495.

Referring toFIGS.11A and11B, the display device1400according to an example embodiment may include a display layer1475including the light emitting devices1420(including a micro light emitting device) and a driving layer1440including a plurality of transistors electrically connected to the light emitting devices1420and driving the light emitting devices1420. Here, the light emitting device1420may be the light emitting devices10,20, and30described above with reference toFIGS.1to10D. The light emitting device1420may be transferred to and fixed on the driving layer1440of the display device1400to form a pixel. When the light emitting device1420is transferred to the driving layer1440, the light emitting device1420may be electrically connected to the transistor, and the light emitting device1420may be operated according to a signal from the transistor. For connection with the transistor, the reflective layer300may be used as a first electrode, and the body of the light emitting device1420may be partially etched to form a second electrode on the first semiconductor layer. The display layer1475including the light emitting device1420may be passivated. In order for the display to implement full colors, an RGB display method in which each of the light emitting devices1420emitting red R, green G, and blue B is transferred to and fixed in one pixel may be used. According to another example embodiment, a method using color conversion layers in which the light emitting devices1420emitting blue B are transferred and fixed in one pixel and the color conversion layers1495are formed on the light emitting devices1420may be used.FIG.11Ashows that the light emitting devices1420emitting different colors of R, G, and B are transferred into one pixel, andFIG.11Bshows that the light emitting devices1420emitting blue B are transferred into one pixel and the color conversion layer1495is positioned on the display layer1475. The color conversion layer1495may include a first color conversion layer1495A converting light from the micro LED1420into a first color, a second color conversion layer1495B converting light into a second color, and a third color conversion layer1495C converting light into a third color. For example, the first color may be red light, the second color may be green light, and the third color may be blue light. When the micro LED1420emits blue light, the first color conversion layer1495A may convert blue light into red light, the second color conversion layer1495B may convert blue light into green light, and the third color conversion layer1495C may be a layer including a resin transmitting blue light so that there is no color conversion.

The display device including the light emitting devices10,20, and30described above with reference toFIGS.1to10Dmay be used in various electronic devices.

FIG.12illustrates an example in which the display device according to an example embodiment is applied to a mobile device9100. The mobile device9100may include a display device9110according to an example embodiment. The display device9110may include the light emitting devices10,20, and30described above with reference toFIGS.1to10D. The display device9110may have a foldable structure and may be applied to, for example, a multi-folder display. Here, although the mobile device9100is illustrated as a folder-type display, the mobile device9100may also be applied to a general flat panel display.

FIG.13illustrates an example in which a display device according to an example embodiment is applied to a vehicle. The display device may be applied to a head-up display device9200for a vehicle. The head-up display device9200may include a display device9210provided in a region of the vehicle and at least one light path changing member9220changing a path of light so that a driver may see an image generated by the display device9210.

FIG.14illustrates an example in which a display device is applied to augmented reality (AR) glasses9300or virtual reality (VR) glasses according to an example embodiment. The AR glasses9300may include a projection system9310forming an image and at least one element9320guiding the image from the projection system9310to a user's eye. The projection system9310may include the light emitting devices10,20, and30described above with reference toFIGS.1to10D.

FIG.15is a view illustrating an example in which a display device according to an example embodiment is applied to a large signage9400. The signage9400may be used for outdoor advertisements using a digital information display and may control advertisement content and the like through a communication network.

FIG.16illustrates an example in which a display device according to an example embodiment is applied to a wearable display9500. The wearable display9500may include the light emitting devices10,20, and30described above with reference toFIGS.1to10D.

The display device according to an example embodiment may be applied to LED TVs, liquid crystal displays, mobile displays, smart watches, AR glasses, VR glasses, heads-up displays, or signages. In addition, the display device may be applied to various products such as rollable TVs and stretchable displays.

According to the example embodiments described above, the scattering pattern is embedded in the first semiconductor layer, so that light emitted from the active layer is scattered by the scattering pattern and thus escapes out of the light emitting device. Therefore, the light emitting device having high light extraction efficiency due to the scattering pattern may be provided.

In addition, because the reflective layer is positioned on an upper portion of the body, light emitted upward from the active layer may be reflected in a direction toward the scattering pattern, thereby improving light extraction efficiency of bottom emission.

The example embodiments described above may further include cavities between the scattering pattern and the buffer layer, and light extraction efficiency may be further improved by the cavities.

In addition, the example embodiments described above may further include a void between adjacent cavities, and thus, light extraction efficiency may be further improved by the void.

It should be understood that example embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each example embodiment should typically be considered as available for other similar features or aspects in other embodiments. While example embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims and their equivalents.