KR102251120B1 - Light emitting device - Google Patents

Abstract

The light emitting device according to the embodiment is disposed on the first semiconductor layer and the first semiconductor layer, an active layer including a well layer and a barrier layer having different energy band gaps, a first layer disposed on the barrier layer, and adjacent to the barrier layer And a second semiconductor layer including a second layer on the first layer, disposed between the barrier layer and the first layer, has an energy band gap lower than that of the barrier layer and the first layer, and has a thickness of 0.4 compared to the thickness of the second semiconductor layer. It may include a hole injection layer having a thickness of 0.8 to.

Description

Light emitting device {Light emitting device}

The embodiment relates to a light emitting device.

As a representative example of a light emitting device, LED (Light Emitting Diode) is a device that converts an electric signal into infrared, visible light or light using the characteristics of a compound semiconductor. It is used in automation equipment and the like, and the area of use of LEDs is gradually expanding.

Usually, miniaturized LEDs are made in a surface mount device type to directly mount on a printed circuit board (PCB) substrate, and accordingly, LED lamps used as display devices are also being developed in a surface mount device type. . Such a surface mount device can replace the existing simple lighting lamp, and it is used as a lighting indicator, a character display, and an image display that emits a variety of colors.

As the area of use of the LED is expanded as described above, the luminance required for a light used for life, a light for a rescue signal, etc. is increased, so it is important to increase the luminous efficiency of the LED.

An object of the embodiment is to provide a light emitting device having improved luminous efficiency and reliability by disposing a hole injection layer that prevents diffusion of a p-type dopant between a second semiconductor layer doped with a p-type dopant and an active layer.

The light emitting device according to the embodiment is disposed on the first semiconductor layer and the first semiconductor layer, an active layer including a well layer and a barrier layer having different energy band gaps, and a first layer disposed on the barrier layer and adjacent to the barrier layer. And a second semiconductor layer including a second layer on the first layer, disposed between the barrier layer and the first layer, has an energy band gap lower than that of the barrier layer and the first layer, and has a thickness of 0.4 compared to the thickness of the second semiconductor layer. It may include a hole injection layer having a thickness of 0.8 to.

In the light emitting device according to the embodiment, by disposing a hole injection layer between the second semiconductor layer doped with the p-type dopant and the active layer, the concentration of the p-type dopant diffused into the active layer is reduced, and holes from the second semiconductor layer to the active layer are reduced. By improving the injection efficiency of, there is an advantage in that the luminous efficiency is improved.

In addition, the light emitting device according to the embodiment improves crystal defects by arranging the second semiconductor layer with the first layer and the second layer having different concentrations of the p-type dopant, thereby improving hole injection efficiency and electrons and holes. It is possible to improve the luminous efficiency by improving the probability of recombination.

In addition, the light emitting device according to the embodiment may improve an efficiency droop in which internal quantum efficiency (IQE) decreases as current increases.

1 is a cross-sectional view showing a light emitting device according to a first embodiment.
FIG. 2 is a partially enlarged view of A in FIG. 1.
3 is a diagram showing an energy band diagram of the light emitting device shown in FIG. 1.
4 is a cross-sectional view showing a light emitting device according to a second embodiment.
5 is a cross-sectional view illustrating a light emitting device package including a light emitting device according to an embodiment.
6 is an exploded perspective view of a display device including a light emitting device according to an exemplary embodiment.
7 is a cross-sectional view of the display device of FIG. 6.
8 is an exploded perspective view of a lighting device including a light emitting device according to an embodiment.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in a variety of different forms, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same elements throughout the specification.

Spatially relative terms "below", "beneath", "lower", "above", "upper", etc. It can be used to easily describe the correlation between components and other components. Spatially relative terms should be understood as terms including different directions of components during use or operation in addition to the directions shown in the drawings. For example, if a component shown in a drawing is turned over, a component described as "below" or "beneath" of another component will be placed "above" the other component. I can. Accordingly, the exemplary term “below” may include both directions below and above. Components may be oriented in other directions, and thus spatially relative terms may be interpreted according to the orientation.

The terms used in the present specification are for describing exemplary embodiments and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used herein, "comprises" and/or "comprising" refers to the recited elements, steps and/or actions excluding the presence or addition of one or more other components, steps and/or actions. I never do that.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used with meanings that can be commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not interpreted ideally or excessively unless explicitly defined specifically.

In the drawings, the thickness or size of each component is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size and area of each component do not fully reflect the actual size or area.

In addition, angles and directions mentioned in the process of describing the structure of the embodiment are based on those described in the drawings. In the description of the structure constituting the embodiment in the specification, when the reference point and the positional relationship with respect to the angle are not clearly mentioned, reference will be made to the related drawings.

Hereinafter, the present invention will be described with reference to the drawings for describing a light emitting device according to embodiments of the present invention.

1 is a cross-sectional view showing a light-emitting device according to a first embodiment, FIG. 2 is a partially enlarged view of A in FIG. 1, and FIG. 3 is a diagram showing an energy band diagram of the light-emitting device shown in FIG. 1.

Referring to FIG. 1, a light emitting device 100 according to an embodiment may include a substrate 110 and a light emitting structure 160 disposed on the substrate 110, and the light emitting structure 160 is a first semiconductor layer. 120, the second semiconductor layer 150 disposed on the first semiconductor layer 120, the active layer 130 disposed between the first semiconductor layer 120 and the second semiconductor layer 150, and the active layer 130 ) And a hole injection layer 140 disposed between the second semiconductor layer 150. Here, the second semiconductor layer 150 may include a first layer 151 adjacent to the first semiconductor layer 120 and a second layer 153 disposed on the first layer 151.

The substrate 110 may be formed of a material having a light-transmitting property, for example _{, any one of sapphire (Al 2} O ₃ ), GaN, ZnO, and AlO, but is not limited thereto.

The substrate 110 may be formed of a material suitable for growth of semiconductor materials or a carrier wafer. The substrate 110 may be formed of a material having excellent thermal conductivity, and may include a conductive substrate or an insulating substrate. For example, the substrate 110 may be a _{SiC substrate having a higher thermal conductivity than a sapphire (Al 2} O ₃ ) substrate, or at least one of Si, GaAs, GaP, InP, and Ga ₂ O _3.

An uneven structure (not shown) may be formed on the upper side of the substrate 110 to increase light extraction efficiency.

Meanwhile, a buffer layer (not shown) may be positioned on the substrate 110 to relieve lattice mismatch between the substrate 110 and the first semiconductor layer 120 and allow the semiconductor layer to be easily grown.

The buffer layer (not shown) may be formed in a low temperature atmosphere, and may be made of a material capable of reducing a difference in lattice constant between the light emitting structure 160 and the substrate 110. For example, materials such as GaN, InN, AlN, AlInN, InGaN, AlGaN, and InAlGaN may be included, but are not limited thereto.

The buffer layer (not shown) can be grown as a single crystal on the substrate 110, and the buffer layer (not shown) grown as a single crystal can improve the crystallinity of the first semiconductor layer 120 grown on the buffer layer (not shown). have.

A light emitting structure 160 including a first semiconductor layer 120, an active layer 130, a hole injection layer 140, and a second semiconductor layer 150 may be formed on the buffer layer (not shown).

The first semiconductor layer 120 may be positioned on the buffer layer (not shown).

The first semiconductor layer 120 may be formed of a semiconductor compound doped with an n-type dopant. The n-type dopant doped in the first semiconductor layer 120 may be Si, Ge, Sn, Se, Te, or the like.

The first semiconductor layer 120 may provide electrons to the active layer 130.

The first semiconductor layer 120 _{may have a composition formula of, for example, In x} Al _y Ga _1-xy N (0≦x≦1, 0≦y≦1, 0≦x+y≦1). That is, the first semiconductor layer 120 may include at least one of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like.

In addition, the first semiconductor layer 120 may further include an undoped semiconductor layer (not shown) adjacent to the substrate 110, but is not limited thereto. The undoped semiconductor layer (not shown) may improve the crystal of the first semiconductor layer 120.

The undoped semiconductor layer (not shown) may be the same as the first semiconductor layer 120 except that the n-type dopant is not doped and thus has lower electrical conductivity than the first semiconductor layer 120.

An active layer 130 may be formed on the first semiconductor layer 120. The active layer 130 may be formed of a single or multiple quantum well structure, a quantum-wire structure, a quantum dot structure, or the like using a compound semiconductor material of a group 3-5 element.

When the active layer 130 is formed in a quantum well structure, for example, _{a well layer having a composition formula of In x} Al _y Ga _1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1) ( (Not shown) and In _a Al _b Ga _1-ab N (0≦a≦1, 0≦b≦1, 0≦a+b≦1) having a barrier layer (not shown) having a composition formula of single or multiple quantum It can have a well structure. The well layer may be formed of a material having a band gap smaller than that of the barrier layer.

A detailed description of the barrier layer (not shown) and the well layer (not shown) will be described later.

A conductive cladding layer (not shown) may be formed above or/and below the active layer 130. The conductive cladding layer (not shown) may be formed of an AlGaN-based semiconductor, and may have a band gap larger than that of the active layer 130.

Piezoelectric polarization may occur between the second semiconductor layer 150 and the first semiconductor layer 120 due to a difference in lattice constant between the semiconductor layers and stress due to orientation. Since the semiconductor material forming the light emitting device has a large piezoelectric coefficient, very large polarization may occur even with a small strain. The electric field caused by the two polarizations changes the structure of the energy band of the light emitting device, thereby distorting the distribution of electrons and holes. This effect is called the quantum confined stark effect (QCSE), which induces low internal quantum efficiency in a light emitting device that generates light by recombination of electrons and holes, and emits light such as red shift of the emission spectrum. It may adversely affect the electrical and optical properties of the device.

In particular, the polarization effect as described above is further increased by this strain, and the internal electric field is strengthened, and accordingly, the band is bent according to the electric field and has a pointed shape (between the second semiconductor layer 150 and the active layer 130). A triangle potential well is formed, and a shape in which electrons or holes are concentrated in this triangle potential well may occur. Therefore, the recombination rate of electrons and holes may decrease. That is, there is a problem of lowering the hole injection efficiency from the second semiconductor layer 150 to the active layer 130.

To prevent this phenomenon, a hole injection layer 140 may be disposed on the active layer 130.

The hole injection layer 140 _{may have a composition formula of In x} Ga _1-x N (0<x<1). As a result, the hole injection layer 140 has a piezoelectric polarization that may occur due to a difference in lattice constants between the barrier layer (not shown) of the active layer 130 and the second semiconductor layer 150 closest to the hole injection layer 140. Electron and hole distribution distortion due to polarization can be prevented. The hole injection layer 140 may have a structure in which a plurality of layers are stacked, but is not limited thereto.

The hole injection layer 140 is disposed between the active layer 130 and the second semiconductor layer 150.

The hole injection layer 140 may be formed of an undoped semiconductor layer that is not doped with a dopant, or may have a doping concentration of a p-type dopant lower than that of the second semiconductor layer 150. The p-type dopant may include any one of Mg, Zn, Ca, Sr, and Ba. Accordingly, the hole injection layer 140 may prevent a phenomenon in which the p-type dopant diffuses into the active layer 130, thereby improving the quality of the light emitting device.

The hole injection layer 140 may have lower electrical conductivity than the second semiconductor layer 150.

A detailed description of the hole injection layer 140 will be described later.

A second semiconductor layer 150 may be disposed on the hole injection layer 140.

The second semiconductor layer 150 may be formed of a semiconductor compound doped with a p-type dopant. The p-type dopant doped in the second semiconductor layer 150 may be Mg, Zn, Ca, Sr, Ba, or the like.

The second semiconductor layer 150 injects holes into the active layer 130.

The second semiconductor layer 150 _{may have a composition formula of, for example, In x} Al _y Ga _1-xy N (0≦x≦1, 0≦y≦1, 0≦x+y≦1). That is, the second semiconductor layer 150 may include at least one of GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like.

The second semiconductor layer 150 may include a first layer 151 adjacent to the active layer 130 and a second layer 153 disposed on the first layer 151.

The concentration of the p-type dopant doped in the first layer 151 may be lower than the concentration of the p-type dopant doped in the second layer 153. By making the doping concentration of the p-type dopant of the first layer 151 lower than that of the second layer 153, the efficiency of hole injection from the second semiconductor layer 150 to the active layer 130 is increased, and as the current increases It is possible to improve the efficiency droop (IQE) decrease.

A detailed description of the first layer 151 and the second layer 153 will be described later.

A translucent electrode layer (not shown) may be formed on the second semiconductor layer 150. Translucent electrode layers (not shown) include ITO, IZO (In-ZnO), GZO (Ga-ZnO), AZO (Al-ZnO), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), IrOx, RuOx, It may be formed by including at least one of RuOx/ITO, Ni/IrOx/Au, and Ni/IrOx/Au/ITO.

Accordingly, the light-transmitting electrode layer (not shown) can emit light generated from the active layer 130 to the outside, and is formed on the entire or part of the outer surface of the second semiconductor layer 150 to prevent current crowding. can do.

The first semiconductor layer 120, the active layer 130, the hole injection layer 140, and the second semiconductor layer 150 described above are, for example, metal organic chemical vapor deposition (MOCVD) and chemical vapor deposition. (CVD; Chemical Vapor Deposition), Plasma-Enhanced Chemical Vapor Deposition (PECVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), Sputtering ), and the like, but is not limited thereto.

A first electrode 172 electrically connected to the first semiconductor layer 120 may be disposed on the first semiconductor layer 120. For example, a part of the active layer 130 and the second semiconductor layer 150 may be removed to expose a part of the first semiconductor layer 120, and a first electrode ( 172) may be formed. That is, the first semiconductor layer 120 includes an upper surface facing the active layer 130 and a lower surface facing the substrate 110, the upper surface includes at least one exposed area, and the first electrode 172 is an upper surface It can be placed on the exposed area of the. However, it is not limited thereto.

A method of exposing a part of the first semiconductor layer 120 may use a predetermined etching method, but is not limited thereto. In addition, the etching method may be a wet etching method or a dry etching method.

Also, a second electrode 174 may be formed on the second semiconductor layer 150.

The first and second electrodes 172 and 174 are conductive materials such as In, Co, Si, Ge, Au, Pd, Pt, Ru, Re, Mg, Zn, Hf, Ta, Rh, Ir, W, Ti , Ag, Cr, Mo, Nb, Al, Ni, Cu, and WTi may include a metal selected from, or may include an alloy thereof, may be formed in a single layer or multi-layer, but is not limited thereto.

Referring to FIG. 2, the active layer 130 of the light emitting device 100 may have a multiple quantum well structure, and thus the active layer 130 includes first to third well layers Q1, Q2, Q3, and first to third well layers. It may include a third barrier layer (B1, B2, B3).

In addition, the first to third well layers Q1, Q2, and Q3 and the first to third barrier layers B1, B2, and B3 may have a structure alternately stacked with each other as shown in FIG. 2.

Meanwhile, in FIG. 2, first to third well layers Q1, Q2, Q3 and first to third barrier layers B1, B2, B3, and the first to third well layers Q1 and Q2 are formed, respectively. , Q3) and the first to third barrier layers B1, B2, B3 are shown to be alternately stacked, but are not limited thereto, and the well layers Q1, Q2, Q3 and the barrier layers B1, B2, B3) can be formed to have any number, and the arrangement can also have any arrangement. In addition, as described above, the composition ratio, band gap, and thickness of materials forming each of the well layers Q1, Q2, and Q3, and each of the barrier layers B1, B2, and B3 may be different from each other. It is not limited as shown in 2.

The barrier layers B1, B2, and B3 may have a larger band gap energy than the well layers Q1, Q2, and Q3. For example, the barrier layers B1, B2, and B3 may contain GaN, and the well layers Q1, Q2, and Q3 may contain InGaN.

Referring back to FIGS. 1 and 2, the hole injection layer 140 may be disposed between the active layer 130 and the second semiconductor layer 150. The hole injection layer 140 prevents a phenomenon in which the p-type dopant is diffused from the second semiconductor layer 150 to the active layer 130.

The hole injection layer 140 may include InGaN. The hole injection layer 140 _{has a composition formula of In x} Ga _1-x N (0 <x <1).

The In composition ratio in the hole injection layer 140 may be 10% or less.

That is, the In composition ratio of the hole injection layer 140 may be 0.01 to 0.1111 times the Ga composition ratio. If the In composition ratio is greater than 0.1111 times the Ga composition ratio, the band gap becomes small, so holes are trapped inside the second semiconductor layer 150 due to the barrier layer (not shown) of the active layer 130, and cannot be supplied to the active layer 130. I can. If the In composition ratio is less than 0.01 times the Ga composition ratio, the band gap increases, so holes are excessively supplied from the second semiconductor layer 150 to the active layer 130, thereby increasing the hole injection efficiency, but reducing the recombination rate of holes and electrons. And, as a result, the internal quantum efficiency may decrease, and the luminous efficiency of the light emitting device may decrease.

Referring to FIG. 3, the band gap energy of the hole injection layer 140 may be smaller than the band gap energy of the barrier layers B1, B2 and B3 and the first layer 150.

If the band gap of the hole injection layer 140 is larger than the barrier layers B1, B2, B3, holes are excessively supplied from the second semiconductor layer 150 to the active layer 130, thereby increasing the hole injection efficiency, but holes and electrons The recombination rate of is decreased, and as a result, the internal quantum efficiency decreases, and the luminous efficiency of the light emitting device may decrease.

In addition, if the band gap of the hole injection layer 140 is larger than the first layer 151, the holes are trapped inside the second semiconductor layer 150 due to the barrier layer (not shown) of the active layer 130, and the active layer 130 ) May not be supplied.

The thickness (D1) of the hole injection layer 140 may have a thickness of 0.4 to 0.8 times the thickness of the second semiconductor layer (d1+d2), and 0.2 compared to the thickness of either of the first and second layers (151,153). It may be times to 0.7 times. That is, when the thickness (d1+d2) of the second semiconductor layer is 40 nm or less, the thickness (D1) of the hole injection layer 140 may be 5 to 10 nm. When the thickness D1 of the hole injection layer 140 is thicker than at least one of the first and second layers 151 and 153, the hole injection efficiency from the second semiconductor layer 150 to the active layer 130 is reduced. It may be degraded, and if it is formed thin, a characteristic of the layer itself preventing diffusion into the active layer 130 may disappear.

A second semiconductor layer 150 may be disposed on the hole injection layer 140.

The second semiconductor layer 150 may include a first layer 151 adjacent to the hole injection layer 140 and a second layer 153 disposed on the first layer 151.

The concentration 153 of the p-type dopant doped in the first layer 151 may be lower than the concentration of the p-type dopant doped in the second layer 153. As a result, there is an effect of improving the injection efficiency of holes injected from the second semiconductor layer 150 to the active layer 130 without lowering the luminous intensity of the light emitting device. The second semiconductor layer 150 including the first and second layers 151 and 153 may improve a probability of recombination of electrons and holes in the active layer 130 and improve luminous efficiency of the light emitting device.

That is, as shown in FIG. 3, the band gap energy of the second layer 153 may be greater than the band gap energy of the first layer 151.

As a result, the light emitting device of the embodiment has an effect of improving the luminous efficiency without lowering the luminous intensity. In addition, the operating voltage of the light emitting device is also reduced.

When the p-type dopant is Mg, the concentration of the p-type dopant doped in the first layer 151 may be ^{10 17} to 10 ¹⁸ cm ^-3. When the concentration of the p-type dopant doped in the first layer 151 ^{is greater than 10 18} cm ^-3 , Mg may diffuse into the active layer 130, thereby reducing the quality of the light emitting device. If it is smaller than 10 ¹⁷ cm ^-3 , the average hole concentration inside the second semiconductor layer is low, so that the injection efficiency of holes into the active layer 130 may be reduced.

The concentration of the p-type dopant doped in the second layer 153 may be ^{10 18} to 10 ²¹ cm ^-3.

In addition, when the concentration of the p-type dopant doped in the second layer 153 is ^{less than 10 18} cm ^-3 , the diffusion of Mg into the first layer 151 is lower, and when it is greater than ^{10 21} cm ^{-3, the first layer} As Mg diffused to 151 is increased, there is a concern that it may diffuse from the first layer 151 to the active layer 130.

The thickness d1 of the first layer 151 may be 0.5 to 0.9 times the thickness d2 of the second layer. When the thickness d1 of the first layer 151 is less than 0.5 times the thickness d2 of the second layer 153, the p-type dopant may diffuse into the active layer 130 and is less than 0.9 times. When it is thick, the average hole concentration inside the second semiconductor layer is low, so that the injection efficiency of holes into the active layer 130 may be reduced.

That is, if the thickness of the second semiconductor layer 150 is determined to be 40 nm or less, the thickness of the first layer 151 may be 8 to 15 nm, and the thickness of the second layer 153 may be 10 to 25 nm.

4 is a cross-sectional view showing a light emitting device according to a second embodiment.

Referring to FIG. 4, the light emitting device 200 includes a substrate 210, a first electrode layer 220 disposed on the substrate 210, a second semiconductor layer 230, a hole injection layer 240, and an active layer 250. ), and a light emitting structure 270 including a first semiconductor layer 260 and a second electrode layer 282, and the second semiconductor layer 230 is a first layer 231 adjacent to the active layer 250 And a second layer 233 disposed under the first layer 231.

The substrate 210 may be formed of a material having excellent thermal conductivity, and may be formed of a conductive material, and may be formed of a metal material or a conductive ceramic. The substrate 210 may be formed as a single layer, and may be formed in a double structure or a multiple structure.

That is, the substrate 210 may be formed of a metal, for example, any one selected from Au, Ni, W, Mo, Cu, Al, Ta, Ag, Pt, and Cr, or may be formed of two or more alloys. It can be formed by laminating materials. Further, the substrate 210 may be implemented as a carrier wafer such as Si, Ge, GaAs, ZnO, SiC, SiGe, GaN, and Ga2O3.

Such a substrate 210 may facilitate the release of heat generated from the light emitting device 200 to improve thermal stability of the light emitting device 200.

Meanwhile, a first electrode layer 220 may be formed on the substrate 210, and the first electrode layer 220 includes an ohmic layer (not shown), a reflective layer (not shown), and a bonding layer ( A bonding layer) (not shown) may include at least one layer. For example, the first electrode layer 220 may have a structure of an ohmic layer/reflective layer/bonding layer, a stacked structure of an ohmic layer/reflective layer, or a reflective layer (including ohmic)/bonding layer, but is not limited thereto. For example, the first electrode layer 220 may have a form in which a reflective layer and an ohmic layer are sequentially stacked on an insulating layer.

The reflective layer (not shown) may be disposed between the ohmic layer (not shown) and the insulating layer (not shown), and a material having excellent reflective properties, such as Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg , Zn, Pt, Au, Hf, or formed from a material composed of a selective combination thereof, or formed in a multilayer using the metal material and a transparent conductive material such as IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO I can. In addition, the reflective layer (not shown) may be laminated with IZO/Ni, AZO/Ag, IZO/Ag/Ni, AZO/Ag/Ni, or the like. In addition, when the reflective layer (not shown) is formed of a material in ohmic contact with the light emitting structure 270 (eg, the second semiconductor layer 230), the ohmic layer (not shown) may not be separately formed, and is limited thereto. I don't.

The ohmic layer (not shown) is in ohmic contact with the lower surface of the light emitting structure 270 and may be formed as a layer or a plurality of patterns. For the ohmic layer (not shown), a light-transmitting electrode layer and a metal may be selectively used, for example, indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO). ), IGZO(indium gallium zinc oxide), IGTO(indium gallium tin oxide), AZO(aluminum zinc oxide), ATO(antimony tin oxide), GZO(gallium zinc oxide), IrOx, RuOx, RuOx/ITO, Ni, Ag , Ni/IrOx/Au, and Ni/IrOx/Au/ITO may be used to implement a single layer or a multilayer. The ohmic layer (not shown) is for smoothly injecting carriers into the second semiconductor layer 230 and does not necessarily have to be formed. In addition, the first electrode layer 220 may include a bonding layer (not shown), and in this case, the bonding layer (not shown) is a barrier metal or a bonding metal such as Ti, Au, Sn, Ni , Cr, Ga, In, Bi, Cu, Ag, and may include at least one of Ta, but is not limited thereto.

The light emitting structure 270 may include at least a second semiconductor layer 230, an active layer 250, and a first semiconductor layer 260, and between the second semiconductor layer 230 and the first semiconductor layer 260. The active layer 250 may be published.

A second semiconductor layer 230 may be formed on the first electrode layer 220. The second semiconductor layer 230 may be implemented by doping with a p-type dopant. The second semiconductor layer 230 is _{a semiconductor material having a composition formula of In x} Al _y Ga _1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1), for example, GaN, It may be selected from AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like, and p-type dopants such as Mg, Zn, Ca, Sr, Ba, etc. may be doped.

The second semiconductor layer 230 may include a first layer 231 adjacent to the active layer 250 and a second layer 233 disposed under the first layer 231.

The concentration of the p-type dopant doped in the first layer 231 may be lower than the concentration of the p-type dopant doped in the second layer 233. That is, the band gap energy of the second layer 233 may be greater than the band gap energy of the first layer 231.

By making the doping concentration of the first layer 231 smaller than that of the second layer 233, the hole injection efficiency from the second semiconductor layer 230 to the active layer 250 is increased, and as the current increases, the internal quantum efficiency (IQE: Internal Quantum Efficiency) decreases (Efficiency Droop) can be improved.

As a result, the light emitting device of the embodiment has an effect of improving the luminous efficiency without lowering the luminous intensity. In addition, the operating voltage of the light emitting device is also reduced.

When the p-type dopant is Mg, the concentration of the p-type dopant doped in the first layer 231 may be ^{10 17} to 10 ¹⁸ cm ^-3. When the concentration of the p-type dopant doped in the first layer 231 ^{is greater than 10 18} cm ^-3 , Mg may diffuse into the active layer 250, thereby deteriorating the quality of the light emitting device. If it is smaller than 10 ¹⁷ cm ^-3 , the average hole concentration inside the second semiconductor layer 230 is low, and thus the injection efficiency of holes into the active layer 250 may be reduced.

The concentration of the p-type dopant doped in the second layer 233 may be ^{10 18} to 10 ²¹ cm ^-3.

In addition, when the concentration of the p-type dopant doped in the second layer 233 is ^{less than 10 18} cm ^-3 , the diffusion of Mg into the first layer 231 is lower, and when it is greater than ^{10 21} cm ^{-3, the first layer} As Mg diffused to 231 increases, there is a risk of diffusion from the first layer 231 to the active layer 250.

The thickness of the first layer 231 may be 0.5 to 0.9 times the thickness of the second layer 233. When the thickness d3 of the first layer 231 is less than 0.5 times the thickness d4 of the second layer 233, the p-type dopant may diffuse into the active layer 250 and is less than 0.9 times. When the thickness is thick, the average hole concentration inside the second semiconductor layer is low, so that the injection efficiency of holes into the active layer 250 may be reduced.

That is, if the thickness of the second semiconductor layer 230 is determined to be 40 nm or less, the thickness of the first layer 231 may be 8 to 15 nm, and the thickness of the second layer 233 may be 10 to 25 nm.

A hole injection layer 240 may be formed on the second semiconductor layer 230.

The hole injection layer 240 is disposed between the second semiconductor layer 230 and the active layer 250 to prevent the p-type dopant from being diffused from the second semiconductor layer 230 to the active layer 250. .

The hole injection layer 240 may be formed of an undoped semiconductor layer that is not doped with a dopant, or may have a doping concentration of a p-type dopant lower than that of the second semiconductor layer 230. The p-type dopant may include any one of Mg, Zn, Ca, Sr, and Ba. Accordingly, the hole injection layer 240 may prevent a phenomenon in which the p-type dopant diffuses into the active layer 250, thereby improving the quality of the light emitting device.

The hole injection layer 240 may have lower electrical conductivity than the second semiconductor layer 230.

The In composition ratio of the hole injection layer 240 may be 0.01 to 0.1111 times the Ga composition ratio. If the In composition ratio is greater than 0.1111 times the Ga composition ratio, the band gap becomes smaller, so holes are trapped inside the second semiconductor layer 230 due to the barrier layer (not shown) of the active layer 250, and cannot be supplied to the active layer 250. I can. If the In composition ratio is less than 0.01 times the Ga composition ratio, the band gap increases, so holes are excessively supplied from the second semiconductor layer 230 to the active layer 250, thereby increasing the hole injection efficiency, but reducing the recombination rate of holes and electrons. And, as a result, the internal quantum efficiency may decrease, and the luminous efficiency of the light emitting device may decrease.

The thickness D2 of the hole injection layer 240 may be thinner than at least one of the first and second layers 231 and 233, or 0.2 times or more than the thickness of any one of the first and second layers 231 and 233. It can be 0.7 times. That is, when the total thickness d3+d4 of the first layer d3 and the second layer d4 is 40 nm or less, the thickness D2 of the hole injection layer 240 may be 5 to 10 nm. When the thickness D2 of the hole injection layer 240 is thicker than at least one of the first and second layers 231 and 233, the hole injection efficiency from the second semiconductor layer 230 to the active layer 250 is reduced. It may be degraded, and if it is formed thin, the characteristic of the layer itself preventing diffusion of the p-type dopant into the active layer 250 may disappear.

The active layer 250 may be formed on the hole injection layer 240. The active layer 250 may be formed of a single or multiple quantum well structure, a quantum-wire structure, a quantum dot structure, or the like using a compound semiconductor material of a group 3-5 element.

When the active layer 250 is formed in a quantum well structure, for example, _{a well layer having a composition formula of In x} Al _y Ga _1-xy N (0 ≤ x ≤ 1, 0 ≤ y ≤ 1, 0 ≤ x + y ≤ 1) and In _a Al _b Ga _1-ab N (0≤a≤1, 0≤b≤1, 0≤a+b≤1) can have a single or quantum well structure having a barrier layer (not shown) having a composition formula have. The well layer (not shown) may be formed of a material having a band gap smaller than that of the barrier layer (not shown).

Like the first embodiment, the active layer 250 may have a multiple quantum well structure, and thus the active layer 130 includes first to third well layers (not shown) and first to third barrier layers (not shown). It may include.

In addition, the first to third well layers (not shown) and the first to third barrier layers (not shown) may have a structure in which they are alternately stacked, but the present invention is not limited thereto.

The well layer (not shown) and the barrier layer (not shown) may be formed to have any number, and the arrangement may also have any arrangement. In addition, as described above, a composition ratio, a band gap, and a thickness of a material forming each well layer (not shown) and each barrier layer (not shown) may be different from each other.

The barrier layer (not shown) may have a larger band gap energy than the well layer (not shown). For example, a barrier layer (not shown) may contain GaN, and a well layer (not shown) may contain InGaN.

The band gap energy of the hole injection layer 240 may be smaller than the band gap energy of the barrier layer (not shown) and the first layer 231.

If the band gap of the hole injection layer 240 is larger than the barrier layer (not shown), holes are excessively supplied from the second semiconductor layer 230 to the active layer 250, thereby increasing the hole injection efficiency, but the recombination rate of holes and electrons This decreases, and as a result, the internal quantum efficiency decreases, and the luminous efficiency of the light emitting device may decrease.

In addition, when the band gap of the hole injection layer 240 is larger than the first layer 231, holes are trapped inside the second semiconductor layer 230 due to the barrier layer (not shown) of the active layer 250, and the active layer 250 ) May not be supplied.

A conductive cladding layer (not shown) may be formed above or/and below the active layer 250. The conductive cladding layer (not shown) may be formed of an AlGaN-based semiconductor, and may have a band gap larger than that of the active layer 250.

A first semiconductor layer 260 doped with an n-type dopant may be formed on the active layer 250. The first semiconductor layer 260 is, for example, _{a semiconductor material having a composition formula of In x} Al _y Ga _1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1), for example It may be selected from GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like, and for example, n-type dopants such as Si, Ge, Sn, Se, and Te may be doped.

A second electrode layer 282 electrically connected to the first semiconductor layer 260 may be formed on the first semiconductor layer 260, and the second electrode layer 282 includes at least one pad or/and an electrode having a predetermined pattern. It may include. The second electrode layer 282 may be disposed in a center region, an outer region, or a corner region of the upper surface of the first semiconductor layer 260, but is not limited thereto. The second electrode layer 282 may be disposed in a region other than the first semiconductor layer 260, but is not limited thereto.

The second electrode layer 282 is a conductive material such as In, Co, Si, Ge, Au, Pd, Pt, Ru, Re, Mg, Zn, Hf, Ta, Rh, Ir, W, Ti, Ag, Cr , Mo, Nb, Al, Ni, Cu, and WTi may be formed in a single layer or multi-layer using a metal or alloy selected from.

Meanwhile, the light emitting structure 270 may include a third semiconductor layer (not shown) having a polarity opposite to that of the first semiconductor layer 260 on the first semiconductor layer 260. In addition, the second semiconductor layer 230 may be an n-type semiconductor layer, and the first semiconductor layer 260 may be implemented as a p-type semiconductor layer. Accordingly, the light emitting structure layer 270 may include at least one of an N-P junction, a P-N junction, an N-P-N junction, and a P-N-P junction structure.

A light extraction structure 284 may be formed on the light emitting structure 270.

The light extracting structure 284 is formed on the upper surface of the first semiconductor layer 260 or formed on the light-transmitting electrode layer (not shown) after forming a light-transmitting electrode layer (not shown) on the light-emitting structure 270. It can be, but is not limited thereto.

The light extracting structure 284 may be formed on a light-transmitting electrode layer (not shown) or on a part or entire area of an upper surface of the first semiconductor layer 260. The light extracting structure 284 may be formed by performing etching on at least one region of the light-transmitting electrode layer (not shown) or the upper surface of the first semiconductor layer 260, but is not limited thereto.

The etching process includes a wet or/and dry etching process, and according to the etching process, the top surface of the translucent electrode layer (not shown) or the top surface of the first semiconductor layer 260 forms a light extraction structure 284. May include roughness.

The roughness may be irregularly formed with a random size, but is not limited thereto. The roughness is an uneven top surface and may include at least one of a texture pattern, an uneven pattern, and an uneven pattern.

The roughness may be formed to have various shapes, such as a side cross-section of a cylinder, a polygonal column, a cone, a polygonal pyramid, a truncated cone, and a polygonal truncated cone, and preferably includes a horn shape.

Meanwhile, the light extraction structure 284 may be formed by a method such as photo electrochemical (PEC), but is not limited thereto. As the light extraction structure 284 is formed on the light-transmitting electrode layer (not shown) or on the upper surface of the first semiconductor layer 260, the light generated from the active layer 250 is transmitted to the light-transmitting electrode layer (not shown) or the first semiconductor layer Since total reflection from the upper surface of the 260 may be prevented from being reabsorbed or scattered, it may contribute to the improvement of light extraction efficiency of the light emitting device 200.

A passivation (not shown) may be formed on the side and upper regions of the light emitting structure 270, and the passivation (not shown) may be formed of an insulating material.

5 is a cross-sectional view illustrating a light emitting device package including a light emitting device according to an embodiment.

5, the light emitting device package 300 according to the embodiment includes a body 310 having a cavity, a light source unit 320 mounted in the cavity of the body 310, and a resin unit 350 filled in the cavity. can do.

The body 310 is made of a resin material such as polyphthalamide (PPA), silicon (Si), aluminum (Al), aluminum nitride (AlN), liquid crystal polymer (PSG, photo sensitive glass), polyamide 9T (PA9T). ), neo-geotactic polystyrene (SPS), metal material, sapphire (Al2O3), beryllium oxide (BeO), printed circuit board (PCB, Printed Circuit Board), it may be formed of at least one of ceramic.

The body 310 may be formed by injection molding, an etching process, or the like, but is not limited thereto.

The light source unit 320 is disposed on the bottom surface of the body 310, for example, the light source unit 320 may be any one of the light emitting devices illustrated and described in FIGS. 1 to 4. The light-emitting device may be, for example, a colored light-emitting device that emits red, green, blue, or white light or an ultra violet (UV) light-emitting device that emits ultraviolet rays, but is not limited thereto. In addition, one or more light-emitting elements may be mounted.

The body 310 may include a first electrode 330 and a second electrode 340. The first electrode 330 and the second electrode 340 may be electrically connected to the light source unit 320 to supply power to the light source unit 320.

In addition, the first electrode 330 and the second electrode 340 are electrically separated from each other, and reflect light generated from the light source unit 320 to increase light efficiency, and heat generated from the light source unit 320 Can be discharged to the outside.

5 shows that both the first electrode 330 and the second electrode 340 are bonded to the light source unit 320 by a wire 360, but the present invention is not limited thereto. Any one of the electrode 330 and the second electrode 340 may be bonded to the light source unit 320 by a wire 360, and may be electrically connected to the light source unit 320 without a wire 360 by a flip-chip method. have.

The first electrode 330 and the second electrode 340 are made of metal, for example, titanium (Ti), copper (Cu), nickel (Ni), gold (Au), chromium (Cr), and tantalum ( Ta), platinum (Pt), tin (Sn), silver (Ag), phosphorus (P), aluminum (Al), indium (In), palladium (Pd), cobalt (Co), silicon (Si), germanium ( Ge), hafnium (Hf), ruthenium (Ru), iron (Fe) may include one or more materials or alloys. In addition, the first electrode 330 and the second electrode 340 may be formed to have a single-layer or multi-layer structure, but are not limited thereto.

The resin part 350 may be filled in the cavity and may include a phosphor (not shown). The resin part 350 may be formed of transparent silicone, epoxy, and other resin materials, and after filling the cavity, it may be formed by UV or thermal curing.

The type of the phosphor (not shown) may be selected according to the wavelength of light emitted from the light source unit 320 so that the light emitting device package 300 may implement white light.

The phosphor (not shown) included in the resin part 350 is a blue light-emitting phosphor, a cyan light-emitting phosphor, a green light-emitting phosphor, a yellow-green light-emitting phosphor, a yellow light-emitting phosphor, a yellow-red light-emitting phosphor, depending on the wavelength of light emitted from the light source 320 , An orange light-emitting phosphor, and a red light-emitting phosphor may be applied.

That is, the phosphor (not shown) may convert a wavelength of light generated from the light source unit 320. A type of light emitted from the light source unit 320 may be selected according to a wavelength so that the light emitting device package may implement white light. For example, when the light source unit 320 is a blue light emitting diode and a phosphor (not shown) is a yellow phosphor, the yellow phosphor is excited by blue light to emit yellow light, and blue light and blue light generated from the blue light emitting diode As yellow light generated by being excited by light is mixed, the light emitting device package 300 may provide white light.

The light emitting device according to the embodiment may be applied to a lighting system. The lighting system includes a structure in which a plurality of light emitting devices are arrayed, and includes the display device shown in FIGS. 6 and 7, the lighting device shown in FIG. 8, and may include a lighting lamp, a traffic light, a vehicle headlight, an electric sign, and the like.

6 is an exploded perspective view of a display device including a light emitting device according to an exemplary embodiment.

6, the display device 1000 according to the embodiment includes a light guide plate 1041, a light source module 1031 providing light to the light guide plate 1041, a reflective member 1022 under the light guide plate 1041, and , A bottom cover 1011 housing the optical sheet 1051 on the light guide plate 1041, the display panel 1061 on the optical sheet 1051, the light guide plate 1041, the light source module 1031, and the reflective member 1022 It may include, but is not limited thereto.

The bottom cover 1011, the reflective sheet 1022, the light guide plate 1041, and the optical sheet 1051 may be defined as a light unit 1050.

The light guide plate 1041 serves to diffuse light into a surface light source. The light guide plate 1041 is made of a transparent material, for example, among acrylic resins such as PMMA (polymethylmethacrylate), PET (polyethylene terephthalate), PC (polycarbonate), COC (cycloolefin copolymer), and PEN (polyethylene naphthalate) resins. It can contain one.

The light source module 1031 provides light to at least one side of the light guide plate 1041, and ultimately acts as a light source of the display device.

The light source module 1031 includes at least one, and may directly or indirectly provide light from one side of the light guide plate 1041. The light source module 1031 includes a substrate 1033 and a light emitting device 1035 according to the disclosed embodiment, and the light emitting devices 1035 may be arrayed on the substrate 1033 at predetermined intervals.

The substrate 1033 may be a printed circuit board (PCB) including a circuit pattern (not shown). However, the substrate 1033 may include not only a general PCB, but also a metal core PCB (MCPCB, Metal Core PCB), a flexible PCB (FPCB, Flexible PCB), and the like, but is not limited thereto. When the light emitting device 1035 is mounted on a side surface of the bottom cover 1011 or on a heat dissipation plate, the substrate 1033 may be removed. Here, a part of the heat dissipation plate may contact the upper surface of the bottom cover 1011.

In addition, the plurality of light emitting devices 1035 may be mounted on the substrate 1033 such that an emission surface from which light is emitted is spaced apart from the light guide plate 1041 by a predetermined distance, but the embodiment is not limited thereto. The light-emitting device 1035 may directly or indirectly provide light to a light-incident portion, which is one side of the light guide plate 1041, but is not limited thereto.

A reflective member 1022 may be disposed under the light guide plate 1041. The reflective member 1022 reflects light incident on the lower surface of the light guide plate 1041 and directs it upward, thereby improving the luminance of the light unit 1050. The reflective member 1022 may be formed of, for example, PET, PC, PVC resin, or the like, but is not limited thereto. The reflective member 1022 may be an upper surface of the bottom cover 1011, but is not limited thereto.

The bottom cover 1011 may accommodate the light guide plate 1041, the light source module 1031, the reflective member 1022, and the like. To this end, the bottom cover 1011 may be provided with a receiving portion 1012 having a box shape with an open top surface, but the embodiment is not limited thereto. The bottom cover 1011 may be coupled to the top cover, but the embodiment is not limited thereto.

The bottom cover 1011 may be formed of a metal material or a resin material, and may be manufactured using a process such as press molding or extrusion molding. In addition, the bottom cover 1011 may include a metal or non-metal material having good thermal conductivity, but is not limited thereto.

The display panel 1061 is, for example, an LCD panel, and includes first and second substrates made of transparent materials facing each other, and a liquid crystal layer interposed between the first and second substrates. A polarizing plate may be attached to at least one surface of the display panel 1061, and the structure of the polarizing plate is not limited thereto. The display panel 1061 displays information by light passing through the optical sheet 1051. The display device 1000 can be applied to various types of portable terminals, monitors of notebook computers, monitors of laptop computers, televisions, and the like.

The optical sheet 1051 is disposed between the display panel 1061 and the light guide plate 1041, and includes at least one translucent sheet. The optical sheet 1051 may include at least one of, for example, a diffusion sheet, a horizontal and vertical prism sheet, and a brightness enhancement sheet. The diffusion sheet diffuses incident light, the horizontal or/and vertical prism sheet condenses incident light to the display area, and the brightness enhancement sheet reuses lost light to improve brightness. In addition, a protective sheet may be disposed on the display panel 1061, but the embodiment is not limited thereto.

Here, on the light path of the light source module 1031, as an optical member, a light guide plate 1041 and an optical sheet 1051 may be included, but the embodiment is not limited thereto.

7 is a cross-sectional view of the display device of FIG. 6.

Referring to FIG. 7, the display device 1100 includes a bottom cover 1152, a substrate 1120 on which the light emitting devices 1124 disclosed above are arrayed, an optical member 1154, and a display panel 1155.

The substrate 1120 and the light emitting device 1124 may be defined as a light source module 1160. The bottom cover 1152, at least one light source module 1160, and the optical member 1154 may be defined as a light unit 1150. The bottom cover 1152 may include an accommodating part 1153, but the embodiment is not limited thereto. The light source module 1160 includes a substrate 1120 and a plurality of light emitting devices 1124 arranged on the substrate 1120.

Here, the optical member 1154 may include at least one of a lens, a light guide plate, a diffusion sheet, a horizontal and vertical prism sheet, and a brightness enhancement sheet. The light guide plate may be made of a PC material or a polymethyl methacrylate (PMMA) material, and the light guide plate may be removed. The diffusion sheet diffuses incident light, the horizontal and vertical prism sheets condens the incident light to the display area, and the brightness enhancement sheet reuses lost light to improve brightness.

The optical member 1154 is disposed on the light source module 1160, and performs a surface light source, diffusion, or condensation of light emitted from the light source module 1160.

8 is an exploded perspective view of a lighting device including a light emitting device according to an embodiment.

Referring to FIG. 8, the lighting device according to the embodiment includes a cover 2100, a light source module 2200, a radiator 2400, a power supply unit 2600, an inner case 2700, and a socket 2800. I can. In addition, the lighting device according to the embodiment may further include at least one of the member 2300 and the holder 2500. The light source module 2200 may include a light emitting device according to the embodiment.

For example, the cover 2100 may have a shape of a bulb or a hemisphere, and may be provided in a shape with a hollow and an open portion. The cover 2100 may be optically coupled to the light source module 2200. For example, the cover 2100 may diffuse, scatter, or excite light provided from the light source module 2200. The cover 2100 may be a kind of optical member. The cover 2100 may be coupled to the radiator 2400. The cover 2100 may have a coupling portion coupled to the radiator 2400.

A milky white paint may be coated on the inner surface of the cover 2100. The milky white paint may include a diffuser that diffuses light. The surface roughness of the inner surface of the cover 2100 may be larger than the surface roughness of the outer surface of the cover 2100. This is to allow the light from the light source module 2200 to be sufficiently scattered and diffused to be emitted outside.

The material of the cover 2100 may be glass, plastic, polypropylene (PP), polyethylene (PE), polycarbonate (PC), or the like. Here, polycarbonate is excellent in light resistance, heat resistance, and strength. The cover 2100 may be transparent or opaque so that the light source module 2200 can be seen from the outside. The cover 2100 may be formed through blow molding.

The light source module 2200 may be disposed on one surface of the radiator 2400. Accordingly, heat from the light source module 2200 is conducted to the heat sink 2400. The light source module 2200 may include a light emitting device 2210, a connection plate 2230, and a connector 2250.

The member 2300 is disposed on the upper surface of the radiator 2400 and has guide grooves 2310 into which a plurality of light emitting elements 2210 and a connector 2250 are inserted. The guide groove 2310 corresponds to the substrate and the connector 2250 of the light emitting device 2210.

The surface of the member 2300 may be coated or coated with a light reflecting material. For example, the surface of the member 2300 may be coated or coated with a white paint. The member 2300 reflects light reflected on the inner surface of the cover 2100 and returning toward the light source module 2200 toward the cover 2100. Therefore, it is possible to improve the light efficiency of the lighting device according to the embodiment.

The member 2300 may be made of an insulating material, for example. The connection plate 2230 of the light source module 2200 may include an electrically conductive material. Accordingly, electrical contact may be made between the radiator 2400 and the connection plate 2230. The member 2300 is made of an insulating material to block an electrical short between the connection plate 2230 and the radiator 2400. The radiator 2400 receives heat from the light source module 2200 and heat from the power supply unit 2600 to radiate heat.

The holder 2500 blocks the receiving groove 2719 of the insulating part 2710 of the inner case 2700. Accordingly, the power supply unit 2600 accommodated in the insulating unit 2710 of the inner case 2700 is sealed. The holder 2500 has a guide protrusion 2510. The guide protrusion 2510 may have a hole through which the protrusion 2610 of the power supply unit 2600 passes.

The power supply unit 2600 processes or converts an electrical signal provided from the outside and provides it to the light source module 2200. The power supply unit 2600 is accommodated in the storage groove 2719 of the inner case 2700 and is sealed inside the inner case 2700 by the holder 2500.

The power supply unit 2600 may include a protrusion 2610, a guide part 2630, a base 2650, and a protrusion 2670.

The guide part 2630 has a shape protruding from one side of the base 2650 to the outside. The guide part 2630 may be inserted into the holder 2500. A number of components may be disposed on one surface of the base 2650. A number of components include, for example, a DC converter that converts AC power provided from an external power source into a DC power source, a driving chip that controls the driving of the light source module 2200, and an electrostatic device (ESD) for protecting the light source module 2200. discharge) may include a protection element, but is not limited thereto.

The protrusion 2670 has a shape protruding outward from the other side of the base 2650. The protrusion 2670 is inserted into the connection part 2750 of the inner case 2700 and receives an electrical signal from the outside. For example, the protrusion 2670 may be provided equal to or smaller than the width of the connection part 2750 of the inner case 2700. Each end of the "+ wire" and the "- wire" may be electrically connected to the protrusion 2670, and the other end of the "+ wire" and the "- wire" may be electrically connected to the socket 2800.

The inner case 2700 may include a molding unit together with the power supply unit 2600 therein. The molding part is a part where the molding liquid is solidified, and allows the power supply part 2600 to be fixed inside the inner case 2700.

In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific embodiments described above, and in the technical field to which the present invention pertains without departing from the gist of the present invention claimed in the claims. Various modifications may be possible by those of ordinary skill in the art, and these modifications should not be understood individually from the technical spirit or prospect of the present invention.

Claims (15)

A first semiconductor layer;
An active layer disposed on the first semiconductor layer and including a well layer and a barrier layer having different energy band gaps;
A second semiconductor layer disposed on the barrier layer and including a first layer adjacent to the barrier layer and a second layer on the first layer; And
A hole injection layer disposed between the barrier layer and the first layer, having a lower energy band gap than that of the barrier layer and the first layer, and having a thickness of 0.4 to 0.8 times the thickness of the second semiconductor layer; Including,
The hole injection layer has _{a composition ratio of In x} Ga _1-x N (0 <x <1),
The In composition ratio of the hole injection layer is 10% or less, the In composition ratio is 0.01 to 0.1111 times the Ga composition ratio,
The hole injection layer has an electrical conductivity lower than that of the second semiconductor layer,
The thickness of the hole injection layer is 0.2 to 0.7 times the thickness of any one of the first and second layers,
The band gap energy of the first layer is less than the band gap energy of the second layer and the barrier layer,
The first semiconductor layer is doped with an n-type dopant, the second semiconductor layer is doped with a p-type dopant,
The concentration of the p-type dopant doped in the first layer is lower than the concentration of the p-type dopant doped in the second layer,
The first layer has a thickness of 0.5 to 0.9 times the thickness of the second layer. delete delete The method of claim 1,
The n-type dopant is at least one of Si, Ge, Sn, Se, and Te,
The p-type dopant is at least one of Mg, Zn, Ca, Sr, and Ba. The method of claim 1,
The concentration of the p-type dopant doped in the first layer is 10 ¹⁷ to 10 ¹⁸ cm ^-3 ,
The light emitting device having a concentration of the p-type dopant doped in the second layer is 10 ¹⁸ to 10 ²¹ cm ^-3. delete delete delete delete The method of claim 1,
The thickness of the hole injection layer is 5 nm to 10 nm,
The thickness of the first layer is 8 nm to 15 nm,
The second layer has a thickness of 10 nm to 25 nm. delete delete delete delete A light-emitting device package including the light-emitting device of any one of claims 1, 4, 5, and 10

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