KR20150140938A - Light emitting device and light emitting device package - Google Patents

Abstract

An embodiment includes a first conductivity type semiconductor layer; a second conductivity type semiconductor layer arranged on the first conductivity type semiconductor layer; an active layer which includes quantum barrier layers and quantum well layers between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer; a first electron blocking layer which is arranged between the active layer and the first conductivity type semiconductor layer; and a second electron blocking layer arranged between the active layer and the second conductivity type semiconductor layer. The thickness of the first electron blocking layer is different from that of the second blocking layer.

Description

[0001] LIGHT EMITTING DEVICE AND LIGHT EMITTING DEVICE PACKAGE [0002]

Embodiments relate to a light emitting device and a light emitting device package.

A light emitting diode (LED) is a light emitting element that converts current into light. Recently, light emitting diodes have been increasingly used as a light source for displays, a light source for automobiles, and a light source for illumination because the luminance gradually increases.

In recent years, high output light emitting chips capable of realizing full color by generating short wavelength light such as blue or green have been developed. By applying a phosphor that absorbs a part of the light output from the light emitting chip and outputs a wavelength different from the wavelength of the light, the light emitting diodes of various colors can be combined and a light emitting diode emitting white light can be realized Do.

Embodiments provide a light emitting device having an electron blocking layer on the top and bottom surfaces of an active layer.

The embodiment provides a light emitting device having a superlattice structure of an electron blocking layer on the top and bottom surfaces of an active layer, and a barrier layer closest to the second conductivity type semiconductor layer in the active layer.

A light emitting device according to an embodiment includes: a first conductive semiconductor layer; A second conductive semiconductor layer disposed on the first conductive semiconductor layer; An active layer including a plurality of quantum well layers and a plurality of quantum barrier layers between the first conductive semiconductor layer and the second conductive semiconductor layer; A first electron blocking layer disposed between the active layer and the first conductive semiconductor layer; And a second electron blocking layer disposed between the active layer and the second conductive semiconductor layer, wherein the first electron blocking layer and the second electron blocking layer have different thicknesses.

The embodiment can provide an active layer having a new electron blocking structure.

The embodiment can improve the internal quantum efficiency of the active layer.

In the embodiment, the holes injected into the second conductivity type semiconductor layer can be dispersed in the different quantum well layers as much as possible, thereby improving the luminous intensity by improving the re-bonding ratio of the holes.

The embodiment can improve the color purity of light emitted from the active layer.

Embodiments can improve the brightness.

Embodiments can improve the reliability of the light emitting device and the light emitting device package having the same.

1 is a cross-sectional view of a light emitting device according to an embodiment.
2 is an energy band diagram of the light emitting device of FIG.
3 is another example of an energy band diagram of the light emitting device of FIG.
4 is another example of an energy band diagram of the light emitting device of FIG.
5 is a view illustrating a light emitting device having a horizontal electrode structure using the light emitting device of FIG.
6 is a view illustrating a light emitting device having a vertical electrode structure using the light emitting device of FIG.
7 is a view illustrating a light emitting device package having the light emitting device of FIG.

Hereinafter, a light emitting device according to an embodiment and a method of manufacturing the same will be described in detail with reference to the accompanying drawings. In the description of the embodiments, it is to be understood that each layer (film), region, pattern or structure may be formed "on" or "under" a substrate, each layer The terms " on "and " under " include both being formed" directly "or" indirectly " Also, the criteria for top, bottom, or bottom of each layer will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of a light emitting device according to an embodiment, and FIG. 2 is an energy diagram of a light emitting device of FIG.

1 and 2, a light emitting device 100 includes a substrate 111, a buffer layer 113, a low conductivity layer 115, a first conductive semiconductor layer 117, a superlattice layer 118, 1 electron blocking layer 121, an active layer 121, a second electron blocking layer 123, and a second conductivity type semiconductor layer 124.

The substrate 111 may be made of a light-transmitting, insulating, or conductive substrate. For example, the substrate 111 may be made of a material such as sapphire (Al ₂ O ₃ ), SiC, Si, GaAs, GaN, ZnO, Si, GaP, InP, Ge, Ga ₂ O ₃ , At least one of LiGaO ₃ may be used. A plurality of protrusions 112 may be formed on the upper surface of the substrate 111. The plurality of protrusions 112 may be formed through etching of the substrate 111, As shown in FIG. The protrusion 112 may include a stripe shape, a hemispherical shape, or a dome shape. The thickness of the substrate 111 may be in the range of 30 탆 to 150 탆 for growth or support, but is not limited thereto.

A plurality of compound semiconductor layers may be grown on the substrate 111. The plurality of compound semiconductor layers may be grown using an electron beam evaporator, physical vapor deposition (PVD), chemical vapor deposition (CVD), plasma laser deposition (PLD) A dual-type thermal evaporator, a sputtering method, a metal organic chemical vapor deposition (MOCVD) method, and the like.

A buffer layer 113 may be formed on the substrate 111 and the buffer layer 113 may be formed of at least one layer using Group II to VI compound semiconductors. The buffer layer 113 includes a semiconductor layer using a Group III-V compound semiconductor, for example, In _x Al _y Ga _1-xy N (0? _X? 1, 0? Y? 1), and includes at least one of compound semiconductors such as GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN. The buffer layer 113 may be formed in a superlattice structure by alternately arranging different semiconductor layers.

The buffer layer 113 may be formed to mitigate the difference in lattice constant between the substrate 111 and the nitride-based semiconductor layer, and may be defined as a defect control layer. The lattice constant of the buffer layer 113 may have a value between the lattice constant of the substrate 111 and the lattice constant of the nitride semiconductor layer. The buffer layer 113 may be formed of an oxide such as a ZnO layer, but is not limited thereto. The buffer layer 113 may be formed in a range of 30 to 500 nm, but is not limited thereto.

A low conductivity layer 115 is formed on the buffer layer 113. The low conductivity layer 115 is an undoped semiconductor layer and has lower conductivity than that of the first conductivity type semiconductor layer 117. [ The low conduction layer 115 may be formed of a GaN-based semiconductor using a Group III-V compound semiconductor, and the undoped semiconductor layer may have a first conductivity type property without intentionally doping the conductive type dopant. The undoped semiconductor layer may not be formed, but the present invention is not limited thereto.

The first conductivity type semiconductor layer 117 may be formed on the low conductivity layer 115. The first conductive semiconductor layer 117 may be formed of a Group III-V compound semiconductor doped with a first conductive dopant, for example, In _x Al _y Ga _1-xy N (0? X? 1, 0? _Y 1, 0? X + y? 1). When the first conductivity type semiconductor layer 117 is an n-type semiconductor layer, the first conductivity type dopant is an n-type dopant including Si, Ge, Sn, Se, and Te.

2, the superlattice layer 118 is disposed between the first conductivity type semiconductor layer 117 and the active layer 121 and includes at least two different semiconductor layers such as a first layer 81 and a second layer The layers 82 may be arranged alternately. In the superlattice layer 118, the thicknesses of the first layer 81 and the second layer 82 may be equal to or greater than several A '. The first layer 81 may be formed of InGaN or GaN, and the second layer 82 may be formed of GaN or AlGaN. The energy band gap of the first layer 81 may be narrower than the energy band gap of the second layer 82. The first layer 81 and the second layer 82 may include a first conductivity type dopant, such as an n-type dopant. Accordingly, the first layer 81 and the second layer 82 may be formed of a conductive semiconductor layer. The thickness of the first layer 81 may be equal to or thinner than the thickness of the second layer 82. The pair of the first layer 81 and the second layer 82 may be a structure of InGaN / GaN and an InGaN / InGaN structure having different indium compositions. The superlattice layer 118 may not be formed, but is not limited thereto. The superlattice layer 118 may be formed to be thinner than the thickness of the active layer 121 and the indium composition of the first layer 81 may be set to a value smaller than a thickness of the quantum well layer 131 of the active layer 121 ) Of indium. When the indium composition is the same composition as that of the quantum well layer 131 of the active layer 121, crystal grains of the semiconductor layer on the lower surface of the active layer 121 decrease. The superlattice layer 118 may block a potential transferred from the first conductivity type semiconductor layer 117 to reduce dislocation density.

As shown in FIG. 2, the first electron blocking layer 119 may block electrons injected into the active layer 121 to prevent electrons from overflowing through the second conductive semiconductor layer 124. The first electron blocking layer 119 may have a band gap G3 that is wider than an energy band gap of the superlattice layer 118. [ The first electron blocking layer 119 may be formed of a GaN-based semiconductor, for example, an AlGaN-based semiconductor. The band gap G3 of the first electron blocking layer 119 may be wider than the band gap G1 of the barrier layer 133 of the active layer 121. [ The first electron blocking layer 119 may include a first conductive dopant such as an n-type dopant. When the first electron blocking layer 119 is an AlGaN-based semiconductor, the aluminum composition may be lower than the aluminum composition of the second electron blocking layer 121. The thickness of the first electron blocking layer 119 may be less than the thickness of the second electron blocking layer 123 or may be less than the thickness of the second electron blocking layer 123, Or more. The first electron blocking layer 119 may be grown at a temperature higher than 900 ° C. and may be grown to a temperature higher than the growth temperature of the active layer 121.

The active layer 121 is disposed between the first electron blocking layer 119 and the second electron blocking layer 123. The lower surface of the active layer 121 may be in contact with the first electron blocking layer 119 and the upper surface thereof may be in contact with the second electron blocking layer 123. The active layer 121 may be formed of multiple quantum wells (MQW), and may include at least one of a quantum wire structure and a quantum dot structure. The active layer 121 may have a quantum well layer 131 and a quantum barrier layer 133 alternately arranged and a pair of the quantum well layer 131 and the quantum barrier layer 133 may be formed in 2 to 30 cycles have. The quantum well layer 131 may be formed of 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? have. The quantum barrier layer 133 is a semiconductor layer having a band gap wider than the band gap of the quantum well layer 131, for example, In _x Al _y Ga _1-xy N (0? X? 1, 0? Y? 1, 0? X + y? 1). The pair of the quantum well layer 131 and the quantum barrier layer 133 includes at least one of InGaN / GaN, AlGaN / GaN, InGaN / AlGaN, and InGaN / InGaN, for example.

As shown in FIG. 2, the thickness T1 of the quantum well layer 131 may be within a range of 1.5 to 5 nm, and may be within a range of 2 to 4 nm, for example. The thickness T2 of the quantum barrier layer 133 is thicker than the thickness T1 of the quantum well layer 131 and may be formed within a range of 5 to 30 nm and may be formed within a range of 4.5 to 7 nm . The layer near the first conductive semiconductor layer 117 of the quantum barrier layer 133 may include an n-type dopant, but the present invention is not limited thereto.

The active layer 121 may selectively emit light within the wavelength range of the ultraviolet band to the visible light band, and may include at least one of ultraviolet wavelength, blue wavelength, green wavelength, and red wavelength.

A second electron blocking layer 123 is formed on the active layer 121 and the second electron blocking layer 123 has a band gap G1 of the quantum barrier layer 133 of the active layer 121 And has a band gap G5 that is wider than that of the III-V group compound semiconductor, for example, an AlGaN-based semiconductor.

The second conductive type semiconductor layer 124 is formed on the second electron blocking layer 123 and the second conductive type semiconductor layer 124 includes a dopant of the second conductive type. The second conductive semiconductor layer 124 may be formed of any one of compound semiconductors such as GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN. When the second conductive semiconductor layer 124 is a p-type semiconductor layer, the second conductive dopant may include Mg, Zn, Ca, Sr, and Ba as p-type dopants.

The semiconductor structure from the first conductive semiconductor layer 117 to the second conductive semiconductor layer 124 may be defined as a light emitting structure 150. Also, the conductive type of the layers of the light emitting structure 150 may be reversely formed, and the light emitting structure 150 may be formed of any one of an np junction structure, a pn junction structure, an npn junction structure, and a pnp junction structure. In the np and pn junctions, an active layer is disposed between two layers, and an npn junction or a pnp junction includes at least one active layer between three layers.

NH ₃ , TMGa (or TEGa), TMIn, and TMAl may be grown using H ₂ and / or N ₂ as a carrier gas at a predetermined growth temperature (for example, 700 to 900 ° C.) A quantum well layer 131 made of GaN or InGaN, or a quantum barrier layer 133 made of GaN, AlGaN, or InGaN can be formed. The growth temperature is raised while growing the final quantum well structure for the growth of the second electron blocking layer 123. By increasing the growth temperature at this time, the characteristics of the thin film of the last quantum well structure can be improved.

In the active layer 121 of the embodiment, a plurality of quantum well layers 131 and a plurality of quantum barrier layers 133 are alternately stacked. The indium composition ratio of the plurality of quantum well layers 131 ranges from 10 to 13%. The material of the quantum well layer 131 may be changed according to the luminescence peak wavelength. The quantum barrier layer 133 is formed of a nitride semiconductor having an energy band gap G1 that is wider than the band gap G2 of the quantum well layer 131. [

For convenience of explanation, the quantum barrier layer closest to the second electron blocking layer 123 or the second conductivity type semiconductor layer 124 is the first quantum barrier layer B1, and the first quantum well layer W1 Is disposed under the first quantum barrier layer (B1). The first quantum barrier layer B1 is disposed between the second electron blocking layer 123 and the first quantum well layer W1. The first and second electron blocking layers 119 and 123 can reduce electrons from overflowing or escaping from the active layer 121.

Here, the carrier may be a hole, and since the hole has a length of injection or mobility of several tens to several hundreds of times smaller than that of an electron, the amount of holes in a specific region is drastically reduced, and the recombination efficiency is lowered.

2 is a diagram showing an energy band diagram of the active layer of FIG. 2, the vertical axis represents the absolute size (eV) of the energy band gap, and the horizontal axis represents the distance from the first conductivity type semiconductor layer to the second conductivity type semiconductor layer in the growth direction.

Referring to FIGS. 1 and 2, a first quantum barrier layer B1 closest to the second electron blocking layer 123 is disposed in the quantum barrier layer 133, and the first quantum barrier layer B1 And forms a pair with the first quantum well layer W1. The first quantum well layer W1 is disposed closer to the second conductivity type semiconductor layer 124 or the first quantum barrier layer B1 than the first conductivity type semiconductor layer 117. [ The pair structure of the first quantum well layer (W1) / the first quantum barrier layer (B1) may be formed of InGaN / GaN work or InGaN / AlGaN.

The thickness T3 of the first quantum barrier layer B1 may be greater than the thickness T2 of the other barrier layer. For example, the thickness T3 of the first quantum barrier layer B1 may be in the range of 8 nm to 15 nm, and may be formed to be 0.5 nm or more, for example, 3 nm or more thicker than the thickness T2 of the other barrier layer .

The first quantum barrier layer B 1 comprises a plurality of well structures 33 and the plurality of well structures 33 are disposed between the barrier structures 31. The plurality of well structures 33 may be formed of a semiconductor such as InGaN having an indium composition lower than the indium composition of the quantum well layer 131. The pair of the barrier structure 31 and the well structure 33 may be formed of two to three pairs and may be formed of a pair of InGaN / GaN or InGaN / AlGaN. The first quantum barrier layer (B1) is provided in a superlattice form, thereby functioning as a buffer layer for buffering the difference in lattice constant, thereby relaxing the strain of the entire layer.

The thickness of one pair of the barrier structure 33 and the well structure 31 may be in the range of 4 nm to 6 nm. The band gap G4 of the well structure 33 may be narrower than the band gap G1 of the barrier structure 31 and wider than the band gap G2 of the quantum well layer 131. [ The well depth D1 of the well structure 33 may be less than 50% of the barrier height of the barrier structure 31. Each of the barrier structure 31 and the well structure 33 may have a thickness of 2 nm to 3 nm and may have the same thickness or different thicknesses. The barrier structure 31 of the first quantum barrier layer B 1 may be in contact with the second electron blocking layer 123.

The barrier structure 31 and the well structure 33 may comprise a p-type dopant. The p-type dopant may be added to the uppermost layer of the active layer 121 to improve the hole activity. This can solve the problem of lowering the crystal of the second conductivity type semiconductor layer 123 by adding a conductive dopant such as a p-type dopant to the second conductivity type semiconductor layer 124 to a certain level or less.

The first quantum barrier layer B1 may be disposed on the uppermost layer of the active layer 121 to relax strain between the active layer 121 and the second electron blocking layer 123.

3 is a view showing another example of an energy band diagram of the light emitting device of FIG. In describing FIG. 3, the same parts as FIG. 2 will be described with reference to FIG. 2. FIG.

3, the light emitting device includes a first conductive semiconductor layer 117, a superlattice layer 118, a cap layer 118A, a first electron blocking layer 119, an active layer 121, (123) and a second conductivity type semiconductor layer (124).

The cap layer 118A is disposed between the superlattice layer 118 and the first electron blocking layer 119 to protect the first layer 81 which is the last layer of the superlattice layer 118. That is, when the first layer 81 is InGaN, it is possible to prevent evaporation of indium in the growth process of the first electron blocking layer 119. The cap layer 118A may have a thickness equal to or thinner than the thickness of the second layer 82 of the superlattice layer 118. The cap layer 118A may be formed of the same material as the material of the second layer 82, or may be formed of GaN. The band gap G5 of the cap layer 118A may be wider than the band gap of the first layer 81 and narrower than the band gap G3 of the first electron blocking layer 119. [ This cap layer 118A can protect the layer boundary of the superlattice layer 118. [ Also, the first and second electron blocking layers 119 and 123 can prevent the electrons from overflowing and can improve the recombination efficiency in the active layer 121.

4 is another example of the energy diagram of the light emitting device of FIG. In describing FIG. 4, the same parts as FIG. 2 will be described with reference to FIG. 2. FIG.

4, the light emitting device includes a first conductive semiconductor layer 117, a superlattice layer 118, a cap layer 118A, a first electron blocking layer 119, an active layer 121, (123) and a second conductivity type semiconductor layer (124).

The quantum barrier layer closest to the second electron blocking layer 123 of the active layer 121 includes a plurality of well structures 32 and the first quantum barrier layer B1 includes a plurality of well structures 32, Are disposed between the barrier structures 31A, 31. Here, the first barrier structure 31A at the boundary between the first quantum barrier layer B1 and the first quantum well layer W1 may be formed to be thinner than the other barrier structures 31. [ For example, the first barrier structure 31A may be formed to a thickness of 1 nm to 2 nm, and this thickness range may transmit holes through tunneling.

5 is an example of a light emitting device having a horizontal electrode structure using the light emitting device of FIG.

5, the light emitting device 101 includes an electrode layer 141 and a second electrode 145 formed on the light emitting structure 150. The first electrode 143 is formed on the first conductive semiconductor layer 117, .

The electrode layer 141 may be formed of a material having permeability and electrical conductivity as a current diffusion layer. The electrode layer 141 may have a refractive index lower than the refractive index of the compound semiconductor layer.

The electrode layer 141 is formed on the upper surface of the second conductive semiconductor layer 124. The material of the electrode layer 141 may be indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO) zinc oxide, indium gallium zinc oxide (IGZO), indium gallium tin oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), ZnO, IrOx, RuOx, And may be formed of at least one layer. The electrode layer 141 may be formed of a reflective electrode layer, for example, Al, Ag, Pd, Rh, Pt, Ir, or an alloy of two or more thereof.

The second electrode 145 may be formed on the second conductive semiconductor layer 124 and / or the electrode layer 141, and may include an electrode pad. The second electrode 145 may further have a current diffusion pattern of an arm structure or a finger structure. The second electrode 145 may be made of a metal having the characteristics of an ohmic contact, an adhesive layer, and a bonding layer, but is not limited thereto.

A first electrode (143) is formed on a part of the first conductive type semiconductor layer (117). The first electrode 143 and the second electrode 145 may be formed of a metal such as Ti, Ru, Rh, Ir, Mg, Zn, Al, In, Ta, Pd, Co, Ni, Si, Can be selected from among the optional alloys.

An insulating layer may further be formed on the surface of the light emitting device 101. The insulating layer may prevent a short between layers of the light emitting structure 150 and prevent moisture penetration.

6 illustrates an example of a light emitting device having a vertical electrode structure using the light emitting device of FIG.

Referring to FIG. 6, a current blocking layer 161, a channel layer 163, and a second electrode 170 are disposed under the light emitting structure 150. The current blocking layer 161 may include at least one of SiO ₂ , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ and TiO ₂ , and at least one of the channel layers 163 Can be formed.

The current blocking layer 161 is disposed to correspond to the first electrode 181 disposed on the light emitting structure 117 and the thickness direction of the light emitting structure 150. The current blocking layer 161 may cut off current supplied from the second electrode 170 and diffuse the current blocking layer 161 to another path.

The channel layer 163 is formed along the bottom edge of the second conductive semiconductor layer 124, and may be formed in a ring shape, a loop shape, or a frame shape. The channel layer 163 is an ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, SiO 2, SiO x, SiO x N y, Si 3 N 4, Al 2 O 3, TiO at least one of the ₂ . The inner side of the channel layer 163 is disposed below the second conductive semiconductor layer 124 and the outer side of the channel layer 163 is located further outward than the side surface of the light emitting structure 150.

A second electrode 170 may be formed under the second conductive semiconductor layer 124. The second electrode 170 may include a plurality of conductive layers 165, 167, and 169.

The second electrode 170 includes an ohmic contact layer 165, a reflective layer 167, and a bonding layer 169. The ohmic contact layer 165 may be made of a low conductive material such as ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, or Ni or Ag. A reflective layer 167 is formed under the ohmic contact layer 165 and the reflective layer 167 is formed of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, And at least one layer made of a material selected from the group consisting of. The reflective layer 167 may be in contact with the second conductive semiconductor layer 124, and may be in ohmic contact with a metal or ohmic contact with a conductive material such as ITO. However, the reflective layer 167 is not limited thereto.

A bonding layer 169 is formed under the reflection layer 167 and the bonding layer 169 may be used as a barrier metal or a bonding metal. The material may be Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, and Ta and an optional alloy.

A support member 173 is formed under the bonding layer 169 and the support member 173 may be formed of a conductive material such as copper-copper, gold-gold, nickel (Ni-nickel), molybdenum (Mo), copper-tungsten (Cu-W), and carrier wafers (e.g., Si, Ge, GaAs, ZnO, SiC and the like). As another example, the support member 173 may be embodied as a conductive sheet.

Here, the substrate of FIG. 1 is removed. The growth substrate may be removed by a physical method such as laser lift off or chemical method such as wet etching to expose the first conductivity type semiconductor layer 117. The first electrode 181 is formed on the first conductive type semiconductor layer 117 by performing the isolation etching through the direction in which the substrate is removed.

The upper surface of the first conductive semiconductor layer 117 may be formed with a light extraction structure 117A such as a roughness. The outer side of the channel layer 163 may be exposed outside the sidewalls of the light emitting structure 150 and the inner side of the channel layer 163 may contact the bottom surface of the second conductive semiconductor layer 124.

The light emitting device 102 having the vertical electrode structure having the first electrode 181 and the lower supporting member 173 on the light emitting structure 150 can be manufactured.

7 is a view illustrating a light emitting device package having the light emitting device of FIG.

7, the light emitting device package 200 includes a body 210, a first lead electrode 211 and a second lead electrode 212 disposed at least partially in the body 210, The light emitting device 101 electrically connected to the first lead electrode 211 and the second lead electrode 212 on the body 210 and the molding 210 surrounding the light emitting device 101 on the body 210 Member (220).

The body 210 may be formed of a silicon material, a synthetic resin material, or a metal material. The body 210 includes a reflective portion 215 having a cavity and an inclined surface around the body.

The first lead electrode 211 and the second lead electrode 212 are electrically separated from each other and may be formed to penetrate the inside of the body 210. That is, some of the first lead electrode 211 and the second lead electrode 212 may be disposed inside the cavity, and other portions may be disposed outside the body 210.

The first lead electrode 211 and the second lead electrode 212 may supply power to the light emitting device 101 and may reflect light generated from the light emitting device 101 to increase light efficiency, And may also function to discharge heat generated in the light emitting device 101 to the outside.

The light emitting device 101 may be mounted on the body 210 or on the first lead electrode 211 and / or the second lead electrode 212.

The wire 216 of the light emitting device 101 may be electrically connected to any one of the first lead electrode 211 and the second lead electrode 212, but is not limited thereto.

The molding member 220 surrounds the light emitting device 101 to protect the light emitting device 101. In addition, the molding member 220 may include a phosphor, and the wavelength of the light emitted from the light emitting device 101 may be changed by the phosphor.

The light emitting device or the light emitting device package according to the embodiment can be applied to a light unit. The light unit includes a structure in which a plurality of light emitting devices or light emitting device packages are arrayed, and may include an illumination light, a traffic light, a vehicle headlight, an electric signboard, and the like.

The features, structures, effects and the like described in the embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects and the like illustrated in the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of illustration, It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

111: substrate 113: buffer layer
115: Low conduction layer 117: First conduction type semiconductor layer
118: superlattice layer 118A: cap layer
119: first electron blocking layer 121: active layer
123: second electron blocking layer 124: second conductive type semiconductor layer
131, W1: quantum well layer 133, B1: quantum barrier layer

Claims (12)

A first conductive semiconductor layer;
A second conductive semiconductor layer disposed on the first conductive semiconductor layer;
An active layer including a plurality of quantum well layers and a plurality of quantum barrier layers between the first conductive semiconductor layer and the second conductive semiconductor layer;
A first electron blocking layer disposed between the active layer and the first conductive semiconductor layer; And
And a second electron blocking layer disposed between the active layer and the second conductive semiconductor layer,
Wherein the first electron blocking layer and the second electron blocking layer comprise different thicknesses,
Wherein the first quantum barrier layer closest to the second conductivity type semiconductor layer among the plurality of quantum barrier layers includes a plurality of well structures. The light emitting device according to claim 1, wherein the first and second electron blocking layers include AlGaN-based semiconductors, and the first electron blocking layer has a thickness thinner than the thickness of the second electron blocking layer. The light emitting device according to claim 1, further comprising a super lattice layer in which at least two semiconductor layers, which are different from each other, are alternately arranged between the first electron blocking layer and the first conductivity type semiconductor layer. The light emitting device of claim 3, further comprising a cap layer between the superlattice layer and the first electron blocking layer. The light emitting device according to any one of claims 1 to 4, wherein the first quantum barrier layer is in contact with the second electron blocking layer. 6. The light emitting device of claim 5, wherein the first quantum barrier layer comprises a p-type dopant. The light emitting device according to claim 5, wherein the plurality of well structures have a band gap larger than a band gap of the quantum well layer and narrower than a band gap of the quantum barrier layer. 6. The method of claim 5, wherein each of the plurality of well structures is disposed between barrier structures,
Wherein the barrier structure and the well structure pair comprises 2 to 3 pairs. The light emitting device according to claim 8, wherein the thickness of the pair of the barrier structure and the well structure is in the range of 4 nm to 6 nm. 9. The device of claim 8, further comprising a first quantum well layer disposed below the first quantum barrier layer,
Wherein a thickness of the first barrier structure, which is in contact with the first quantum well layer, of the barrier structure of the first quantum barrier layer is thinner than the thickness of the other barrier structure. The light emitting device according to claim 8, wherein the first quantum barrier layer has a thickness 3 nm or more thicker than the thickness of another quantum barrier layer in the active layer. The light emitting device of claim 6, wherein the first conductivity type semiconductor layer comprises an n-type dopant, and the second conductivity type semiconductor layer comprises a p-type dopant.

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