KR20130029593A - Light emitting device - Google Patents

Abstract

PURPOSE: A light emitting device is provided to improve the mobility of holes by forming two regions having different band gaps. CONSTITUTION: A light emitting structure includes a semiconductor layer(120) and a second semiconductor layer(150). The light emitting structure includes an active layer formed between the first and the second semiconductor layer. The active layer includes a well layer(Q1,Q2,Q3) and a barrier layer(B1,B2,B3). The barrier layer includes a first region and a second region which are adjacent to the semiconductor layer. The first and the second region have different band gaps.

Description

[0001]

An embodiment relates to a light emitting element.

LED (Light Emitting Diode) is a device that converts electrical signals into infrared, visible light or light using the characteristics of compound semiconductors. It is used in household appliances, remote controls, display boards, The use area of LED is becoming wider.

In general, miniaturized LEDs are made of a surface mounting device for mounting directly on a PCB (Printed Circuit Board) substrate, and an LED lamp used as a display device is also being developed as a surface mounting device type . Such a surface mount device can replace a conventional simple lighting lamp, which is used for a lighting indicator for various colors, a character indicator, an image indicator, and the like.

As the use area of the LED is widened as described above, it is important to increase the luminance of the LED as the brightness required for a lamp used in daily life and a lamp for a structural signal is increased.

Publication No. 10-2006-0090308 discloses a light emitting device having a multiple quantum well structure. Since the mobility of holes is lower than that of electrons, in the case of a well layer spaced from the hole injection layer, the probability of recombination of electrons and holes may be lowered in the case of a well layer spaced apart from the hole injection layer.

The embodiment provides a light emitting device having improved light emission efficiency.

The light emitting device according to the embodiment includes a light emitting structure including a first semiconductor layer, a second semiconductor layer, and an active layer formed between the first semiconductor layer and the second semiconductor layer, wherein the active layer includes at least one well layer and a barrier. And a well layer comprising a first region adjacent to the first semiconductor layer and a second region adjacent to the second semiconductor layer, wherein the first region and the second region are formed to have different bandgaps of different sizes. .

The embodiment provides a light emitting device in which holes and electrons are provided from the barrier layer to increase the hole electron recombination probability of the well layer, thereby improving luminous efficiency.

1 is a view showing a light emitting device according to an embodiment;
2 is a partially enlarged cross-sectional view of a light emitting device according to the embodiment;
3 is a diagram showing an energy band diagram of a light emitting device according to an embodiment;
4 is an energy band diagram of a light emitting device according to an embodiment;
5 is an energy band diagram of a light emitting device according to an embodiment;
6 is a view showing a light emitting device according to the embodiment;
7 is a partially enlarged cross-sectional view of a light emitting device according to the embodiment;
8 is an energy band diagram of a light emitting device according to an embodiment;
9 is a view showing an energy band diagram of a light emitting device according to the embodiment;
10 is a view showing an energy band diagram of a light emitting device according to the embodiment;
11 is a perspective view of a light emitting device package including a light emitting device according to the embodiment;
12 is a cross-sectional view of a light emitting device package including a light emitting device according to the embodiment;
13 is a cross-sectional view of a light emitting device package including a light emitting device according to the embodiment;
14 is a perspective view of a lighting system including a light emitting device according to the embodiment;
FIG. 15 is a cross-sectional view illustrating a C ′ C ′ cross section of the lighting system of FIG. 15;
16 is an exploded perspective view of a liquid crystal display device including the light emitting device according to the embodiment;
17 is an exploded perspective view of a liquid crystal display including the light emitting device according to the embodiment.

In the description of embodiments, each layer, region, pattern, or structure is “under” a substrate, each layer (film), region, pad, or “on” of a pattern or other structure. In the case of being described as being formed on the upper or lower, the "on", "under", upper, and lower are "direct" "directly" or "indirectly" through other layers or structures.

In addition, the description of the positional relationship between each layer or structure, please refer to this specification, or drawings attached to this specification.

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size and area of each component do not entirely reflect actual size or area.

Referring to FIG. 1, the light emitting device 100 may include a support member 110 and a light emitting structure 160 disposed on the support member 110, and the light emitting structure 160 may include the first semiconductor layer 120. ), An active layer 130, an intermediate layer 140, and a second semiconductor layer 150.

The support member 110 may be formed of any material having optical transparency, for example, sapphire (Al ₂ O ₃ ), GaN, ZnO, or AlO. However, the support member 110 is not limited thereto. Further, it can be a SiC supporting member having a higher thermal conductivity than a sapphire (Al ₂ O ₃ ) supporting member. However, the refractive index of the support member 110 may be smaller than the refractive index of the first semiconductor layer 120 for light extraction efficiency.

On the other hand, a PSS (Patterned SubStrate) structure may be provided on the upper surface of the support member 110 to enhance light extraction efficiency. The support member 110 referred to herein may or may not have a PSS structure.

A buffer layer (not shown) may be disposed on the support member 110 to mitigate lattice mismatch between the support member 110 and the first semiconductor layer 120 and allow the semiconductor layer to grow easily. The buffer layer (not shown) may be formed in a low temperature atmosphere, and may be formed of a material capable of alleviating the difference in lattice constant between the semiconductor layer and the support member. For example, materials such as GaN, InN, AlN, AlInN, InGaN, AlGaN, and InAlGaN can be selected and not limited thereto. The buffer layer (not shown) may grow as a single crystal on the support member 110, and the buffer layer (not shown) grown as the single crystal may improve crystallinity of the first semiconductor layer 120 grown on the buffer layer (not shown). You can.

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

The first semiconductor layer 120 may be located on a buffer layer (not shown). The first semiconductor layer 120 may be formed of an n-type semiconductor layer and may provide electrons to the active layer 130. The first semiconductor layer 120 is, for example, semiconductor material having a compositional formula of _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1) For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, etc. may be selected, and n-type dopants such as Si, Ge, Sn, and the like may be doped.

Further, the semiconductor layer 120 may further include an undoped semiconductor layer (not shown), but the present invention is not limited thereto. The un-doped semiconductor layer is a layer formed for improving the crystallinity of the first semiconductor layer 120 and has a lower electrical conductivity than the first semiconductor layer 120 without doping the n-type dopant. May be the same as the semiconductor layer 120.

The 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 Group 3-V group elements.

If the active layer 130 is formed of a quantum well structure, for example, the well having a composition formula of _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0 ≤y≤1, 0≤x + y≤1) It may have a single or multiple quantum well structure having a layer and a barrier layer having a composition formula of In _a Al _b Ga _{1 -a- b} N (0≤a≤1, 0≤b≤1, 0≤a + b≤1). Can be. The well layer may be formed of a material having a band gap smaller than the band gap of the barrier layer.

A conductive clad layer (not shown) may be formed on and / or below the active layer 130. The conductive clad 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.

The second semiconductor layer 150 may be implemented as a p-type semiconductor layer to inject holes into the active layer 130. A second semiconductor layer 150 is, for example, semiconductor material having a compositional formula of _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1) For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, etc. may be selected, and p-type dopants such as Mg, Zn, Ca, Sr, and Ba may be doped.

Meanwhile, the intermediate layer 140 may be formed between the active layer 130 and the second semiconductor layer 150, and the intermediate layer 140 is injected from the first semiconductor layer 120 into the active layer 130 when a high current is applied. The electron may be an electron blocking layer that prevents electrons from recombining in the active layer 130 and flows into the second semiconductor layer 150. The intermediate layer 140 has a band gap relatively larger than that of the active layer 130, whereby electrons injected from the first semiconductor layer 130 are injected into the second semiconductor layer 150 without being recombined in the active layer 130. Can be prevented. Accordingly, it is possible to increase the probability of recombination of electrons and holes in the active layer 140 and to prevent a leakage current.

Meanwhile, the above-described intermediate layer 140 may have a bandgap larger than the bandgap of the barrier layer included in the active layer 130, and may be formed of a semiconductor layer including Al, such as p-type AlGaN, but is not limited thereto. .

The first semiconductor layer 120, the active layer 130, the intermediate layer 140, and the second semiconductor layer 150 may be, for example, metal organic chemical vapor deposition (MOCVD) or chemical vapor deposition (MOCVD). Chemical Vapor Deposition (CVD), Plasma-Enhanced Chemical Vapor Deposition (PECVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), Sputtering It may be formed using a method such as, but is not limited thereto.

In addition, the doping concentrations of the conductive dopants in the first semiconductor layer 120 and the second semiconductor layer 150 can be uniformly or nonuniformly formed. That is, the plurality of semiconductor layers may be formed to have various doping concentration distributions, but the invention is not limited thereto.

The first semiconductor layer 120 may be a p-type semiconductor layer, the second semiconductor layer 150 may be an n-type semiconductor layer, and an n-type or p-type semiconductor may be formed on the second semiconductor layer 150. [ A third semiconductor layer (not shown) may be formed. Accordingly, the light emitting device 100 may have at least one of np, pn, npn, and pnp junction structures.

A part of the first semiconductor layer 120 may be exposed and the first electrode 174 may be formed on the exposed first semiconductor layer 120. In this case, Can be formed. That is, the first semiconductor layer 120 includes a top surface facing the active layer 130 and a bottom surface facing the supporting member 110, and an upper surface includes a region exposed at least one region, and the first electrode 174 Can be disposed on the exposed area of the upper surface.

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

Also, a second electrode 172 may be formed on the second semiconductor layer 150.

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

FIG. 2 is an enlarged cross-sectional view of a region A of FIG. 1.

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

Here, the well layer closest to the first semiconductor layer 120, and the barrier layer are defined as a first well layer Q1 and a first barrier layer B1.

The first through third well layers Q1, Q2 and Q3 and the first through third barrier layers B1, B2 and B3 may have a structure in which they are alternately stacked as shown in FIG.

2, the first through third well layers Q1, Q2 and Q3 and the first through third barrier layers B1, B2 and B3 are formed and the first through third barrier layers B1 and B2 Q2 and Q3 and the barrier layers B1, B2 and Q3 and the first through third well layers Q1, Q2 and Q3 are alternately stacked, B3 may be formed to have any number, and the arrangement may also have any arrangement. In addition, as described above, the composition ratios, band gaps, and thicknesses of the materials forming the respective well layers Q1, Q2, and Q3, and the respective barrier layers B1, B2, and B3 may be different from each other. It is not limited as shown in 2.

3 to 5 are diagrams showing energy band diagrams of light emitting devices according to embodiments.

Each barrier layer (B1, B2, B3) may be formed with one side has a bandgap larger than the other side.

For example, as illustrated in FIG. 3, the barrier layers B1, B2, and B3 may be formed to have a band gap larger than a region adjacent to the second semiconductor layer 150. Can be.

Meanwhile, as illustrated in FIG. 3, the band gaps of the barrier layers B1, B2, and B3 may be formed in a slop shape having an inclination angle, or may be formed in a step shape, but are not limited thereto.

In addition, at least one barrier layer (B1, B2, B3) may be formed to have a different bandgap in each region, and at least one barrier layer (B1, B2, B3) may be formed to have a uniform bandgap. It is not limited.

As one side of each barrier layer B1, B2, B3 has a bandgap larger than the other side, the composition of the barrier layer may be different depending on the region. For example, in _a barrier layer having a composition of In _a Al _b Ga _{1 -a- b} N (0≤a≤1, 0≤b≤1, 0≤a + b≤1), the composition at the side with the larger band gap is The band gap may have a larger Al content than the smaller side.

Meanwhile, the Al content of each barrier layer (B1, B2, B3) may be 30% to 1%, which may be any one of a molar ratio, a volume ratio, and a mass ratio. On the other hand, when the band gap of the barrier layers (B1, B2, B3) is formed in a slop shape, the Al content may vary linearly in each barrier layer (B1, B2, B3), but is not limited thereto. Therefore, the Al content of the barrier layers B1, B2, and B3 may vary linearly within 30%.

Meanwhile, when a region having a large band gap of the barrier layers B1, B2, and B3 is called a first region, the Al content of the first region may be 20 to 30%, and the barrier layers B1, B2, and B3 may be When the region having a small band gap is referred to as the second region, the Al content of the second region may be 0 to 10%, but is not limited thereto. In this case, the content may be atomic%, but is not limited thereto.

On the other hand, the thickness and the band gap size of each barrier layer (B1, B2, B3) may be different from each other, and is not limited as shown in FIG.

In the semiconductor layer, a piezoelectric polariziton may be generated due to a difference in lattice constant between the semiconductor layers and stress due to orientation. The semiconductor material forming the light emitting element has a large value of the piezoelectric coefficient and thus can cause very large polarization even at small strains. The electric field caused by the two polarizations changes the energy band structure of the quantum well structure, thereby distorting the distribution of electrons and holes. This effect is called the quantum confined stark effect (QCSE), which causes low internal quantum efficiency in light emitting devices that generate light by recombination of electrons and holes, and emits light such as red shift in the emission spectrum. It may adversely affect the electrical and optical characteristics of the device.

InN, GaN, and AlN have different lattice constants. Therefore, when a layer including each of InN, GaN, and AlN is formed to be in contact with each other, strain is generated, and a piezoelectric polarization due to the strain and an electric field vector due to the piezoelectric polarization are generated. On the other hand, since the lattice constant has the order of InN> GaN> AlN, when the layer containing a large number of In and the layer containing a large amount of Al are in contact with each other, the effect of strain and piezoelectric polarization due to strain is further increased, and the strength of the electric field vector is also increased. Is enlarged.

Referring to FIG. 4, for example, the first barrier layer B1 has a band gap larger than a region adjacent to the first semiconductor layer 120 than a region adjacent to the second semiconductor layer 150. The region adjacent to the first semiconductor layer 120 has a larger AlGaN content than the region adjacent to the second semiconductor layer 150, so the lattice constant difference between the first barrier layer B1 and the first well layer Q1 is equal to It is formed larger than the lattice constant difference between the two well layers Q2 and the first barrier layer B1. Therefore, a larger strain occurs at the interface between the first barrier layer B1 and the first well layer Q1, and the direction of the electric field vector E is from the second semiconductor layer 150 to the first semiconductor layer 120. ) Direction. Therefore, electrons (e−) in the first barrier layer (B1) move in the direction of the second well layer (Q2), and holes (e +) move in the direction of the first well layer (Q1), and thus the first well layer (Q1). ) May provide holes (e +) and electrons (e−) to the second well layer (Q2).

That is, the bandgap of each barrier layer B1, B2, B3 has a larger bandgap and a larger AlGaN content than the region adjacent the first semiconductor layer 120 than the region adjacent the second semiconductor layer 150. The direction of the electric field vector of each of the barrier layers B1, B2, and B3 is toward the first semiconductor layer 120 in the direction of the second semiconductor layer 150. The electrons in each of the barrier layers B1, B2, and B3 move in the direction of the second semiconductor layer 150 by the electric field having the vectors in the above-described directions, while the holes generated in the direction of the first semiconductor layer 120 Go to. Therefore, each barrier layer (B1, B2, B3) can inject holes and electrons into the well layers (Q1, Q2, Q3), the probability of recombination of holes and electrons in the well layers (Q1, Q2, Q3) Increasingly, the luminous efficiency of the light emitting device 100 may be improved.

In addition, as the barrier layers B1, B2, and B3 include AlGaN and have a large bandgap, an electron blocking layer (EBL) for restricting electrons injected from the first semiconductor layer 120 may be used. Can function. Accordingly, electron overflowing phenomenon in which electrons injected from the first semiconductor layer 120 crosses the active layer 130 to the second semiconductor layer 150 is prevented and reliability of the light emitting device 100 is improved. Can be improved.

In addition, as the barrier layers B1, B2, and B3 include AlGaN and have a large band gap, the movement paths of electrons and ESDs injected from the first semiconductor layer 120 may be dispersed. As the movement paths of the electrons are dispersed, electrons and holes may be recombined in a wider area of the active layer 130. Therefore, the luminous efficiency of the light emitting device 100 can be improved. In addition, the ESD transmitted from the first semiconductor layer 120 has the greatest breaking force when forming a single path, and may damage the light emitting device 100. Since the transmission path of the ESD is dispersed by the barrier layers B1, B2, and B3 having a large band gap, damage to the light emitting device 100 by ESD may be prevented, and thus reliability of the light emitting device 100 may be improved.

Meanwhile, the barrier layers B1, B2, and B3 may include a doped region in which at least one region is doped with a p-type dopant, for example, Mg. Since the barrier layers B1, B2, and B3 include the doped regions, the operating voltage of the light emitting device 100 may be improved and the hole injection efficiency may increase.

The doped region may be formed to be spaced apart from the well layers Q1, Q2, and Q3. Since the doped region is formed to be spaced apart from the well layers Q1, Q2, and Q3, the light emitting efficiency of the light emitting device 100 may be improved.

5 is a diagram illustrating an energy band diagram of a light emitting device according to an embodiment.

The barrier layers B1, B2, and B3 may have different bandgaps, for example, as illustrated in FIG. 5, the first barrier layer B1 adjacent to the first semiconductor layer 120 may have the largest bandgap. Can be. Therefore, the maximum band gap size of the first barrier layer B1 may be larger than the maximum band gap size of the second and third barrier layers B2 and B3, but is not limited thereto.

As the barrier layer B1 adjacent to the first semiconductor layer 120 has the largest band gap, the first barrier layer B1 has a greater Al content than the second and third well layers B2 and B3. Can be.

Since the mobility of holes is smaller than electrons, the injection efficiency decreases as the holes injected from the second semiconductor layer 150 are spaced apart from the second semiconductor layer 150. As the hole injection efficiency decreases, the probability of recombination of holes and electrons decreases. For example, the probability of recombination of holes and electrons in the first well layer Q1 may be smaller than that of the third well layer Q3, which leads to a decrease in luminous efficiency of the light emitting device 100.

As the first well layer Q1 has the largest AlGaN content, it may have the largest piezoelectric polarization effect, and an electric field having the largest vector may be formed. Accordingly, hole generation of the first well layer Q1 may be further activated to improve hole injection efficiency of the first well layer Q1 having the lowest injection efficiency of holes injected from the second semiconductor layer 150. .

6 is a view showing a light emitting device according to the embodiment.

Referring to FIG. 6, the light emitting device 200 according to the embodiment includes a support member 210, a first electrode layer 220, a first semiconductor layer 230, and an active layer 250 disposed on the support member 210. And a light emitting structure 270 including a second semiconductor layer 260, and a second electrode layer 282.

The support member 210 may be formed using a material having a high thermal conductivity, or may be formed of a conductive material. The support member 210 may be formed using a metal material or a conductive ceramic. The support member 210 may be formed as a single layer, and may be formed as a double structure or a multiple structure.

That is, the support member 210 may be formed of any one selected from a metal, for example, Au, Ni, W, Mo, Cu, Al, Ta, Ag, Pt, and Cr, or may be formed of two or more alloys. The above materials can be laminated. In addition, the support member 210 is Si, Ge, GaAs, ZnO, SiC, SiGe, GaN, Ga ₂ O ₃ It may be implemented as a carrier wafer such as.

Such a support member 210 facilitates the release of heat generated in the light emitting device 200, thereby improving the thermal stability of the light emitting device 200.

A first electrode layer 220 may be formed on the support member 210. The first electrode layer 220 may include an ohmic layer (not shown), a reflective layer (not shown) and a bonding layer (not shown). For example, the first electrode layer 220 may be a structure of an ohmic layer / a reflection layer / a bonding layer, a laminate structure of an ohmic layer / a reflection layer, or a structure of a reflection layer (including an ohmic layer) / a bonding layer. For example, the first electrode layer 220 may be formed by sequentially stacking a reflective layer and an ohmic layer 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 have excellent reflective properties such as Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg , Zn, Pt, Au, Hf, or a combination of these materials, or a combination of these materials or IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, to form a multi-layer using a transparent conductive material such as Can be. Further, the reflective layer (not shown) can be laminated with IZO / Ni, AZO / Ag, IZO / Ag / Ni, AZO / Ag / Ni and 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 first semiconductor layer 230), the ohmic layer (not shown) may not be formed separately, and the present invention is not limited thereto. I do not.

The ohmic layer (not shown) is in ohmic contact with the bottom surface of the light emitting structure 270, and may be formed in a layer or a plurality of patterns. The ohmic layer (not shown) may be formed of a transparent electrode layer and a metal. For example, ITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide) ), IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IrO _x , RuO _x , RuO _x / Ni, Ag, Ni / IrO _x / Au, and Ni / IrO _x / Au / ITO. The ohmic layer (not shown) is for smoothly injecting a carrier into the first semiconductor layer 230 and is not necessarily formed.

The first electrode layer 220 may include a bonding layer (not shown), and the bonding layer may include a barrier metal or a bonding metal such as Ti, Au, Sn, Ni , Cr, Ga, In, Bi, Cu, Ag, or Ta.

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

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

The active layer 250 may be formed on the first semiconductor layer 230. 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 Group 3-V group elements.

Well active layer 250 has a composition formula in this case formed of a quantum well structure, for _{example, In x Al y Ga 1 -x-} y N (0≤x≤1, 0 ≤y≤1, 0≤x + y≤1) It can have a single or quantum well structure having a layer and a barrier layer having a composition formula of In _a Al _b Ga _{1 -a- b} N (0≤a≤1, 0≤b≤1, 0≤a + b≤1). have. The well layer may be formed of a material having a band gap smaller than the band gap of the barrier layer.

A conductive clad layer (not shown) may be formed on and / or below the active layer 250. The conductive clad 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.

Meanwhile, an intermediate layer 240 may be formed between the active layer 250 and the first semiconductor layer 230, and the intermediate layer 240 is injected from the second semiconductor layer 260 into the active layer 250 when a high current is applied. It may be an electron blocking layer that prevents electrons from flowing into the first semiconductor layer 230 without recombination in the active layer 250. Electrons injected from the second semiconductor layer 260 are injected into the first semiconductor layer 230 without recombination in the active layer 250 because the intermediate layer has a band gap relatively larger than that of the active layer 250 The phenomenon can be prevented. Accordingly, the probability of recombination of electrons and holes in the active layer 250 can be increased and leakage current can be prevented.

Meanwhile, the above-described intermediate layer 240 may have a bandgap larger than the bandgap of the barrier layer included in the active layer 250, and may be formed of a semiconductor layer including Al, such as p-type AlGaN, but is not limited thereto. .

A second semiconductor layer 260 may be formed on the active layer 250. The second semiconductor layer 260 may be implemented as an n-type semiconductor layer, and the n-type semiconductor layer may be, for example, In _x Al _y Ga _{1 -xy} N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x a semiconductor material having a compositional formula of + y ≦ 1), for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like, and for example, n, such as Si, Ge, Sn, Se, Te, etc. Type dopants may be doped.

A second electrode layer 282 electrically connected to the second semiconductor layer 260 may be formed on the second semiconductor layer 260. The second electrode layer 282 may include at least one pad or / . ≪ / RTI > The second electrode layer 282 may be disposed in the center region, the outer region, or the edge region of the upper surface of the second semiconductor layer 260, but the present invention is not limited thereto. The second electrode layer 282 may be disposed in a region other than the upper portion of the second semiconductor layer 260, but the present invention is not limited thereto.

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

Meanwhile, the light emitting structure 270 may include a third semiconductor layer (not shown) having a polarity opposite to that of the second semiconductor layer 260 on the second semiconductor layer 260. Also, the first semiconductor layer 230 may be an n-type semiconductor layer, and the second semiconductor layer 260 may be 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 extracting structure 284 may be formed on the upper portion of the light emitting structure 270.

The light extracting structure 270 may be formed on the upper surface of the second semiconductor layer 260 or may be formed on a light transmitting electrode layer (not shown) after a light transmitting electrode layer (not shown) is formed on the light emitting structure 270 But not limited to,

The light extracting structure 284 may be formed in a light transmitting electrode layer (not shown), or in a part or all of the upper surface of the second 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 second semiconductor layer 260, but is not limited thereto. The etching process includes a wet etching process and / or a dry etching process. As the etching process is performed, the upper surface of the light transmitting electrode layer (not shown) or the upper surface of the second semiconductor layer 260 forms the light extracting structure 284 And may include roughness. The roughness may be irregularly formed in a random size, but is not limited thereto. The roughness may be at least one of a texture pattern, a concave-convex pattern, and an uneven pattern, which is an uneven surface.

Roughness may be formed so that the side cross section has a variety of shapes, such as cylinder, polygonal pillar, cone, polygonal pyramid, truncated cone, polypyramid.

Meanwhile, the light extracting structure 284 may be formed by a photoelectrochemical (PEC) method or the like, but is not limited thereto. Light generated from the active layer 250 may be transmitted through a light-transmitting electrode layer (not shown) or a second semiconductor layer (not shown) as the light extracting structure 284 is formed on the upper surface of the light- Can be prevented from being totally reflected and reabsorbed or scattered from the upper surface of the light emitting device 260, thereby contributing to improvement of light extraction efficiency of the light emitting device 200.

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

FIG. 7 is an enlarged cross-sectional view of a region B of FIG. 6.

Referring to FIG. 7, the active layer 250 of the light emitting device 200 may have a multi-quantum well structure, and thus, the active layer 230 may include the first to third well layers Q1, Q2, and Q3 and the first to third layers. It may include a third barrier layer (B1, B2, B3).

Here, the barrier layer and the well layer formed closest to the second semiconductor layer 260 are defined as the first barrier layer B1 and the first well layer Q1, respectively.

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 in which they are alternately stacked as shown in FIG. 7.

Meanwhile, in FIG. 7, the first to third well layers Q1, Q2, and Q3 and the first to third barrier layers B1, B2, and B3 are formed, respectively, and the first to third barrier layers B1, B2, B3) and the first to third well layers Q1, Q2, and Q3 are alternately formed, but are not limited thereto, and the well layers Q1, Q2, and Q3 and the barrier layers B1, B2, and B3 may be alternately formed. ) May be formed to have any number, and the arrangement may also have any arrangement. In addition, as described above, the composition ratios, band gaps, and thicknesses of the materials forming the respective well layers Q1, Q2, and Q3, and the respective barrier layers B1, B2, and B3 may be different from each other. It is not limited as shown in 7.

8 and 10 are diagrams illustrating energy band diagrams of a light emitting device according to an embodiment. In addition, the content common to the content demonstrated in FIGS. 3-5 is abbreviate | omitted.

Each barrier layer (B1, B2, B3) may be formed with one side has a bandgap larger than the other side.

For example, as illustrated in FIG. 8, the barrier layers B1, B2, and B3 may be formed to have a band gap larger than a region adjacent to the first semiconductor layer 230. Can be.

Meanwhile, as illustrated in FIG. 8, the band gaps of the barrier layers B1, B2, and B3 may be formed in a slop shape having an inclination angle, or may be formed in a step shape, but are not limited thereto.

In addition, at least one barrier layer (B1, B2, B3) may be formed to have a different bandgap in each region, and at least one barrier layer (B1, B2, B3) may be formed to have a uniform bandgap. It is not limited.

As one side of each barrier layer B1, B2, B3 has a bandgap larger than the other side, the composition of the barrier layer may be different depending on the region. For example, in _a barrier layer having a composition of In _a Al _b Ga _{1 -a- b} N (0≤a≤1, 0≤b≤1, 0≤a + b≤≤≤), the composition at the side with the larger band gap is The band gap may have a larger Al content than the smaller side.

Meanwhile, the Al content of each barrier layer (B1, B2, B3) may be 30% to 1%, which may be any one of a molar ratio, a volume ratio, and a mass ratio. On the other hand, when the band gap of the barrier layers (B1, B2, B3) is formed in a slop shape, the Al content may vary linearly, but is not limited thereto. Therefore, the Al content of the barrier layers B1, B2, and B3 may vary linearly within 30%.

On the other hand, the thickness and the band gap size of each barrier layer (B1, B2, B3) may be different from each other, and is not limited as shown in FIG.

Referring to FIG. 9, for example, the first barrier layer B1 may have a band gap larger than an area adjacent to the second semiconductor layer 260 than the area adjacent to the first semiconductor layer 230. Thus, the region adjacent to the second semiconductor layer 260 has a higher AlGaN content than the region adjacent to the first semiconductor layer 230, and thus the lattice constant difference between the first barrier layer B1 and the first well layer Q1 is different. Is greater than the lattice constant difference between the second well layer Q2 and the first barrier layer B1. Therefore, a larger strain occurs at the interface between the first barrier layer B1 and the first well layer Q1, and the direction of the electric field vector is directed from the first semiconductor layer 230 to the second semiconductor layer 260. Is headed. Therefore, electrons (e−) in the first barrier layer (B1) move in the direction of the second well layer (Q2), and holes (e +) move in the direction of the first well layer (Q1), and thus the first well layer (Q1). ) May provide holes (e +) and electrons (e−) to the second well layer (Q2).

That is, the band gap of each barrier layer B1, B2, B3 has a larger bandgap and a larger AlGaN content than the region adjacent to the second semiconductor layer 260 in the region adjacent to the second semiconductor layer 230. The direction of the electric field vector of each of the barrier layers B1, B2, and B3 is toward the second semiconductor layer 260 from the first semiconductor layer 230. The electrons in each of the barrier layers B1, B2, and B3 move in the direction of the first semiconductor layer 230 by the electric field having the vectors in the directions described above, while the holes generated in the second semiconductor layer 260 move in the direction of the second semiconductor layer 260. Go to. Therefore, each barrier layer (B1, B2, B3) can inject holes and electrons into the well layers (Q1, Q2, Q3), the probability of recombination of holes and electrons in the well layers (Q1, Q2, Q3) Increasingly, the luminous efficiency of the light emitting device 200 may be improved.

In addition, as the barrier layers B1, B2, and B3 include AlGaN and have a large bandgap, an electron blocking layer (EBL) for restricting electrons injected from the second semiconductor layer 260 may be used. Can function. Therefore, the electron overflow phenomenon in which electrons injected from the second semiconductor layer 260 crosses the active layer 240 to the first semiconductor layer 230 is prevented and reliability of the light emitting device 200 is improved. Can be improved.

In addition, as the barrier layers B1, B2, and B3 include AlGaN and have a large band gap, the movement paths of electrons and ESDs injected from the second semiconductor layer 260 may be dispersed. As the movement path of electrons is dispersed, recombination of electrons and holes may be formed in a wider area of the active layer 240. Therefore, the luminous efficiency of the light emitting device 200 can be improved. The ESD delivered from the second semiconductor layer 260 has the greatest breaking force when forming a single path, and may damage the light emitting device 200. The transmission path of the ESD is dispersed by the barrier layers B1, B2, and B3 having a large band gap, thereby preventing damage to the light emitting device 200 by the ESD, and thus, the reliability of the light emitting device 200 may be improved.

Meanwhile, the barrier layers B1, B2, and B3 may include a doped region in which at least one region is doped with a p-type dopant, for example, Mg. Since the barrier layers B1, B2, and B3 include the doped regions, the operating voltage of the light emitting device 200 may be improved and the hole injection efficiency may increase.

The doped region may be formed to be spaced apart from the well layers Q1, Q2, and Q3. Since the doped region is formed to be spaced apart from the well layers Q1, Q2, and Q3, the light emitting efficiency of the light emitting device 200 may be improved.

10 is a diagram illustrating an energy band diagram of a light emitting device according to the embodiment.

The barrier layers B1, B2, and B3 may have different bandgaps, for example, as illustrated in FIG. 10, the first barrier layer B1 adjacent to the second semiconductor layer 260 may have the largest bandgap. Can be.

As the barrier layer B1 adjacent to the second semiconductor layer 260 has the largest band gap, the first barrier layer B1 has a higher Al content than the second and third well layers B2 and B3. Can be.

Since the mobility of holes is smaller than that of electrons, the hole injection efficiency of the well layers Q1, Q2, and Q3 decreases as it is spaced apart from the first semiconductor layer 230. As the hole injection efficiency decreases, the probability of recombination of holes and electrons decreases. For example, the probability of recombination of holes and electrons in the first well layer Q1 may be smaller than that of the third well layer Q3, which leads to a decrease in luminous efficiency of the light emitting device 200.

As the first well layer Q1 has the largest AlGaN content, it may have the largest piezoelectric polarization effect, and an electric field having the largest vector may be formed. Accordingly, hole generation of the first well layer Q1 may be further activated to improve the hole injection efficiency of the first well layer Q1 having the lowest injection efficiency of the holes injected from the first semiconductor layer 230. .

11 to 13 are a perspective view and a cross-sectional view showing a light emitting device package according to the embodiment.

11 to 13, the light emitting device package 500 includes a body 510 having a cavity 520, first and second lead frames 540 and 550 mounted on the body 510, and a first one. And a light emitting device 530 electrically connected to the second lead frames 540 and 550, and an encapsulant (not shown) filled in the cavity 520 to cover the light emitting device 530.

The body 510 may be made of a resin material such as polyphthalamide (PPA), silicon (Si), aluminum (Al), aluminum nitride (AlN), liquid crystal polymer (PSG), polyamide 9T (SPS), a metal material, sapphire (Al ₂ O ₃ ), beryllium oxide (BeO), and a printed circuit board (PCB). The body 510 may be formed by injection molding, etching, or the like, but is not limited thereto.

The inner surface of the body 510 may be formed with an inclined surface. The reflection angle of the light emitted from the light emitting device 530 can be changed according to the angle of the inclined surface, and thus the directivity angle of the light emitted to the outside can be controlled.

Concentration of light emitted to the outside from the light emitting device 530 increases as the directivity angle of light decreases. Conversely, as the directivity angle of light increases, the concentration of light emitted from the light emitting device 530 decreases.

The shape of the cavity 520 formed in the body 510 may be circular, rectangular, polygonal, elliptical, or the like, and may have a curved shape, but the present invention is not limited thereto.

The light emitting device 530 is mounted on the first lead frame 540 and may be, for example, a light emitting device emitting light of red, green, blue, white, or UV (ultraviolet) light emitting device emitting ultraviolet light. But it is not limited thereto. In addition, one or more light emitting elements 530 may be mounted.

The light emitting device 530 may be a horizontal type or a vertical type formed on the upper or lower surface of the light emitting device 530 or a flip chip Applicable.

The encapsulant (not shown) may be filled in the cavity 520 to cover the light emitting device 530.

The encapsulant (not shown) may be formed of silicon, epoxy, or other resin material. The encapsulant may be filled in the cavity 520 and ultraviolet or thermally cured.

In addition, the encapsulant (not shown) may include a phosphor, and the phosphor may be selected to be a wavelength of light emitted from the light emitting device 530 so that the light emitting device package 500 may emit white light.

The phosphor may be one of a blue light emitting phosphor, a blue light emitting phosphor, a green light emitting phosphor, a sulfur green light emitting phosphor, a yellow light emitting phosphor, a yellow red light emitting phosphor, an orange light emitting phosphor, and a red light emitting phosphor depending on the wavelength of light emitted from the light emitting device 530 Can be applied.

That is, the phosphor may be excited by the light having the first light emitted from the light emitting device 530 to generate the second light. For example, when the light emitting element 530 is a blue light emitting diode and the phosphor is a yellow phosphor, the yellow phosphor may be excited by blue light to emit yellow light, and blue light and blue light emitted from the blue light emitting diode As the excited yellow light is mixed, the light emitting device package 500 can provide white light.

Similarly, when the light emitting element 530 is a green light emitting diode, the magenta phosphor or the blue and red phosphors are mixed, and when the light emitting element 530 is a red light emitting diode, the cyan phosphors or the blue and green phosphors are mixed For example.

Such a fluorescent material may be a known fluorescent material such as a YAG, TAG, sulfide, silicate, aluminate, nitride, carbide, nitridosilicate, borate, fluoride or phosphate.

The first and second lead frames 540 and 550 may be formed of a metal material such as titanium, copper, nickel, gold, chromium, tantalum, (Pt), tin (Sn), silver (Ag), phosphorus (P), aluminum (Al), indium (In), palladium (Pd), cobalt (Co), silicon (Si), germanium , Hafnium (Hf), ruthenium (Ru), and iron (Fe). Also, the first and second lead frames 540 and 550 may be formed to have a single layer or a multilayer structure, but the present invention is not limited thereto.

The first and second lead frames 540 and 550 are separated from each other and electrically separated from each other. The light emitting device 530 is mounted on the first and second lead frames 540 and 550, and the first and second lead frames 540 and 550 are in direct contact with the light emitting device 530 or a soldering member (not shown). May be electrically connected through a material having conductivity such as C). In addition, the light emitting device 530 may be electrically connected to the first and second lead frames 540 and 550 through wire bonding, but is not limited thereto. Accordingly, when power is supplied to the first and second lead frames 540 and 550, power may be applied to the light emitting device 530. Meanwhile, a plurality of lead frames (not shown) may be mounted in the body 510 and each lead frame (not shown) may be electrically connected to the light emitting device 530, but is not limited thereto.

Meanwhile, referring to FIG. 13, the light emitting device package 500 according to the embodiment may include an optical sheet 580, and the optical sheet 580 may include a base portion 582 and a prism pattern 584. Can be.

The base portion 582 is made of a transparent material having excellent thermal stability as a support for forming the prism pattern 584. For example, the base portion 582 is made of polyethylene terephthalate, polycarbonate, polypropylene, polyethylene, polystyrene, and polyepoxy. It may be made of any one selected from the group, but is not limited thereto.

In addition, the base portion 582 may include a phosphor (not shown). As an example, the base portion 582 may be formed by curing the phosphor (not shown) evenly in a state in which the base portion 582 is uniformly dispersed. As such, when the base portion 582 is formed, the phosphor (not shown) may be uniformly distributed over the base portion 582.

On the other hand, a three-dimensional prism pattern 584 that refracts and collects light may be formed on the base portion 582. The material constituting the prism pattern 584 may be acrylic resin, but is not limited thereto.

The prism pattern 584 includes a plurality of linear prisms arranged in parallel with one another in one direction on one surface of the base portion 582, and a vertical cross section of the linear prism in the axial direction may be triangular.

Since the prism pattern 584 has the effect of condensing light, when the optical sheet 580 is attached to the light emitting device package 500 of FIG. 6C, the linearity of the light is improved, so that the brightness of the light of the light emitting device package 500 is increased. Can be improved.

On the other hand, the prism pattern 584 may include a phosphor (not shown).

The phosphor (not shown) is uniformly formed in the prism pattern 584 by forming the prism pattern 584 in a dispersed state, for example, by mixing with an acrylic resin to form a paste or slurry, and then forming the prism pattern 584. Can be included.

As such, when the phosphor (not shown) is included in the prism pattern 584, the uniformity and distribution of the light of the light emitting device package 500 may be improved, and in addition to the light condensing effect by the prism pattern 584, the phosphor (not shown) may be used. Due to the light scattering effect, the directivity of the light emitting device package 500 can be improved.

A plurality of light emitting device packages 500 according to the embodiment may be arranged on a substrate, and a light guide plate, a prism sheet, a diffusion sheet, or the like, which is an optical member, may be disposed on an optical path of the light emitting device package 500. Such a light emitting device package, a substrate, and an optical member can function as a light unit. Another embodiment may be implemented as a display device, an indicator device, or a lighting system including the light emitting device or the light emitting device package described in the above embodiments, and for example, the lighting system may include a lamp or a street lamp.

14 is a perspective view illustrating a lighting apparatus including a light emitting device package according to an embodiment, and FIG. 15 is a cross-sectional view illustrating a C-C 'cross section of the lighting apparatus of FIG. 14.

Referring to FIGS. 14 and 15, the lighting device 600 may include a body 610, a cover 630 fastened to the body 610, and a closing cap 650 located at both ends of the body 610. have.

A light emitting device module 640 is coupled to a lower surface of the body 610. The body 610 is electrically conductive so that heat generated from the light emitting device package 644 can be emitted to the outside through the upper surface of the body 610. [ And a metal material having an excellent heat dissipation effect.

The light emitting device package 644 may be mounted on the PCB 642 in a multi-color, multi-row manner to form an array. The light emitting device package 644 may be mounted at equal intervals or may be mounted with various spacings as required. As the PCB 642, MPPCB (Metal Core PCB) or FR4 material PCB can be used.

Since the light emitting device package 644 may have an improved heat dissipation function including an extended lead frame (not shown), reliability and efficiency of the light emitting device package 644 may be improved, and the light emitting device package 622 and the light emitting device may be improved. The service life of the lighting device 600 including the device package 644 may be extended.

The cover 630 may be formed in a circular shape so as to surround the lower surface of the body 610, but is not limited thereto.

The cover 630 protects the internal light emitting element module 640 from foreign substances or the like. The cover 630 may include diffusion particles so as to prevent glare of light generated in the light emitting device package 644 and uniformly emit light to the outside, and may include at least one of an inner surface and an outer surface of the cover 630 A prism pattern or the like may be formed on one side. Further, the phosphor may be applied to at least one of the inner surface and the outer surface of the cover 630.

Since the light generated in the light emitting device package 644 is emitted to the outside through the cover 630, the cover 630 must have a high light transmittance and sufficient heat resistance to withstand the heat generated in the light emitting device package 644 The cover 630 may be formed of a material including polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), or the like. The finishing cap 650 is located at both ends of the body 610 and can be used to seal the power supply unit (not shown). In addition, the finishing cap 650 is provided with the power supply pin 652, so that the lighting apparatus 600 according to the embodiment can be used immediately without a separate device on the terminal from which the conventional fluorescent lamp is removed.

16 is an exploded perspective view of a liquid crystal display including the light emitting device according to the embodiment.

FIG. 16 illustrates an edge-light method, and the liquid crystal display 700 may include a liquid crystal display panel 710 and a backlight unit 770 for providing light to the liquid crystal display panel 710.

The liquid crystal display panel 710 can display an image using light provided from the backlight unit 770. The liquid crystal display panel 710 may include a color filter substrate 712 and a thin film transistor substrate 714 facing each other with a liquid crystal therebetween.

The color filter substrate 712 can realize the color of an image to be displayed through the liquid crystal display panel 710.

The thin film transistor substrate 714 is electrically connected to the printed circuit board 718 on which a plurality of circuit components are mounted through the driving film 717. The thin film transistor substrate 714 may apply a driving voltage provided from the printed circuit board 718 to the liquid crystal in response to a driving signal provided from the printed circuit board 718. [

The thin film transistor substrate 714 may include a thin film transistor and a pixel electrode formed as a thin film on another substrate of a transparent material such as glass or plastic.

The backlight unit 770 includes a light emitting element module 720 that outputs light, a light guide plate 730 that changes the light provided from the light emitting element module 720 into a surface light source and provides the light to the liquid crystal display panel 710, A plurality of films 750, 766, and 764 for uniformly distributing the luminance of light provided from the light guide plate 730 and improving vertical incidence and a reflective sheet (not shown) for reflecting the light emitted to the rear of the light guide plate 730 to the light guide plate 730 740).

The light emitting device module 720 may include a PCB substrate 722 for mounting a plurality of light emitting device packages 724 and a plurality of light emitting device packages 724 to form an array.

Meanwhile, the backlight unit 770 includes a diffusion film 766 for diffusing light incident from the light guide plate 730 toward the liquid crystal display panel 710, and a prism film 750 for condensing the diffused light to improve vertical incidence. It may be configured as), and may include a protective film 764 for protecting the prism film 750.

17 is an exploded perspective view of a liquid crystal display including the light emitting device according to the embodiment. However, the parts shown and described in FIG. 17 will not be repeatedly described in detail.

17 is a direct view, the liquid crystal display device 800 may include a liquid crystal display panel 810 and a backlight unit 870 for providing light to the liquid crystal display panel 810.

Since the liquid crystal display panel 810 is the same as that described with reference to FIG. 8, a detailed description thereof will be omitted.

The backlight unit 870 includes a plurality of light emitting element modules 823, a reflective sheet 824, a lower chassis 830 in which the light emitting element module 823 and the reflective sheet 824 are accommodated, And a plurality of optical films 860. The diffuser plate 840 and the plurality of optical films 860 are disposed on the light guide plate 840. [

LED Module 823 A plurality of light emitting device packages 822 and a plurality of light emitting device packages 822 may be mounted to include a PCB substrate 821 to form an array.

The reflective sheet 824 reflects light generated from the light emitting device package 822 in a direction in which the liquid crystal display panel 810 is positioned, thereby improving light utilization efficiency.

Light generated in the light emitting element module 823 is incident on the diffusion plate 840 and an optical film 860 is disposed on the diffusion plate 840. The optical film 860 may include a diffusion film 866, a prism film 850, and a protective film 864.

Meanwhile, the light emitting device according to the embodiment is not limited to the configuration and method of the embodiments described above, but the embodiments may be modified so that all or some of the embodiments may be selectively And may be configured in combination.

In addition, although the embodiments have been illustrated and described above, the present invention is not limited to the above-described specific embodiments, and the general knowledge in the art to which the invention pertains without departing from the gist of the invention claimed in the claims. Of course, various modifications can be made by the person having the above, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

100 light emitting element 120 first semiconductor layer
130: active layer 140: intermediate layer
150: second semiconductor layer 160: light emitting structure
Q1, Q2, Q3: well layer B1, B2, B3: barrier layer

Claims (14)

And a light emitting structure including a first semiconductor layer, a second semiconductor layer, and an active layer formed between the first semiconductor layer and the second semiconductor layer.
The active layer comprises at least one well layer and a barrier layer,
The barrier layer comprises a first region adjacent to the first semiconductor layer and a second region adjacent to the second semiconductor layer,
The first region and the second region of the light emitting device having a band gap of different sizes. The method of claim 1,
The first semiconductor layer is doped with an n-type dopant,
And the second semiconductor layer is doped with a p-type dopant. The method of claim 1,
The first region has a larger band gap than the second region. The method of claim 1,
Wherein the barrier layer comprises
A light emitting device having a band gap that decreases as the first semiconductor layer moves from the first semiconductor layer toward the second semiconductor layer. The method of claim 2,
The n-type dopant is
At least one of Si, Ge, Sn,
The p-type dopant is
A light emitting device comprising at least one of Mg, Zn, Ca, Sr, Ba. The method of claim 1,
The barrier layer comprises Al,
The light emitting device of claim 1, wherein the first region and the second region have different Al atomic% contents. The method according to claim 6,
Al content of the first region,
20 to 30 atomic% light emitting device. The method according to claim 6,
Al content of the second region,
A light emitting device which is 0 to 10 atomic%. The method according to claim 6,
Wherein the barrier layer comprises
A light emitting device having an Al content that decreases as the first semiconductor layer progresses from the second semiconductor layer. The method of claim 1,
The barrier layer comprises a first and a second barrier layer,
The first barrier layer is formed between the first semiconductor layer and the second barrier layer. 11. The method of claim 10,
The maximum band gap of the first barrier layer is
The light emitting device having a value larger than the maximum band gap of the second barrier layer. The method of claim 1,
Wherein the barrier layer comprises
A light emitting device comprising at least one region doped with a p-type dopant. The method of claim 12.
The doped region is,
A light emitting device formed to be spaced apart from the well layer. A light emitting device package comprising the light emitting device of claim 1.

Images