KR102181490B1 - Light emitting device and lighting system - Google Patents

Abstract

The light emitting device according to the embodiment includes a first conductivity type semiconductor layer; An active layer disposed on the first conductivity type semiconductor layer and including a plurality of quantum wells and a plurality of quantum walls; And a second conductivity type semiconductor layer on the active layer. Wherein the plurality of quantum walls includes at least one first quantum wall adjacent to the first conductivity type semiconductor layer and at least one second quantum wall adjacent to the second conductivity type semiconductor layer, and the first The quantum wall is characterized by including a p-type dopant.
According to the embodiment, it is possible to provide a light emitting device having improved luminous efficiency, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system by electronically combining holes and electrons across a plurality of quantum wells.
According to the embodiment, it is possible to provide a light emitting device having improved luminous efficiency, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system by electronically combining holes and electrons across a plurality of quantum wells.

Description

Light emitting device and lighting system {LIGHT EMITTING DEVICE AND LIGHTING SYSTEM}

The embodiment relates to a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system.

Light Emitting Device is a pn junction diode that converts electrical energy into light energy. It can be created as a compound semiconductor such as Group III and Group V on the periodic table. Various colors can be realized by controlling the composition ratio of the compound semiconductor. It is possible.

When the forward voltage is applied, the electrons in the n-layer and the holes in the p-layer are combined to emit energy equivalent to the band gap energy of the conduction band and the balance band. , This energy is mainly emitted in the form of heat or light, and when radiated in the form of light, it becomes a light emitting device.

For example, nitride semiconductors are attracting great interest in the development of optical devices and high-power electronic devices due to their high thermal stability and wide band gap energy. In particular, a blue light-emitting device, a green light-emitting device, and an ultraviolet (UV) light-emitting device using a nitride semiconductor are commercialized and widely used.

As the demand for high-efficiency LEDs has recently increased, improving luminance has become an issue.

As a way to improve the luminous intensity, there have been attempts to improve the structure of the active layer (MQW), improve the electron blocking layer (EBL), and improve the active layer, but there is no significant effect.

The embodiment is to provide a light emitting device capable of improving luminous intensity, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system.

The light emitting device according to the embodiment includes a first conductivity type semiconductor layer; An active layer disposed on the first conductivity type semiconductor layer and including a plurality of quantum wells and a plurality of quantum walls; And

A second conductivity type semiconductor layer on the active layer; Wherein the plurality of quantum walls includes at least one first quantum wall adjacent to the first conductivity type semiconductor layer and at least one second quantum wall adjacent to the second conductivity type semiconductor layer, and the first The quantum wall is characterized by including a p-type dopant.

A light emitting device according to another aspect may include a first conductivity type semiconductor layer; An active layer disposed on the first conductivity type semiconductor layer and including a plurality of quantum wells and a plurality of quantum walls; And a second conductivity type semiconductor layer disposed on the active layer, wherein the quantum wall includes a first capping layer, a doping layer on the first capping layer, and a second capping layer on the doping layer. It features.

The lighting system according to the embodiment may include a light emitting unit including the light emitting device.

According to the embodiment, a light emitting device having an optimal structure capable of increasing luminous intensity, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system can be provided.

In addition, according to the embodiment, it is possible to provide a light emitting device with improved luminous efficiency, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system by electronically combining a hole and a hole across a plurality of quantum wells.

In addition, according to the embodiment, there is an advantage of improving the quality of the active layer, reducing the operating voltage and improving reliability and reproducibility.

In addition, according to the embodiment, it is possible to provide a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and a lighting system capable of improving quantum confinement effect, improving luminous efficiency, and improving device reliability.

1 is a cross-sectional view of a light emitting device according to an embodiment.
2 is a cross-sectional view of an active layer according to an embodiment.
3 is a first exemplary diagram of an energy band diagram of a light emitting device according to an embodiment.
4 is a cross-sectional view of a single quantum wall according to another embodiment.
5 is a second exemplary diagram of an energy band diagram of a light emitting device according to another embodiment.
6 is a graph comparing the operating voltages of light-emitting devices composed of quantum walls not including a p-type dopant and operating voltages of light-emitting devices composed of quantum walls including a p-type dopant.
7 is a graph comparing the luminous efficiency of a light-emitting device composed of a quantum wall not including a p-type dopant and a light-emitting device composed of a quantum wall including a p-type dopant.
8 to 12 are cross-sectional views illustrating a method of manufacturing a light emitting device according to an embodiment.

In the description of the embodiment, each layer (film), region, pattern, or structure is "on/over" or "under" of the substrate, each layer (film), region, pad, or patterns. In the case of being described as being formed in, "on/over" and "under" include both "directly" or "indirectly" formed do. In addition, standards for the top/top or bottom of each layer will be described based on the drawings.

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

( Example )

1 is a cross-sectional view of a light emitting device according to an embodiment.

The light emitting device 100 may be applied to the horizontal type light emitting device illustrated in FIG. 1, but is not limited thereto, and may also be applied to a vertical light emitting device and a flip chip light emitting device.

Referring to FIG. 1, a light emitting device 100 according to an embodiment includes a first conductivity type semiconductor layer 112 and an active layer 114 including a quantum well and a quantum wall on the first conductivity type semiconductor layer 112. ), a barrier layer 127 on the active layer 114, an electron blocking layer 128 on the barrier layer 127, and a second conductivity type semiconductor layer on the electron blocking layer 128 (116) may be included.

According to the related technology of the invention ('related technology' means that it is not a clearly known technology at the time of filing this invention), the light emitting device has an n-type semiconductor layer, an active layer, and a p-type semiconductor layer as a basic light emitting structure, The active layer has a multi-quantum well structure, thereby promoting recombination of electrons and holes to increase luminous efficiency.

The active layer of such a multi-quantum well can obtain the greatest luminous efficiency when bonding occurs after electrons and holes are trapped throughout the quantum well.

However, electrons can be trapped throughout all quantum wells due to their large mobility, but holes are quantum adjacent to the layer (for example, the second conductivity type semiconductor layer 116) into which holes are injected due to the small mobility. The number of traps in quantum wells other than wells is significantly reduced.

Therefore, light emission is concentrated only in the quantum well adjacent to the semiconductor layer in which holes are injected, and light is hardly emitted from the quantum well adjacent to the semiconductor layer (for example, the first conductivity type semiconductor layer 112) in which electrons are injected. There is a problem of lowering efficiency.

Meanwhile, in order to control the energy band gap between the quantum well and the quantum wall, the active layer 114 rapidly changes the composition ratio of the semiconductor layer constituting it, so that defects between the quantum well and the quantum wall interface There is a problem that arises.

In order to solve these problems, holes are injected throughout the active layer 114 to increase luminous efficiency, and a multi-quantum well structure having good crystallinity is required.

1 is a cross-sectional view of a light emitting device according to an embodiment, FIG. 2 is a cross-sectional view of an active layer 114 according to the embodiment, and FIG. 3 is a first exemplary diagram of an energy band diagram of a light emitting device according to the embodiment.

1 to 3, the light emitting device 100 according to the embodiment includes a first conductivity type semiconductor layer 112, a quantum well 200 and a quantum wall on the first conductivity type semiconductor layer 112 An active layer 114 including 300), a barrier layer 127 on the active layer 114, an electron blocking layer 128 on the barrier layer 127, and an electron blocking layer 128 on the electron blocking layer 128. It may include a two-conductivity semiconductor layer 116.

In the active layer 114, electrons injected through the first conductivity-type semiconductor layer 112 and holes injected through the second conductivity-type semiconductor layer 116 formed later meet each other, so that the active layer 114 (light-emitting layer) material is unique. It is a layer that emits light with a wavelength determined by the energy band of.

The active layer 114 may be formed of at least one of a single quantum well structure, a multi quantum well structure (MQW), a quantum-wire structure, or a quantum dot structure.

The quantum well/quantum wall of the active layer 114 may be formed in one or more pair structures among InGaN/GaN, InGaN/InGaN, GaN/AlGaN, InAlGaN/GaN, GaAs(InGaAs)/AlGaAs, GaP(InGaP)/AlGaP. However, it is not limited thereto. The quantum well 200 may be formed of a material having a lower band gap than the band gap of the quantum wall.

For example, referring to FIG. 2, the active layer 114 may be formed such that a plurality of quantum wells 200 having a small energy band gap and a plurality of quantum walls 300 having a large energy band gap are alternately stacked.

Hereinafter, a quantum well and a quantum wall adjacent to the first conductivity-type semiconductor layer 112 are formed into a first quantum well 210 and a first quantum wall 310, respectively, and adjacent to the second conductivity-type semiconductor layer 116. The quantum well and the quantum wall will be described as a second quantum well 220 and a second quantum wall 320, respectively.

Referring to FIG. 3, electrons injected from the first conductivity type semiconductor layer 112 may be trapped throughout the quantum well 200 because they have fast mobility, but in the second conductivity type semiconductor layer 116 The injected holes are concentrated and trapped in the second quantum well 220.

In order to effectively inject holes throughout the quantum well 200, a p-type dopant for supplying holes may be included in the quantum wall 300.

For example, by doping a p-type dopant on the first quantum wall 310 adjacent to the first conductivity-type semiconductor layer 112, holes generated in the first quantum wall 310 are converted into the first quantum well 210 Can be injected into

In more detail, the number of the first quantum walls 310 may correspond to a number between 20 to 50% of the total quantum walls 300, and Mg is 10 ¹⁸ to 10 ^{20 in} the first quantum wall 310. It can be doped at a concentration of /cm3.

When the p-type first quantum wall 310 has a number of 20% or less in the entire quantum wall 300, the hole injection effect of the p-type dopant is rapidly lowered, so that luminous efficiency may be degraded. Conversely, when the p-type first quantum wall 310 has a number of 50% or more in the entire quantum wall 300, a p-type dopant, which is an impurity, may destroy the quantum well 200.

Through this, holes are injected throughout the quantum well 200 so that electrons and holes can be combined, so that luminous efficiency can be improved.

In addition, the p-type dopant may act as a surfactant, thereby increasing the quality of the active layer 114.

However, as described above, since the p-type dopant is an impurity, it may diffuse into the quantum well 200 and destroy the quantum well 200.

Hereinafter, a structure of the quantum wall 300 for preventing diffusion of the p-type dopant from the quantum wall 300 to the quantum well 200 will be described.

4 is a cross-sectional view of a single quantum wall according to another exemplary embodiment, and FIG. 5 is a second exemplary diagram of an energy band diagram of a light emitting device according to another exemplary embodiment.

The description of the first layer 311 of the first quantum wall 310 described below may be understood as being applied to all layers included in the first quantum wall 310.

4, the first layer 311 of the first quantum wall 310 includes a first capping layer 311a, a doping layer 311b on the first capping layer 311a, and the doping. A second capping layer 311c may be included on the layer 311b.

The dopant of the doping layer 311b is a p-type dopant, and may include Mg, Zn, Ca, Sr, Ba, etc.

Mg may be doped at a concentration of 10 ¹⁸ ~ 10 ²⁰ /cm3 to the doping layer 311b. If the Mg is doped to 10 ¹⁸ /cm3 or less, the hole injection effect is lowered, so that the effectiveness of the doping layer 311b may be lost.If the Mg is doped to 10 ²⁰ /cm3 or more, the diffusion power of Mg increases, and the quantum well 200 Because it can contaminate.

The first capping layer 311a and the second capping layer 311c serve to prevent diffusion of the p-type dopant of the doping layer 311b into the quantum well 200 disposed above or below.

That is, the first layer 311 of the first quantum wall 310 includes a dopant only in a region isolated from the quantum well 200 disposed above and below so that the dopant does not diffuse out of the first layer 311. Can be prevented.

The doped layer 311b may be formed to have a thickness of 20% or less of the first layer 311 of the first quantum wall 310. For example, when the first capping layer 311a and the second capping layer 311c each have a thickness of 2 nm, the doping layer 311b may have a thickness of 1 nm or less. In addition, these capping layers may prevent diffusion of the p-type dopant.

5, the first layer 311, the second layer 312, and the third layer 313 on the first quantum wall 310 include a capping layer and a doping layer 311b, 312b, 313b, respectively. can do.

The capping layer disposed above and below each of the doping layers 311b prevents the p-type dopant from spreading into the quantum wells 200 disposed above and below, while the holes generated in the doping layer 311b are formed in the quantum well 200. Can be injected with.

Meanwhile, the capping layer and the doping layer 311b included in each of the layers included in the first quantum wall 310 may be formed with the same thickness and the same doping concentration, and may be formed with different thicknesses and different doping concentrations. May be.

For example, the doped layer 311b of the first layer 311 closest to the first conductivity type semiconductor layer 112 may be doped at a high concentration, and the first conductivity type semiconductor layer 112 The doped layer 313b of the far-isolated third layer 313 may be doped with a low concentration.

That is, the doping concentration of the doping layer may gradually decrease as the layer adjacent to the first conductivity type semiconductor layer 112 goes toward the isolated layer.

Alternatively, the doped layer 311b of the first layer 311 closest to the first conductivity type semiconductor layer 112 may be formed to be thick, and the first conductive type semiconductor layer 112 is separated from the first conductive type semiconductor layer 112. The doped layer 313b of the third layer 313 may be formed thin.

That is, the thickness of the doped layer may gradually decrease as the layer adjacent to the first conductivity-type semiconductor layer 112 goes toward the isolated layer.

Through this, sufficient holes can be supplied to the quantum well adjacent to the first conductivity-type semiconductor layer 112, which is the most difficult hole injection, so that uniform hole-electron coupling across the quantum well 200 can be induced.

Table 1 is a table comparing the characteristics of a light-emitting device composed of a quantum wall that does not contain a p-type dopant (Experiment 1) and a light-emitting device composed of a quantum wall including a p-type dopant (Experiment 2).

6 is a graph comparing the operating voltages of light-emitting devices composed of quantum walls not including a p-type dopant and operating voltages of light-emitting devices composed of quantum walls including a p-type dopant.

7 is a graph comparing the luminous efficiency of a light-emitting device composed of a quantum wall not including a p-type dopant and a light-emitting device composed of a quantum wall including a p-type dopant.

Referring to Table 1 and FIGS. 6 to 7, it can be seen that a light emitting device including a quantum wall doped with a p-type dopant according to an exemplary embodiment has improved power, operating voltage, and luminous efficiency compared to conventional light emitting devices.

In more detail, referring to Table 1, compared to Experiment 1, in Experiment 2, the operating voltage Vf3 decreased and the power Po increased. In particular, looking at the integrating sphere data, it can be seen that the luminous efficiency of the light emitting device in Experiment 2 increased by 2% or more.

In addition, in the case of repeating the experiment, referring to FIG. 6, it can be seen that when the operating voltage is measured under the condition of Experiment 1, the operating voltage is generally large and the dispersion is large and reproducibility is poor.

On the other hand, in the case of measuring the operating voltage under the condition of Experiment 2, it can be seen that the operating voltage is generally small and the distribution is small, and reliability and reproducibility are excellent.

7, it can be seen that the luminous efficiency of Experiment 2 is higher than that of Experiment 1 over the entire amount of current.

That is, a light-emitting device including a quantum wall doped with a p-type dopant can increase luminous efficiency by increasing the quantum well 200 contributing to light emission, and the p-type dopant operates by improving the interface of the active layer 114 The voltage may decrease and the distribution of operating voltages may decrease.

8 to 12 are cross-sectional views illustrating a method of manufacturing a light emitting device according to an embodiment.

Hereinafter, a method of manufacturing the light emitting device 100 according to this embodiment will be described with reference to FIGS. 8 to 12.

First, a substrate 105 is prepared as shown in FIG. 8. The substrate 105 may be formed of a material having excellent thermal conductivity, and may be a conductive substrate or an insulating substrate. For example, the substrate 105 may be formed of at least one of sapphire (Al2O3), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga203. A Patterned Sapphire Substrate (PSS) P may be formed on the substrate 105, but the embodiment is not limited thereto.

The substrate 105 may be wet cleaned to remove impurities from the surface.

Thereafter, a light emitting structure 110 including a first conductivity type semiconductor layer 112, an active layer 114, and a second conductivity type semiconductor layer 116 may be formed on the substrate 105.

In this case, a buffer layer 107 may be formed on the substrate 105. The buffer layer 107 can alleviate lattice mismatch between the material of the light emitting structure 110 and the substrate 105, and the material of the buffer layer 107 is a group 3-5 compound semiconductor such as GaN, InN, AlN , InGaN, AlGaN, InAlGaN, may be formed of at least one of AlInN.

An undoped semiconductor layer 108 may be formed on the buffer layer 107, but the embodiment is not limited thereto.

The first conductivity type semiconductor layer 112 may be formed of a semiconductor compound. It may be implemented as a compound semiconductor such as Group 3-5 and Group 2-6, and may be doped with a first conductivity type dopant. When the first conductivity-type semiconductor layer 112 is an n-type semiconductor layer, the first conductivity-type dopant is an n-type dopant, and may include Si, Ge, Sn, Se, and Te, but is not limited thereto.

The first conductivity type semiconductor layer 112 may include a semiconductor material having a composition formula of InxAlyGa1-x-yN (0≦x≦1, 0≦y≦1, 0≦x+y≦1).

The first conductivity type semiconductor layer 112 may be formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP, InP.

The first conductivity-type semiconductor layer 112 may be formed of an n-type GaN layer using a method such as chemical vapor deposition (CVD), molecular beam epitaxy (MBE), sputtering, or hydroxide vapor phase epitaxy (HVPE). . In addition, the first conductivity-type semiconductor layer 112 includes a silane gas containing n-type impurities such as trimethyl gallium gas (TMGa), ammonia gas (NH3), nitrogen gas (N2), and silicon (Si) in the chamber ( SiH4) may be implanted to form.

Next, in the embodiment, a gallium nitride-based superlattice layer 124 may be formed on the first conductivity type semiconductor layer 112. The gallium nitride-based superlattice layer 124 can effectively alleviate an odd stress due to lattice mismatch between the first conductivity type semiconductor layer 112 and the active layer 114. For example, the gallium nitride-based superlattice layer 124 may be formed of InyAlxGa(1-x-y)N(0≦x≦1, 0≦y≦1)/GaN, but is not limited thereto.

In addition, the gallium nitride-based superlattice layer 124 may serve as a barrier so that the p-type dopant included in the active layer 114 does not diffuse into the first conductivity-type semiconductor layer 112.

Thereafter, referring to FIG. 9, an active layer 114 is formed on the gallium nitride-based superlattice layer 124.

In the active layer 114, electrons injected through the first conductivity-type semiconductor layer 112 and holes injected through the second conductivity-type semiconductor layer 116 formed later meet each other, so that the active layer 114 (light-emitting layer) material is unique. It is a layer that emits light with a wavelength determined by the energy band of.

The active layer 114 may be formed of at least one of a single quantum well structure, a multi quantum well structure (MQW), a quantum-wire structure, or a quantum dot structure. For example, the active layer 114 may be injected with trimethyl gallium gas (TMGa), ammonia gas (NH3), nitrogen gas (N2), trimethyl indium gas (TMIn), or a p-type dopant to form a multiple quantum well structure. However, it is not limited thereto.

The quantum well/quantum wall of the active layer 114 may be formed in one or more pair structures among InGaN/GaN, InGaN/InGaN, GaN/AlGaN, InAlGaN/GaN, GaAs(InGaAs)/AlGaAs, GaP(InGaP)/AlGaP. However, it is not limited thereto. The quantum well may be formed of a material having a lower band gap than the band gap of the quantum wall.

For example, referring to FIG. 2, the active layer 114 may be formed such that a plurality of quantum wells 200 having a small energy band gap and a plurality of quantum walls having a large energy band gap are alternately stacked.

At this time, in order to effectively inject holes throughout the quantum well 200, a p-type dopant may be doped when forming the quantum wall.

For example, Mg may be doped into the first quantum wall 310 adjacent to the first conductivity type semiconductor layer 112.

In order to prevent the P-type dopant from diffusing into the quantum well 200, quantum wall layers included in the first quantum wall 310 may be formed to include a capping layer and a doping layer 311b.

For example, the first quantum walls 310 first form a first capping layer 311a, then add a p-type dopant to form a doping layer 311b, and a second capping layer on the doped layer 311b. A layer 311c may be formed.

In addition, the doped layer 311b may be formed to have a thickness of 20% or less of the first layer of the first quantum wall 310. For example, when the thickness of the first capping layer 311a and the second capping layer 311c is 2 nm, the thickness of the doping layer 311b is 1 nm or less, and the capping layers are p-type It is possible to prevent diffusion of dopants.

In the embodiment, in order to minimize the stress applied to the quantum well 200 and at the same time effectively increase the quantum confinement effect, an undoped last barrier 127 may be formed on the active layer 114.

In an embodiment, the barrier layer 127 is a first Inp1Ga1-p1N layer on the last quantum well closest to the second conductivity type semiconductor layer 116 of the quantum well 200 (however, 0<p1<1) (127a) and an AlqGa1-qN layer on the first Inp1Ga1-p1N layer 127a (however, 0<q<1) (127b) and a second Inp2Ga1-p2N layer on the AlqGa1-qN layer 127b (However, 0 &lt; p2 &lt; 1) may include (127c).

According to the embodiment, the band gap energy level is relatively increased as Al in the AlqGa1-qN layer 127b is provided, so that the energy band gap of the AlqGa1-qN layer 127b is the first Inp1Ga1-p1N layer 127a. ) And the energy band gap of the second Inp2Ga1-p2N layer 127c.

In addition, since the energy band gap of the AlqGa1-qN layer 127b in the barrier layer 127 is larger than the energy band gap of the quantum wall in the active layer 114, electrons in the quantum well 200 can be effectively confined.

According to an embodiment, the lattice constant in the plane direction of the first Inp1Ga1-p1N layer 127a and the second Inp2Ga1-p2N layer 127c in the barrier layer 127 is greater than that of the AlqGa1-qN layer 127b. Because it is large, the stress applied to the quantum well 200 from the AlqGa1-qN layer 127b can be relaxed.

In addition, due to this, by reducing the internal field acting on the quantum well 200 in the active layer 114, it is possible to improve the luminous efficiency by increasing the probability of light emission coupling between electrons and holes in the quantum well 200.

The barrier layer 127 according to the embodiment may minimize stress applied to the active layer 114 and at the same time effectively confine electrons in the active layer 114 quantum mechanically.

Further, according to the embodiment, the AlqGa1-qN layer 127b is not doped with a p-type, and the plane direction lattice constant of the AlqGa1-qN layer 127b is the first Inp1Ga1-p1N layer 127a and the second Inp2Ga1-p2N. Since it is smaller than the layer 127c, it is possible to improve long-term reliability of the device by effectively blocking the penetration of Mg, which is a p-type dopant, from the second conductivity-type semiconductor layer 116 toward the active layer 114.

Next, as shown in FIG. 10, an AlxInyGa(1-xy)N series (however, 0≤x≤1, 0≤y≤1) electron blocking layer 128 and the electron blocking layer on the barrier layer 127 A second conductivity-type semiconductor layer 116 may be formed on 128.

The electron blocking layer 128 serves as an electron blocking and an MQW cladding of the active layer 114 to improve luminous efficiency.

The electron blocking layer 128 may have an energy band gap larger than the energy band gap of the active layer 114. The electron blocking layer 128 may be formed of a superlattice, but is not limited thereto.

In addition, the electron blocking layer 128 may be doped with p-type impurities. For example, the electron blocking layer 128 is doped with Mg in a concentration range of about 10 ¹⁸ ~ 10 ²⁰ /cm3 using a method such as ion implantation to effectively block overflowing electrons and increase hole injection efficiency. I can make it.

Next, a second conductivity type semiconductor layer 116 is formed on the electron blocking layer 128.

The second conductivity type semiconductor layer 116 may be formed of a semiconductor compound. It may be implemented with a compound semiconductor such as Group 3-5 and Group 2-6, and may be doped with a second conductivity type dopant.

For example, the second conductivity type semiconductor layer 116 may include a semiconductor material having a composition formula of InxAlyGa1-x-yN (0≤x≤1, 0≤y≤1, 0≤x+y≤1). I can. When the second conductivity-type semiconductor layer 116 is a p-type semiconductor layer, the second conductivity-type dopant is a p-type dopant and may include Mg, Zn, Ca, Sr, Ba, or the like.

Next, a light-transmitting electrode 130 is formed on the second conductivity-type semiconductor layer 116, and the light-transmitting electrode 130 may include a light-transmitting ohmic layer, and a single metal so that carrier injection can be efficiently performed. Alternatively, it can be formed by stacking multiple metal alloys and metal oxides.

The light-transmitting electrode 130 includes indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), and indium gallium tin oxide (IGTO). oxide), AZO(aluminum zinc oxide), ATO(antimony tin oxide), GZO(gallium zinc oxide), IZON(IZO Nitride), AGZO(Al-Ga ZnO), IGZO(In-Ga ZnO), ZnO, IrOx, It may be formed by including at least one of RuOx and NiO, but is not limited to these materials.

In an embodiment, the first conductivity-type semiconductor layer 112 may be implemented as an n-type semiconductor layer, and the second conductivity-type semiconductor layer 116 may be implemented as a p-type semiconductor layer, but is not limited thereto. In addition, a semiconductor, for example, an n-type semiconductor layer (not shown) having a polarity opposite to that of the second conductivity type may be formed on the second conductivity type semiconductor layer 116. Accordingly, the light emitting structure 110 may be implemented in any one of an n-p junction structure, a p-n junction structure, an n-p-n junction structure, and a p-n-p junction structure.

Next, as shown in FIG. 11, the light-transmitting electrode 130, the second conductivity-type semiconductor layer 116, the electron blocking layer 128, the barrier layer 127, so that the first conductivity-type semiconductor layer 112 is exposed. Part of the active layer 114 and the gallium nitride-based superlattice layer 124 may be removed.

Next, as shown in FIG. 12, a second electrode 132 is formed on the light-transmitting electrode 130, and a first electrode 131 is formed on the exposed first conductivity-type semiconductor layer 112. The light emitting device 100 may be formed according to the following.

The light emitting device according to this embodiment may be installed in the light emitting device package.

In addition, in the light emitting device package in which the light emitting device according to the embodiment is installed, a plurality of light emitting device packages are arranged on a substrate, and an optical member such as a light guide plate, a prism sheet, a diffusion sheet, a fluorescent sheet, etc. are disposed on a path of light emitted from the light emitting device package I can. Such a light-emitting device package, a substrate, and an optical member may function as a backlight unit or a lighting unit. For example, the lighting system may include a backlight unit, a lighting unit, an indicator device, a lamp, and a street light.

Features, structures, effects, and the like described in the embodiments above are included in at least one embodiment, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, and the like illustrated in each embodiment can be implemented by combining or modifying other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to such combinations and modifications should be interpreted as being included in the scope of the embodiments.

Although the embodiments have been described above, these are only examples and are not intended to limit the embodiments, and those of ordinary skill in the field to which the embodiments belong are not departing from the essential characteristics of the embodiments. It will be seen that branch transformation and application are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the embodiments set in the appended claims.

First conductivity type semiconductor layer 112, active layer 114
Quantum well 200, quantum wall 300, barrier layer 127,
Electron blocking layer 128, second conductivity type semiconductor layer 116

Claims (10)

A first conductivity type semiconductor layer;
An active layer disposed on the first conductivity type semiconductor layer and including a plurality of quantum wells and a plurality of quantum walls; And
A second conductivity type semiconductor layer on the active layer; Including,
The first conductivity-type semiconductor layer is an n-type semiconductor layer, the second conductivity-type semiconductor layer is a p-type semiconductor layer,
The plurality of quantum walls include a plurality of first quantum walls adjacent to the first conductivity type semiconductor layer and at least one second quantum wall adjacent to the second conductivity type semiconductor layer,
The plurality of first quantum walls include a p-type dopant,
The number of the plurality of first quantum walls corresponds to 20-50% of the total number of quantum walls,
Each of the plurality of first quantum walls,
A first capping layer;
A doping layer disposed on the first capping layer and including a p-type dopant; And
Comprising a second capping layer disposed on the doping layer,
The thickness of the doping layer is 20% or less of the thickness of the first quantum wall,
Among the plurality of first quantum walls, a doping concentration of the doping layer of the first quantum wall closest to the first conductivity type semiconductor layer is of the first quantum wall isolated farthest from the first conductivity type semiconductor layer. A light emitting device higher than the doping concentration of the doping layer. delete delete delete The method of claim 1,
The p-type dopant is a light emitting device of Mg, Zn, Ca, Sr, or Ba. The method of claim 1,
A gallium nitride-based superlattice layer disposed between the first conductivity type semiconductor layer and the active layer to prevent diffusion of a dopant; And
A light emitting device further comprising a barrier layer disposed between the active layer and the second conductive semiconductor layer. delete delete delete A lighting system comprising a light-emitting unit including the light-emitting element according to any one of claims 1 to 6.

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