KR20150027536A - Light emitting device - Google Patents

Abstract

The embodiment of the present invention provides a light emitting device which includes a first conductive semiconductor layer, an active layer which is arranged on the first conductive semiconductor layer, an electron blocking layer which is arranged on the active layer, an interface layer which is arranged on the electron blocking layer, and a second conductive semiconductor layer which is arranged on the interface layer. Wherein, the energy band gap of the interface layer is smaller than the energy band gap of the electron blocking layer and is larger than the energy band gap of the second conductive semiconductor layer.

Description

[0001] LIGHT EMITTING DEVICE [0002]

An embodiment relates to a light emitting element.

GaN, and AlGaN are widely used for optoelectronics and electronic devices due to their advantages such as wide and easy bandgap energy.

Particularly, a light emitting device such as a light emitting diode (Ligit Emitting Diode) or a laser diode using a semiconductor material of a 3-5 group or a 2-6 group compound semiconductor has been widely used in various fields such as red, green, blue and ultraviolet It can realize various colors, and it can realize efficient white light by using fluorescent material or color combination. It has low power consumption, semi-permanent lifetime, fast response speed, safety, and environment compared to conventional light sources such as fluorescent lamps and incandescent lamps Affinity.

Therefore, a transmission module of the optical communication means, a light emitting diode backlight replacing a cold cathode fluorescent lamp (CCFL) constituting a backlight of an LCD (Liquid Crystal Display) display device, a white light emitting element capable of replacing a fluorescent lamp or an incandescent lamp Diode lighting, automotive headlights, and traffic lights.

1 is a cross-sectional view of a conventional light emitting device.

A conventional light emitting device 100 includes a light emitting structure 120 including a first conductive semiconductor layer 122, an active layer 124, and a second conductive semiconductor layer 126 on a substrate 100 made of sapphire or the like The first electrode 170 and the second electrode 180 are disposed on the first conductive semiconductor layer 122 and the second conductive semiconductor layer 126 and the light emitting structure 120 and the substrate 110, the buffer layer 115 may be disposed.

In the light emitting device 100, electrons injected through the first conductive type semiconductor layer 122 and holes injected through the second conductive type semiconductor layer 126 meet to form an energy band inherent to the active layer 124 And emits light having energy determined by the light intensity. The light emitted from the active layer 124 may be different depending on the composition of the material of the active layer 124 and may be blue light, ultraviolet light (UV), deep ultraviolet light (Deep UV), or the like.

However, the conventional light emitting device described above has the following problems. The electrons injected from the first conductivity type semiconductor layer pass through the active layer to the second conductivity type semiconductor layer so that the combination of electrons and holes is not the active layer but the second conductivity type semiconductor layer, .

In order to solve this problem, there is an attempt to prevent electrons from overflowing into the second conductivity type semiconductor layer by disposing an electron blocking layer between the active layer and the second conductivity type semiconductor layer.

However, the mobility of electrons is much larger than the mobility of holes, so electrons can still travel in the direction of the second conductivity type semiconductor layer through the above-described electron blocking layer. If the doping amount of aluminum (Al) is increased in the electron blocking layer to solve such a problem, the quality of the electron blocking layer may be deteriorated.

The embodiments attempt to improve the quality of the light emitting device and improve the light efficiency.

The embodiment includes a first conductivity type semiconductor layer; An active layer disposed on the first conductive semiconductor layer; An electron blocking layer disposed on the active layer; An interface layer disposed on the electron blocking layer and having an energy band gap smaller than that of the electron blocking layer and larger than the following second conductivity type semiconductor layer; And a second conductive semiconductor layer disposed on the interface layer.

The interface layer may be of the second conductivity type.

The interface layer may comprise InGaN.

The interfacial layer may have a thickness of from 1 nanometer to 100 nanometers.

The composition ratio of In in the interface layer may be within 10%.

The interface layer may be doped with magnesium (Mg).

The magnesium in the interfacial layer may be doped to a concentration of 5 x 10 ¹⁹ to 1 x 10 ²¹ .

The light emitting device according to the embodiment may confine the electrons overflowed from the electron blocking layer toward the second conductivity type semiconductor layer at the interface layer to prevent leakage current. In addition, the second conductive dopant, magnesium, is doped to improve the hole gathering effect, thereby improving the efficiency of hole injection into the active layer, and the light efficiency of the entire light emitting device package can be improved.

1 is a cross-sectional view of a conventional light emitting device,
2A is a cross-sectional view of an embodiment of a light emitting device,
FIG. 2B is a detailed view of the structure of the light emitting structure of FIG. 2B,
FIGS. 3A to 3D are views showing one embodiment of energy bandgap in the light emitting structure of FIG. 2A,
4 is a cross-sectional view of another embodiment of the light emitting device,
5 is a view showing an embodiment of a light emitting device package including a light emitting device,
6 is a view illustrating an embodiment of a video display device including a light emitting device,
7 is a view showing an embodiment of a lighting apparatus including a light emitting element.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

In the description of the embodiment according to the present invention, in the case of being described as being formed "on or under" of each element, the upper (upper) or lower (lower) or under are all such that two elements are in direct contact with each other or one or more other elements are indirectly formed between the two elements. Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

FIG. 2A is a cross-sectional view of an embodiment of a light emitting device, and FIG. 2B is a detailed view of the structure of the light emitting structure of FIG. 2B.

In the light emitting device 200a according to the present embodiment, a buffer layer 215 and a light emitting structure 220 are disposed on a substrate 210. [

The substrate 210 may be formed of a material suitable for semiconductor material growth or a carrier wafer, may be formed of a material having excellent thermal conductivity, and may include a conductive substrate or an insulating substrate. For example, at least one of sapphire (Al ₂ O ₃ ), SiO ₂ , SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge and Ga ₂ O ₃ can be used.

When the substrate 210 is formed of sapphire or the like and the light emitting structure 220 including GaN or AlGaN is disposed on the substrate 210, the lattice mismatch between GaN and AlGaN and sapphire is very large Since the difference in thermal expansion coefficient between them is also very large, dislocations, melt-backs, cracks, pits, and surface morphology defects that deteriorate the crystallinity may occur The buffer layer 215 can be formed of AlN or the like.

Although not shown, an undoped GaN layer or an AlGaN layer may be disposed between the buffer layer 215 and the light emitting structure 220 to prevent the potentials and the like from being transmitted into the light emitting structure 220.

The light emitting structure 220 includes a first conductive semiconductor layer 222, an active layer 224 and a second conductive semiconductor layer 226. The light emitting structure 220 includes an active layer 224 and a second conductive semiconductor layer 226, The electron blocking layer 230 and the interface layer 240 may be disposed between the electron blocking layer 230 and the interfacial layer 240.

The first conductive semiconductor layer 222 may be formed of a compound semiconductor such as Group III-V or Group II-VI, and may be doped with a first conductive dopant. The first conductive semiconductor layer 222 is a semiconductor material having a composition formula of Al _x In _y Ga _(1-xy) N (0? X? 1, 0? _Y? 1, 0? _X + y? , GaN, InAlGaN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP.

When the first conductivity type semiconductor layer 222 is an n-type semiconductor layer, the first conductivity type dopant may include n-type dopants such as Si, Ge, Sn, Se, and Te. The first conductivity type semiconductor layer 2222 may be formed as a single layer or a multilayer, but is not limited thereto.

The active layer 224 is disposed between the first conductivity type semiconductor layer 222 and the second conductivity type semiconductor layer 226 and includes a single well structure, a multiple well structure, a single quantum well structure, A multi quantum well (MQW) structure, a quantum dot structure, or a quantum wire structure.

InGaN / InGaN, InGaN / InGaN, AlGaN / GaN, InAlGaN / GaN, GaAs (InGaAs), and AlGaN / AlGaN / InGaN / GaN, / AlGaAs, GaP (InGaP) / AlGaP, but is not limited thereto. The well layer may be formed of a material having an energy band gap smaller than the energy band gap of the barrier layer.

The second conductive semiconductor layer 226 may be formed of a semiconductor compound. The second conductive semiconductor layer 226 may be formed of a compound semiconductor such as a Group III-V or a Group II-VI, and may be doped with a second conductive dopant. The second conductivity type semiconductor layer 226 is formed of a semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + For example, the second conductive semiconductor layer 226 may be made of Al _x Ga _(1-x) N, and the second conductive semiconductor layer 226 may be formed of Al _x Ga _{y (1-x)} N, .

When the second conductivity type semiconductor layer 226 is a p-type semiconductor layer, the second conductivity type dopant may be a p-type dopant such as Mg, Zn, Ca, Sr, and Ba. The second conductivity type semiconductor layer 226 may be formed as a single layer or a multilayer, but is not limited thereto.

An electron blocking layer 230 may be disposed between the active layer 224 and the second conductivity type semiconductor layer 226 adjacent to the active layer 224.

The electron blocking layer 230 may comprise AlGaN and may be doped with a second conductivity type dopant.

An interfacial layer (Extra InGaN layer, EIL 240) is disposed between the electron blocking layer 230 and the second conductive semiconductor layer 240, which may include InGaN and may be doped with a second conductive dopant , And can serve as an electron restraining layer.

The thickness t ₁ of the interfacial layer 240 can be from 1 nanometer to 100 nanometers and can be from several nanometers to tens of nanometers, have. If the thickness t ₁ of the interfacial layer 240 is too small, the effect of the electronic bond described below may be deteriorated. If the thickness t ₁ is excessively large, the amount of indium (In) may increase and the quality may deteriorate.

The composition ratio of indium in the interface layer 240 may be within 10%. If indium is doped in the interface layer 240 by more than 10%, the energy band gap of the interface layer 240 is too low to act as a quantum well. In the interface layer 240, electrons and holes combine to emit light Light of a wavelength region different from that of the active layer 224 may be emitted to cause peak separation of light.

The interface layer 240 may be doped with magnesium (Mg), which may be doped at a concentration of 5 x 10 ¹⁹ to 1 x 10 ²¹ . When the magnesium is doped, the energy band gap of the interface layer 240 may be lowered. In this case, the quality of the interface layer 240 can be prevented from being lowered by lowering the energy band gap by increasing only the indium composition.

If the doping concentration of magnesium is lower than the above-mentioned value, the doping effect is not sufficient, and if it is higher, the doping of the interface layer 240 may be problematic and the quality may be deteriorated due to over-ping.

The interface layer 240 may prevent leakage current by confining electrons overflowing from the electron blocking layer 230 toward the second conductivity type semiconductor layer 226 due to the structure described above . In addition, the second conductive dopant, magnesium, is doped to improve the hole gathering effect, thereby improving the efficiency of hole injection into the active layer.

3A to 3D are views showing one embodiment of the energy bandgap in the light emitting structure of FIG. 2A.

3A, the energy band gap of the interface layer EIL is smaller than the energy band gap of the electron blocking layer EBL and smaller than the energy band gap of the second conductivity type semiconductor layer (p-GaN) Can be larger than the energy bandgap of the quantum wall. Such a configuration may be confined to the interface layer EIL even if electrons overflow the electron blocking layer EBL from the active layer, and electrons and holes may combine with each other in the interface layer EIL so that no light is emitted.

3B, the energy band gap of the interface layer EIL increases with an inclination from the electron blocking layer EBL toward the second conductivity type semiconductor layer p-GaN, May be reduced with an inclination in the direction of the second conductivity type semiconductor layer (p-GaN) from the electron blocking layer (EBL).

The energy band gap of the interface layer EIL increases stepwise from the electron blocking layer EBL toward the second conductivity type semiconductor layer p-GaN in the embodiment shown in FIG. 3C, The composition may be decreased stepwise from the electron blocking layer (EBL) toward the second conductivity type semiconductor layer (p-GaN).

The energy band gap of the interface layer EIL decreases stepwise from the electron blocking layer EBL toward the second conductivity type semiconductor layer p-GaN in the embodiment shown in Fig. The composition may be increased stepwise from the electron blocking layer (EBL) toward the second conductivity type semiconductor layer (p-GaN).

The light-transmitting conductive layer 250 may be disposed on the second conductivity type semiconductor layer 226.

In order to supply current to the first conductivity type semiconductor layer 222 when the substrate 210 is an insulating substrate, the first conductivity type semiconductor layer 222 may be mesa-etched from the light-transmitting conductive layer 250 to a portion of the first conductivity type semiconductor layer 222, Type semiconductor layer 222 may be exposed.

The first electrode 270 may be disposed on the exposed first conductive semiconductor layer 222 and the second electrode 280 may be disposed on the transmissive conductive layer 230. At least one of the first electrode 270 and the second electrode 280 may include at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu) And may be formed as a single layer or a multi-layer structure.

When the light emitting structure 220 is made of GaN or the like and emits visible light in the blue region, the transparent conductive layer 250 is disposed on the light emitting structure 220 to form the second conductive semiconductor layer 226 so that current can be supplied evenly over a wide area. When the light emitting structure 220 is made of AlGaN or the like and emits light in the ultraviolet to deep ultraviolet region, the GaN layer may be disposed on the light emitting structure 220, and the GaN layer may be doped with the second conductivity type dopant .

4 is a cross-sectional view of another embodiment of the light emitting device.

In the light emitting device 200b according to the present embodiment, the light emitting structure 220 includes a first conductive semiconductor layer 222, an active layer 224, and a second conductive semiconductor layer 226. The active layer 224, The electron blocking layer 230 and the interface layer 240 may be disposed between the second conductivity type semiconductor layer 226 and the composition and operation are the same as those of the above-described embodiment.

The surface of the first conductivity type semiconductor layer 222 may be patterned to improve light extraction efficiency. The first electrode 270 may be disposed on the first conductivity type semiconductor layer 222. Although not shown, The surface of the first conductivity type semiconductor layer 222 where the first electrode 270 is disposed may not be patterned.

A passivation layer 290 may be formed around the light emitting structure 220. The passivation layer 290 may be made of an insulating material and the insulating material may be made of a non-conductive oxide or nitride. As an example, the passivation layer 290 may be formed of a silicon oxide (SiO ₂ ) layer, an oxynitride layer, or an aluminum oxide layer.

A second electrode is disposed under the light emitting structure 220, and the ohmic layer 262 and the reflective layer 264 can serve as a second electrode.

The ohmic layer 262 may be about 200 Angstroms thick. The ohmic layer 262 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), indium gallium tin oxide ), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IZON (IZO nitride), AGZO (Al- GaZnO), IGZO , RuOx / ITO, Ni / IrOx / Au, and Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Sn, In, Ru, Mg, Hf, and is not limited to such a material.

The reflective layer 264 may be formed of a metal such as molybdenum (Mo), aluminum (Al), silver (Ag), nickel (Ni), platinum (Pt), rhodium Metal layer. Aluminum, silver, and the like can effectively reflect the light generated in the active layer 124 to greatly improve the light extraction efficiency of the semiconductor device, and molybdenum can be advantageous for plating growth of protrusions described later.

The support substrate 268 may be formed of a conductive material such as a metal or a semiconductor material. A metal having excellent electrical conductivity or thermal conductivity can be used and a material having a high thermal conductivity (e.g., metal) can be formed so that heat generated during operation of the semiconductor device can be sufficiently diffused. For example, a material selected from the group consisting of molybdenum (Mo), silicon (Si), tungsten (W), copper (Cu) and aluminum (Al) (Cu-W), a carrier wafer (e.g., GaN, Si, Ge, GaAs, ZnO, SiGe, SiC, SiGe, Ga ₂ O _3, etc.) And the like.

The supporting substrate 268 may have a thickness ranging from 50 to 200 nm so as to have a mechanical strength sufficient for separation into separate chips through a scribing process and a breaking process without causing warping of the entire nitride semiconductor. Micrometer < / RTI > thickness.

The bonding layer 266 bonds the reflective layer 150 and the support substrate 170 and may be formed of gold (Au), tin (Sn), indium (In), aluminum (Al), silicon (Si) Nickel (Ni), and copper (Cu), or an alloy thereof.

The light emitting devices according to the embodiments may confine the electrons overflowed from the electron blocking layer toward the second conductivity type semiconductor layer in the interface layer to prevent leakage current. In addition, the second conductive dopant, magnesium, is doped to improve the hole gathering effect, thereby improving the efficiency of hole injection into the active layer.

5 is a view illustrating an embodiment of a light emitting device package including a light emitting device.

The light emitting device package 400 according to the embodiment includes a body 410 including a cavity, a first lead frame 421 and a second lead frame 422 provided on the body 410, The light emitting device 200a according to the above-described embodiments, which is installed in the cavity 410 and is electrically connected to the first lead frame 421 and the second lead frame 422, and a molding part 470 formed in the cavity, .

The body 410 may be formed of a silicon material, a synthetic resin material, or a metal material. If the body 410 is made of a conductive material such as a metal material, an insulating layer may be coated on the surface of the body 410 to prevent an electrical short between the first and second lead frames 421 and 422 .

The first lead frame 421 and the second lead frame 422 are electrically separated from each other and supply current to the light emitting device 200a. The first lead frame 421 and the second lead frame 422 can reflect the light generated from the light emitting device 200a to increase the light efficiency and reduce the heat generated from the light emitting device 200a to the outside It may be discharged.

The light emitting device 200a may include a vertical light emitting device or a flip chip type light emitting device in addition to the horizontal light emitting device and the electrode pad 430 may be connected to the bonding pads on the second lead frame 422 through the wires 450. [ (Not shown).

The molding part 470 can surround and protect the light emitting device 200a. In addition, the phosphor 480 is conformally coated on the molding part 470 in a separate layer from the molding part 470. In this structure, the phosphor 480 is distributed so that the wavelength of the light emitted from the light emitting device 200a can be changed in the entire region where the light of the light emitting device package 400 is emitted.

The light of the first wavelength range emitted from the light emitting device 200a is excited by the phosphor 480 and converted into light of the second wavelength range and the light of the second wavelength range passes through the lens (not shown) The light path can be changed.

The light emitting devices disposed inside the light emitting device package 400 confine the electrons overflowed from the electron blocking layer toward the second conductivity type semiconductor layer at the interface layer to prevent leakage current have. In addition, the second conductive dopant, magnesium, is doped to improve the hole gathering effect, thereby improving the efficiency of hole injection into the active layer, and the light efficiency of the entire light emitting device package can be improved.

The light emitting device package may be mounted as one or a plurality of light emitting devices according to the embodiments described above, but the present invention is not limited thereto.

Hereinafter, an image display apparatus and a lighting apparatus will be described as an embodiment of an illumination system in which the above-described light emitting device package is disposed.

6 is a view showing an embodiment of a video display device including a light emitting device.

As shown in the figure, the image display device 900 according to the present embodiment includes a light source module, a reflection plate 920 on the bottom cover 910, a reflection plate 920 disposed in front of the reflection plate 920, A first prism sheet 950 and a second prism sheet 960 disposed in front of the light guide plate 940 and a second prism sheet 960 disposed between the first prism sheet 960 and the second prism sheet 960, A panel 970 disposed in front of the panel 970 and a color filter 980 disposed in the front of the panel 970.

The light source module comprises a light emitting device package 935 on a circuit board 930. Here, the circuit board 930 may be a PCB or the like, and the light emitting device disposed in the light emitting device package 935 is as described above.

The image display apparatus may use not only an edge type backlight unit shown in Fig. 6, but also a direct type backlight unit.

The light emitting device used in the above-described image display device can prevent leakage current by confining electrons overflowing from the electron blocking layer toward the second conductivity type semiconductor layer in the interface layer. In addition, the second conductive dopant, magnesium, is doped to improve the hole gathering effect, thereby improving the efficiency of hole injection into the active layer, and the light efficiency of the entire light emitting device package can be improved.

7 is a view showing an embodiment of a lighting device in which a light emitting element is disposed.

The lighting apparatus according to the embodiment may include a cover 1100, a light source module 1200, a heat discharger 1400, a power supply unit 1600, an inner case 1700, and a socket 1800. In addition, the illumination device according to the embodiment may further include at least one of the member 1300 and the holder 1500, and the light source module 1200 may include the light emitting device according to the above-described embodiments.

The cover 1100 may have a shape of a bulb or a hemisphere and may be provided in a shape in which the hollow is hollow and a part is opened. The cover 1100 may be optically coupled to the light source module 1200. For example, the cover 1100 can diffuse, scatter, or excite light provided from the light source module 1200. The cover 1100 may be a kind of optical member. The cover 1100 may be coupled to the heat discharging body 1400. The cover 1100 may have an engaging portion that engages with the heat discharging body 1400.

The inner surface of the cover 1100 may be coated with a milky white paint. Milky white paints may contain a diffusing agent to diffuse light. The surface roughness of the inner surface of the cover 1100 may be formed larger than the surface roughness of the outer surface of the cover 1100. This is for sufficiently diffusing and diffusing light from the light source module 1200 and emitting it to the outside.

The cover 1100 may be made of glass, plastic, polypropylene (PP), polyethylene (PE), polycarbonate (PC), or the like. Here, polycarbonate is excellent in light resistance, heat resistance and strength. The cover 1100 may be transparent so that the light source module 1200 is visible from the outside, and may be opaque. The cover 1100 may be formed by blow molding.

The light source module 1200 may be disposed on one side of the heat discharger 1400. Accordingly, the heat from the light source module 1200 is conducted to the heat discharging body 1400. The light source module 1200 may include a light emitting device package 1210, a connection plate 1230, and a connector 1250.

The member 1300 is disposed on the upper surface of the heat discharging body 1400 and has guide grooves 1310 into which the plurality of light emitting device packages 1210 and the connector 1250 are inserted. The guide groove 1310 corresponds to the substrate of the light emitting device package 1210 and the connector 1250.

The surface of the member 1300 may be coated or coated with a light reflecting material. For example, the surface of the member 1300 may be coated or coated with a white paint. The member 1300 reflects the light reflected by the inner surface of the cover 1100 and returns toward the light source module 1200 toward the cover 1100. Therefore, the light efficiency of the illumination device according to the embodiment can be improved.

The member 1300 may be made of an insulating material, for example. The connection plate 1230 of the light source module 1200 may include an electrically conductive material. Therefore, electrical contact can be made between the heat discharging body 1400 and the connecting plate 1230. The member 1300 may be made of an insulating material to prevent an electrical short between the connection plate 1230 and the heat discharger 1400. The heat discharger 1400 receives heat from the light source module 1200 and heat from the power supply unit 1600 to dissipate heat.

The holder 1500 closes the receiving groove 1719 of the insulating portion 1710 of the inner case 1700. Therefore, the power supply unit 1600 housed in the insulating portion 1710 of the inner case 1700 is sealed. The holder 1500 has a guide protrusion 1510. The guide protrusion 1510 has a hole through which the projection 1610 of the power supply unit 1600 passes.

The power supply unit 1600 processes or converts an electric signal provided from the outside and provides the electric signal to the light source module 1200. The power supply unit 1600 is housed in the receiving groove 1719 of the inner case 1700 and is sealed inside the inner case 1700 by the holder 1500. The power supply unit 1600 may include a protrusion 1610, a guide 1630, a base 1650, and an extension 1670.

The guide portion 1630 has a shape protruding outward from one side of the base 1650. The guide portion 1630 may be inserted into the holder 1500. A plurality of components may be disposed on one side of the base 1650. The plurality of components may include, for example, a DC converter for converting an AC power supplied from an external power source to a DC power source, a driving chip for controlling driving of the light source module 1200, an ESD (ElectroStatic discharge) protective device, and the like, but the present invention is not limited thereto.

The extension 1670 has a shape protruding outward from the other side of the base 1650. The extension portion 1670 is inserted into the connection portion 1750 of the inner case 1700 and receives an external electrical signal. For example, the extension portion 1670 may be provided to be equal to or smaller than the width of the connection portion 1750 of the inner case 1700. One end of each of the positive wire and the negative wire is electrically connected to the extension portion 1670 and the other end of the positive wire and the negative wire are electrically connected to the socket 1800 .

The inner case 1700 may include a molding part together with the power supply unit 1600 in the inner case 1700. The molding part is a hardened portion of the molding liquid so that the power supply providing part 1600 can be fixed inside the inner case 1700.

The light emitting device used in the illumination device according to the present embodiment can confine current flowing from the electron blocking layer toward the second conductivity type semiconductor layer in the interface layer to prevent leakage current. In addition, the second conductive dopant, magnesium, is doped to improve the hole gathering effect, thereby improving the efficiency of hole injection into the active layer, and the light efficiency of the entire light emitting device package can be improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

100, 200a, 200b: Light emitting device package
110, 210: substrate 115, 215: buffer layer
220: light emitting structure 230: electron blocking layer
240: interface layer 400: light emitting device package
500: Video display device

Claims (7)

A first conductive semiconductor layer;
An active layer disposed on the first conductive semiconductor layer;
An electron blocking layer disposed on the active layer;
An interface layer disposed on the electron blocking layer and having an energy band gap smaller than that of the electron blocking layer and larger than the following second conductivity type semiconductor layer; And
And a second conductivity type semiconductor layer disposed on the interface layer. The method according to claim 1,
Wherein the interface layer is a second conductive type. 3. The method according to claim 1 or 2,
Wherein the interface layer comprises InGaN. The method according to claim 1,
Wherein the interface layer has a thickness of 1 nanometer to 100 nanometers. 3. The method of claim 2,
And the composition ratio of In in the interface layer is within 10%. The method according to claim 1,
Wherein the interface layer is doped with magnesium (Mg). The method according to claim 6,
And the magnesium in the interface layer is doped at a concentration of 5 x 10 ¹⁹ to 1 x 10 ²¹ .

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