KR101969336B1 - Light emitting device - Google Patents

Abstract

Embodiments relate to a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and an illumination system.
The light emitting device according to the embodiment includes a first conductive semiconductor layer 112; An active layer 114 on the first conductive semiconductor layer 112; A second conductivity type gallium nitride based layer 128 on the active layer 114; And a second conductive type semiconductor layer (116) on the second conductive type gallium nitride based layer, wherein the second conductive type gallium nitride based layer (128) is formed on the active layer (114) An Al _x Ga _(1-x) N layer (where 0 <x <1) (128a); The second conductivity type Al _x Ga _(1-x) N layer on the second conductivity type _{(128a) In y Al z Ga} (1-yz) N super lattice layer (where, 0≤y <1, 0≤z <1) 128b; And a second conductive GaN layer 128c on the second conductive In _y Al _z Ga _(1-yz) N superlattice layer 128b.

Description

[0001] LIGHT EMITTING DEVICE [0002]

Embodiments relate to a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and an illumination system.

A light emitting device can be produced by combining p-n junction diodes having the characteristic that electric energy is converted into light energy by elements of Group III and Group V on the periodic table. LEDs can be implemented in various colors by controlling the composition ratio of compound semiconductors.

When a forward voltage is applied to a light emitting device, the electrons in the n-layer and the holes in the p-layer are coupled to emit energy corresponding to the energy gap between the conduction band and the valance band. It emits mainly in the form of heat or light, and emits in the form of light.

For example, nitride semiconductors have received great interest in the development of optical devices and high power electronic devices due to their high thermal stability and wide bandgap energy. Particularly, blue light emitting devices, green light emitting devices, ultraviolet (UV) light emitting devices, and the like using nitride semiconductors have been commercialized and widely used.

Recently, demand for high-efficiency LEDs has been on the rise.

There have been attempts to improve the structure of the active layer (MQW), the improvement of the electron blocking layer (EBL), and the improvement of the lower layer of the active layer.

Embodiments provide a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and an illumination system capable of improving brightness.

The light emitting device according to the embodiment includes a first conductive semiconductor layer 112; An active layer 114 on the first conductive semiconductor layer 112; A second conductivity type gallium nitride based layer 128 on the active layer 114; And a second conductive type semiconductor layer (116) on the second conductive type gallium nitride based layer, wherein the second conductive type gallium nitride based layer (128) is formed on the active layer (114) An Al _x Ga _(1-x) N layer (where 0 <x <1) (128a); The second conductivity type Al _x Ga _(1-x) N layer on the second conductivity type _{(128a) In y Al z Ga} (1-yz) N super lattice layer (where, 0≤y <1, 0≤z <1) 128b; And a second conductive GaN layer 128c on the second conductive In _y Al _z Ga _(1-yz) N superlattice layer 128b.

According to the embodiments, it is possible to provide a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and an illumination system having an optimal structure capable of improving brightness.

In addition, according to the embodiments, it is possible to provide a light emitting device, an emitting device, a light emitting device package, and an illumination system having an ideal electron blocking layer structure that is excellent in hole injection efficiency and can effectively block leakage of electrons.

1 is a cross-sectional view of a light emitting device according to an embodiment.
2 is a partial illustration of an energy band diagram of a light emitting device according to an embodiment.
FIGS. 3 to 5 illustrate examples of a method of manufacturing a light emitting device according to an embodiment.
6 is a cross-sectional view of a light emitting device package according to an embodiment.
Figures 7 to 9 show a lighting device according to an embodiment.
10 and 11 are views showing another example of the lighting apparatus according to the embodiment;
12 is a perspective view of a backlight unit according to an embodiment;

In the description of the embodiments, it is to be understood that each layer (film), area, pattern or structure may be referred to as being "on" or "under" the substrate, each layer Quot; on " and " under " are intended to include both "directly" or "indirectly" do. Also, the criteria for top, bottom, or bottom of each layer will be described with reference to the drawings.

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 of each component does not entirely reflect the actual size.

(Example)

1 is a cross-sectional view of a light emitting device 100 according to an embodiment.

The light emitting device 100 according to the embodiment includes a first conductive semiconductor layer 112, an active layer 114 on the first conductive semiconductor layer 112, And a second conductive type semiconductor layer (116) on the gallium nitride based layer (128) and the second conductive type gallium nitride based layer (128).

According to the related art of the invention (which means that the related art is not a technology obviously known at the time of filing of the invention), a so-called electron blocking layer is formed on the active layer in order to block electrons having high mobility And the electron blocking layer is sufficiently larger in energy band gap than the last GaN quantum wall so that the electrons supplied from the n-GaN layer do not pass through the light emitting layer but fall into the p-GaN without participating in light emission.

The structure of the electron blocking layer in the related art is a thick p-AlGaN single layer or a superlattice structure in which p-AlGaN / p-GaN is repeatedly laminated.

However, in the related art, when a p-AlGaN electron blocking layer is thin in the case of a thick p-AlGaN single layer, in order to solve the problem of electrons moving toward p-GaN through quantum mechanical tunneling, The p-AlGaN electron blocking layer is thick enough to prevent the p-AlGaN electron blocking layer from being formed. However, the thick p-AlGaN electron blocking layer acts as an energy barrier to the holes to be injected from the p-GaN into the light emitting layer, have.

On the other hand, in the superlattice structure in which p-AlGaN / p-GaN is repeated, a thin p-AlGaN layer and a thin p-GaN layer are alternately laminated. Hole injecting holes can pass through the superlattice layer through quantum mechanical tunneling, thereby improving the problem of low hole injection efficiency of the electron blocking layer of the thick p-AlGaN single layer. However, since electrons can also pass through the thin p-AlGaN layer through quantum mechanical tunneling, there is a problem that the leakage of electrons from the light emitting layer toward the p-GaN can not be effectively blocked.

Therefore, in the related art, in the electron blocking layer technique based on the p-AlGaN monolayer, the structure effectively blocking the electron leakage has a very low hole injection efficiency, and the electron blocking layer superlattice structure, which improves the hole injection efficiency, There is a technical contradiction that is deteriorated.

As a result, it is required to develop an ideal electron blocking layer structure which is excellent in hole injection efficiency and can effectively block leakage of electrons.

FIG. 1 is a cross-sectional view of a light emitting device 100 according to an embodiment, and FIG. 2 is a partial exemplary view of an energy band diagram of a light emitting device according to an embodiment.

The light emitting device 100 according to the embodiment includes a first conductive semiconductor layer 112, a superlattice layer 124 of gallium nitride series on the first conductive semiconductor layer 112, A second conductive type gallium nitride based layer 128 on the active layer 114 and a second conductive type gallium nitride based on the second conductive type gallium nitride based layer 128 on the superlattice layer 124, Type semiconductor layer (116).

In this embodiment, the second conductivity type gallium nitride based layer 128 may include a second conductivity type Al _x Ga _(1-x) N layer (where 0 <x <1) 128a ) And a second conductive type In _y Al _z Ga _(1-yz) N super lattice layer ₍ 2) on the second conductive type Al _x Ga _1-x N layer (0 <x < A second conductive GaN layer (128b) is formed on the second conductive type In _y Al _z Ga _(1-yz) N superlattice layer 128b (0? Y <1, 0? Z < 128c.

In one embodiment, the second conductivity type gallium nitride based layer 128 is formed of the second conductivity type Al _x Ga _(1-x) N layer 128a and the second conductivity type In _y Al _z Ga _{1-yz )} N super lattice layer 128b and the second conductive type GaN layer 128c may be repeatedly formed at a plurality of periods in a single period.

The second conductivity type Al _x Ga _(1-x) N layer (128a) is the second relative to the conductive-type GaN layer (128c) adjacent to the active layer 114, the second conductive type GaN layer (128c) May be adjacent to the second conductivity type semiconductor layer 116 as compared to the second conductivity type Al _x Ga _(1-x) N layer 128a.

In the embodiment, the second conductive type In _y Al _z Ga _(1-yz) N superlattice layer 128b has a superlattice structure in which two thin layers having different energy band gaps are alternately repeatedly laminated at least once .

In the embodiment, the average energy band gap of the second conductivity type In _y Al _z Ga _(1-yz) N superlattice layer 128b is larger than the size of the second conductivity type Al _x Ga _(1-x) N layer 128a Of the second conductive type GaN layer 128c and larger than the average energy band gap of the second conductive type GaN layer 128c.

In the embodiment, the energy band gap of each layer can be controlled by controlling the concentration of In and Al and the thickness of each layer (the energy level can be increased if the thickness is thin).

The energy bandgap in the second conductive type Al _x Ga _(1-x) N layer 128a may decrease in the direction of the second conductive type GaN layer 128c.

In contrast to the simple superlattice structure of the related art, the second conductivity type gallium nitride based layer 128 according to the embodiment has electrons leaked from the active layer 114 toward the second conductivity type semiconductor layer 116, -Type Al _x Ga _(1-x) N layer 128a but has a relatively high energy barrier. Accordingly, leakage of electrons from the active layer 114 toward the second conductivity type semiconductor layer 116 can be effectively blocked.

In addition, in the embodiment, the energy band gap may increase from the second conductive type GaN layer 128c toward the second conductive type Al _x Ga _(1-x) N layer 128a.

For example, in the case of holes injected into the active layer 114 from the second conductivity type semiconductor layer 116, the energy band of the second conductivity type In _y Al _z Ga _(1-yz) N superlattice layer 128b Since the gap has a value between the energy band gap of the second conductive type Al _x Ga _(1-x) N layer 128a and the second conductive type GaN layer 128c, _(1-x) N layer 128a through the second conductive type In _y Al _z Ga _(1-yz) N superlattice layer 128b in a stepwise manner in the first conductive type Al _x Ga The hole injection is facilitated.

Further, in the embodiment, the plane-direction average lattice constant of the second conductive type In _y Al _z Ga _(1-yz) N superlattice layer 128b is larger than the plane-direction average lattice constant of the second conductivity type Al _x Ga _(1-x) Directional average lattice constant of the second conductive type GaN layer 128a and larger than the plane direction average lattice constant of the second conductive type GaN layer 128c.

In the embodiment, the average lattice constant of the second conductivity type In _y Al _z Ga _(1-yz) N superlattice layer 128b is greater than the average plane lattice constant of the second conductivity type Al _x Ga _(1-x) N layer 128a because the first of the values between the face direction average lattice constant of the second conductivity type GaN layer (128c) of the second conductivity type _{Al x Ga (1-x)} N layer (128a) and the second conductive type GaN layer (128c) The interfacial stress caused by the lattice mismatch is relaxed and the interfacial defect formation is suppressed.

Accordingly, the injected holes can effectively perform a two _- dimensional current spreading in the second conductive In _y Al _z Ga _(1-yz) N superlattice layer 128b, and thus the current can be uniformly injected into the entire active layer The internal quantum efficiency of the light-emitting layer can be increased.

According to the embodiment, the second conductivity type Al _x Ga _(1-x) N layer 128a of the second conductivity type gallium nitride based layer 128 and the second conductivity type In _y Al _z Ga _{(1-yz )} N superlattice layer 128b and the second conductive GaN layer 128c are organic bonds to each other so as to have an excellent hole injection efficiency and at the same time to effectively prevent leakage of electrons, A method of manufacturing a light emitting device, a light emitting device package, and an illumination system.

Hereinafter, a method of manufacturing a light emitting device according to an embodiment will be described with reference to FIGS.

First, the substrate 105 is prepared as shown in FIG. 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 is a sapphire (Al ₂ O _3), SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, and Ga ₂ 0 ₃ May be used. A patterned sapphire substrate (PSS) P may be formed on the substrate 105, but the present invention is not limited thereto.

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

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

At this time, a buffer layer 107 may be formed on the substrate 105. The buffer layer 107 may relieve lattice mismatching between the material of the light emitting structure 110 and the substrate 105. The material of the buffer layer 107 may be a Group III-V compound semiconductor such as GaN, InN, AlN , InGaN, AlGaN, InAlGaN, and AlInN.

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

The first conductive semiconductor layer 112 may be formed of a semiconductor compound. Group 3-Group 5, Group 2-Group 6, and the like, and the first conductive type dopant may be doped. When the first conductive semiconductor layer 112 is an N-type semiconductor layer, the first conductive dopant may include Si, Ge, Sn, Se, and Te as an N-type dopant.

The first conductive semiconductor layer 112 may include 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 + .

The first conductive 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 and InP.

The first conductive semiconductor layer 112 may be formed by a CVD method or molecular beam epitaxy (MBE), sputtering, or vapor phase epitaxy (HVPE). . The first conductive semiconductor layer 112 may be formed by depositing a silane containing an n-type impurity such as trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ) Gas (SiH ₄ ) may be implanted and formed.

Next, in the embodiment, the 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 a stress caused by lattice mismatch between the first conductivity type semiconductor layer 112 and the active layer 114. For example, the gallium nitride superlattice layer 124 may be formed of In _y Al _x Ga _{y (1-xy)} N (0 x 1, 0 y 1) / GaN, It is not.

Thereafter, the active layer 114 is formed on the gallium nitride-based superlattice layer 124.

Electrons injected through the first conductive type semiconductor layer 112 and holes injected through the second conductive type semiconductor layer 116 formed after the first and second conductive type semiconductor layers 116 and 116 are mutually combined to form an energy band unique to the active layer Which emits light having an energy determined by &lt; RTI ID = 0.0 &gt;

The active layer 114 may be formed of at least one of a single quantum well structure, a multi quantum well (MQW) structure, a quantum-wire structure, or a quantum dot structure. For example, the active layer 114 may be formed with a multiple quantum well structure by injecting trimethyl gallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) But is not limited thereto.

The well layer / barrier layer of the active layer 114 may be formed of any one or more pairs of InGaN / GaN, InGaN / InGaN, GaN / AlGaN, InAlGaN / GaN, GaAs (InGaAs) / AlGaAs, GaP But is not limited thereto. The well layer may be formed of a material having a band gap lower than the band gap of the barrier layer.

An embodiment of the present invention is to provide a light emitting device having an ideal electron blocking layer structure which is excellent in hole injection efficiency and can effectively block leakage of electrons.

The second conductive type gallium nitride based layer 128 is formed on the active layer 114 by forming a second conductive type AlGaN layer 128 on the active layer 114. The second conductive type gallium nitride based layer 128 is formed on the active layer 114, _x- Ga _(1-x) N layer (where 0 <x <1) 128a and the second conductive Al _x Ga _(1-x ) first on the second conductive type _{in y Al z Ga (1-} yz) N super lattice layer (where, 0≤y <1, 0≤z <1 ) (128b) and the second conductive type in _y Al _z Ga _{( 1-yz)} N & lt _{; /} RTI &gt; superlattice layer 128b.

In one embodiment, the second conductivity type gallium nitride based layer 128 is formed of the second conductivity type Al _x Ga _(1-x) N layer 128a and the second conductivity type In _y Al _z Ga _{1-yz )} N super lattice layer 128b and the second conductive type GaN layer 128c may be repeatedly formed at a plurality of periods in a single period.

In the embodiment, the second conductive type In _y Al _z Ga _(1-yz) N superlattice layer 128b has a superlattice structure in which two thin layers having different energy band gaps are alternately repeatedly laminated at least once .

In the embodiment, the average energy band gap of the second conductivity type In _y Al _z Ga _(1-yz) N superlattice layer 128b is larger than the size of the second conductivity type Al _x Ga _(1-x) N layer 128a Of the second conductive type GaN layer 128c and larger than the average energy band gap of the second conductive type GaN layer 128c.

The energy bandgap in the second conductive type Al _x Ga _(1-x) N layer 128a may decrease in the direction of the second conductive type GaN layer 128c.

The second conductivity type gallium nitride based layer 128 according to the embodiment has a structure in which the electrons leaked from the active layer 114 toward the second conductivity type semiconductor layer 116 are the second conductivity type Al _x Ga _(1-x) N Lt; RTI ID = 0.0 &gt; 128a &lt; / RTI &gt; Accordingly, leakage of electrons from the active layer 114 toward the second conductivity type semiconductor layer 116 can be effectively blocked.

In addition, in the embodiment, the energy band gap may increase from the second conductive type GaN layer 128c toward the second conductive type Al _x Ga _(1-x) N layer 128a.

For example, in the case of holes injected into the active layer 114 from the second conductivity type semiconductor layer 116, the energy band of the second conductivity type In _y Al _z Ga _(1-yz) N superlattice layer 128b Since the gap has a value between the energy band gap of the second conductive type Al _x Ga _(1-x) N layer 128a and the second conductive type GaN layer 128c, _(1-x) N layer 128a through the second conductive type In _y Al _z Ga _(1-yz) N superlattice layer 128b in a stepwise manner in the first conductive type Al _x Ga The hole injection is facilitated.

Further, in the embodiment, the plane-direction average lattice constant of the second conductive type In _y Al _z Ga _(1-yz) N superlattice layer 128b is larger than the plane-direction average lattice constant of the second conductivity type Al _x Ga _(1-x) Directional average lattice constant of the second conductive type GaN layer 128a and larger than the plane direction average lattice constant of the second conductive type GaN layer 128c.

In the embodiment, the average lattice constant of the second conductivity type In _y Al _z Ga _(1-yz) N superlattice layer 128b is greater than the average plane lattice constant of the second conductivity type Al _x Ga _(1-x) N layer 128a because the first of the values between the face direction average lattice constant of the second conductivity type GaN layer (128c) of the second conductivity type _{Al x Ga (1-x)} N layer (128a) and the second conductive type GaN layer (128c) The interfacial stress caused by the lattice mismatch is relaxed and the interfacial defect formation is suppressed.

Accordingly, the injected holes can effectively perform a two _- dimensional current spreading in the second conductive type In _y Al _z Ga _(1-yz) N superlattice layer 128b, and the current can be uniformly injected into the entire active layer The internal quantum efficiency of the light-emitting layer can be increased.

According to the embodiments, it is possible to provide a light emitting device having an ideal electron blocking layer structure and a method of manufacturing the light emitting device, which are excellent in hole injection efficiency and can effectively block leakage of electrons.

Next, a second conductive type semiconductor layer 116 is formed on the second conductive type gallium nitride based layer 128.

The second conductive semiconductor layer 116 may be formed of a semiconductor compound. 3-group-5, group-2-group-6, and the like, and the second conductivity type dopant may be doped.

For example, the second conductive semiconductor layer 116 may have a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + And the like. When the second conductive semiconductor layer 116 is a p-type semiconductor layer, the second conductive dopant may include Mg, Zn, Ca, Sr, and Ba as p-type dopants.

Next, a light transmitting electrode 130 is formed on the second conductive semiconductor layer 116, and the light transmitting electrode 130 may include a light transmitting ohmic layer. In order to efficiently perform carrier injection, Or a metal alloy, a metal oxide, or the like.

The transmissive electrode 130 may be formed of one of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide ZnO, ZnO, IrOx, AlGaO, AlGaO, AZO, ATO, GZO, IZO, RuOx, and NiO, and is not limited to such a material.

In an embodiment, the first conductive semiconductor layer 112 may be an n-type semiconductor layer, and the second conductive semiconductor layer 116 may be a p-type semiconductor layer. Also, on the second conductive semiconductor layer 116, a semiconductor (e.g., an n-type semiconductor) (not shown) having a polarity opposite to that of the second conductive type may be formed. Accordingly, the light emitting structure 110 may have 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.

4, the light-transmitting electrode 130, the second conductivity type semiconductor layer 116, the second conductivity type gallium nitride series layer 128, the active layer 130, and the second conductivity type semiconductor layer 112 are formed to expose the first conductivity type semiconductor layer 112, A part of the superlattice layer 114 and the gallium nitride superlattice layer 124 can be removed.

5, a second electrode 132 is formed on the transmissive electrode 130, and a first electrode 131 is formed on the exposed first conductive semiconductor layer 112. Next, as shown in FIG.

According to the embodiments, it is possible to provide a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and an illumination system having an optimal structure capable of improving brightness.

In addition, according to the embodiments, it is possible to provide a light emitting device, an emitting device, a light emitting device package, and an illumination system having an ideal electron blocking layer structure that is excellent in hole injection efficiency and can effectively block leakage of electrons.

6 is a view illustrating a light emitting device package 200 provided with a light emitting device according to embodiments.

The light emitting device package 200 according to the embodiment includes a package body 205, a third electrode layer 213 and a fourth electrode layer 214 provided on the package body 205, a package body 205, And a molding member 230 surrounding the light emitting device 100. The light emitting device 100 is electrically connected to the third electrode layer 213 and the fourth electrode layer 214,

The package body 205 may be formed of a silicon material, a synthetic resin material, or a metal material, and the inclined surface may be formed around the light emitting device 100.

The third electrode layer 213 and the fourth electrode layer 214 are electrically isolated from each other and provide power to the light emitting device 100. The third electrode layer 213 and the fourth electrode layer 214 may function to increase light efficiency by reflecting the light generated from the light emitting device 100, And may serve to discharge heat to the outside.

The light emitting device 100 may be a horizontal type light emitting device as illustrated in FIG. 1, but is not limited thereto. Vertical light emitting devices and flip chip light emitting devices may also be used.

The light emitting device 100 may be mounted on the package body 205 or on the third electrode layer 213 or the fourth electrode layer 214.

The light emitting device 100 may be electrically connected to the third electrode layer 213 and / or the fourth electrode layer 214 by a wire, flip chip, or die bonding method. The light emitting device 100 is electrically connected to the third electrode layer 213 through the wire 230 and is electrically connected to the fourth electrode layer 214 directly.

The molding member 230 surrounds the light emitting device 100 to protect the light emitting device 100. In addition, the molding member 230 may include a phosphor 232 to change the wavelength of light emitted from the light emitting device 100.

A light guide plate, a prism sheet, a diffusion sheet, a fluorescent sheet, and the like, which are optical members, may be disposed on a path of light emitted from the light emitting device package. The light emitting device package, the substrate, and the optical member may function as a backlight unit or function as a lighting unit. For example, the lighting system may include a backlight unit, a lighting unit, a pointing device, a lamp, and a streetlight.

7 to 9 are views showing a lighting apparatus according to an embodiment.

FIG. 7 is a perspective view of the illumination device according to the embodiment viewed from above, FIG. 8 is a perspective view of the illumination device shown in FIG. 7, and FIG. 9 is an exploded perspective view of the illumination device shown in FIG.

7 to 9, the illumination device according to the embodiment includes a cover 2100, a light source module 2200, a heat discharger 2400, a power supply unit 2600, an inner case 2700, a socket 2800, . &Lt; / RTI &gt; Further, the illumination device according to the embodiment may further include at least one of the member 2300 and the holder 2500. The light source module 2200 may include a light emitting device or a light emitting device package according to the embodiment.

For example, the cover 2100 may have a shape of a bulb or a hemisphere, and may be provided in a shape in which the hollow is hollow and a part is opened. The cover 2100 may be optically coupled to the light source module 2200. For example, the cover 2100 may diffuse, scatter, or excite light provided from the light source module 2200. The cover 2100 may be a kind of optical member. The cover 2100 may be coupled to the heat discharging body 2400. The cover 2100 may have an engaging portion that engages with the heat discharging body 2400.

The inner surface of the cover 2100 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 2100 may be larger than the surface roughness of the outer surface of the cover 2100. This is for sufficiently diffusing and diffusing the light from the light source module 2200 and emitting it to the outside.

The cover 2100 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 2100 may be an opaque layer 126 and may be opaque so that the light source module 2200 can be seen from the outside. The cover 2100 may be formed by blow molding.

The light source module 2200 may be disposed on one side of the heat discharging body 2400. Accordingly, heat from the light source module 2200 is conducted to the heat discharger 2400. The light source module 2200 may include a light source unit 2210, a connection plate 2230, and a connector 2250.

The member 2300 is disposed on the upper surface of the heat discharging body 2400 and has guide grooves 2310 through which the plurality of light source portions 2210 and the connector 2250 are inserted. The guide groove 2310 corresponds to the substrate of the light source unit 2210 and the connector 2250.

The surface of the member 2300 may be coated or coated with a light reflecting material. For example, the surface of the member 2300 may be coated or coated with a white paint. The member 2300 reflects the light reflected by the inner surface of the cover 2100 toward the cover 2100 in the direction toward the light source module 2200. Therefore, the light efficiency of the illumination device according to the embodiment can be improved.

The member 2300 may be made of an insulating material, for example. The connection plate 2230 of the light source module 2200 may include an electrically conductive material. Therefore, electrical contact can be made between the heat discharging body 2400 and the connecting plate 2230. The member 2300 may be formed of an insulating material to prevent an electrical short circuit between the connection plate 2230 and the heat discharging body 2400. The heat discharger 2400 receives heat from the light source module 2200 and heat from the power supply unit 2600 to dissipate heat.

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

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

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

The guide portion 2630 has a shape protruding outward from one side of the base 2650. The guide portion 2630 may be inserted into the holder 2500. A plurality of components may be disposed on one side of the base 2650. The plurality of components include, for example, a DC converter for converting AC power supplied from an external power source into DC power, a driving chip for controlling driving of the light source module 2200, an ESD (ElectroStatic discharge) protective device, and the like, but the present invention is not limited thereto.

The extension portion 2670 has a shape protruding outward from the other side of the base 2650. The extension portion 2670 is inserted into the connection portion 2750 of the inner case 2700 and receives an external electrical signal. For example, the extension portion 2670 may be provided to be equal to or smaller than the width of the connection portion 2750 of the inner case 2700. One end of each of the positive wire and the negative wire is electrically connected to the extension portion 2670 and the other end of the positive wire and the negative wire are electrically connected to the socket 2800 .

The inner case 2700 may include a molding part together with the power supply part 2600. The molding part is a hardened portion of the molding liquid so that the power supply unit 2600 can be fixed inside the inner case 2700.

10 and 11 are views showing another example of the lighting apparatus according to the embodiment.

10 is a perspective view of a lighting apparatus according to the embodiment, and Fig. 11 is an exploded perspective view of the lighting apparatus shown in Fig.

10 and 11, the lighting device according to the embodiment includes a cover 3100, a light source 3200, a heat sink 3300, a circuit portion 3400, an inner case 3500, and a socket 3600 . The light source unit 3200 may include a light emitting device or a light emitting device package according to the embodiment.

The cover 3100 has a bulb shape and is hollow. The cover 3100 has an opening 3110. The light source unit 3200 and the member 3350 can be inserted through the opening 3110. [

The cover 3100 may be coupled to the heat discharging body 3300 and surround the light source unit 3200 and the member 3350. The light source part 3200 and the member 3350 may be shielded from the outside by the combination of the cover 3100 and the heat discharging body 3300. The coupling between the cover 3100 and the heat discharging body 3300 may be combined through an adhesive, or may be combined by various methods such as a rotational coupling method and a hook coupling method. The rotation coupling method is a method in which the cover 3100 is coupled with the heat discharging body 3300 by the rotation of the cover 3100 in such a manner that the thread of the cover 3100 is engaged with the thread groove of the heat discharging body 3300 In the hook coupling method, the protrusion of the cover 3100 is inserted into the groove of the heat discharging body 3300, and the cover 3100 and the heat discharging body 3300 are coupled.

The cover 3100 is optically coupled to the light source unit 3200. Specifically, the cover 3100 may diffuse, scatter, or excite light from the light emitting device 3230 of the light source unit 3200. The cover 3100 may be a kind of optical member. Here, the cover 3100 may have a phosphor inside / outside or in the inside thereof to excite light from the light source part 3200.

The inner surface of the cover 3100 may be coated with a milky white paint. Here, the milky white paint may include a diffusing agent for diffusing light. The surface roughness of the inner surface of the cover 3100 may be larger than the surface roughness of the outer surface of the cover 3100. This is for sufficiently scattering and diffusing light from the light source part 3200.

The cover 3100 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 3100 may be a transparent material that can be seen from the outside of the light source unit 3200 and the member 3350, and may be an invisible and opaque material. The cover 3100 may be formed, for example, by blow molding.

The light source unit 3200 is disposed on the member 3350 of the heat sink 3300 and may be disposed in a plurality of units. Specifically, the light source portion 3200 may be disposed on at least one of the plurality of side surfaces of the member 3350. The light source unit 3200 may be disposed at the upper end of the member 3350.

In Figure 11, the light source 3200 may be disposed on three of the six sides of the member 3350. However, the present invention is not limited thereto, and the light source portion 3200 may be disposed on all the sides of the member 3350. The light source unit 3200 may include a substrate 3210 and a light emitting device 3230. The light emitting device 3230 may be disposed on one side of the substrate 3210.

The substrate 3210 has a rectangular plate shape, but is not limited thereto and may have various shapes. For example, the substrate 3210 may have a circular or polygonal plate shape. The substrate 3210 may be a printed circuit pattern on an insulator. For example, the substrate 3210 may be a printed circuit board (PCB), a metal core PCB, a flexible PCB, a ceramic PCB . &Lt; / RTI &gt; In addition, a COB (Chips On Board) type that can directly bond an unpackaged LED chip on a printed circuit board can be used.

In addition, the substrate 3210 may be formed of a material that efficiently reflects light, or may be formed of a color whose surface efficiently reflects light, for example, white, silver, or the like. The substrate 3210 may be electrically connected to the circuit unit 3400 housed in the heat discharging body 3300. The substrate 3210 and the circuit portion 3400 may be connected, for example, via a wire. The wire may pass through the heat discharging body 3300 to connect the substrate 3210 and the circuit unit 3400.

The light emitting device 3230 may be a light emitting diode chip that emits red, green, or blue light, or a light emitting diode chip that emits UV light. Here, the light emitting diode chip may be a lateral type or a vertical type, and the light emitting diode chip may emit blue, red, yellow, or green light. .

The light emitting device 3230 may have a phosphor. The phosphor may be at least one of a garnet system (YAG, TAG), a silicate system, a nitride system, and an oxynitride system. Alternatively, the fluorescent material may be at least one of a yellow fluorescent material, a green fluorescent material, and a red fluorescent material.

The heat discharging body 3300 may be coupled to the cover 3100 to dissipate heat from the light source unit 3200. The heat discharging body 3300 has a predetermined volume and includes an upper surface 3310 and a side surface 3330. A member 3350 may be disposed on the upper surface 3310 of the heat discharging body 3300. An upper surface 3310 of the heat discharging body 3300 can be engaged with the cover 3100. The upper surface 3310 of the heat discharging body 3300 may have a shape corresponding to the opening 3110 of the cover 3100.

A plurality of radiating fins 3370 may be disposed on the side surface 3330 of the heat discharging body 3300. The radiating fin 3370 may extend outward from the side surface 3330 of the heat discharging body 3300 or may be connected to the side surface 3330. The heat dissipation fin 3370 may increase the heat dissipation area of the heat dissipator 3300 to improve heat dissipation efficiency. Here, the side surface 3330 may not include the radiating fin 3370.

The member 3350 may be disposed on the upper surface 3310 of the heat discharging body 3300. The member 3350 may be integral with the top surface 3310 or may be coupled to the top surface 3310. The member 3350 may be a polygonal column.

Specifically, the member 3350 may be a hexagonal column. The hexagonal column member 3350 has an upper surface, a lower surface, and six sides. Here, the member 3350 may be a circular column or an elliptic column as well as a polygonal column. When the member 3350 is a circular column or an elliptic column, the substrate 3210 of the light source portion 3200 may be a flexible substrate.

The light source unit 3200 may be disposed on six sides of the member 3350. The light source unit 3200 may be disposed on all six sides and the light source unit 3200 may be disposed on some of the six sides. In Fig. 11, the light source unit 3200 is disposed on three sides of six sides.

The substrate 3210 is disposed on a side surface of the member 3350. The side surface of the member 3350 may be substantially perpendicular to the upper surface 3310 of the heat discharging body 3300. Accordingly, the upper surface 3310 of the substrate 3210 and the heat discharging body 3300 may be substantially perpendicular to each other.

The material of the member 3350 may be a material having thermal conductivity. This is to receive the heat generated from the light source 3200 quickly. The material of the member 3350 may be, for example, aluminum (Al), nickel (Ni), copper (Cu), magnesium (Mg), silver (Ag), tin (Sn) Or the member 3350 may be formed of a thermally conductive plastic having thermal conductivity. Thermally conductive plastics are advantageous in that they are lighter in weight than metals and have unidirectional thermal conductivity.

The circuit unit 3400 receives power from the outside and converts the supplied power to the light source unit 3200. The circuit unit 3400 supplies the converted power to the light source unit 3200. The circuit unit 3400 may be disposed on the heat discharging body 3300. Specifically, the circuit unit 3400 may be housed in the inner case 3500 and stored in the heat discharging body 3300 together with the inner case 3500. The circuit portion 3400 may include a circuit board 3410 and a plurality of components 3430 mounted on the circuit board 3410.

The circuit board 3410 has a circular plate shape, but is not limited thereto and may have various shapes. For example, the circuit board 3410 may be in the shape of an oval or polygonal plate. Such a circuit board 3410 may be one in which a circuit pattern is printed on an insulator. The circuit board 3410 is electrically connected to the substrate 3210 of the light source unit 3200. The electrical connection between the circuit board 3410 and the substrate 3210 may be connected by wire, for example. The wires may be disposed inside the heat discharging body 3300 to connect the circuit board 3410 and the substrate 3210.

The plurality of components 3430 include, for example, a DC converter for converting AC power supplied from an external power source to DC power, a driving chip for controlling the driving of the light source 3200, An electrostatic discharge (ESD) protection device, and the like.

The inner case 3500 houses the circuit portion 3400 therein. The inner case 3500 may have a receiving portion 3510 for receiving the circuit portion 3400. The receiving portion 3510 may have a cylindrical shape as an example. The shape of the accommodating portion 3510 may vary depending on the shape of the heat discharging body 3300. The inner case 3500 can be housed in the heat discharging body 3300. The receiving portion 3510 of the inner case 3500 may be received in a receiving portion formed on the lower surface of the heat discharging body 3300.

The inner case 3500 may be coupled to the socket 3600. The inner case 3500 may have a connection portion 3530 that engages with the socket 3600. The connection portion 3530 may have a threaded structure corresponding to the thread groove structure of the socket 3600. The inner case 3500 is nonconductive. Therefore, electrical short circuit between the circuit portion 3400 and the heat discharging body 3300 is prevented. For example, the inner case 3500 may be formed of plastic or resin.

The socket 3600 may be coupled to the inner case 3500. Specifically, the socket 3600 may be engaged with the connection portion 3530 of the inner case 3500. The socket 3600 may have the same structure as a conventional incandescent bulb. The circuit portion 3400 and the socket 3600 are electrically connected. The electrical connection between the circuit part 3400 and the socket 3600 may be connected via a wire. Accordingly, when external power is applied to the socket 3600, the external power may be transmitted to the circuit unit 3400. The socket 3600 may have a screw groove structure corresponding to the threaded structure of the connection portion 3550.

12 is an exploded perspective view 1200 of a backlight unit according to an embodiment. However, the backlight unit 1200 of FIG. 12 is an example of the illumination system, and the present invention is not limited thereto.

The backlight unit 1200 according to the embodiment includes a light guide plate 1210, a light emitting module unit 1240 for providing light to the light guide plate 1210, a reflection member 1220 below the light guide plate 1210, But the present invention is not limited thereto, and may include a bottom cover 1230 for housing the light emitting module unit 1210, the light emitting module unit 1240, and the reflecting member 1220.

The light guide plate 1210 serves to diffuse light into a surface light source. The light guide plate 1210 may be made of a transparent material such as acrylic resin such as PMMA (polymethyl methacrylate), polyethylene terephthalate (PET), polycarbonate (PC), cycloolefin copolymer (COC), and polyethylene naphthalate Resin. &Lt; / RTI &gt;

The light emitting module part 1240 provides light to at least one side of the light guide plate 1210 and ultimately acts as a light source of a display device in which the backlight unit is installed.

The light emitting module 1240 may be in contact with the light guide plate 1210, but is not limited thereto. Specifically, the light emitting module 1240 includes a substrate 1242 and a plurality of light emitting device packages 200 mounted on the substrate 1242. The substrate 1242 is mounted on the light guide plate 1210, But is not limited to.

The substrate 1242 may be a printed circuit board (PCB) including a circuit pattern (not shown). However, the substrate 1242 may include not only a general PCB, but also a metal core PCB (MCPCB), a flexible PCB (FPCB), and the like.

The plurality of light emitting device packages 200 may be mounted on the substrate 1242 such that a light emitting surface on which the light is emitted is spaced apart from the light guiding plate 1210 by a predetermined distance.

The reflective member 1220 may be formed under the light guide plate 1210. The reflection member 1220 reflects the light incident on the lower surface of the light guide plate 1210 so as to face upward, thereby improving the brightness of the backlight unit. The reflective member 1220 may be formed of, for example, PET, PC, or PVC resin, but is not limited thereto.

The bottom cover 1230 may receive the light guide plate 1210, the light emitting module 1240, and the reflective member 1220. For this purpose, the bottom cover 1230 may be formed in a box shape having an opened upper surface, but the present invention is not limited thereto.

The bottom cover 1230 may be formed of a metal material or a resin material, and may be manufactured using a process such as press molding or extrusion molding.

According to the embodiments, it is possible to provide a light emitting device, a method of manufacturing a light emitting device, a light emitting device package, and an illumination system having an optimal structure capable of improving brightness.

In addition, according to the embodiments, it is possible to provide a light emitting device, an emitting device, a light emitting device package, and an illumination system having an ideal electron blocking layer structure that is excellent in hole injection efficiency and can effectively block leakage of electrons.

The features, structures, effects and the like described in the embodiments 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 the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong. Accordingly, the contents of such combinations and modifications should be construed as being included in the scope of the embodiments.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. It can be seen that the modification and application of branches are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

The first conductive semiconductor layer 112,
A superlattice layer 124 of gallium nitride type,
The active layer 114, the second conductivity type semiconductor layer 116,
A second conductivity type gallium nitride based layer 128,
A second conductive type Al _x Ga _(1-x) N layer (where 0 <x <1) 128a,
The second conductive type In _y Al _z Ga _(1-yz) N superlattice layer (where 0? Y <1, 0? Z <1) 128b,
The second conductive type GaN layer 128c,

Claims (6)

A first conductive semiconductor layer;
An active layer on the first conductive semiconductor layer;
A second conductivity type gallium nitride based layer on the active layer;
And a second conductivity type semiconductor layer on the second conductivity type gallium nitride series layer,
Wherein the second conductivity type gallium nitride based layer comprises
A second conductivity type Al _x Ga _(1-x) N layer on the active layer (where, 0 <x <1);
The second conductivity type Al _x Ga _(1-x) N layer on the second conductive type _{In y Al z Ga (1-} yz) N super lattice layer (where, 0≤y <1, 0≤z <1 ) ; And
And a second conductive type GaN layer on the second conductive type In _y Al _z Ga _(1-yz) N superlattice layer,
Wherein the second conductive type gallium nitride based layer is formed of the second conductive type Al _x Ga _(1-x) N layer, the second conductive type In _y Al _z Ga _(1-yz) N super lattice layer, Type GaN layers are repeatedly layered in one period,
The average energy band gap of the second conductivity type In _y Al _z Ga _(1-yz) N super lattice layer is larger than the average energy band gap size of the second conductivity type Al _x Ga _(1-x) N layer And is larger than the average energy band gap of the second conductive type GaN layer,
The energy band gap decreases in the direction of the second conductivity type GaN layer from the second conductivity type Al _x Ga _(1-x) N layer,
_(1-yz) N super lattice layer of the second conductivity type In _y Al _z Ga _{1 -yz} N is smaller than the planar direction average lattice constant of the second conductivity type Al _x Ga _(1-x) N layer And the second conductivity type GaN layer is larger than a plane direction average lattice constant of the second conductivity type GaN layer. delete delete delete The method according to claim 1,
And a superlattice layer of a gallium nitride series on the first conductive type semiconductor layer. 6. The method of claim 5,
Wherein the second conductive type Al _x Ga _(1-x) N layer is adjacent to the active layer as compared to the second conductive type GaN layer,
Wherein the second conductivity type GaN layer is adjacent to the second conductivity type semiconductor layer as compared to the second conductivity type Al _x Ga _(1-x) N layer.

Images