KR20150083236A - A light emitting device - Google Patents

Abstract

An embodiment of the present invention includes a substrate, a buffer layer arranged on the substrate, dislocation preventing particles arranged on the buffer layer, and a light emitting structure which includes a first conductivity type semiconductor layer which is arranged on the buffer layer, an active layer arranged on the first conductivity type semiconductor layer, and a second conductivity type semiconductor layer arranged on the active layer. The dislocation preventing particles are formed with a single layer on the surface of the buffer layer. The transfer or transmission of dislocations existing on the buffer layer to the light emitting structure can be prevented.

Description

A LIGHT EMITTING DEVICE

An embodiment relates to a light emitting element.

BACKGROUND ART Light emitting devices such as a light emitting diode (LD) or a laser diode using semiconductor materials of Group 3-5 or 2-6 group semiconductors are widely used for various colors such as red, green, blue, and ultraviolet And it is possible to realize white light rays with high efficiency by using fluorescent materials or colors, and it is possible to realize low energy consumption, semi-permanent life time, quick response speed, safety and environment friendliness compared to conventional light sources such as fluorescent lamps and incandescent lamps .

In general, a light emitting diode includes a light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer on a sapphire substrate, a first electrode electrically connected to the first conductive semiconductor layer, And a second electrode electrically connected to the second conductivity type semiconductor layer. The first and second conductivity type semiconductor layers and the second conductivity type semiconductor layer may have a structure in which electrons and holes injected through the first conductivity type semiconductor layer and the second conductivity type semiconductor layer are recombined in the active layer, have.

Since the substrate and the light emitting structure are different materials, a lattice mismatch is large and a difference in thermal expansion coefficient therebetween is large, so that a high density threading dislocation may occur. Such a threading dislocation acts as a non-radiative recombination center or a leakage current path, which may cause a decrease in the efficiency of the light emitting device.

The embodiment provides a light emitting device capable of improving the quality of a light emitting structure.

A light emitting device according to an embodiment includes a substrate; A buffer layer disposed on the substrate; Dislocation inhibiting particles disposed on the buffer layer; And a second conductivity type semiconductor layer disposed on the buffer layer, an active layer disposed on the first conductivity type semiconductor layer, and a second conductivity type semiconductor layer disposed on the active layer, Wherein the dislocation inhibiting particles are formed as a single layer on the surface of the buffer layer and inhibit the dislocations present in the buffer layer from being transferred or propagated to the light emitting structure.

The dislocation inhibiting particles may be selected from the group consisting of silica spheres, TiO ₂ Particles, or metal particles.

The dislocation inhibiting particles may be arranged to expose at least a portion of the buffer layer.

A part of the first conductivity type semiconductor layer may be interposed between the dislocation suppressing particles and a part of the interposed first conductivity type semiconductor layer may contact the buffer layer.

And an undoped semiconductor layer disposed between the buffer layer and the light emitting structure, wherein the dislocation inhibiting particles are disposed on the un-acted semiconductor layer, and at least a part of the un- Can be exposed.

The embodiment can improve the quality of the light emitting structure.

1 is a cross-sectional view of a light emitting device according to an embodiment.
Fig. 2 shows that the dislocation inhibiting particles shown in Fig. 1 block the potential.
3A to 3D show a method of manufacturing a light emitting device according to an embodiment.
Figure 4 shows silica spheres applied by spin coating.
5 shows a light emitting device package according to an embodiment.
6 shows a lighting device including a light emitting device according to an embodiment.
7 shows a display device including a light emitting device package according to an embodiment.
8 shows a head lamp including the light emitting device package according to the embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. In the description of the embodiments, it is to be understood that each layer (film), region, pattern or structure may be referred to as being "on" or "under" a substrate, each layer It is to be understood that the terms " on "and " under" include both " directly "or" indirectly " do. In addition, the criteria for the top / bottom or bottom / bottom of each layer are described with reference to the drawings.

In the drawings, dimensions are exaggerated, omitted, or schematically illustrated for convenience and clarity of illustration. Also, the size of each component does not entirely reflect the actual size. The same reference numerals denote the same elements throughout the description of the drawings. Hereinafter, a light emitting device according to an embodiment will be described with reference to the accompanying drawings.

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

Referring to FIG. 1, a light emitting device 100 includes a substrate 110, a buffer layer 120, an undoped semiconductor layer 125, dislocation suppressing particles 101, a light emitting structure 130, (140), a first electrode (152), and a second electrode (154).

The substrate 110 may be formed of a carrier wafer, a material suitable for semiconductor material growth. Further, the substrate 110 may be formed of a material having excellent thermal conductivity, and may be a conductive substrate or an insulating substrate.

For example, the substrate 110 may be a material comprising at least one of sapphire (Al ₂ O ₃ ), GaN, SiC, ZnO, Si, GaP, InP, Ga ₂ O ₃ , GaAs. (Not shown) may be formed on the upper surface of the substrate 110 to extract light, and may be, for example, patterned sapphire substrate (PSS).

The buffer layer 120 is disposed between the substrate 110 and the light emitting structure 130 and generates a dislocation due to lattice mismatching and a difference in thermal expansion coefficient between the substrate 110 and the light emitting structure 130 Can be suppressed.

The buffer layer 120 may be made of a compound semiconductor of Group 2 to Group 6 elements.

For example, the buffer layer 120 may be formed of any one of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, and AlInN, and may be doped or not doped with a dopant.

The undoped semiconductor layer 125 may be disposed between the buffer layer 120 and the light emitting structure 130 and mitigates the difference in lattice constant between the buffer layer 120 and the light emitting structure 130, It can play a role of improving.

For example, the undoped semiconductor layer 125 may be an undoped GaN layer or an undoped AlGaN layer.

Either or both of the buffer layer 120 and the undoped semiconductor layer 125 may or may not be formed, and the structure is not limited to this structure.

The dislocation inhibiting particles 101 may be disposed on the unshown semiconductor layer 125 and may be disposed on the buffer layer 120 when the unshown semiconductor layer 125 is omitted.

For example, the dislocation inhibiting particles 101 may contact the upper surface of the unshown semiconductor layer 125 and may expose at least a portion of the upper surface of the unshown semiconductor layer 125.

When the unshown semiconductor layer 125 is omitted, the dislocation inhibiting particles 101 may contact the upper surface of the buffer layer 120 and may expose at least a part of the upper surface of the buffer layer 120.

For example, the dislocation inhibiting particles 101 may be a silica sphere, which is a circular particle composed of SiO ₂ , and may be made of a material capable of forming a shpere shape such as TiO ₂ or metal particles .

For example, some dislocation inhibiting particles may contact each other and some dislocation inhibiting particles may be spaced apart from each other. Or the first disposition inhibiting particles contacting with each other may be spaced apart from the second disposition inhibiting particles contacting each other.

The diameter of the dislocation inhibiting particles may be such that the dislocations generated within the light emitting structure 120 can be blocked and the light emitting structure 130 can be grown.

The density of the dislocation inhibiting particles and the distance between the dislocation inhibiting particles are adjustable according to the density of the solution 301 shown in Fig. 3A, and the speed of spin coating.

The light emitting structure 130 may include a first conductive semiconductor layer 132, an active layer 134, and a second conductive semiconductor layer 136.

The first conductivity type semiconductor layer 132 may be disposed on the unshown semiconductor layer 125 and may be disposed on the buffer layer 120 when the unshown semiconductor layer 125 is omitted.

The first conductivity type semiconductor layer 132 may be a compound semiconductor such as a group III-V group, a group II-VI group, or the like. For example, the first conductive semiconductor layer 132 may include any one of InAlGaN, GaN, AlGaN, InGaN, AlN, and InN, and the first conductive type dopant may be doped.

The first conductive type first semiconductor layer 132-1 is a semiconductor semiconductor having a composition formula of In _x Al _y Ga _{1 -xy} N (0? X? 1, 0 <y? 1, 0? X + y? , And an n-type dopant (e.g., Si, Ge, Se, Te) may be doped.

The active layer 134 is disposed on the first conductivity type semiconductor layer 132 and includes electrons and holes provided from the first conductivity type semiconductor layer 132 and the second conductivity type semiconductor layer 136, It is possible to generate light by the energy generated in the recombination process.

The active layer 134 may be a semiconductor compound, for example, a compound semiconductor of Group 3-V-5 or Group 2-VI-6, and may be a single well structure, a multi-well structure, a Quantum-Wire structure, Dot) structure.

The active layer 134 may have a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + y? In the case where the active layer 134 is a quantum well structure, the active layer 132 is formed of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + And a barrier layer (not shown) having a composition formula of In _a Al _b Ga _{1 -a- b} N (0? A? 1, 0? _B ? 1, 0? A + ).

The well layer and the barrier layer may be laminated alternately at least once, and the energy band gap of the well layer may be smaller than the energy band gap of the barrier layer.

The second conductive semiconductor layer 136 may be disposed on the active layer 134 and may be a compound semiconductor such as Group 3-Group 5, Group 2-Group 6, etc., and may be doped with a second conductive type dopant .

The second conductivity type semiconductor layer 136 may be a semiconductor having a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + y? . For example, the second conductivity type semiconductor layer 136 may include any one of InAlGaN, GaN, AlGaN, InGaN, AlN and InN, and a p-type dopant such as Mg, Zn, Ca, Sr, .

The conductive layer 140 may be disposed on the second conductive type semiconductor layer 136.

The conductive layer 140 can smoothly supply current from the second electrode 154 to the second conductive type semiconductor layer 136 and can improve the light extraction efficiency because of its good light transmitting property.

The conductive layer 140 may be formed of a transparent conductive oxide such as indium tin oxide (ITO), tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), indium aluminum zinc oxide Indium Gallium Zinc Oxide), IGTO (Indium Gallium Tin Oxide), AZO (Aluminum Zinc Oxide), ATO (Antimony Tin Oxide), GZO (Gallium Zinc Oxide), IrOx, RuOx, RuOx / ITO, Ni, / Au, or Ni / IrOx / Au / ITO.

The first electrode 152 may be electrically connected to the first conductive semiconductor layer 132.

For example, the light emitting structure 132 may expose a portion of the first conductivity type semiconductor layer 132 and the first electrode 152 may be disposed on a portion of the exposed first conductivity type semiconductor layer 132 And may be in ohmic contact with a part of the exposed first conductivity type semiconductor layer 132.

The second electrode 152 may be electrically connected to the first conductive layer 140. For example, the second electrode 152 may be in contact with the first conductive layer 140.

The first electrode 162 and the second electrode 164 may include at least one of aluminum (Al), titanium (Ti), chrome (Cr), nickel (Ni), copper (Cu) Or a multi-layer structure.

Fig. 2 shows that the dislocation inhibiting particles shown in Fig. 1 block the potential.

Referring to FIG. 2, the buffer layer 120 can suppress the generation of dislocations due to a difference in lattice constant between the substrate 110 and the light emitting structure 130. However, there may be dislocations 201 and 202 generated due to the difference in lattice constant or thermal expansion coefficient between the substrate 110 and the buffer layer 120.

These potentials 201 and 202 are grown together by growing the unshown semiconductor layer 125 and the light emitting structure 120 on the buffer layer 120 to penetrate the unshown semiconductor layer 125 and the light emitting structure 130 Which may be threading dislocations.

However, the dislocation inhibiting particles 101 of the embodiment prevent or prevent the portion 201 of the dislocations existing in the buffer layer 120 and the undoped semiconductor layer 125 from proceeding or transferring to the light emitting structure 130 The density of the threading dislocations present in the structure 130 can be lowered.

Therefore, in the embodiment, the potentials 201 and 202 generated due to the difference in lattice constant or thermal expansion coefficient between the substrate 110 and the buffer layer 120 due to the dislocation inhibiting particles are transferred to or propagated to the light emitting structure 130 And the quality of the light emitting structure 130 can be improved.

Further, in the embodiment, by reducing the threading dislocation density, it is possible to suppress the occurrence of leakage current and to prevent the efficiency from decreasing.

3A to 3D show a manufacturing method of the light emitting device 100 according to the embodiment. The same reference numerals as in Fig. 1 denote the same components, and a description of the same components will be simplified or omitted.

Referring to FIG. 3A, a buffer layer 120 and an undoped semiconductor layer 125 are grown on a substrate 110. In other embodiments, formation of the unshown semiconductor layer 125 may be omitted.

Subsequently, the dislocation inhibiting particles 101 are applied on the unshown semiconductor layer 125 using spin coating. For example, the dislocation inhibiting particles may be silica particles.

For example, a solution 301 containing silica spheres is coated on the surface of the unshown semiconductor layer 125 by spin coating, and a solution (not shown) coated on the surface of the unshown semiconductor layer 125 301 can be evaporated to form silica spheres on the unshown semiconductor layer 125. [

For example, the solution 301 may be water, methanol, or Mono Ethylene Glycol (MEG), but is not limited thereto.

When the unselected semiconductor layer 125 is omitted, the dislocation inhibiting particles 101 may be coated on the buffer layer 120 by spin coating.

Figure 4 shows silica spheres applied by spin coating.

4, the silica spheres may be formed on the surface of the unshown semiconductor layer 125 as a single layer by spin coating, and the silica spheres may expose at least a portion of the surface of the unshown semiconductor layer 125 . The reason why the silica spheres are formed as a single layer is that if the silica spheres are formed into a plurality of layers, the light emitting structure may not be grown.

By the spin coating, the silica spheres may be regularly or irregularly arranged on the surface of the unselected semiconductor layer 125.

Next, referring to FIG. 3B, a first conductive semiconductor layer 132 is formed on the unselected semiconductor layer 125 on which the dislocation inhibiting particles 101 are formed. The dislocation suppressing particles 101 may expose at least a portion of the un-conductive semiconductor layer 125 and may grow the first conductive semiconductor layer 132 on the exposed un-exposed semiconductor layer 125.

Referring to FIG. 3C, an active layer 134 and a second conductive semiconductor layer 136 are formed on the first conductive semiconductor layer 132.

The buffer layer 120, the un-conductive semiconductor layer 125, the first conductive semiconductor layer 132, the active layer 134, and the second conductive semiconductor layer 136 may be formed by metal organic chemical vapor deposition (MOCVD) Chemical Vapor Deposition (CVD), Plasma-Enhanced Chemical Vapor Deposition (PECVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Deposition (HVPE) Phase Epitaxy) or the like.

A part of the first conductivity type semiconductor layer 132 may be interposed or disposed between the dislocation suppressing particles 101 and the first conductivity type semiconductor layer 132 interposed therebetween may be in contact with the un- . The first conductivity type semiconductor layer 132 may be in contact with the buffer layer 120 between the dislocation particles 101 when the undoped semiconductor layer 125 is omitted.

Next, the second conductivity type semiconductor layer 136, the active layer 134, and the first conductivity type semiconductor layer 132 are etched through the etching process to expose a portion of the first conductivity type semiconductor layer 132.

Next, referring to FIG. 3D, a conductive layer 140 is formed on the second conductive semiconductor layer 136.

Next, a first electrode 152 is formed on a part of the first conductive semiconductor layer 132 exposed, and a second electrode 154 is formed on the conductive layer 140.

The embodiment has an advantage of being able to simply form the dislocation inhibiting particles 101 using spin coating and by controlling the spin speed of the spin coating, the coating time, and the density of the dislocation inhibiting particles contained in the solution, The distance and density of the inhibiting particles can be easily controlled.

5 shows a light emitting device package according to an embodiment.

5, the light emitting device package includes a package body 510, a first conductive layer 512, a second conductive layer 514, a light emitting device 520, a reflector 530, a wire 530, And a stratum 540.

The package body 510 may be formed of a substrate having good insulating or thermal conductivity, such as a silicon based wafer level package, a silicon substrate, silicon carbide (SiC), aluminum nitride (AlN) Or may be a structure in which a plurality of substrates are stacked. The embodiments are not limited to the material, structure, and shape of the body described above.

The package body 510 may have a cavity formed of a side surface and a bottom surface on one side of the upper surface. At this time, the side wall of the cavity may be formed to be inclined.

The first conductive layer 512 and the second conductive layer 514 are disposed on the surface of the package body 510 so as to be electrically separated from each other in consideration of heat discharge or mounting of the light emitting device. The light emitting device 520 may be electrically connected to the first conductive layer 512 and the second conductive layer 514. Here, the light emitting device 520 may be the embodiment shown in FIG.

The reflection plate 530 may be disposed on the cavity side wall of the package body 510 to direct light emitted from the light emitting element 520 in a predetermined direction. The reflection plate 530 is made of a light reflection material, and may be, for example, a metal coating or a metal flake.

The resin layer 540 surrounds the light emitting element 520 located in the cavity of the package body 510 to protect the light emitting element 520 from the external environment. The resin layer 540 may be made of a colorless transparent polymer resin material such as epoxy or silicone. The resin layer 540 may include a phosphor to change the wavelength of light emitted from the light emitting device 520.

A plurality of light emitting device packages according to the embodiments may be arrayed on a substrate, and a light guide plate, a prism sheet, a diffusion sheet, and the like may be disposed on the light path of the light emitting device package. The light emitting device package, the substrate, and the optical member may function as a backlight unit.

Still another embodiment may be implemented as a display device, an indicating device, and a lighting system including the light emitting device or the light emitting device package described in the above embodiments. For example, the lighting system may include a lamp and a streetlight.

6 shows a lighting device including a light emitting device according to an embodiment.

6, the illumination device 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.

The light source module 1200 may include the light emitting device 100 shown in FIG. 1 or the light emitting device package shown in FIG.

The cover 1100 may be in the form of a bulb or a hemisphere, and may be hollow in shape and partially open. The cover 1100 may be optically coupled to the light source module 1200. For example, the cover 1100 may 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 can 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 because light from the light source module 1200 is sufficiently scattered and diffused to be emitted 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, but it is not limited thereto 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 and the heat generated from the light source module 1200 may be conducted to the heat discharger 1400. The light source module 1200 may include a light source 1210, a connection plate 1230, and a connector 1250.

The member 1300 may be disposed on the upper surface of the heat discharging body 1400 and has a guide groove 1310 into which the plurality of light source portions 1210 and the connector 1250 are inserted. The guide groove 1310 may correspond to or align with the substrate and connector 1250 of the light source 1210.

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 may be reflected by the inner surface of the cover 1100 and may reflect the light returning toward the light source module 1200 toward the cover 1100 again. 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 formed of an insulating material so as to prevent an electrical short circuit between the connection plate 1230 and the heat discharger 1400. The heat dissipation member 1400 can dissipate heat by receiving heat from the light source module 1200 and heat from the power supply unit 1600.

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 can be hermetically sealed. The holder 1500 may have a guide protrusion 1510 and the guide protrusion 1510 may have a hole through which the protrusion 1610 of the power supply unit 1600 penetrates.

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

The guide portion 1630 may have a shape protruding outward from one side of the base 1650. The guide portion 1630 can be inserted into the holder 1500. A plurality of components can 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 into a DC power source, a driving chip for controlling driving of the light source module 1200, an ESD (ElectroStatic discharge protection device, but are not limited thereto.

The extension 1670 may have a shape protruding outward from the other side of the base 1650. The extension portion 1670 can be inserted into the connection portion 1750 of the inner case 1700 and can receive an external electrical signal. For example, the extension portion 1670 may be equal to or less than the width of the connection portion 1750 of the inner case 1700. Each of the "+ wire" and the "wire" may be electrically connected to the extension portion 1670 and the other end of the "wire" and the "wire" may be electrically connected to the socket 1800 .

The inner case 1700 may include a molding part together with the power supply part 1600 therein. The molding part is a part where the molding liquid is hardened, so that the power supply providing part 1600 can be fixed inside the inner case 1700.

7 shows a display device including a light emitting device package according to an embodiment.

7, the display device 800 includes a bottom cover 810, a reflection plate 820 disposed on the bottom cover 810, light emitting modules 830 and 835 for emitting light, a reflection plate 820 An optical sheet including a light guide plate 840 disposed in front of the light emitting modules 830 and 835 and guiding light emitted from the light emitting modules 830 and 835 to the front of the display device and prism sheets 850 and 860 disposed in front of the light guide plate 840, An image signal output circuit 872 connected to the display panel 870 and supplying an image signal to the display panel 870; a display panel 870 disposed in front of the display panel 870; Gt; 880 &lt; / RTI &gt; Here, the bottom cover 810, the reflection plate 820, the light emitting modules 830 and 835, the light guide plate 840, and the optical sheet may form a backlight unit.

The light emitting module may include light emitting device packages 835 mounted on the substrate 830. The substrate 830 may be a PCB or the like. The light emitting device package 835 may be the embodiment shown in FIG. 5 including the light emitting device 100 shown in FIG.

The bottom cover 810 can house components within the display device 800. [ Also, the reflection plate 820 may be formed as a separate component as shown in the drawing, or may be provided on the rear surface of the light guide plate 840 or on the front surface of the bottom cover 810 in a state of being coated with a highly reflective material .

Here, the reflection plate 820 can be made of a material having a high reflectance and can be used in an ultra-thin shape, and polyethylene terephthalate (PET) can be used.

The light guide plate 830 may be formed of polymethyl methacrylate (PMMA), polycarbonate (PC), or polyethylene (PE).

The first prism sheet 850 may be formed of a light-transmissive and elastic polymeric material on one side of the support film, and the polymer may have a prism layer in which a plurality of three-dimensional structures are repeatedly formed. Here, as shown in the drawings, the plurality of patterns may be provided with a floor and a valley repeatedly as stripes.

In the second prism sheet 860, the direction of the floor and the valley on one side of the supporting film may be perpendicular to the direction of the floor and the valley on one side of the supporting film in the first prism sheet 850. This is for evenly distributing the light transmitted from the light emitting module and the reflective sheet to the front surface of the display panel 1870.

Although not shown, a diffusion sheet may be disposed between the light guide plate 840 and the first prism sheet 850. The diffusion sheet may be made of polyester and polycarbonate-based materials, and the light incidence angle can be maximized by refracting and scattering light incident from the backlight unit. The diffusion sheet includes a support layer including a light diffusing agent, a first layer formed on the light exit surface (first prism sheet direction) and a light incidence surface (in the direction of the reflection sheet) . &Lt; / RTI &gt;

In an embodiment, the diffusion sheet, the first prism sheet 850, and the second prism sheet 860 make up an optical sheet, which may be made of other combinations, for example a microlens array, A combination of one prism sheet and a microlens array, or the like.

The display panel 870 may include a liquid crystal display (LCD) panel, and may include other types of display devices that require a light source in addition to the liquid crystal display panel 860.

8 shows a head lamp 900 including the light emitting device package according to the embodiment. 8, the head lamp 900 includes a light emitting module 901, a reflector 902, a shade 903, and a lens 904.

The light emitting module 901 may include a plurality of light emitting device packages (not shown) disposed on a substrate (not shown). Here, the light emitting device package may be the embodiment shown in FIG. 5 including the light emitting device 100 shown in FIG.

The reflector 902 reflects the light 911 emitted from the light emitting module 901 in a predetermined direction, for example, toward the front 912.

The shade 903 is disposed between the reflector 902 and the lens 904 and reflects off or reflects a part of the light reflected by the reflector 902 toward the lens 904 to form a light distribution pattern desired by the designer. The one side portion 903-1 and the other side portion 903-2 of the shade 903 may have different heights from each other.

The light emitted from the light emitting module 901 can be reflected by the reflector 902 and the shade 903 and then transmitted through the lens 904 and directed toward the front of the vehicle body. The lens 904 can refract the light reflected by the reflector 902 forward.

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

101: Dislocation inhibiting particles 110:
120: buffer layer 125: unselected semiconductor layer
130: light emitting structure 132: first conductivity type semiconductor layer
134: active layer 136: second conductivity type semiconductor layer
140: conductive layer 152: first electrode
154: second electrode.

Claims (5)

Board;
A buffer layer disposed on the substrate;
Dislocation inhibiting particles disposed on the buffer layer; And
A light emitting structure including a first conductive semiconductor layer disposed on the buffer layer, a first conductive semiconductor layer disposed on the buffer layer, an active layer disposed on the first conductive semiconductor layer, and a second conductive semiconductor layer disposed on the active layer, / RTI &gt;
The dislocation-
Wherein the buffer layer is formed as a single layer on the surface of the buffer layer and inhibits transmission or progression of dislocations present in the buffer layer to the light emitting structure. The method according to claim 1, wherein the dislocation-
Silica spheres, TiO ₂ Particles, or metal particles. The method according to claim 1,
Wherein the dislocation inhibiting particles are arranged to expose at least a part of the buffer layer. The method according to claim 1,
Wherein a part of the first conductivity type semiconductor layer is interposed between the dislocation inhibiting particles and a part of the interposed first conductivity type semiconductor layer is in contact with the buffer layer. The method according to claim 1,
And an undoped semiconductor layer disposed between the buffer layer and the light emitting structure,
Wherein the dislocation inhibiting particles are disposed on the unshown semiconductor layer and expose at least a part of the unshifted semiconductor layer.

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