KR20160041563A - A light emitting device package - Google Patents

Abstract

According to an embodiment of the present invention, a light emitting device comprises: a first conductive semiconductor layer; an active layer arranged on the first conductive semiconductor layer; a second conductive semiconductor layer arranged on the active layer; and an electron blocking layer arranged between the active layer and the second conductive semiconductor layer. The electron blocking layer includes a first layer and a second layer arranged to be alternated at least once. The first layer is a nitride semiconductor layer including indium, and the second layer is a nitride semiconductor layer including aluminum. P-type dopants are doped on the first layer. The light emitting device of the present invention can improve luminous efficiency and can reduce operating voltage while improving quality of the layers.

Description

A LIGHT EMITTING DEVICE PACKAGE

An embodiment relates to a light emitting element.

Light emitting diodes (LEDs) using semiconductor materials of Group 3-5 or Group 2-6 compound semiconductors can realize various colors such as red, green, blue, and ultraviolet rays through the development of thin film growth technology and device materials, By using fluorescent materials or combining colors, it is possible to realize white light with high efficiency, and it has advantages of low power consumption, semi-permanent lifetime, fast response speed, safety, and environment friendliness compared to conventional light sources such as fluorescent lamps and incandescent lamps. For the structure of such a light-emitting device, reference may be made to US Pat.

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.

Embodiments provide a light emitting device capable of improving light efficiency, lowering an operating voltage, and improving film quality.

A light emitting device according to an embodiment includes a first conductive semiconductor layer; An active layer disposed on the first conductive semiconductor layer; A second conductive semiconductor layer disposed on the active layer; And an electron blocking layer disposed between the active layer and the second conductive type semiconductor layer, wherein the electron blocking layer includes a first layer and a second layer alternately disposed one or more times, The second layer is a nitride semiconductor layer containing aluminum, and the first layer is doped with a p-type dopant.

Wherein the first layer has a composition formula of _{In x Al y Ga 1 -x- y} N (0 <x≤1, 0≤y <1, 0 <x + y <1), the second layer is Al _z Ga _{1 - z} N (0 < z < 1).

The content of indium contained in the first layer may be 1% to 2%.

The content of aluminum contained in the second layer may be 17% to 20%.

The electron blocking layer may include a plurality of first layers and a plurality of second layers, and the farther away from the active layer, the thinner the first layers may be.

The thickness of each of the second layers may be equal to each other.

The first and second layers may be superlattice structures.

The energy band gap of the second layers may be greater than the energy band gap of the first layers.

The p-type dopant may be Mg, Zn, Ca, Sr, or Ba.

The electron blocking layer comprises nine pairs of first and second layers, wherein each of the first layers included in the first through third pairs has a thickness of 3 nm, and the first layers included in the fourth through sixth pairs Each thickness is 2 nm, and the thickness of each of the first layers included in the seventh to ninth phases may be 1 nm.

Embodiments can improve light efficiency, lower operating voltage, and improve film quality.

1 is a cross-sectional view of a light emitting device according to an embodiment.
Fig. 2 shows an embodiment of the electron blocking layer shown in Fig.
FIG. 3 shows the energy band gap of the light emitting structure shown in FIGS. 1 and 2. FIG.
4 is a graph illustrating an improvement in the operating voltage of the light emitting device according to the embodiment.
5 is a cross-sectional view of a light emitting device according to another embodiment.
6 shows a light emitting device package according to an embodiment.
7 shows the operating voltage and resistance according to the applied current of the light emitting device according to the embodiment.
8 shows a lighting device including a light emitting device package according to an embodiment.
9 shows a display device including a light emitting device package according to an 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.

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 light emitting structure 120, a conductive layer 130, a first electrode 142, and a second electrode 144.

The substrate 110 supports the light emitting structure 120.

The substrate 110 may be formed of a material suitable for semiconductor 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, substrate 110 is a sapphire substrate, a silicon (Si) substrate, a zinc oxide (ZnO) substrate, and any one of the nitride semiconductor substrate, oxide, or GaN, InGaN, AlGaN, AlInGaN, GaP, InP, Ga ₂ 0 _3, GaAs may be laminated on the substrate.

The light emitting structure 120 is disposed on the substrate 110, and generates light. The light emitting structure 120 may include a first conductive semiconductor layer 122, an active layer 124, an electron blocking layer 125, and a second conductive semiconductor layer 126. The light emitting structure 120 includes a first conductive semiconductor layer 122, an active layer 124, an electron blocking layer 125, and a second conductive semiconductor layer 126 sequentially formed on the substrate 110 As shown in FIG.

In order to alleviate the lattice mismatch due to the difference in lattice constant and thermal expansion coefficient between the substrate 110 and the light emitting structure 120 and to improve the crystal quality of the light emitting structure, the first conductivity type semiconductor layer 122 and the substrate 110 A buffer layer (not shown) may be disposed.

The buffer layer may be a nitride semiconductor including Group 3 elements and Group 5 elements.

For example, the buffer layer may include at least one of InAlGaN, GaN, AlN, AlGaN, and InGaN. The buffer layer may be a single layer or a multi-layer structure, and a Group 2 element or a Group 4 element may be doped with an impurity.

In order to improve crystallinity of the first conductivity type semiconductor layer 122, an unshown semiconductor layer (not shown) may be disposed between the buffer layer and the first conductivity type semiconductor layer 122. The un-doped semiconductor layer may be the same as the first conductive type semiconductor layer 122 except that the n-type dopant is not doped and has a lower electrical conductivity than the first conductive type semiconductor layer 122.

The light emitting structure 120 may have a groove exposing a portion of the first conductivity type semiconductor layer 122 in order to arrange the first electrode 142.

The conductive layer 130 is disposed on the light emitting structure. For example, the conductive layer 130 may be disposed on the second conductive type semiconductor layer, and may not only reduce the total internal reflection, Can be increased.

The conductive layer 130 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. Although not shown, the conductive layer 130 may have a concavo-convex structure on its upper surface to improve light extraction efficiency.

The first electrode 142 is disposed on the exposed first conductivity type semiconductor layer 122 and contacts the first conductivity type semiconductor layer 122. The second electrode 144 is disposed on the conductive layer 130 and contacts the conductive layer 130.

The first conductive semiconductor layer 122 may be disposed on the substrate 110, and may be a compound semiconductor such as a group III-V, a group II-VI, or the like, and the first conductive type dopant may be doped .

For example, the first conductivity type semiconductor layer 122 may be a semiconductor having a composition formula of In _x Al _y Ga _(1-xy) N (0? X? 1, 0? _Y? 1, 0? _X + For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN or the like, and an n-type dopant such as Si, Ge, Sn, Se or Te can be doped.

The active layer 124 may be disposed between the first conductive semiconductor layer 122 and the second conductive semiconductor layer 126.

The active layer 124 is formed by the energy generated in the recombination process of electrons and holes provided from the first conductivity type semiconductor layer 122 and the second conductivity type semiconductor layer 1124, Can be generated.

The active layer 124 may be a semiconductor compound of Group 3-V-5, Group 2-VI, and the like, for example, a group III-V group, a group II-VI-VI compound semiconductor. The active layer 124 may be a semiconductor having a composition formula of In _x Al _y Ga _{1 -xy} N (0 <x? 1, 0? _Y <1, 0? _X + y? 1) But is not limited to, a multi-quantum well structure including a quantum well layer and a quantum barrier layer alternately disposed. In other embodiments, the active layer 124 may have a single well structure, a Quantum-Wire structure, a Quantum Dot, or a Quantum Disk structure.

The energy band gap of the quantum barrier layer may be greater than the energy band gap of the quantum well layer.

The second conductive semiconductor layer 126 may be disposed on the active layer 124 and may be a compound semiconductor such as a Group 3-Group 5, Group 2, or Group 6, and may have a polarity opposite to that of the first conductive type A second conductivity type dopant may be doped.

The second conductivity type semiconductor layer 126 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? 1) For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN and the like, and a p-type dopant such as Mg, Zn, Ca, Sr and Ba may be doped.

The electron blocking layer 125 is disposed between the active layer 124 and the second conductivity type semiconductor layer 126. When electrons injected from the first conductivity type semiconductor layer 122 to the active layer 124 are emitted from the second conductivity type semiconductor layer 126, Thereby blocking overflow to layer 126.

The electron blocking layer 125 may include a first layer (a1 to an, n> 1) and a second layer (b1 to bn, n> 1) arranged alternately one or more times.

The first layer (a1 through an, n> 1 is a natural number) may be a nitride semiconductor layer containing indium, and the second layer (b1 to bn, n> 1 is a natural number) may be a nitride semiconductor layer containing aluminum.

The first layer (a1 to an n, a natural number of 1) has a composition formula of In _x Al _y Ga _{1 -x- y} N (0 <x? 1, 0? Y <1, 0 <x + y < And a p-type dopant such as Mg, Zn, Ca, Sr, Ba or the like may be doped in the second conductive type dopant.

The second layer (a natural number of b1 to bn, n> 1) may have a composition formula of Al _z Ga _{1 - z} N (0 <z <1).

The thickness of the electron blocking layer 125 may be 30 nm to 50 nm.

When the thickness of the electron blocking layer 125 is less than 30 nm, the electrons injected from the active layer 124 can not be prevented from overflowing. When the thickness of the electron blocking layer 125 is larger than 50 nm, The hole injection efficiency of the hole injection layer is lowered and the light efficiency can be reduced.

FIG. 2 shows an embodiment of the electron blocking layer 125 shown in FIG.

Referring to Fig. 2, the electron blocking layer 125 may include first layers a1 to a9 and second layers b1 to b9 arranged alternately nine times.

For example, the electron blocking layer 125 may comprise nine pairs, and each pair may comprise a first layer and a second layer.

Each of the first layers al to a9 may have an InGaN composition and may be doped with a p-type dopant Mg. Each of the second layers b1 to b9 may have an AlGaN composition.

The content of indium (In) in each of the first layers (a1 to a9) may be 1% to 2%.

Since indium is highly volatile, when the indium content is less than 1%, indium may be completely volatilized when the electron blocking layer 125 is formed. If the indium content is more than 2%, the energy bandgap of the electron blocking layer 125 may be lowered, so that it may be difficult to perform the electron blocking function, and the film quality of the electron blocking layer and the second conductivity type semiconductor layer may deteriorate .

The content of aluminum (Al) in the second layers b1 to b9 may be between 17% and 20%

When the aluminum content of the second layers b1 to b9 is less than 17%, the energy bandgap becomes small and can not serve as the electron blocking layer, and the aluminum content of the second layers b1 to b9 is larger than 20% The efficiency of hole injection into the active layer 124 may be lowered and the luminous intensity may be lowered.

The thickness of the first layers a1 to a9 may be thinner as they are located farther from the active layer 124. [ That is, the thickness of the first layers a1 to a9 may decrease as the active layer 124 proceeds from the active layer 124 to the second conductive semiconductor layer 126.

The thickness d1 of each of the first layers a1, a2 and a3 included in the first to third pairs may be 3 nm and the thicknesses d1 of the first layers a4 and a5 included in the fourth to sixth pairs , a6) may be 2 nm and the thickness d3 of each of the first layers a7, a8 and a9 included in the 7th to 9th pairs may be 1 nm.

The first through third pairs may be three pairs closest to the active layer 124 and the seventh through ninth pairs may be three pairs closest to the second conductive semiconductor layer 126. The fourth through sixth pairs may be located between the first through third pairs and the seventh through ninth pairs.

The thickness of each of the second layers b1 to b9 may be the same. For example, the thickness of each of the second layers b1 to b9 may be 2 nm.

The reason why the thicknesses of the first layers a1 to a9 are reduced as they are located farther from the active layer 124 and closer to the second conductivity type semiconductor layer 126 is to improve hole injection efficiency into the active layer 124, and to prevent the quality from deteriorating. The higher the indium content, the lower the film quality.

FIG. 3 shows the energy bandgap of the light emitting structure 120 shown in FIGS. 1 and 2.

Referring to FIG. 3, the energy band gap E2 of the barrier layer QB of the active layer 124 is greater than the energy band gap E1 of the well layer QW (E2> E1)).

The energy band gap E3 of the first layers a1 to a9 and the energy band gap E4 of the second layers b1 to b9 of the electron blocking layer 125 are the same as the energy band gap E2 of the barrier layer QB of the active layer 124 Is greater than the energy band gap E2 (E3, E4 > E2).

The energy band gap E4 of the second layers b1 to b9 of the electron blocking layer 125 is larger than the energy band gap E3 of the first layers a1 to a9 (E4 > E3).

The energy band gaps of the first layers a1 to a9 may be equal to each other and the energy band gaps of the second layers b1 to b9 may be equal to each other.

In general, since the mobility of holes is slower than the mobility of electrons, the efficiency of injecting holes into the active layer is lowered and the brightness may be lowered. Mg may be implanted into the electron blocking layer to improve the injection efficiency of holes. However, as the concentration of Mg increases, Mg is mixed between the electron blocking layer and the second conductivity type semiconductor layer, The film quality of the layer may be deteriorated, and as a result, the light absorptivity may be increased and the light intensity may be lowered.

The activation energy is lowered by Mg added to the first layers (a1 to a9) containing indium, so that the hole concentration and hole mobility can be increased, The embodiment can improve the light amount.

In addition, since the resistance of the electron blocking layer 125 is decreased in the embodiment, the hole injection efficiency can be increased, thereby lowering the operating voltage.

In addition, the embodiment can improve the crystallinity of the second conductivity type semiconductor layer 126 and improve current dispersion.

As described above, the thickness of the first layers a1 to a9 is reduced by the distance from the active layer 124 to the second conductivity type semiconductor layer 126, so that the film quality of the second conductivity type semiconductor layer 126 Can be improved.

In addition, since the electron blocking layer 125 has a superlattice structure in which a first layer having an InGaN composition and a second layer having an AlGaN composition are alternately arranged, the strain may be reduced, The film quality of the layer 126 can be improved.

In addition, the current dispersion can be improved by different interfaces of InGaN / AlGaN, so that the embodiments can be improved in light efficiency.

7 shows the operating voltage and resistance according to the applied currents VF1, VF2 and VF3 of the light emitting device 100 according to the embodiment. Case 1 represents the operating voltage and resistance for the light emitting device including the bulk barrier structure and Case 2 represents the operating voltage and resistance for the light emitting device 100 including the barrier layer 125 according to the embodiment. Operating voltage, and resistance.

7, when the current to be applied to the light emitting device 100 is 2 microamperes, the voltage VF1 applied to the light emitting device of case 1 may be 2.29 [V] May be 2.27 [V].

The voltage VF2 applied to the light emitting device of case 1 may be 2.43 V when the current to be applied to the light emitting device 100 is 10 microamperes and may be applied to the light emitting device 100 of case 2 The voltage VF2 may be 2.41 [V].

Finally, when the current applied to the light emitting device 100 is 20 milliamperes, the voltage VF3 applied to the light emitting device of case 1 may be 3.17 [V], and the voltage VF3 applied to the light emitting device 100 of case 2 may be The applied voltage VF1 may be 3.11 [V]. VF3 of case 1 and case 2 may be the operating voltage of the light emitting devices.

The difference between the voltages (for example, VF1 and VF2) applied to the light emitting elements of the case 1 and the case 2 in the low current region (for example, 2 or 10 microamperes) is 0.02 [V] The difference between the operating voltages (VF3) of case 1 and case 2 can be 0.06 [V] for micro amperes.

Also, it can be seen that the resistance of case 2 is lower than that of case 1, and the operating voltage of case 2 is lower than that of case 1. Thus, the embodiment can lower the operating voltage.

4 is a graph illustrating an improvement in the operating voltage of the light emitting device 100 according to the embodiment.

g1 represents an operating voltage for a light emitting device including a bulk structure electron blocking layer having a thickness of 30 nm, and g2 represents an operating voltage for the embodiment.

Referring to FIG. 4, it can be seen that the operation voltage of g2 is lower than the operation voltage of g1. As the current density increases, the difference between the operation voltage of g1 and the operation voltage of g2 increases.

5 is a cross-sectional view of a light emitting device 200 according to another 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. 5, the light emitting device 200 includes a second electrode 405, a passivation layer 430, a light emitting structure 120, a passivation layer 440, and a first electrode 450.

The second electrode 405 together with the first electrode 450 provides power to the light emitting structure 120. The second electrode 405 may include a support substrate 422, a bonding layer 424, a barrier layer 426, a reflective layer 428, and an ohmic layer 429.

The support substrate 422 supports the light emitting structure 120 and may be formed of a conductive material. For example, the supporting substrate 422 may be made of a material selected from the group consisting of copper (Cu), gold (Au), nickel (Ni), molybdenum (Mo), copper-tungsten GaAs, ZnO, SiC).

The barrier layer 426 is disposed on the support substrate 422 and blocks the metal ions of the support substrate 422 from diffusing into the reflective layer 428 and the ohmic layer 429. For example, the barrier layer 426 comprises at least one of Ni, Pt, Ti, W, V, Fe, Mo and may be a single layer or multilayer.

The bonding layer 424 is disposed between the supporting substrate 422 and the barrier layer 426.

The bonding layer 424 serves as a bonding layer so that the reflective layer 428 and the ohmic layer 429 can be bonded to the supporting substrate 422. The bonding layer 424 may include at least one of a bonding metal, for example, Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag or Ta.

A reflective layer 428 is disposed on the barrier layer 426.

The reflective layer 428 reflects light incident from the light emitting structure 120, thereby improving light extraction efficiency. The reflective layer 428 may be formed of a metal or an alloy including at least one of a reflective material, for example, Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au and Hf. The reflective layer 428 may be formed of a metal or an alloy and a transparent conductive material such as IZO, IZTO, IAZO, IGZO, IGTO, AZO, or ATO. For example, the reflective layer 428 may be formed of IZO / Ni, AZO / Ag, IZO / Ag / Ni, AZO / Ag / Ni,

The ohmic layer 429 is disposed on the reflective layer 428. The ohmic layer 429 is in ohmic contact with the second conductive semiconductor layer 126 of the light emitting structure 120 to supply power to the light emitting structure 120 smoothly. The ohmic layer 429 may selectively use a light-transmitting conductive layer and a metal. For example, the ohmic layer 429 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 tin oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IrO _x , RuO _x , RuO _x / ITO, Ni, Ag, Ni / IrO _x / IrO _x / Au / ITO.

The protective layer 430 is disposed on the second electrode 405. The protective layer 430 can reduce the phenomenon that the interface between the light emitting structure 120 and the barrier layer 426 is peeled off and the reliability of the light emitting device 200 is deteriorated. The protective layer 430 may be a conductive material or a nonconductive material. For example, the conductive protective layer may be formed of a transparent conductive oxide film or may include at least one of a metal material such as Ti, Ni, Pt, Pd, Rh, Ir, The nonconductive protective layer may also be formed of a material having a lower electrical conductivity than the reflective layer 428 or the ohmic layer 429, a material forming a Schottky contact with the second conductive semiconductor layer 126, or an electrically insulating material have. For example, non-conductive protective layer may be formed of ZnO or SiO _2.

The light emitting structure 120 is disposed on the second electrode 405.

The light emitting structure 120 includes a second conductive semiconductor layer 126, an electron blocking layer 125, an active layer 124, and a first conductive semiconductor layer 122 sequentially stacked on a second electrode 405 . The light emitting structure 120 may be the same as that described in FIG. 1, and a description thereof will be omitted in order to avoid redundancy.

The passivation layer 440 may be formed on the side of the light emitting structure 120 to electrically protect the light emitting structure 120, but the present invention is not limited thereto. The passivation layer 440 is an insulating material, e.g., SiO _2, SiO _x, SiO _x N _y, Si ₃ N ₄ , Al ₂ O ₃ . A roughness (not shown) may be formed on the upper surface of the first conductive semiconductor layer 122 to increase light extraction efficiency. The first electrode 450 is disposed on the upper surface of the light emitting structure 120.

As described above, the embodiment shown in FIG. 5 can prevent the quality of the light emitting structure 120 from being deteriorated by the electron blocking layer 125, improve the luminous efficiency, and lower the operating voltage.

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

Referring to FIG. 6, 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, wires 522 and 524, And a resin layer 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 package body 510 may have a cavity formed of side and bottom in one side region, but is not limited thereto. The side surface of the cavity may be formed obliquely. The embodiments are not limited to the material, structure, and shape of the body described above.

The first conductive layer 512 and the second conductive layer 514 may be disposed on the surface of the package body 510 such that the first conductive layer 512 and the second conductive layer 514 are electrically separated from each other in consideration of heat dissipation or mounting of the light emitting device 520.

The light emitting device 520 is electrically connected to the first conductive layer 512 and the second conductive layer 514. The light emitting device 520 may be any one of the embodiments 100 and 200.

The reflection plate 530 may be formed on a side surface of the cavity of the package body 510 to direct light emitted from the light emitting device 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.

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

8, the lighting apparatus 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 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 light source portion 1210 may include the light emitting device package shown in FIG.

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.

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

9, 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 described above with reference to 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.

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.

110: substrate 120: light emitting structure
122: first conductivity type semiconductor layer 124: active layer
125: electron blocking layer 126: second conductivity type semiconductor layer
130: conductive layer 142: first electrode
144: second electrode a1 to a9: first layers
b1 to b9: second layers.

Claims (10)

A first conductive semiconductor layer;
An active layer disposed on the first conductive semiconductor layer;
A second conductive semiconductor layer disposed on the active layer; And
And an electron blocking layer disposed between the active layer and the second conductive semiconductor layer,
Wherein the electron blocking layer
A first layer and a second layer alternately disposed one or more times,
Wherein the first layer is a nitride semiconductor layer containing indium, the second layer is a nitride semiconductor layer containing aluminum, and the first layer is doped with a p-type dopant. The method according to claim 1,
The first layer has a composition formula of In _x Al _y Ga _{1 -x- y} N (0 <x? 1, 0? Y <1, 0 <x + y <
And the second layer has a composition formula of Al _z Ga _{1 - z} N (0 <z <1). 3. The method of claim 2,
Wherein a content of indium contained in the first layer is 1% to 2%. 3. The method of claim 2,
And the content of aluminum contained in the second layer is 17% to 20%. The method according to claim 1,
Wherein the electron blocking layer comprises a plurality of first layers and a plurality of second layers,
Wherein a thickness of the first layers is thinner in a farther position from the active layer. 6. The method of claim 5,
And each of the second layers has the same thickness. 6. The method of claim 5,
Wherein the first layers and the second layers are superlattice structures. 6. The method of claim 5,
Wherein an energy band gap of the second layers is larger than an energy band gap of the first layers. The method according to claim 1,
Wherein the p-type dopant is Mg, Zn, Ca, Sr, or Ba. The method according to claim 1,
Wherein the electron blocking layer comprises nine pairs of first and second layers,
The thickness of each of the first layers included in the first to third pairs is 3 nm,
The thickness of each of the first layers included in the fourth to sixth pairs is 2 nm,
And each of the first layers included in the seventh to ninth phases has a thickness of 1 nm.

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