KR101805192B1 - 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.
A light emitting device according to an embodiment includes a first conductive semiconductor layer; An active layer formed on the first conductivity type semiconductor layer including a quantum well and a quantum wall; An electron blocking layer on the active layer; And a second conductivity type semiconductor layer on the electron blocking layer, wherein the electron blocking layer comprises a first group blocking layer having a first energy band gap equal to or greater than an energy band gap of the quantum wall, Blocking layer; And a third electron blocking layer having a third energy band gap greater than or equal to the first energy band gap.

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 is a device in which electric energy is converted into light energy. For example, LEDs can be implemented in various colors by controlling the composition ratio of compound semiconductors.

The nitride semiconductor thin film-based light emitting device 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. Accordingly, 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 diode lighting device capable of replacing a fluorescent lamp or an incandescent lamp, And traffic lights.

The expansion of the application range of the nitride semiconductor light emitting device basically requires the development of high output and high efficiency technology of the light emitting device.

In the nitride semiconductor light emitting device having a multi-quantum well structure active layer according to the related art, all of the quantum well layers in the active layer are not uniformly dispersed and accommodated in the carriers, and only a small number of quantum well layers adjacent to the hole injection layer There is a problem that it mainly contributes to light emission. Therefore, when the injection current amount is sufficiently large, surplus electrons which are not effectively trapped in the active layer are generated.

These surplus electrons do not participate in generating light and disappear themselves in the active layer or leak out of the active layer.

Leakage to the outside of the active layer occurs mainly in the form of a quantum barrier overflow of injected carriers.

In addition, since the electrons injected into the active layer in the conventional nitride semiconductor light emitting device have a hot carrier property, there is a serious carrier overflow problem.

As a result, as the injected current increases, the non-emission loss of electrons and holes increases, and the emission efficiency of the active layer, for example, the internal quantum efficiency, is seriously reduced.

Thus, according to the prior art, an electron blocking layer is formed between the P-GaN layer and the active layer. The electron blocking layer is sufficiently larger in energy band gap than the quantum wall of the active layer so that electrons supplied from the N-GaN layer do not pass through the active layer but fall into the P-GaN layer without participating in light emission.

On the other hand, according to the prior art, when the electron blocking layer is thick, it acts as an energy barrier to the holes to be injected from the P-GaN layer into the active layer, thereby significantly lowering the injection efficiency of holes.

On the other hand, if the electron blocking layer is thin in the prior art, holes injected from the P-GaN layer into the active layer can pass through the superlattice layer through quantum mechanical tunneling. Thus, the problem of low hole injection efficiency of the thick electron blocking layer can be improved. However, since electrons can also pass through the electron blocking layer through quantum mechanical tunneling, the electrons can not effectively block leakage of electrons from the active layer toward the P-GaN layer.

Embodiments of the present invention provide a light emitting device having an electron blocking layer that is excellent in hole injection efficiency and can effectively prevent leakage of electrons, a method of manufacturing a light emitting device, a light emitting device package, and an illumination system.

A light emitting device according to an embodiment includes a first conductive semiconductor layer; An active layer formed on the first conductivity type semiconductor layer including a quantum well and a quantum wall; An electron blocking layer on the active layer; And a second conductivity type semiconductor layer on the electron blocking layer, wherein the electron blocking layer comprises a first group blocking layer having a first energy band gap equal to or greater than an energy band gap of the quantum wall, Blocking layer; And a third electron blocking layer having a third energy band gap greater than or equal to the first energy band gap.

According to the light emitting device, the method of manufacturing the light emitting device, the light emitting device package, and the illumination system according to the embodiment, the hole injection efficiency is excellent and the leakage of electrons can be effectively blocked.

1 is a schematic view of an energy band gap of a light emitting device according to a first embodiment;
FIG. 2 is a schematic view of an energy band gap of the light emitting device according to the second embodiment. FIG.
3 is a cross-sectional view of a light emitting device according to an embodiment.
4 is a cross-sectional view of a light emitting device package according to an embodiment.
5 is a perspective view of a lighting unit according to an embodiment;
6 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 schematic view of an energy band gap of the light emitting device 100 according to the first embodiment.

The light emitting device 100 according to the embodiment includes the first conductivity type semiconductor layer 110 and the active layer including the quantum well 120w and the quantum wall 120b and formed on the first conductivity type semiconductor layer 110 An electron blocking layer 130 formed on the active layer 120 and a second conductive semiconductor layer 141 formed on the electron blocking layer 130.

In one embodiment, the electron blocking layer 130 includes a first electron blocking layer 131 having a first energy band gap Eg1 equal to or greater than an energy band gap Egb of the quantum wall, Group superlattice electron blocking layer 130B including a third electron blocking layer 133 having a first energy band gap Eg1 and a third energy band gap Eg3 equal to or greater than the first energy band gap Eg1 .

The A group superlattice electron blocking layer 130A is disposed between the active layer 120 and the second conductivity type semiconductor layer 141 and the B group superlattice electron blocking layer 130B is disposed between the A group superlattice And may be disposed between the electron blocking layer 130A and the second conductive semiconductor layer 141. [

The electron blocking layer 130 may include a C group superlattice electron blocking layer 130C including a fifth electron blocking layer 135 having a fifth energy band gap Eg5 equal to or greater than the third energy band gap Eg3 And the C group superlattice electron blocking layer 130C may be disposed between the B group superlattice electron blocking layer 130B and the second conductivity type semiconductor layer 141. [

The A-group superlattice electron blocking layer 130A, the B-group superlattice electron blocking layer 130B, or the C-group superlattice electron blocking layer 130C may be doped with P-type, but the present invention is not limited thereto.

The light emitting device according to the embodiment includes a plurality of P-type superlattice electron blocking layers having an energy bandgap equal to or greater than the energy band gap Egb of the quantum wall between the active layer 120 and the second conductivity type semiconductor layer 141 The hole injection efficiency can be improved and at the same time, the leakage of electrons can be effectively blocked.

In the embodiment, the P-type superlattice electron blocking layer may be composed of two or more multiple p-type superlattices, and each p-type superlattice layer may have a different Al composition and alternate two energy band gaps May be repeatedly layered at least once.

Electrons leaked from the active layer toward the P-type hole injection layer in the direction of the second conductivity type semiconductor layer are divided into the A group superlattice electron blocking layer 130A, the B group superlattice electron blocking layer 130A, The lattice electron blocking layer 130B and the C group superlattice electron blocking layer 130C gradually have a larger energy barrier. Therefore, the leakage of electrons from the active layer toward the hole injection layer can be effectively blocked.

According to the embodiment, in the case of holes injected into the active layer from the second conductivity type semiconductor layer which is a hole injection layer, the C group superlattice electron blocking layer 130C, the B group superlattice electron blocking layer 130B and the A group Since the superlattice electron blocking layer 130A has a smaller energy barrier progressively smaller, the injection efficiency of holes can be effectively increased.

Hereinafter, the superlattice electron blocking layer of each group will be described in more detail.

In an embodiment, the barrier 120b of the active layer 120 may include Al in a predetermined composition.

The A-group superlattice electron blocking layer 130A includes a first electron blocking layer 131 having a first energy band gap Eg1 equal to or greater than an energy band gap Egb of the quantum wall and an energy band gap And a second electron blocking layer 132 having a second energy band gap Eg2 of not more than the first energy band gap Eg1 and not more than the first energy band gap Eg1.

For example, the first electron blocking layer 131 may include Al _x1 In _y1 Ga _{(1-x1- y1 )} N (where 0? _{X1 ? 1} , 0? Y1? 1) barrier layer 132 comprises _{Al x2 in y2 Ga (1-} x2- y2) N ( However, 0≤x2≤1, 0≤y2≤1), and the Al of the first electron blocking layer 131 The composition (x1) may be not less than the composition (x2) of Al of the second electron blocking layer 132.

The composition x1 of Al of the first electron blocking layer 131 may be higher than the composition x2 of Al of the second electron blocking layer 132 and the Al composition of the second electron blocking layer 132 The composition (x2) may be higher than the composition of Al of the barrier, but is not limited thereto.

The B group superlattice electron blocking layer 130B includes a third electron blocking layer 133 having a third energy band gap Eg3 equal to or greater than the first energy band gap Eg1, And a fourth electron blocking layer 134 having a fourth energy band gap Eg4 of not more than the first energy band gap Eg1 and not more than the first energy band gap Eg1.

For example, the third electron blocking layer 133 may include Al _{x 3} In _{y 3} Ga _{(1-x 3-y 3 )} N (where _{0? X 3? 1, 0? Y 3? 1 )} The barrier layer 134 includes Al _{x 4} In _{y 4} Ga _{(1-x 4 -y 4 )} N (where 0 _{x 4 1 and 0 y 4 1} ), and Al of the third electron blocking layer 133 The composition x3 may be not less than the Al composition x1 of the first electron blocking layer 131 and the Al composition x4 of the fourth electron blocking layer 134 may be less than the Al composition of the barrier 120b. But it is not limited thereto.

The light emitting device according to the embodiment includes a plurality of P-type superlattice electron blocking layers having an energy bandgap equal to or greater than the energy band gap Egb of the quantum wall between the active layer 120 and the second conductivity type semiconductor layer 141 The hole injection efficiency can be improved and at the same time, the leakage of electrons can be effectively blocked.

For example, according to the embodiment, electrons leaked from the active layer toward the second conductivity type semiconductor layer, which is the P-type hole injection layer, are formed in the A group superlattice electron blocking layer 130A, And the Group B superlattice electron blocking layer gradually have a larger energy barrier. Therefore, the leakage of electrons from the active layer toward the hole injection layer can be effectively blocked.

According to the embodiment, in the case of holes injected into the active layer in the second conductivity type semiconductor layer, which is a hole injection layer, the B group superlattice electron blocking layer 130B and the A group superlattice electron blocking layer 130A are gradually , The injection efficiency of the holes can be effectively increased.

In addition, in the embodiment, the C group superlattice electron blocking layer 130C includes a fifth electron blocking layer 135 having a fifth energy band gap Eg5 of the third energy band gap Eg3 or more, And a sixth electron blocking layer 136 having a sixth energy band gap Eg6 of not less than the energy band gap Egb and not more than the first energy band gap Eg1.

For example, the fifth electron blocking layer 135, _x5 In _y5 Ga comprises an Al _{(1-x5- y5)} N (However, 0≤x5≤1, 0≤y5≤1) the sixth electronic barrier layer 136 of Al of Al _{x6 y6} in Ga _{(1-y6 x6-)} including N (where, 0≤x6≤1, 0≤y6≤1), and the fifth electron blocking layer 135 The composition (x5) may be not less than the composition (x3) of Al of the third electron blocking layer 133.

In the embodiment, the P-type superlattice electron blocking layer may be composed of two or more multiple p-type superlattices, and each p-type superlattice layer may have a different Al composition and two layers having different energy band gaps may be alternately And may be repeatedly laminated at least once.

Electrons leaked from the active layer toward the P-type hole injection layer in the direction of the second conductivity type semiconductor layer are divided into the A group superlattice electron blocking layer 130A, the B group superlattice electron blocking layer 130A, The lattice electron blocking layer 130B and the C group superlattice electron blocking layer 130C gradually have a larger energy barrier. Therefore, the leakage of electrons from the active layer toward the hole injection layer can be effectively blocked.

According to the embodiment, in the case of holes injected into the active layer from the second conductivity type semiconductor layer which is a hole injection layer, the C group superlattice electron blocking layer 130C, the B group superlattice electron blocking layer 130B and the A group Since the superlattice electron blocking layer 130A has a smaller energy barrier progressively smaller, the injection efficiency of holes can be effectively increased.

2 is a schematic view of the energy band gap of the light emitting device 102 according to the second embodiment.

The second embodiment can employ the technical features of the first embodiment, and will be described below with emphasis on the features of the second embodiment.

In the second embodiment, the A-group superlattice electron blocking layer 130A 'includes a first electron blocking layer 131 having a first energy band gap Eg1 equal to or greater than the energy band gap Egb of the quantum wall, And a second electron blocking layer 132a having a second energy band gap Eg2a equal to or greater than the energy band gap Egb and equal to or less than the first energy band gap Eg1.

For example, the first electron blocking layer 131 may include Al _{x 1} In _{y 1} Ga _{(1-x1- y1 )} N (where 0? _{X1 ? 1} , 0? Y1? 1) barrier layer (132a) comprises _{Al x2 in y2 Ga (1-} x2- y2) N ( However, 0≤x2≤1, 0≤y2≤1), and the Al of the first electron blocking layer 131 The composition (x1) may be not less than the composition (x2) of Al of the second electron blocking layer 132a.

The B group superlattice electron blocking layer 130B 'in the second embodiment has a third electron blocking layer 133 having a third energy band gap Eg3 equal to or larger than the first energy band gap Eg1, And a fourth electron blocking layer 134a having a fourth energy band gap Eg4a which is not less than the energy band gap Eg2a but not more than the third energy band gap Eg3.

For example, the third electron blocking layer 133 may include Al _{x 3} In _{y 3} Ga _{(1-x 3-y 3 )} N (where _{0? X 3? 1, 0? Y 3? 1 )} The blocking layer 134a includes Al _{x 4} In _{y 4} Ga _{(1-x 4 -y 4 )} N (0 _{x 4 1, 0 y 4 1} ), and Al of the fourth electron blocking layer 134a The composition x4 may be not less than the Al composition x2 of the second electron blocking layer 132a and not more than the Al composition x3 of the third electron blocking layer 133. [

According to the embodiment, electrons leaked from the active layer toward the P-type hole injection layer in the direction of the second conductivity type semiconductor layer include the A group superlattice electron blocking layer 130A ', the B group The superlattice electron blocking layer 130B 'gradually has a larger energy barrier. Therefore, the leakage of electrons from the active layer toward the hole injection layer can be effectively blocked.

In the case of holes injected into the active layer from the second conductivity type semiconductor layer, which is a hole injection layer according to the embodiment, the B group superlattice electron blocking layer 130B 'and the A group superlattice electron blocking layer 130A' As a result, the injection efficiency of the holes can be effectively increased since they have gradually smaller energy barrier.

According to the embodiment, when the energy band gap Eg4a of the fourth electron blocking layer 134a is larger than the energy band gap Eg2a of the second electron blocking layer, the leakage of electrons from the active layer toward the hole injection layer can be suppressed Since the difference in the energy barrier between the superlattice electron blocking layers is reduced, the injected holes can be smoothly moved, and the injection efficiency of the holes can be effectively increased.

Second Embodiment The electron blocking layer 130 'may include a C group superlattice electron blocking layer 130C' having a fifth energy band gap Eg5 of a third energy band gap Eg3 or more.

For example, the C group superlattice electron blocking layer 130 C 'may be disposed between the B group superlattice electron blocking layer 130 B' and the second conductivity type semiconductor layer 141.

For example, the C group superlattice electron blocking layer 130C 'may include a fifth electron blocking layer 135 having a fifth energy band gap Eg5 of the third energy band gap Eg3 or more, And a sixth electron blocking layer 136a having a sixth energy band gap Eg6a of not less than the band gap Eg4a but not more than the fifth energy band gap Eg5.

The fifth electron blocking layer 135 is Al _x5 In _y5 Ga _{(x5- 1-y5)} N includes (but, 0≤x5≤1, 0≤y5≤1), the sixth electron blocking layer (136a ) is _{Al x6 in y6 Ga (1-} x6- y6) N ( However, the composition of Al of 0≤x6≤1, 0≤y6≤1) includes, and the sixth electron blocking layer (136a) to (x6) May be not less than the Al composition (x4) of the fourth electron blocking layer 134a and not more than the Al composition (x5) of the fifth electron blocking layer 135.

According to the embodiment, electrons leaked from the active layer toward the P-type hole injection layer in the direction of the second conductivity type semiconductor layer include the A group superlattice electron blocking layer 130A ', the B group The superlattice electron blocking layer 130B 'and the C group superlattice electron blocking layer 130C' gradually have a larger energy barrier. Therefore, the leakage of electrons from the active layer toward the hole injection layer can be effectively blocked.

In the case of holes injected into the active layer in the second conductivity type semiconductor layer which is a hole injection layer according to the embodiment, the C group superlattice electron blocking layer 130C ', the B group superlattice electron blocking layer 130B' Since the Group A superlattice electron blocking layer 130A 'has a gradually smaller energy barrier on the tail side, the injection efficiency of holes can be effectively increased.

According to the embodiment, the energy band gap Eg6a of the sixth electron blocking layer 134a is larger than the energy band gap Eg4a of the fourth electron blocking layer 134a, (Eg4a) is larger than the energy band gap (Eg2a) of the second electron blocking layer, the leakage of electrons from the active layer toward the hole injection layer can be blocked more effectively and the difference in energy barrier between the superlattice electron blocking layers is reduced The injected holes can be moved smoothly, and the injection efficiency of the holes can be effectively increased.

According to the light emitting device, the method of manufacturing the light emitting device, the light emitting device package, and the illumination system according to the embodiment, the hole injection efficiency is excellent and the leakage of electrons can be effectively blocked.

3 schematically illustrates the structure of the light emitting device 100 according to the embodiment.

Although the embodiment has been described mainly with respect to the vertical light emitting device, this is merely an example, and can be applied to a horizontal light emitting device, a flip chip light emitting device, a hybrid light emitting device including a via hole, and the like.

The light emitting device 100 according to the embodiment includes the light emitting structure including the first conductive semiconductor layer 110, the active layer 120, and the second conductive semiconductor layer 141, and the light emitting structure including the second conductive semiconductor layer 141 A second electrode layer 140 formed on the first conductive semiconductor layer 110 and a first electrode 150 on the first conductive semiconductor layer 110.

The embodiment may include an electron blocking layer 130 between the active layer 120 and the second conductive semiconductor layer 141.

When the first conductive semiconductor layer 110 is an N-type semiconductor layer, the first conductive semiconductor layer 110 may be formed of a Group III-V compound semiconductor doped with a first conductive dopant. The first conductive dopant may include, but is not limited to, Si, Ge, Sn, Se, and Te as an N-type dopant.

The first conductive semiconductor layer 110 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 110 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 active layer 120 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 120 may be formed with multiple quantum well structures 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 120 may be formed of any one or more pairs of InGaN / GaN, InGaN / InGaN, GaN / AlGaN, InAlGaN / GaN, GaAs (InGaAs), / AlGaAs, GaP (InGaP) But is not limited to. The well layer may be formed of a material having a band gap lower than the band gap of the barrier layer.

The electron blocking layer 130 may include an A group superlattice electron blocking layer 130A having a first energy band gap Eg1 equal to or greater than the energy band gap Egb of the quantum wall and an A group superlattice electron blocking layer 130A having the first energy band gap Eg1 Group superlattice electron blocking layer 130B having a third energy band gap Eg3 equal to or larger than the third energy band gap Eg2.

The A group superlattice electron blocking layer 130A is disposed between the active layer 120 and the second conductivity type semiconductor layer 141 and the B group superlattice electron blocking layer 130B is disposed between the A group superlattice And may be disposed between the electron blocking layer 130A and the second conductive semiconductor layer 141. [

The electron blocking layer 130 may include a C group superlattice electron blocking layer 130C having a fifth energy band gap Eg5 equal to or greater than the third energy band gap Eg3, The lattice electron blocking layer 130C may be disposed between the B group superlattice electron blocking layer 130B and the second conductivity type semiconductor layer 141.

The second conductive semiconductor layer 141 may be formed of a compound semiconductor of a group III-V element doped with a second conductive dopant, for example, In _x Al _y Ga _{1 -x- y} N (0? X? Y < = 1, 0 x + y < = 1). The second conductive semiconductor layer 141 may be selected from GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP and AlGaInP. When the second conductive semiconductor layer 141 is a P-type semiconductor layer, the second conductive dopant may include Mg, Zn, Ca, Sr, and Ba as a P-type dopant. The second conductive semiconductor layer 141 may be formed as a single layer or a multilayer, but the present invention is not limited thereto.

In an exemplary embodiment, the first conductive semiconductor layer 110 may be an N-type semiconductor layer, and the second conductive semiconductor layer 141 may be a P-type semiconductor layer. Also, on the second conductive semiconductor layer 141, a semiconductor, for example, an N-type semiconductor layer (not shown) having a polarity opposite to that of the second conductive type may be formed. Accordingly, the light emitting structure can be implemented by 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.

The second electrode layer 140 may include a bonding layer 142, an ohmic layer 144, a reflective layer 146, a conductive supporting substrate 148, and the like.

For example, the bonding layer 142 may include at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu,

For example, the ohmic layer 144 may include at least one of ITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide), IAZO (indium aluminum zinc oxide), IGZO (ZnO), indium gallium tin oxide (AZO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IZON nitride, AGZO Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Ni, IrOx / Au, and Ni / IrOx / , Au, and Hf, and is not limited to such a material.

In addition, the reflective layer 146 may reflect light incident from the light emitting structure to improve light extraction efficiency.

The reflective layer 146 may be formed of a metal or an alloy including at least one of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au and Hf. The reflective layer 146 may be formed of a multilayer structure using a metal or an alloy and a light transmitting conductive material such as IZO, IZTO, IAZO, IGZO, IGTO, AZO, or ATO. For example, IZO / Ni, AZO / Ag, IZO / Ag / Ni, AZO / Ag / Ni, or the like.

In addition, the conductive supporting substrate 148 supports the light emitting structure and can provide power to the light emitting structure. The conductive support substrate 148 may be made of a metal, a metal alloy, or a conductive semiconductor material having excellent electrical conductivity.

For example, the conductive support substrate can be made of a material selected from the group consisting of copper (Cu), copper alloy, gold (Au), nickel (Ni), molybdenum (Mo), copper- , Si, Ge, GaAs, GaN, ZnO, SiGe, SiC, and the like).

The conductive support substrate may be formed by an electrochemical metal deposition method, a plating method, a bonding method using a yttetic metal, or the like.

According to the light emitting device, the method of manufacturing the light emitting device, the light emitting device package, and the illumination system according to the embodiment, the hole injection efficiency is excellent and the leakage of electrons can be effectively blocked.

4 is a view illustrating a light emitting device package 200 having a light emitting device according to embodiments.

The light emitting device package 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 light emitting device 100 electrically connected to the third electrode layer 213 and the fourth electrode layer 214 and a molding member 240 surrounding the light emitting device 100 are included.

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 vertical type light emitting device, but the present invention is not limited thereto, and a horizontal light emitting device may 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 240 surrounds the light emitting device 100 to protect the light emitting device 100. In addition, the molding member 240 may include a phosphor 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.

5 is a perspective view 1100 of a lighting unit according to an embodiment. However, the illumination unit 1100 of Fig. 5 is an example of the illumination system and is not limited thereto.

The illumination unit 1100 may include a case body 1110, a light emitting module 1130 installed in the case body 1110, a connection unit 1130 installed in the case body 1110, Terminal 1120. [0031]

The case body 1110 is preferably formed of a material having a good heat dissipation property, and may be formed of, for example, a metal material or a resin material.

The light emitting module unit 1130 may include a substrate 1132 and at least one light emitting device package 200 mounted on the substrate 1132.

The substrate 1132 may be a circuit pattern printed on an insulator. For example, the PCB 1132 may be a printed circuit board (PCB), a metal core PCB, a flexible PCB, a ceramic PCB . ≪ / RTI >

Further, the substrate 1132 may be formed of a material that efficiently reflects light, or may be formed of a color whose surface is efficiently reflected, for example, white, silver, or the like.

The at least one light emitting device package 200 may be mounted on the substrate 1132. Each of the light emitting device packages 200 may include at least one light emitting diode (LED) 100. The light emitting diode 100 may include a colored light emitting diode that emits red, green, blue, or white colored light, and a UV light emitting diode that emits ultraviolet (UV) light.

The light emitting module unit 1130 may be arranged to have a combination of various light emitting device packages 200 to obtain color and brightness. For example, a white light emitting diode, a red light emitting diode, and a green light emitting diode may be arranged in combination in order to secure a high color rendering index (CRI).

The connection terminal 1120 may be electrically connected to the light emitting module 1130 to supply power. In an embodiment, the connection terminal 1120 is connected to the external power source by being inserted in a socket manner, but is not limited thereto. For example, the connection terminal 1120 may be formed in a pin shape and inserted into an external power source or may be connected to an external power source through a wiring.

6 is an exploded perspective view 1200 of a backlight unit according to an embodiment. However, the backlight unit 1200 of FIG. 6 is an example of the illumination system, and 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. ≪ / RTI >

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 light emitting device, the method of manufacturing the light emitting device, the light emitting device package, and the illumination system according to the embodiment, the hole injection efficiency is excellent and the leakage of electrons can be effectively blocked.

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.

Claims (16)

A first conductive semiconductor layer;
An active layer including a quantum well and a quantum wall on the first conductive type semiconductor layer;
An electron blocking layer on the active layer; And
And a second conductivity type semiconductor layer on the electron blocking layer,
Wherein the electron blocking layer
A first electron blocking layer having a first energy band gap equal to or greater than an energy band gap of the quantum wall and a second electron blocking layer having a second energy band gap equal to or greater than an energy band gap of the quantum wall, An A group superlattice electron blocking layer;
A third electron blocking layer having a third energy band gap greater than or equal to the first energy band gap and a fourth electron blocking layer having a fourth energy band gap greater than the energy band gap of the quantum wall and less than the first energy band gap, A B group superlattice electron blocking layer; And
A fifth electron blocking layer having a fifth energy band gap greater than or equal to the third energy band gap and a sixth electron blocking layer having a sixth energy band gap greater than or equal to the energy band gap of the quantum wall, And a C group superlattice electron blocking layer,
The fourth energy band gap is greater than the second energy band gap,
And the sixth energy band gap is larger than the fourth energy band gap. The method according to claim 1,
Wherein the A group superlattice electron blocking layer is disposed between the active layer and the second conductivity type semiconductor layer,
And the B group superlattice electron blocking layer is disposed between the A group superlattice electron blocking layer and the second conductivity type semiconductor layer. delete 3. The method of claim 2,
Wherein the first electron blocking layer includes Al _{x 1} In _{y 1} Ga _(1-x1-y1) N (where 0 _{? X1? 1} , 0? Y1? 1)
Wherein the second electron blocking layer comprises Al _{x 2} In _{y 2} Ga _{(1-x 2-y 2)} N (where _{0? X 2? 1} , 0? Y 2? 1)
Wherein the composition (x1) of Al in the first electron blocking layer is not less than the composition (x2) of Al in the second electron blocking layer. delete 5. The method of claim 4,
Wherein the third electron blocking layer comprises Al _{x 3} In _{y 3} Ga _{(1-x 3-y 3)} N (where _{0? X 3? 1} , 0? Y _{3? 1} )
Wherein the fourth electron blocking layer comprises Al _x 4 In _{y 4} Ga _{(1-x 4-y 4)} N (where 0 _{x 4 1} , 0 _{y 4 1} )
And the composition (x3) of Al in the third electron blocking layer is not less than the composition (x1) of Al in the first electron blocking layer. delete 3. The method according to claim 1 or 2,
The C group superlattice electron blocking layer
And a light emitting element disposed between the B group superlattice electron blocking layer and the second conductivity type semiconductor layer. delete 9. The method of claim 8,
Includes the fifth electron blocking layer is _{Al x5 In y5 Ga (1-} x5-y5) N ( However, 0≤x5≤1, 0≤y5≤1),
Wherein the sixth electron blocking layer comprises Al _x 6 In _y Ga _(1-x6-y6) N (where _{0? X6? 1} , 0? Y6? 1)
And the composition (x5) of Al in the fifth electron blocking layer is not less than the composition (x3) of Al in the third electron blocking layer. delete 11. The method of claim 10,
Wherein the third electron blocking layer comprises Al _{x 3} In _{y 3} Ga _{(1-x 3-y 3)} N (where _{0? X 3? 1} , 0? Y _{3? 1} )
Wherein the fourth electron blocking layer comprises Al _x 4 In _{y 4} Ga _{(1-x 4-y 4)} N (where 0 _{x 4 1} , 0 _{y 4 1} )
Wherein the composition (x4) of Al in the fourth electron blocking layer is not less than the composition (x2) of Al of the second electron blocking layer and not more than the composition (x3) of Al of the third electron blocking layer. delete delete delete 13. The method of claim 12,
Includes the fifth electron blocking layer is _{Al x5 In y5 Ga (1-} x5-y5) N ( However, 0≤x5≤1, 0≤y5≤1),
Wherein the sixth electron blocking layer comprises Al _x 6 In _y Ga _(1-x6-y6) N (where _{0? X6? 1} , 0? Y6? 1)
The composition (x6) of Al in the sixth electron blocking layer is not less than the composition (x4) of Al of the fourth electron blocking layer and not more than the composition (x5) of Al of the fifth electron blocking layer.

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