KR20130043708A

KR20130043708A - Light emitting device

Info

Publication number: KR20130043708A
Application number: KR1020110107683A
Authority: KR
Inventors: 황성민
Original assignee: 엘지이노텍 주식회사
Priority date: 2011-10-20
Filing date: 2011-10-20
Publication date: 2013-05-02

Abstract

The light emitting device according to the embodiment includes a first light emitting structure including a first semiconductor layer, a second semiconductor layer, and a first active layer formed between the first and second semiconductor layers, and the first light emitting structure. A second light emitting structure comprising a third semiconductor layer, a fourth semiconductor layer, and a second active layer formed between the third and fourth semiconductor layers, and formed between the first light emitting structure and the second light emitting structure, An intermediate layer having electrical conductivity, a first electrode connected with the first semiconductor layer, a second electrode connected with the second and third semiconductor layers, and a third electrode connected with the fourth semiconductor layer, and The first and third semiconductor layers are doped with the first conductivity type, and the second and fourth semiconductor layers are doped with the second conductivity type.

Description

[0001] LIGHT EMITTING DEVICE [0002]

An embodiment relates to a light emitting element.

LED (Light Emitting Diode) is a device that converts electrical signals into infrared, visible light or light using the characteristics of compound semiconductors. It is used in household appliances, remote controls, display boards, The use area of LED is becoming wider.

In general, miniaturized LEDs are made of a surface mounting device for mounting directly on a PCB (Printed Circuit Board) substrate, and an LED lamp used as a display device is also being developed as a surface mounting device type . Such a surface mount device can replace a conventional simple lighting lamp, which is used for a lighting indicator for various colors, a character indicator, an image indicator, and the like.

Patent Document 10-2009-0082453 (hereinafter referred to as "prior art 1") in the light emitting device unit, the rectifier circuit unit for converting AC power to DC power, and the smoothing circuit unit for controlling the size of the rectified power supply to the light emitting device unit Disclosed is a light emitting device comprising a.

However, in the prior art 1, the rectifier circuit part and the smoothing circuit part are required to drive the light emitting element part from the AC power source, so that the economic efficiency of the light emitting device may be impaired.

The embodiment provides a light emitting device capable of driving both forward voltage and reverse voltage in an AC power supply.

The light emitting device according to the embodiment can be driven at both the forward voltage and the reverse voltage in the AC power supply. Therefore, an AC power source can be used as a power source of the light emitting device without a separate rectifying circuit. Thus, separate devices and devices, such as rectifier circuits or ESD devices, may be omitted from the AC power source.

In addition, in the light emitting device according to the embodiment, forward voltage driving and reverse voltage driving in an AC power source may be performed in one chip. Therefore, luminous efficiency per unit area can be improved.

In addition, since the light emitting device according to the embodiment includes a forward voltage driving light emitting structure and an reverse voltage driving light emitting structure in one chip in an AC power source and can be grown in one process, the light emitting device manufacturing process is simplified and the Economics can be improved.

1A is a cross-sectional view of a light emitting device according to an embodiment;
1B is a cross-sectional view of a light emitting device according to the embodiment;
2 is a plan view of a light emitting device according to an embodiment;
3 is a circuit diagram of a light emitting device according to an embodiment;
4 is a driving diagram when a forward voltage is applied to the light emitting device according to the embodiment;
5 is a driving diagram when applying a reverse voltage of the light emitting device according to the embodiment;
6 is a cross-sectional view of a light emitting device according to the embodiment;
7 is a cross-sectional view of a light emitting device according to the embodiment;
8 is a cross-sectional view of a light emitting device according to the embodiment;
9 is a cross-sectional view of a light emitting device according to the embodiment;
10 is a cross-sectional view of a light emitting device according to the embodiment;
11 is a cross-sectional view of a light emitting device according to the embodiment;
12 is a cross-sectional view of a light emitting device according to the embodiment;
13 is a cross-sectional view of a light emitting device according to the embodiment;
14 is a cross-sectional view of a light emitting device according to the embodiment;
15 is a cross-sectional view of a light emitting device according to the embodiment;
16 is a cross-sectional view of a light emitting device according to the embodiment;
17 is a cross-sectional view of a light emitting device according to the embodiment;
18 is a cross-sectional view of a light emitting device according to the embodiment;
19 is a partially enlarged cross-sectional view of a light emitting device according to the embodiment;
20 is a view showing an energy band diagram of a light emitting device according to the embodiment;
21 is a view showing an energy band diagram of a light emitting device according to the embodiment;
22 is a perspective view of a light emitting device package including a light emitting device according to the embodiment;
23 is a cross-sectional view of a light emitting device package including a light emitting device according to the embodiment;
24 is a cross-sectional view of a light emitting device package including a light emitting device according to the embodiment;
25 is a perspective view of a lighting system including a light emitting device according to the embodiment;
FIG. 26 is a sectional view taken along line C-C 'of the lighting system of FIG. 27;
27 is an exploded perspective view of a liquid crystal display device including a light emitting device according to the embodiment; and
28 is an exploded perspective view of a liquid crystal display including the light emitting device according to the embodiment.

Advantages and features of the present invention, and methods of achieving the same will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

The terms spatially relative, "below", "beneath", "lower", "above", "upper" May be used to readily describe a device or a relationship of components to other devices or components. Spatially relative terms should be understood to include, in addition to the orientation shown in the drawings, terms that include different orientations of the device during use or operation. For example, when flipping a device shown in the figure, a device described as "below" or "beneath" of another device may be placed "above" of another device. Thus, the exemplary term "below" can include both downward and upward directions. The device can also be oriented in other directions, so that spatially relative terms can be interpreted according to orientation.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. It is noted that the terms "comprises" and / or "comprising" used in the specification are intended to be inclusive in a manner similar to the components, steps, operations, and / Or additions.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used in a sense that can be commonly understood by those skilled in the art. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

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 and area of each component do not entirely reflect actual size or area.

Further, the angle and direction mentioned in the description of the structure of the light emitting device in the embodiment are based on those shown in the drawings. In the description of the structure of the light emitting device in the specification, reference points and positional relationship with respect to angles are not explicitly referred to, refer to the related drawings.

1A and 1B are cross-sectional views of a light emitting device 100 according to an embodiment, and FIG. 2 is a plan view of a light emitting device 100 according to an embodiment.

1A to 2, a light emitting device 100 according to an embodiment may include a first semiconductor layer 122, a second semiconductor layer 126, and first and second semiconductor layers 122 and 126. A first light emitting structure 120 including a first active layer 124 formed on the first light emitting structure 120, a third semiconductor layer 132, a fourth semiconductor layer 136, and a second light emitting structure 120 formed on the first light emitting structure 120. A second light emitting structure 130 including a second active layer 134 formed between the third and fourth semiconductor layers 132 and 136, and a first electrode 142 connected to the first semiconductor layer 122; And a second electrode 144 connected with the second and third semiconductor layers 126 and 132, and a third electrode 146 connected with the fourth semiconductor layer 136. The semiconductor layers 122 and 132 may be doped with the first conductivity type, and the second and fourth semiconductor layers 126 and 136 may be doped with the second conductivity type.

The substrate 110 may be formed of a material having a light transmitting property, for example, any one of sapphire (Al ₂ O ₃ ), GaN, ZnO, AlO, but is not limited thereto. In addition, the substrate 110 may be a SiC substrate having a higher thermal conductivity than sapphire (Al ₂ O ₃ ).

Meanwhile, a buffer layer 112 may be disposed on the substrate 110 to mitigate lattice mismatch between the substrate 110 and the first light emitting structure 120 and to easily grow the semiconductor layer. The buffer layer 112 may be formed in a low temperature atmosphere, and may be formed of a material capable of alleviating the difference in lattice constant between the semiconductor layer and the substrate 110. For example, materials such as GaN, InN, AlN, AlInN, InGaN, AlGaN, and InAlGaN can be selected and not limited thereto. The buffer layer 112 may grow as a single crystal on the substrate 110, and the buffer layer 112 grown as the single crystal may improve the crystallinity of the first light emitting structure 120 growing on the buffer layer 112.

The first light emitting structure 120 including the first semiconductor layer 122, the first active layer 124, and the second semiconductor layer 126 may be formed on the buffer layer (not shown).

The first semiconductor layer 122 may be positioned on the buffer layer 112. The first semiconductor layer 122 may be doped with a first conductivity type. In this case, the first conductivity type may be n type. For example, the first semiconductor layer 122 may be implemented as an n-type semiconductor layer, and may provide electrons to the first active layer 124. The first semiconductor layer 122 may be a nitride based semiconductor layer. For example, semiconductor material having a compositional formula of the first semiconductor layer 122 is _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1) It may include, for example, may include GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN. Meanwhile, the first semiconductor layer 122 may be a zinc oxide semiconductor layer. For example, the first semiconductor layer 122 may include a semiconductor material having a composition formula of In _x Al _y Zn ₁ _-x- _y O (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). And include, for example, ZnO, AlO, AlZnO, InZnO, InO, InAlZnO. AlInO, and the like, but are not limited thereto. In addition, the first semiconductor layer 122 may be doped with n-type dopants such as Si, Ge, Sn, and the like.

In addition, an undoped semiconductor layer (not shown) may be further included below the first semiconductor layer 122, but embodiments are not limited thereto. The undoped semiconductor layer (not shown) is a layer formed to improve the crystallinity of the first semiconductor layer 122, except that the n-type dopant is not doped and thus has lower electrical conductivity than that of the first semiconductor layer 122. And may be the same as the first semiconductor layer 122.

The first active layer 124 may be formed on the first semiconductor layer 122. The first active layer 124 may be formed of a single or multiple quantum well structure, a quantum-wire structure, a quantum dot structure, or the like using a compound semiconductor material of a group III-V group element. .

When the first active layer 124 has a quantum well structure, the first active layer 124 may have a multi-quantum well structure. In addition, the first active layer 124 may be a nitride-based or zinc oxide-based semiconductor layer. For example, the first active layer 124 is _{In x Al y Ga 1 -x- y} N well layer having a composition formula of (0≤x≤1, 0 ≤y≤1, 0≤x + y≤1) and In _a It may have a single or multiple quantum well structure having a barrier layer having a composition formula of Al _b Ga ₁ _-a- _b N (0 _{≦ a ≦} ₁ , 0 _≦ _b _≦ ₁ , 0 ≦ a + b ≦ 1). On the other hand, the well layer has a composition formula of In _x Al _y Zn ₁ _-x- _y O (0≤x≤1, 0≤y≤1, 0≤x + y≤1), and the barrier layer is In _a Al _b Zn _1-ab O (0 ≦ a ≦ ₁ , 0 ≦ b ≦ 1, 0 ≦ a + b ≦ 1), but is not limited thereto. Meanwhile, the well layer may be formed of a material having a band gap smaller than the band gap of the barrier layer.

In addition, when the first active layer 124 has a multi-quantum well structure, each well layer (not shown), the barrier layer (not shown) may have different compositions, different thicknesses, and different band gaps, This will be described later.

A conductive clad layer (not shown) may be formed on or under the first active layer 124. The conductive cladding layer (not shown) may be formed of, for example, an AlGaN-based or AlZnO-based semiconductor, and may have a band gap larger than that of the first active layer 124.

The second semiconductor layer 126 may be doped with a second conductivity type. In this case, the second conductivity type may be p-type. For example, the second semiconductor layer 126 may be implemented as a p-type semiconductor layer to inject holes into the first active layer 124. The second semiconductor layer 126 may be a nitride based semiconductor layer. For example, semiconductor material having a composition formula of the second semiconductor layer 126 is _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1) It may include, for example, may include GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN. Meanwhile, the second semiconductor layer 126 may be a zinc oxide semiconductor layer. For example, the second semiconductor layer 126 may include a semiconductor material having a composition formula of In _x Al _y Zn ₁ _-x- _y O (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). And ZnO, AlO, AlZnO, InZnO, InO, InAlZnO. AlInO, and the like, but is not limited thereto. The second semiconductor layer 126 may be doped with p-type dopants such as Mg, Zn, Ca, Sr, and Ba.

The first semiconductor layer 122, the first active layer 124, and the second semiconductor layer 126 may be, for example, metal organic chemical vapor deposition (MOCVD) or chemical vapor deposition (CVD). Vapor Deposition, Plasma-Enhanced Chemical Vapor Deposition (PECVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), Sputtering, etc. It may be formed using, but is not limited thereto.

In addition, the doping concentrations of the conductive dopants in the first semiconductor layer 122 and the second semiconductor layer 126 may be uniformly or non-uniformly formed. That is, the plurality of semiconductor layers may be formed to have various doping concentration distributions, but the invention is not limited thereto.

In addition, the first semiconductor layer 122 may be implemented as a p-type semiconductor layer, the second semiconductor layer 126 may be implemented as an n-type semiconductor layer, and the n-type or p-type semiconductor is formed on the second semiconductor layer 126. A semiconductor layer (not shown) including a layer may be formed. Accordingly, the first light emitting structure 120 may have at least one of np, pn, npn, and pnp junction structures.

The second light emitting structure 130 may be formed on the first light emitting structure 120.

The second light emitting structure 130 may include a third semiconductor layer 132, a second active layer 134, and a fourth semiconductor layer 136.

The third semiconductor layer 132 may be positioned on the second semiconductor layer 126. The third semiconductor layer 132 may be doped with the same first conductive type as the first semiconductor layer 122. For example, when the first semiconductor layer 122 is doped with the first conductivity type, the third semiconductor layer 132 may also be doped with the first conductivity type. In this case, the first conductivity type may be n type. For example, the third semiconductor layer 132 may be implemented as an n-type semiconductor layer, and may provide electrons to the second active layer 134.

The third semiconductor layer 132 may be a nitride based semiconductor layer. For example, the third semiconductor layer 132 may include semiconductor material having a compositional 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 may be included. Meanwhile, the third semiconductor layer 132 may be a zinc oxide semiconductor layer. For example, the third semiconductor layer 132 is a semiconductor material having a composition formula of In _x Al _y Zn ₁ _-x- _y O (0≤x≤1, 0≤y≤1, 0≤x + y≤1). , For example ZnO, AlO, AlZnO, InZnO, InO, InAlZnO. The third semiconductor layer 132 may be doped with an n-type dopant such as Si, Ge, Sn, or the like.

The second active layer 134 may be formed on the third semiconductor layer 132. The second active layer 134 may be formed of a single or multiple quantum well structure, a quantum-wire structure, a quantum dot structure, or the like using a compound semiconductor material of a group III-V group element. .

The second active layer 134 may be formed in a quantum well structure. In addition, the second active layer 134 may be a nitride-based or zinc oxide-based semiconductor layer. For example, the second active layer 134 may include a well layer having a composition formula of In _x Al _y Ga _1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1) and In _a Al _b It may have a single or multiple quantum well structure having a barrier layer having a composition formula of Ga _1-a- _b N (0 _{≦ a ≦} ₁ , 0 _≦ _b _≦ ₁ , 0 ≦ a + b ≦ 1). On the other hand, the well layer has a composition formula of In _x Al _y Zn ₁ _-x- _y O (0≤x≤1, 0≤y≤1, 0≤x + y≤1), and the barrier layer is In _a Al _b Zn _1-a- _b O ( _{0≤a≤1, 0≤b≤1, 0≤a} + b≤1) may be formed to have a composition formula, but is not limited thereto. Meanwhile, the well layer may be formed of a material having a band gap smaller than the band gap of the barrier layer.

In addition, when the second active layer 134 has a multi-quantum well structure, each well layer (not shown) may have a different composition and a different band gap, which will be described later.

A conductive clad layer (not shown) may be formed on or under the second active layer 134. The conductive cladding layer (not shown) may be formed of, for example, an AlGaN-based or AlZnO-based semiconductor, and may have a band gap larger than that of the second active layer 134.

The fourth semiconductor layer 136 may be doped with a second conductivity type such as the second semiconductor layer 126. For example, when the second semiconductor layer 126 is of the second conductivity type, the fourth semiconductor layer 136 may also be doped to the second conductivity type. In this case, the second conductivity type may be p-type. For example, the fourth semiconductor layer 136 may be implemented as a p-type semiconductor layer to inject holes into the second active layer 134.

The fourth semiconductor layer 136 may be a nitride based semiconductor layer. For example, the fourth semiconductor material having a composition formula of the semiconductor layer 136 is _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x + y≤1) It may include, for example, may include GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN. Meanwhile, the fourth semiconductor layer 136 may be a zinc oxide semiconductor layer. For example, the fourth semiconductor layer 136 is a semiconductor material having a composition formula of In _x Al _y Zn ₁ _-x- _y O (0≤x≤1, 0≤y≤1, 0≤x + y≤1). It may include, for example ZnO, AlO, AlZnO, InZnO, InO, InAlZnO. AlInO, and the like, but is not limited thereto. Meanwhile, the fourth semiconductor layer 136 may be doped with p-type dopants such as Mg, Zn, Ca, Sr, and Ba.

For example, the third semiconductor layer 132, the second active layer 134, and the fourth semiconductor layer 136 may be formed of, for example, metal organic chemical vapor deposition (MOCVD) or chemical vapor deposition (CVD). Vapor Deposition, Plasma-Enhanced Chemical Vapor Deposition (PECVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), Sputtering, etc. It may be formed using, but is not limited thereto.

In addition, the doping concentrations of the conductive dopants in the third semiconductor layer 132 and the fourth semiconductor layer 136 may be uniformly or non-uniformly formed. That is, the plurality of semiconductor layers may be formed to have various doping concentration distributions, but the invention is not limited thereto.

In addition, the third semiconductor layer 132 may be implemented as a p-type semiconductor layer, the fourth semiconductor layer 136 may be implemented as an n-type semiconductor layer, and the n-type or p-type semiconductor is formed on the fourth semiconductor layer 136. A semiconductor layer (not shown) including a layer may be formed. Accordingly, the second light emitting structure 130 may have at least one of np, pn, npn, and pnp junction structures.

The first light emitting structure 120 and the second light emitting structure 130 may be integrally formed. For example, the first light emitting structure 120 and the second light emitting structure 130 may be sequentially grown, but the present invention is not limited thereto. The second light emitting structure 130 may be formed of the same material, but is not limited thereto. In addition, as described above, the first and second light emitting structures 120 and 130 may have at least one of np, pn, npn, and pnp junction structures, respectively, and thus, the light emitting device 100 may include npnp, nppn, It may have at least one of npnpn, nppnp, pnnp, pnpn, pnnpn, pnpnp, npnnp, npnpn, npnnpn, npnpnp, pnpnp, pnppn, pnpnpn, and pnppnp junction structures, but is not limited thereto.

Meanwhile, the light generated by the first light emitting structure 120 and the second light emitting structure 130 may have different wavelengths, and the amount of light generated may also be different from each other. For example, the amount of light generated by the first light emitting structure 120 may be greater than the amount of light generated by the second light emitting structure 130 in consideration of loss when passing through the second light emitting structure 130.

In addition, the first light emitting structure 120 and the second light emitting structure 130 may have different structures, materials, thicknesses, compositions, and sizes, but are not limited thereto.

1A to 2, the light emitting device 100 is illustrated as including a first light emitting structure 120 and a second light emitting structure 130 formed on the first light emitting structure 120, but is not limited thereto. No, the light emitting device 100 may include at least two light emitting structures (not shown).

The first electrode 142 may be formed on at least one surface of the first semiconductor layer 122. For example, a portion of the first and second light emitting structures 120 and 130 may be removed to expose a portion of the first semiconductor layer 122, and the first electrode 142 may be exposed on the exposed first semiconductor layer 122. ) May be formed. That is, as shown in FIG. 1A, the first semiconductor layer 122 includes a top surface facing the first active layer 124 and a bottom surface facing the substrate 110, and the top surface includes a region where at least one region is exposed. The first electrode 142 may be disposed on the exposed area of the upper surface.

The second electrode 144 may be formed on at least one region of the second semiconductor layer 126 and the third semiconductor layer 132. For example, at least one region of the second light emitting structure 130 may be removed to expose one region of the second semiconductor layer 126 and the third semiconductor layer 132, and the second electrode 144 may be exposed to the exposed region. ) May be formed. That is, as shown in FIG. 1A, the second and third semiconductor layers 126 and 132 include an upper surface facing the fourth semiconductor layer 136 and a lower surface facing the substrate 110, and the upper surface at least one region is exposed. And the second electrode 144 may be disposed on the exposed area of the upper surface. Meanwhile, one region of the third semiconductor layer 132 may pass through to expose a portion of the second semiconductor layer 126. The second electrode 144 may be connected to the second semiconductor layer 126 through the third semiconductor layer 132 through the through region.

The third electrode 146 may be formed on the fourth semiconductor layer 136. The third electrode 146 may be formed in at least one region on the fourth semiconductor layer 136, and may be formed in the center or corner region of the fourth semiconductor layer 136, but is not limited thereto.

Meanwhile, a method of exposing a part of the first semiconductor layer 122, the second semiconductor layer 126, and the third semiconductor layer 132 may use a predetermined etching method, but is not limited thereto. The etching method may be a wet etching method or a dry etching method.

For example, the etching method may be a mesa etching method. That is, first mesa etching is performed on the first light emitting structure 120 and the second light emitting structure 130 to expose one region of the first semiconductor layer 122, and the third semiconductor layer 132. The second mesa etching may be performed on one region of the second light emitting structure 130 to expose one region of the second light emitting structure 130.

The first electrode 142 is formed on the first semiconductor layer 122, the second electrode 144 is formed on the second and third semiconductor layers 126 and 132, and the fourth semiconductor layer 136 is formed on the first semiconductor layer 122. As the third electrode 146 is formed, the first to third electrodes 142, 144, and 146 may be formed in the same direction.

The first electrode 142 and the third electrode 146 may be connected to each other. For example, the first electrode 142 and the third electrode 146 may be continuously formed as one member. Therefore, power having the same polarity may be applied to the first semiconductor layer 122 and the fourth semiconductor layer 136 through the first electrode 142 and the third electrode 146.

In addition, the second electrode 144 is formed on the second semiconductor layer 126 and the third semiconductor layer 132 to supply power having the same polarity to the second semiconductor layer 126 and the third semiconductor layer 132. Meanwhile, a method of removing portions of the first and second light emitting structures 120 and 130 may use a predetermined etching method, but is not limited thereto. The etching method may be a wet etching method or a dry etching method.

Meanwhile, the first to third electrodes 142, 144, and 146 may be conductive materials, for example, In, Co, Si, Ge, Au, Pd, Pt, Ru, Re, Mg, Zn, Hf, Ta, Rh, It may include a metal selected from Ir, W, Ti, Ag, Cr, Mo, Nb, Al, Ni, Cu, and WTi, or may include an alloy thereof, and the metal material and IZO, IZTO, IAZO , IGZO, IGTO, AZO, ATO, and the like may include a transparent conductive material, but is not limited thereto.

In addition, at least one of the first and second electrodes 140 and 150 may have a single layer or a multilayer structure, but is not limited thereto.

Hereinafter, an operation of the light emitting device 100 according to the embodiment will be described with reference to FIGS. 3 to 5. In the following description, it is assumed that the first and third semiconductor layers 122 and 132 are n-type semiconductor layers, and the second and fourth semiconductor layers 126 and 136 are p-type semiconductor layers.

3 is a circuit diagram of a light emitting device 100 according to an embodiment.

As described above, the first electrode 142 is connected to the first semiconductor layer 122, the second electrode 144 is connected to the second semiconductor layer 126, and the third semiconductor layer 132, and The electrode 146 may be connected to the fourth semiconductor layer 136, and the first electrode 142 and the third electrode 146 may be connected to each other. In this case, when the first and third semiconductor layers 122 and 132 are doped with the first conductivity type, and the second and fourth semiconductor layers 126 and 136 are doped with the second conductivity type, light emission according to an exemplary embodiment As shown in FIG. 3, the device 100 may have a circuit structure in which two light emitting diodes are connected in an anti-parallel structure.

4 is a view illustrating driving of the light emitting device 100 according to the embodiment when a forward bias is applied.

As shown in FIG. 4, in an AC power source, a positive voltage (+) may be connected to the second electrode 144, and a negative voltage (−) may be connected to the first and third electrodes 142 and 146. have. Accordingly, the first energization direction power may be applied to the light emitting device 100.

In this case, a first current path A flowing from the second semiconductor layer 126 through the active layer 124 to the first semiconductor layer 124 is formed in the first light emitting structure 120. As described above, since the second semiconductor layer 126 is a p-type semiconductor layer and the first semiconductor layer 122 is formed of an n-type semiconductor layer, the first light emitting structure 120 is turned on so that the first active layer 124 is formed. ) Can generate light.

On the other hand, a positive voltage (+) is connected to the third semiconductor layer 132 and a negative voltage (-) is connected to the fourth semiconductor layer 136, and a reverse voltage is applied to the second light emitting structure 130. Thus, no current path is formed and the second light emitting structure 130 is turned off.

5 is a view illustrating driving of the light emitting device 100 when a reverse bias is applied to the light emitting device 100 according to the embodiment.

As illustrated in FIG. 5, a negative voltage (−) may be supplied to the second electrode 144, and a positive voltage (+) may be supplied to the first and third electrodes 142 and 146. Accordingly, the second conduction direction power source may be applied to the light emitting device 100. On the other hand, the first conduction direction and the second conduction direction described above may be opposite.

In this case, a second current path B flowing from the fourth semiconductor layer 136 through the second active layer 134 to the third semiconductor layer 134 is formed in the second light emitting structure 130. As described above, since the fourth semiconductor layer 136 is a p-type semiconductor layer, and the third semiconductor layer 132 is formed of an n-type semiconductor layer, the second light emitting structure 130 is turned on to form the second active layer 134. Can generate light.

Meanwhile, in the first light emitting structure 120, a positive voltage (+) is connected to the first semiconductor layer 122 and a negative voltage (−) is connected to the second semiconductor layer 126, thereby applying a reverse voltage. Thus, no current path is formed and the first light emitting structure 120 is turned off.

As shown in FIG. 4 and FIG. 5, the light emitting device 100 according to the embodiment may emit light for both forward bias and reverse bias in an AC power source.

Therefore, when the AC power source is used as the power source of the light emitting device 100, a separate rectifying circuit or a plurality of light emitting devices is not required. Therefore, the light emitting device 100 according to the embodiment and the light emitting device 100 according to the embodiment are The economics of the apparatus used can be improved.

In addition, since the light emitting device 100 formed of a single chip can emit light with respect to both the constant voltage bias and the reverse voltage bias, the light emission efficiency per unit area of the light emitting device 100 can be improved.

In addition, since a current path is formed for both the constant voltage and the reverse voltage, damage to the light emitting device 100 by ESD may be prevented, and a separate ESD protection device may not be required. In addition, since a separate ESD device may not be provided in the light emitting device package or the lighting device using the light emitting device 100 according to the embodiment, the volume of the light emitting device package or the lighting device may be reduced and the light of the ESD device may be reduced. Losses can be prevented.

In addition, each light emitting structure 120 and 130 generating light with respect to the reverse bias and the forward bias is included in one light emitting device 100 and each light emitting structure 120 and 13 is integrally formed so that one process In the first and second light emitting structures 120 and 130 may be grown. Therefore, the economics of the manufacturing process of the light emitting device 100 can be improved.

Meanwhile, referring back to FIGS. 1A to 5, the light emitting device 100 according to the embodiment may be formed between the second light emitting structure 130 and the first light emitting structure 120 and the second light emitting structure 130. The intermediate layer 150 may be included.

The intermediate layer 150 may have a predetermined thickness to isolate the first light emitting structure 120 from the second light emitting structure 130.

The intermediate layer 150 may be formed to have electrical conductivity and light transmittance. For example, the intermediate layer 150 may be formed of an oxide-based material such as ZnO, MgO, TiO ₂ , or may be formed of a material such as silicon doped with a predetermined dopant such as a first conductive type or a second conductive type dopant. It may be, but not limited to. Meanwhile, the intermediate layer 150 may have a single layer, a multilayer structure, or may have a predetermined pattern, but is not limited thereto.

Meanwhile, the intermediate layer 150 may be grown together when the first and second light emitting structures 120 and 130 are grown, or the first light emitting structure 120 may be grown after the second light emitting structure 130 is grown on a substrate formed of silicon. It may be formed by attaching the substrate on, but is not limited thereto.

Meanwhile, as illustrated in FIG. 1B, at least one region of the intermediate layer 150 may be removed to form a hole 152 in at least one region of the intermediate layer 150, and the second electrode may be formed through the hole 152. The 144 and the second semiconductor layer 126 may be in contact with each other.

Since the intermediate layer 150 is formed between the first light emitting structure 120 and the second light emitting structure 130, a current supplied from the second electrode 144 may flow through the intermediate layer 150. Accordingly, the current provided from the second electrode 144 may be supplied to the second semiconductor layer 126 and the third semiconductor layer 132 through the intermediate layer 150, and current spreading may be improved. Therefore, the luminous efficiency of the light emitting device 100 can be improved.

On the other hand, if the intermediate layer 150 is too thick, the luminous efficiency of the light emitting device 100 may be inhibited, and if the intermediate layer 150 is too thin, the current spreading effect may not be achieved, so that the thickness of the intermediate layer 150 10 nm to 1 um.

6 is a cross-sectional view of a light emitting device 100 according to the embodiment.

Referring to FIG. 6, the light emitting device 100 according to the embodiment is formed on the substrate 110, the substrate 110, and the first semiconductor layer 122, the second semiconductor layer 126, and the first semiconductor layer 126. And a first light emitting structure 120 including a first active layer 124 formed between the second semiconductor layers 122 and 126, and a third semiconductor layer 132 formed on the first light emitting structure 120. And a second light emitting structure 130 including a fourth semiconductor layer 136 and a second active layer 134 formed between the third and fourth semiconductor layers 132 and 136, and the substrate 110. May include a first uneven portion 114.

The first uneven portion 114 may be formed in at least one region of the surface of the substrate 110, but is not limited thereto. For example, as shown in FIG. 6, it may be formed in the region in contact with the buffer layer 112, or as shown in FIG. 7, but may be formed in the side region of the substrate 110, but is not limited thereto.

For example, the first uneven portion 114 may have a PSS (Patterned SubStrate) structure having a predetermined pattern, but is not limited thereto.

The first uneven portion 114 may be formed in a predetermined polygonal shape as shown in FIGS. 6 and 7, or may have a lens-shaped curvature as shown in FIG. 8, but is not limited thereto.

The first uneven portion 114 may etch a region of the substrate 110 by a predetermined etching process when the substrate 110 is manufactured, or first and second light emitting structures 120 and 130 on the substrate 110. After the growth, the substrate 110 may be formed by cutting the substrate 110 by a method such as a laser scribing process, but is not limited thereto.

As the first uneven portion 114 is formed on the surface of the substrate 110, total reflection of light at the interface between the substrate 110 and the buffer layer 112 or the outer surface of the substrate 110 may be prevented. . Therefore, the light extraction efficiency of the light emitting device 110 can be improved.

9 and 10 are cross-sectional views showing a light emitting device 100 according to the embodiment.

Referring to FIG. 9, the light emitting device 100 according to the embodiment may be formed on the substrate 110, the substrate 110, and the first semiconductor layer 122, the second semiconductor layer 126, and the first semiconductor layer 126. And a first light emitting structure 120 including a first active layer 124 formed between the second semiconductor layers 122 and 126, and a third semiconductor layer 132 formed on the first light emitting structure 120. And a second light emitting structure 130 including a fourth semiconductor layer 136 and a second active layer 134 formed between the third and fourth semiconductor layers 132 and 136. Second uneven parts 160 may be formed in at least one region of the side surfaces of the light emitting structures 120 and 130.

The second uneven portion 160 may be formed in at least one region of the side surfaces of the first and second light emitting structures 120 and 130, and may be formed in several regions or the entire region, but is not limited thereto. The second uneven portion 160 may be formed by performing etching on at least one region of the side surfaces of the first and second light emitting structures 120 and 130, but is not limited thereto.

Meanwhile, the etching process may include a wet and / or dry etching process, but is not limited thereto.

The etching process may be formed through a wet etching process using an etchant such as photo electrochemical (PEC) or KOH solution.

According to the etching process, second uneven parts 160 are formed on side surfaces of the first and second light emitting structures 120 and 130, and the height thereof may be 0.1 μm to 3 μm. The second uneven portion 160 may be irregularly formed in a random size or may have a desired shape and arrangement, but is not limited thereto. The second uneven portion 160 may be an uneven surface and may include at least one of a texture pattern, an uneven pattern, and an uneven pattern.

In addition, the shape of the second uneven portion 160 may be formed to have various shapes such as a cylinder, a polygonal pillar, a cone, a polygonal pyramid, a truncated cone, a polygonal truncated cone, and preferably includes a horn shape.

The second uneven portion 160 prevents light generated from the first and second active layers 124 and 134 from totally reflecting from the side surfaces of the first and second light emitting structures 120 and 130 to be reabsorbed or scattered. The light extraction structure is formed. That is, the second uneven portion 160 has an incident angle of less than or equal to a critical angle when light generated from the first and second active layers 124 and 134 is incident on the side surfaces of the first and second light emitting structures 120 and 130. Can be formed.

As the second uneven portion 160 is formed on the side surfaces of the first and second light emitting structures 120 and 130, light generated from the first and second active layers 124 and 134 is first and second. Since it is possible to prevent the total reflection from the side of the light emitting structure (120, 130) to be reabsorbed or scattered, it can contribute to the improvement of the light extraction efficiency of the light emitting device (100).

Meanwhile, as illustrated in FIG. 10, side surfaces of the first and second light emitting structures 120 and 130 may be formed to have an inclination angle. As the side surfaces of the first and second light emitting structures 120 and 130 are formed to have an inclination angle, an etching process is performed on the side surfaces of the first and second light emitting structures 120 and 130 to form second uneven portions ( 160 may be easy to form. In addition, the light distribution pattern of the light emitting device 100 may be improved by the light traveling through the side surfaces of the first and second light emitting structures 120 and 130 in various directions including the lateral direction.

On the other hand, when the inclination angle is too large or too small, the ratio of the size of the first and second active layers 124 and 134 to the size of the light emitting device 100 is reduced, so that the luminous efficiency of the light emitting device 100 is reduced. The angle of inclination may be between 50 ° and 90 °.

Meanwhile, the growth surfaces of the first and second light emitting structures 120 and 130 may be nonpolar or semipolar crystal surfaces. For example, the C-plane {0001} of the GaN crystals forming the first and second light emitting structures 120 and 130 may be formed on the sides of the first and second light emitting structures 120 and 130, and thus Ga-face, or N-face, may be formed on the side surfaces of the first and second light emitting structures 120 and 130.

That is, when the growth surfaces of the first and second light emitting structures 120 and 130 are nonpolar or semipolar crystal surfaces, the Ga-face or N-face may be formed on the side surfaces of the first and second light emitting structures 120 and 130. Can be formed. Since the Ga-face and the N-face may be easily etched through a wet etching process, the uneven portions 160 may be formed on the side surfaces of the first and second light emitting structures 120 and 130 through the wet etching process. have. In addition, since the growth surfaces of the first and second light emitting structures 120 and 130 are formed as non-polar or semi-polar crystal surfaces, the piezoelectric polarization and the electrostatic field due to the piezoelectric polarization are weakened. The probability of recombination of electrons and holes in the second active layers 132 and 134 is increased, and the luminous efficiency of the light emitting device 100 can be improved.

11 is a cross-sectional view of a light emitting device according to the embodiment.

Referring to FIG. 11, the light emitting device 100 according to the embodiment is formed on the substrate 110, the substrate 110, and the first semiconductor layer 122, the second semiconductor layer 126, and the first semiconductor layer 126. And a first light emitting structure 120 including a first active layer 124 formed between the second semiconductor layers 122 and 126, and a third semiconductor layer 132 formed on the first light emitting structure 120. And a second light emitting structure 130 including a fourth semiconductor layer 136 and a second active layer 134 formed between the third and fourth semiconductor layers 132 and 136. 142 and the third electrode 146 are connected, and a first insulating layer 148 is formed between the first electrode 142 and the third electrode 146 and the first and second light emitting structures 120 and 130. The second insulating layer 149 may be formed between the second electrode 144 and the second light emitting structure 130.

The first electrode 142 and the third electrode 146 may be connected to each other, for example, may be formed continuously as shown in FIG. Since the first electrode 142 and the third electrode 146 are connected and integrally formed, the electrode may be easily formed.

The first insulating layer 148 is formed between the first and third electrodes 142 and 146 and the side portions of the first and second light emitting structures 120 and 130 to form the first and third electrodes 142 and 146. It is possible to prevent the first and second light emitting structures 120 and 130 from being shorted unnecessarily.

That is, the first insulating layer 149 may be formed on the sidewalls of the first and second light emitting structures 120 and 130 described above.

The second insulating layer 149 may be formed on the sidewall of the second light emitting structure 130 to prevent the second electrode 144 and the second light emitting structure 130 from being unnecessarily shorted.

That is, the second insulating layer 149 may be formed on sidewalls of the second light emitting structure 130 described above.

The first and second insulating layers 148 and 149 are electrically insulating materials such as SiO ₂ , SiO _x , SiO _x N _y , Si ₃ N ₄ , Al ₂ O ₃ , TiO _x , TiO ₂ , Ti, Al It may include any one of Cr, but is not limited thereto.

12 is a cross-sectional view of a light emitting device according to the embodiment.

Referring to FIG. 12, the light emitting device 100 according to the embodiment may be formed on the substrate 110, the substrate 110, and the first semiconductor layer 122, the second semiconductor layer 126, and the first semiconductor layer 126. And a first light emitting structure 120 including a first active layer 124 formed between the second semiconductor layers 122 and 126, and a third semiconductor layer 132 formed on the first light emitting structure 120. And a second light emitting structure 130 including a fourth semiconductor layer 136 and a second active layer 134 formed between the third and fourth semiconductor layers 132 and 136. The three electrodes 142, 144, and 146 may have a multilayer structure.

Hereinafter, the third electrode 146 will be described, but it is obvious that the present invention can be applied to the first and second electrodes 142 and 144 as well as the third electrode 146.

Referring to FIG. 12, the third electrode 146 may include a bonding layer 146a, a reflective layer 146b, and a protective layer 146c. In addition, the wire bonding layer 146d may be further included to connect the wires when the light emitting device package (not shown) is manufactured as described below.

The reflective layer 146b may include silver alloy.

Since the reflective layer 146b includes silver (Ag) having high reflectivity, the reflectivity of the third electrode 146 may be improved and the luminous efficiency of the light emitting device 100 may be improved. In addition, by being made of a silver alloy, it is possible to prevent the point where Vf increases when the third electrode 146 is heat treated, and the occurrence of Galvanic corrosion or the like due to a contact potential difference or the like.

On the other hand, when the fourth semiconductor layer 136 is formed of an n-type semiconductor layer and the reflective layer 146b is formed of simple silver, it may be difficult for the third electrode 146 and the fourth semiconductor layer 136 to form ohmic contact. have. However, as the reflective layer 146b includes a silver alloy, high reflectivity by silver may be ensured, and at the same time, the third semiconductor layer 136 and the first third electrode 146 may form ohmic contacts.

Meanwhile, the silver alloy may include silver (Ag) and at least one of Cu, Re, Bi, Al, Zn, W, Sn, In, and Ni, but is not limited thereto. On the other hand, silver alloy is 100? To 700? It can be formed by performing an alloy in.

On the other hand, silver (Ag) may contain 50 wt% or more, but is not limited thereto.

The bonding layer 146a may be formed of at least one of Cr, Ti, V, Ta, and Al. The bonding layer 146a may improve adhesion between the third electrode 146 and the third semiconductor layer 136. It suppresses excessive diffusion and migration of silver contained in. In addition, the protective layer 146c may be formed of at least one of Cr, Ti, Ni, Pd, Pt, W, Co, and Cu, which suppresses excessive injection of external oxygen and excessive external diffusion of silver particles, It can prevent agglomeration and public phenomena.

Meanwhile, the bonding layer 146a, the reflective layer 146b, and the protective layer 146c may be sequentially deposited or formed at the same time, and the annealing process may be performed after the formation, but is not limited thereto. Meanwhile, only the bonding layer 146a and the reflective layer 146b may be sequentially deposited or simultaneously formed, but are not limited thereto. Meanwhile, when the bonding layer 146a and the reflective layer 146b are simultaneously formed and alloyed, they may be formed of one layer Ag _x M _y A _z (1 ≧ x ≧ 0.5).

When the third electrode 146 configured as described above is subjected to heat treatment, the third electrode 146 may be bonded to the fourth semiconductor layer 136 with low contact resistance and strong adhesive force.

In addition, since no galvanic corrosion or the like occurs due to heat treatment and excessive diffusion of silver particles by the heat treatment is prevented by the bonding layer 146a and the protective layer 146c, the third electrode 146 has high light unique to silver. Reflectivity characteristics can be maintained.

Meanwhile, when the light emitting device 100 is mounted on a light emitting device package (not shown), the wire bonding layer 146d may be formed such that a wire connected to apply an external power source is bonded. The wire bonding layer 146d may include, for example, gold, but is not limited thereto.

Meanwhile, at least one of the first to third electrodes 142, 144, and 146 may be a pad electrode.

13 and 14 are cross-sectional views of the light emitting device 100 according to the embodiment.

Referring to FIG. 13, the light emitting device according to the embodiment includes a substrate 110, a first semiconductor layer 122, a second semiconductor layer 126, and first and second electrodes formed on the substrate 110. A first light emitting structure 120 including a first active layer 124 formed between the semiconductor layers 122 and 126, and a third semiconductor layer 132 and a fourth formed on the first light emitting structure 120. A second light emitting structure 130 including a semiconductor layer 136 and a second active layer 134 formed between the third and fourth semiconductor layers 132 and 136, and including the second light emitting structure 130. The transmissive electrode layer 170 may be formed on the substrate.

The transparent electrode layer 170 may include a light transmissive conductive material such as IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, but is not limited thereto.

By forming the transparent electrode layer 170 on the second light emitting structure 130, current spreading may be improved. Therefore, the current provided to the second light emitting structure 130 may be evenly spread so that the recombination rate between electrons and holes in the second active layer 134 may increase.

Meanwhile, as illustrated in FIG. 14, at least one region of the transparent electrode layer 170 may be removed to expose the fourth semiconductor layer 136 and the fourth semiconductor layer 136 and the third electrode 146 may be in contact with each other. It is not limited thereto.

In this case, the fourth semiconductor layer 136 and the third electrode 146 may form a Schottky junction. In this case, the metal material forming the third electrode 146 may have a higher work function than the fourth semiconductor layer 136. As the fourth semiconductor layer 136 and the third electrode 146 form a Schottky junction, the current supplied through the third electrode 146 is not concentrated under the third electrode 146, and thus the transparent electrode layer 170 is provided. Flow through) may improve current spreading.

15 is a cross-sectional view of a light emitting device 100 according to the embodiment.

Referring to FIG. 15, the light emitting device 100 according to the embodiment may be formed on the substrate 110, the substrate 110, and the first semiconductor layer 122, the second semiconductor layer 126, and the first semiconductor layer 126. And a first light emitting structure 120 including a first active layer 124 formed between the second semiconductor layers 122 126, a third semiconductor layer 132 formed on the first light emitting structure 120, And a second light emitting structure 130 including a fourth semiconductor layer 136 and a second active layer 134 formed between the third and fourth semiconductor layers 132 and 136. Several translucent structures 172 on 130, and transmissive electrode layers 170 may be formed on the translucent structures 172.

The light transmissive structure 172 may be formed such that several structures having light transmissivity are arranged on the fourth semiconductor layer 136. The light-transmitting structure 172 may include, for example, materials of Al ₂ O ₃ , SiO ₂ , IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, and the like, but is not limited thereto.

The translucent structure 172 is formed by, for example, several particles having a predetermined size scattered on the fourth semiconductor layer 136, or a layer having a predetermined thickness and roughness formed on the fourth semiconductor layer! 36. It can be formed by this, but is not limited thereto. On the other hand, the light-transmitting structure 172 may be disposed having a predetermined pattern, or randomly distributed, but is not limited thereto.

Meanwhile, as illustrated in FIG. 15, the transparent electrode layer 170 may be formed on the transparent structure 172. The formation of the transmissive electrode layer 170 on the translucent structure 172 improves current spreading and prevents the translucent structure 172 from escaping from the fourth semiconductor layer 136 or damaging the translucent structure 172. Can be.

By forming several translucent structures 172 on the fourth semiconductor layer 136, the second uneven portion 174 having a predetermined roughness may be formed on the fourth semiconductor layer 136.

The second uneven portion 174 may be formed to have a regular shape and arrangement, and may be formed to have an irregular shape and arrangement, but is not limited thereto. The second uneven portion 174 is an uneven upper surface, and a plurality of irregular shapes are arranged or form a predetermined pattern to form at least one of a texture pattern, an uneven pattern, and an uneven pattern. It may include, but is not limited to.

The second concave-convex portion 174 may be formed to have various shapes such as a cylinder, a polygonal pillar, a cone, a polygonal pyramid, a truncated cone, a polygonal truncated cone, and preferably includes a horn shape.

The second uneven portion 174 forms a light extraction structure that prevents light generated from the first and second active layers 124 and 134 from being totally reflected on the upper surface of the second light emitting structure 130 to be reabsorbed or scattered. do. That is, the second uneven portion 174 may form an angle of incidence below the critical angle when light generated from the first and second active layers 124 and 134 is incident on the upper surface of the second light emitting structure 130.

As the second uneven portion 174 is formed on the top surface of the second light emitting structure 130, light generated from the first and second active layers 124 and 134 is totally reflected at the top surface of the second light emitting structure 130. Since it can be prevented to be reabsorbed or scattered, it can contribute to the improvement of the light extraction efficiency of the light emitting device 100.

16 is a cross-sectional view of a light emitting device according to the embodiment.

Referring to FIG. 16, the light emitting device 100 according to the embodiment may be formed on the substrate 110, the substrate 110, and the first semiconductor layer 122, the second semiconductor layer 126, and the first semiconductor layer 126. And a first light emitting structure 120 including a first active layer 124 formed between the second semiconductor layers 122 and 126, and a third semiconductor layer 132 formed on the first light emitting structure 120. And a second light emitting structure 130 including a fourth semiconductor layer 136 and a second active layer 134 formed between the third and fourth semiconductor layers 132 and 136. The light emitting structures 120 and 130 may include electron blocking layers (EBLs) 128 and 138, respectively.

For example, as illustrated in FIG. 17, the first light emitting structure 120 may include a first electron blocking layer 128, and the second light emitting structure 130 may include a second electron blocking layer 138. .

The first and second electron confinement layers 128 and 138 have relatively larger bandgaps than the first and second active layers 124 and 134, thereby implanting from the first and third semiconductor layers 122 and 132. The electrons can be prevented from being injected into the second and fourth semiconductor layers 126 and 136 without being recombined in the first and second active layers 124 and 134. Accordingly, the probability of recombination of electrons and holes in the first and second active layers 124 and 134 may be increased, and leakage current may be prevented.

Meanwhile, the above-described first and second electron limiting layers 128 and 138 may have a bandgap larger than that of the barrier layers included in the first and second active layers 124 and 134, for example, p-type AlGaN. It may be formed of a semiconductor layer including Al, such as, but not limited to.

Meanwhile, the first and second electron limiting layers 128 and 138 may be disposed between the first semiconductor layer 122 and the second semiconductor layer 126, and between the third semiconductor layer 132 and the fourth semiconductor layer 136. Can be formed. In FIG. 18, a first electron limiting layer 128 is formed between the second semiconductor layer 126 and the first active layer 124, and second electrons are formed between the fourth semiconductor layer 136 and the second active layer 134. The restriction layer 138 is formed, but is not limited thereto. That is, as shown in FIG. 19, a first electron limiting layer 128 is formed between the first semiconductor layer 122 and the first active layer 124, and the third semiconductor layer 132 and the second active layer 134 are formed. The second electron limiting layer 138 may be formed between the layers, but is not limited thereto.

18 is a cross-sectional view of a light emitting device according to the embodiment, FIG. 19 is an enlarged cross-sectional view showing a region C of FIG. 18, and FIGS. 20 and 21 are diagrams showing energy band diagrams of the light emitting device according to the embodiment.

Referring to FIG. 18, the second active layer 134 of the light emitting device 100 may have a multi-quantum well structure. For example, the second active layer 134 may include first to third well layers Q1, Q2, and Q3 and first to third barrier layers B1, B2, and B3.

Hereinafter, the multi-quantum well structure of the second active layer 134 will be described, but the first active layer 124 may also have a multi-quantum well structure, and the following description is also the same for the first active layer 124.

The first to third well layers Q1, Q2, and Q3 and the first to third barrier layers B1, B2, and B3 may have a structure in which they are alternately stacked as shown in FIG. 21.

Meanwhile, in FIG. 19, the first to third well layers Q1, Q2, and Q3 and the first to third barrier layers B1, B2, and B3 are formed, respectively, and the first to third barrier layers B1, B2, B3) and the first to third well layers Q1, Q2, and Q3 are alternately formed, but are not limited thereto, and the well layers Q1, Q2, and Q3 and the barrier layers B1, B2, and B3 may be alternately formed. ) May be formed to have any number, and the arrangement may also have any arrangement. In addition, as described above, the composition ratios, band gaps, and thicknesses of the materials forming the respective well layers Q1, Q2, and Q3, and the respective barrier layers B1, B2, and B3 may be different from each other. It is not limited as shown in 21.

20 to 21, the band gap of the third well layer Q3 may be larger than the band gaps of the first and second well layers Q1 and Q2.

The band gap of the third well layer Q3 adjacent to the fourth semiconductor layer 136, which provides holes in the second active layer 134, is larger than the band gaps of the first and second well layers Q1 and Q2. As it is formed, the movement of holes can be facilitated. Accordingly, the efficiency of injecting holes into the first and second well layers Q1 and Q2 and the overall hole injection efficiency may be increased.

In addition, since the band gap of the third well layer Q3 is larger than the first and second well layers Q1 and Q2 and smaller than the barrier layers B1, B2 and B3, the barrier layers B1 and B2 having a large band gap are provided. , B3) and the second semiconductor layer 126 and the band gap between the small band gap well layers Q1, Q2, and Q3, to alleviate interlayer stress generation, thereby further improving the reliability of the light emitting device 100. Can be.

On the other hand, in as described above, the well layer (Q1, Q2, Q3) is _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0 ≤y≤1, 0≤x + y≤1) It may have a composition formula. The higher the In content of the well layers Q1, Q2, and Q3, the smaller the band gap. On the contrary, the smaller the In content of the well layers Q1, Q2, and Q3, the smaller the band gap of the well layers Q1, Q2, and Q3. Can be large.

For example, the In content of the third well layer Q3 may be 90% to 99% of the In content of the first and second well layers Q1 and Q2. When the In content is less than 90%, the difference in lattice constant between the first and second well layers Q1 and Q2 becomes larger in the band gap of the third well layer Q3, and the crystallinity is lowered. In addition, when In content is 99% or more, there is no big difference with 1st and 2nd well layers Q1 and Q2, and it does not have a big influence on hole injection and hardening improvement. The ratio may be any one of a molar ratio, a volume ratio, and a mass ratio, but is not limited thereto.

On the other hand, the piezoelectric polariziton generated by the stress due to the lattice constant difference and the orientation between the semiconductor layers may occur in the semiconductor layer. The semiconductor material forming the light emitting element has a large value of the piezoelectric coefficient and thus can cause very large polarization even at small strains. The electric field caused by the two polarizations changes the energy band structure of the quantum well structure, thereby distorting the distribution of electrons and holes. This effect is called the quantum confined stark effect (QCSE), which causes low internal quantum efficiency in light emitting devices that generate light by recombination of electrons and holes, and emits light such as red shift in the emission spectrum. It may adversely affect the electrical and optical characteristics of the device.

As it described above, the composition formula of the well layer (Q1, Q2, Q3) is _{In x Al y Ga 1 -x- y} N (0≤x≤1, 0 ≤y≤1, 0≤x + y≤1) The barrier layers B1, B2, and B3 may have a composition formula of In _a Al _b Ga ₁ _-a- _b N (0≤a≤1, 0≤b≤1, 0≤a + b≤1). . The lattice constant of InN is larger than GaN, and as the In content included in the well layers Q1, Q2, and Q3 increases, the lattice constant of the well layers Q1, Q2, and Q3 increases, so that the barrier layers B1, B2, and B3 The difference in lattice constant between the well layers Q1, Q2, and Q3 increases, which results in more strain between the layers. Due to this strain, the polarization effect as described above is further increased to strengthen the internal electric field. Accordingly, the band bends according to the electric field, resulting in a pointed triangle potential well, and the shape where electrons or holes are concentrated in the triangle potential well. May occur. Therefore, the recombination rate of electrons and holes may decrease.

According to an embodiment, as the In content of the third well layer Q3 decreases to decrease the lattice constant, the lattice constant difference between the barrier layers B1, B2 and B3 and the third well layer Q3 may decrease. Can be. Therefore, the generation of the above-described triangle potential wells can be reduced, thus the recombination rate of electrons and holes can be increased, and the luminous efficiency of the light emitting device 100 can be improved.

In addition, the band gap of the third well layer Q3 adjacent to the fourth semiconductor layer 126 is large and has a high potential barrier, thereby providing a carrier (for example, a hole) provided in the second semiconductor layer 126. Resistivity can lead to hole diffusion. Recombination of electrons and holes occurs in a wider range over the area of the second active layer 134 through the path diffusion of holes, thereby improving the coupling ratio of electrons and holes, thus improving the luminous efficiency of the light emitting device 100. Can be.

On the other hand, since the crystal defects due to the lattice constant difference between the substrate 110 and the first light emitting structure 120 formed on the substrate 110 tend to increase in accordance with the growth direction, it is most spaced apart from the substrate 110. The fourth semiconductor layer 136 formed at the position may have the largest crystal defect. Considering the fact that the hole mobility is lower than the electron mobility, the decrease in the hole injection efficiency due to the decrease in the crystallinity of the fourth semiconductor layer 136 is the luminous efficiency of the light emitting device 100. Can be lowered.

However, as in the embodiment, since the band gap of the third well layer Q3 of the second active layer 134 is formed to be large, the propagation of crystal defects can be blocked, so that the crystal defects of the fourth semiconductor layer 136 can be improved. In addition, the luminous efficiency of the light emitting device 100 may be improved.

Meanwhile, as illustrated in FIG. 21, the band gaps of the first to third well layers Q1, Q2, and Q3 may be formed to be large in sequence.

That is, the content of In included in the first to third well layers Q1, Q2, and Q3 may be sequentially decreased from the first well layer Q1 to the third well layer Q3.

The holes of the first to third well layers Q1, Q2, and Q3 are formed as the well layers Q1, Q2, and Q3 have larger band gaps as they are adjacent to the fourth semiconductor layer 136 that injects holes. Injection efficiency may be improved, and thus, light emission efficiency of the light emitting device 100 may be improved.

In addition, as the band gaps are sequentially increased from the first well layer Q1 to the third well layer Q3, the well layers Q1, Q2, and Q3, the barrier layers B1, B2, and B3, and the third, The difference in the lattice constant between the fourth semiconductor layers 132 and 134 is alleviated, thereby reducing the occurrence of the triangle potential well, thus increasing the recombination rate of electrons and holes, and improving the luminous efficiency of the light emitting device 100. Can be.

On the other hand, the thickness of the well layer (not shown) of the first active layer 124, the thickness and the band gap size of the first to third well layers (Q1, Q2, Q3) of the second active layer 134 may be different from each other. Can be.

For example, the energy level formula of light generated in the well layer is as follows.

At this time, L corresponds to the thicknesses d1 and d2 of the well layer. Therefore, as the thicknesses of the first to third well layers Q1, Q2 and Q3 become thicker, the energy level of light generated in the first to third well layers Q1, Q2 and Q3 becomes lower.

The thickness of the well layer (not shown) of the first active layer 124 and the thickness of the first to third well layers Q1, Q2, and Q3 of the second active layer are formed to be different from each other, thereby forming the first light emitting structure 120. ) And the second light emitting structure 130 may generate light having different wavelengths. For example, the first light emitting structure 120 may generate blue light, and the second light emitting structure 130 may generate green light. Accordingly, the light emitting device 100 may emit light of a plurality of colors, and may generate predetermined light such as white light without using a separate photocatalyst such as a phosphor (not shown) through overlapping of the multicolored light.

22 to 24 are a perspective view and a cross-sectional view showing a light emitting device package according to the embodiment.

22 to 24, the light emitting device package 500 may include a body 510 having a cavity 520, first and second lead frames 540 and 550 mounted on the body 510, and a first one. And a light emitting device 530 electrically connected to the second lead frames 540 and 550, and a resin layer (not shown) filled in the cavity 520 to cover the light emitting device 530.

The body 510 may be made of a resin material such as polyphthalamide (PPA), silicon (Si), aluminum (Al), aluminum nitride (AlN), liquid crystal polymer (PSG), polyamide 9T (SPS), a metal material, sapphire (Al ₂ O ₃ ), beryllium oxide (BeO), and a printed circuit board (PCB). The body 510 may be formed by injection molding, etching, or the like, but is not limited thereto.

The inner surface of the body 510 may be formed with an inclined surface. The reflection angle of the light emitted from the light emitting device 530 can be changed according to the angle of the inclined surface, and thus the directivity angle of the light emitted to the outside can be controlled.

Concentration of light emitted to the outside from the light emitting device 530 increases as the directivity angle of light decreases. Conversely, as the directivity angle of light increases, the concentration of light emitted from the light emitting device 530 decreases.

The shape of the cavity 520 formed in the body 510 may be circular, rectangular, polygonal, elliptical, or the like, and may have a curved shape, but the present invention is not limited thereto.

The light emitting device 530 is mounted on the first lead frame 540 and may be, for example, a light emitting device emitting light of red, green, blue, white, or UV (ultraviolet) light emitting device emitting ultraviolet light. But it is not limited thereto. In addition, one or more light emitting elements 530 may be mounted.

The light emitting device 530 may be a horizontal type or a vertical type formed on the upper or lower surface of the light emitting device 530 or a flip chip Applicable.

Meanwhile, the light emitting device 530 according to the embodiment may include first and second light emitting structures (not shown), and the first and second light emitting structures (not shown) may be driven in a reverse bias and a forward bias, respectively. . Therefore, the light emitting device package 500 according to the embodiment can emit light in both the reverse bias and the forward bias in the AC power source, the luminous efficiency can be improved.

In addition, since a separate ESD device is not required in the AC power source, light loss by the ESD device in the light emitting device package 500 may be prevented.

The resin layer (not shown) may be filled in the cavity 520 to cover the light emitting device 530.

The resin layer (not shown) may be formed of silicon, epoxy, and other resin materials, and may be formed by filling the cavity 520 and then UV or heat curing the same.

In addition, the resin layer (not shown) may include a phosphor, and the kind of the phosphor may be selected by the wavelength of the light emitted from the light emitting device 530 so that the light emitting device package 500 may realize the white light.

The phosphor may be one of a blue light emitting phosphor, a blue light emitting phosphor, a green light emitting phosphor, a sulfur green light emitting phosphor, a yellow light emitting phosphor, a yellow red light emitting phosphor, an orange light emitting phosphor, and a red light emitting phosphor depending on the wavelength of light emitted from the light emitting device 530 Can be applied.

That is, the phosphor may be excited by the light having the first light emitted from the light emitting device 530 to generate the second light. For example, when the light emitting element 530 is a blue light emitting diode and the phosphor is a yellow phosphor, the yellow phosphor may be excited by blue light to emit yellow light, and blue light and blue light emitted from the blue light emitting diode As the excited yellow light is mixed, the light emitting device package 500 can provide white light.

Similarly, when the light emitting element 530 is a green light emitting diode, the magenta phosphor or the blue and red phosphors are mixed, and when the light emitting element 530 is a red light emitting diode, the cyan phosphors or the blue and green phosphors are mixed For example.

Such a fluorescent material may be a known fluorescent material such as a YAG, TAG, sulfide, silicate, aluminate, nitride, carbide, nitridosilicate, borate, fluoride or phosphate.

The first and second lead frames 540 and 550 may be formed of a metal material such as titanium, copper, nickel, gold, chromium, tantalum, (Pt), tin (Sn), silver (Ag), phosphorus (P), aluminum (Al), indium (In), palladium (Pd), cobalt (Co), silicon (Si), germanium , Hafnium (Hf), ruthenium (Ru), and iron (Fe). Also, the first and second lead frames 540 and 550 may be formed to have a single layer or a multilayer structure, but the present invention is not limited thereto.

The first and second lead frames 540 and 550 are separated from each other and electrically separated from each other. The light emitting device 530 is mounted on the first and second lead frames 540 and 550, and the first and second lead frames 540 and 550 are in direct contact with the light emitting device 530 or a soldering member (not shown). May be electrically connected through a material having conductivity such as C). In addition, the light emitting device 530 may be electrically connected to the first and second lead frames 540 and 550 through wire bonding, but is not limited thereto. Accordingly, when power is supplied to the first and second lead frames 540 and 550, power may be applied to the light emitting device 530. Meanwhile, a plurality of lead frames (not shown) may be mounted in the body 510 and each lead frame (not shown) may be electrically connected to the light emitting device 530, but is not limited thereto.

Meanwhile, referring to FIG. 24, the light emitting device package 500 according to the embodiment may include an optical sheet 580, and the optical sheet 580 may include a base portion 582 and a prism pattern 584. Can be.

The base portion 582 is made of a transparent material having excellent thermal stability as a support for forming the prism pattern 584. For example, the base portion 582 is made of polyethylene terephthalate, polycarbonate, polypropylene, polyethylene, polystyrene, and polyepoxy. It may be made of any one selected from the group, but is not limited thereto.

In addition, the base portion 582 may include a phosphor (not shown). As an example, the base portion 582 may be formed by curing the phosphor (not shown) evenly in a state in which the base portion 582 is uniformly dispersed. As such, when the base portion 582 is formed, the phosphor (not shown) may be uniformly distributed over the base portion 582.

On the other hand, a three-dimensional prism pattern 584 that refracts and collects light may be formed on the base portion 582. The material constituting the prism pattern 584 may be acrylic resin, but is not limited thereto.

The prism pattern 584 includes a plurality of linear prisms arranged in parallel with one another in one direction on one surface of the base portion 582, and a vertical cross section of the linear prism in the axial direction may be triangular.

Since the prism pattern 584 has an effect of condensing light, when the optical sheet 580 is attached to the light emitting device package 500, the linearity of the light may be improved, and thus the brightness of the light of the light emitting device package 500 may be improved. have.

On the other hand, the prism pattern 584 may include a phosphor (not shown).

The phosphor (not shown) is uniformly formed in the prism pattern 584 by forming the prism pattern 584 in a dispersed state, for example, by mixing with an acrylic resin to form a paste or slurry, and then forming the prism pattern 584. Can be included.

As such, when the phosphor (not shown) is included in the prism pattern 584, the uniformity and distribution of the light of the light emitting device package 500 may be improved, and in addition to the light condensing effect by the prism pattern 584, the phosphor (not shown) may be used. Due to the light scattering effect, the directivity of the light emitting device package 500 can be improved.

A plurality of light emitting device packages 500 according to the embodiment may be arranged on a substrate, and a light guide plate, a prism sheet, a diffusion sheet, or the like, which is an optical member, may be disposed on an optical path of the light emitting device package 500. Such a light emitting device package, a substrate, and an optical member can function as a light unit. Another embodiment may be implemented as a display device, an indicator device, or a lighting system including the light emitting device or the light emitting device package described in the above embodiments, and for example, the lighting system may include a lamp or a street lamp.

25 is a perspective view illustrating a lighting apparatus including a light emitting device package according to an embodiment, and FIG. 26 is a cross-sectional view illustrating a C-C 'cross section of the lighting apparatus of FIG. 25.

25 and 26, the lighting device 600 may include a body 610, a cover 630 fastened to the body 610, and a closing cap 650 located at both ends of the body 610. have.

A light emitting device module 640 is coupled to a lower surface of the body 610. The body 610 is electrically conductive so that heat generated from the light emitting device package 644 can be emitted to the outside through the upper surface of the body 610. [ And a metal material having an excellent heat dissipation effect.

The light emitting device package 644 may be mounted on the PCB 642 in a multi-color, multi-row manner to form an array. The light emitting device package 644 may be mounted at equal intervals or may be mounted with various spacings as required. As the PCB 642, MPPCB (Metal Core PCB) or FR4 material PCB can be used.

On the other hand, the light emitting device package 644 according to the embodiment includes a light emitting device (not shown), the light emitting device (not shown) includes a first and a second light emitting structure (not shown), the first and second The light emitting structure (not shown) may be driven at reverse bias and forward bias, respectively. Therefore, the lighting device 600 according to the embodiment can emit light in both the reverse bias and the forward bias in the AC power source, the flicker phenomenon can be eliminated and the luminous efficiency can be improved.

Since the light emitting device package 644 may have an improved heat dissipation function including an extended lead frame (not shown), reliability and efficiency of the light emitting device package 644 may be improved, and the light emitting device package 622 and the light emitting device may be improved. The service life of the lighting device 600 including the device package 644 may be extended.

The cover 630 may be formed in a circular shape so as to surround the lower surface of the body 610, but is not limited thereto.

The cover 630 protects the internal light emitting element module 640 from foreign substances or the like. The cover 630 may include diffusion particles so as to prevent glare of light generated in the light emitting device package 644 and uniformly emit light to the outside, and may include at least one of an inner surface and an outer surface of the cover 630 A prism pattern or the like may be formed on one side. Further, the phosphor may be applied to at least one of the inner surface and the outer surface of the cover 630.

On the other hand, since the light generated from the light emitting device package 644 is emitted to the outside through the cover 630, the cover 630 should have excellent light transmittance, and has sufficient heat resistance to withstand the heat generated from the light emitting device package 644. The cover 630 is preferably formed of a material including polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), or the like. .

The finishing cap 650 is located at both ends of the body 610 and can be used to seal the power supply unit (not shown). In addition, the finishing cap 650 is provided with the power supply pin 652, so that the lighting apparatus 600 according to the embodiment can be used immediately without a separate device on the terminal from which the conventional fluorescent lamp is removed.

27 is an exploded perspective view of a liquid crystal display including the light emitting device according to the embodiment.

FIG. 27 is an edge-light method, and the liquid crystal display 700 may include a liquid crystal display panel 710 and a backlight unit 770 for providing light to the liquid crystal display panel 710.

The liquid crystal display panel 710 can display an image using light provided from the backlight unit 770. The liquid crystal display panel 710 may include a color filter substrate 712 and a thin film transistor substrate 714 facing each other with a liquid crystal therebetween.

The color filter substrate 712 can realize the color of an image to be displayed through the liquid crystal display panel 710.

The thin film transistor substrate 714 is electrically connected to the printed circuit board 718 on which a plurality of circuit components are mounted through the driving film 717. The thin film transistor substrate 714 may apply a driving voltage provided from the printed circuit board 718 to the liquid crystal in response to a driving signal provided from the printed circuit board 718. [

The thin film transistor substrate 714 may include a thin film transistor and a pixel electrode formed as a thin film on another substrate of a transparent material such as glass or plastic.

The backlight unit 770 includes a light emitting element module 720 that outputs light, a light guide plate 730 that changes the light provided from the light emitting element module 720 into a surface light source and provides the light to the liquid crystal display panel 710, A plurality of films 750, 766, and 764 for uniformly distributing the luminance of light provided from the light guide plate 730 and improving vertical incidence and a reflective sheet (not shown) for reflecting the light emitted to the rear of the light guide plate 730 to the light guide plate 730 740).

The light emitting device module 720 may include a PCB substrate 722 for mounting a plurality of light emitting device packages 724 and a plurality of light emitting device packages 724 to form an array.

On the other hand, the backlight unit 770 according to the embodiment includes a light emitting device (not shown), the light emitting device (not shown) includes a first and second light emitting structure (not shown), the first and second light emission The structure (not shown) can drive in reverse bias and forward bias, respectively. Therefore, the backlight unit 770 according to the embodiment can emit light in both the reverse bias and the forward bias in the AC power source, the flicker phenomenon can be eliminated and the luminous efficiency can be improved.

Meanwhile, the backlight unit 770 includes a diffusion film 766 for diffusing light incident from the light guide plate 730 toward the liquid crystal display panel 710, and a prism film 750 for condensing the diffused light to improve vertical incidence. It may be configured as), and may include a protective film 764 for protecting the prism film 750.

28 is an exploded perspective view of a liquid crystal display including the light emitting device according to the embodiment. However, the parts shown and described in FIG. 27 will not be repeatedly described in detail.

28 is a direct view, the liquid crystal display device 800 may include a liquid crystal display panel 810 and a backlight unit 870 for providing light to the liquid crystal display panel 810.

Since the liquid crystal display panel 810 is the same as that described with reference to FIG. 27, a detailed description thereof will be omitted.

The backlight unit 870 includes a plurality of light emitting element modules 823, a reflective sheet 824, a lower chassis 830 in which the light emitting element module 823 and the reflective sheet 824 are accommodated, And a plurality of optical films 860. The diffuser plate 840 and the plurality of optical films 860 are disposed on the light guide plate 840. [

LED Module 823 A plurality of light emitting device packages 822 and a plurality of light emitting device packages 822 may be mounted to include a PCB substrate 821 to form an array.

On the other hand, the backlight unit 870 according to the embodiment includes a light emitting device (not shown), the light emitting device (not shown) includes a first and second light emitting structure (not shown), the first and second light emission The structure (not shown) can drive in reverse bias and forward bias, respectively. Therefore, the backlight unit 870 according to the embodiment can emit light in both the reverse bias and the forward bias in the AC power source, the flicker phenomenon can be eliminated and the luminous efficiency can be improved.

The reflective sheet 824 reflects light generated from the light emitting device package 822 in a direction in which the liquid crystal display panel 810 is positioned, thereby improving light utilization efficiency.

Light generated in the light emitting element module 823 is incident on the diffusion plate 840 and an optical film 860 is disposed on the diffusion plate 840. The optical film 860 may include a diffusion film 866, a prism film 850, and a protective film 864.

Meanwhile, the light emitting device according to the embodiment is not limited to the configuration and method of the embodiments described above, but the embodiments may be modified so that all or some of the embodiments may be selectively And may be configured in combination.

In addition, while the preferred embodiments have been shown and described, the present invention is not limited to the specific embodiments described above, and the present invention is not limited to the specific embodiments described above, and the present invention may be used in the art without departing from the gist of the invention as claimed in the claims. Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

100 light emitting element 120 first light emitting structure
122: first semiconductor layer 124: first active layer
126: second semiconductor layer 130: second light emitting structure
132: third semiconductor layer 134: second active layer
136: fourth semiconductor layer 142: first electrode
144: second electrode 146: third electrode
150: middle layer

Claims

A first light emitting structure comprising a first semiconductor layer, a second semiconductor layer, and a first active layer formed between the first and second semiconductor layers;
A second light emitting structure on the first light emitting structure and including a third semiconductor layer, a fourth semiconductor layer, and a second active layer formed between the third and fourth semiconductor layers;
An intermediate layer formed between the first light emitting structure and the second light emitting structure and having light transmission and electrical conductivity;
A first electrode electrically connected to the first semiconductor layer;
A second electrode electrically connected to the second and third semiconductor layers; And
And a third electrode electrically connected to the fourth semiconductor layer.
The first and third semiconductor layers are doped with a first conductivity type,
And the second and fourth semiconductor layers are doped with a second conductivity type.

The method of claim 1,
The first, second, and third electrodes of the light emitting device are formed in the same direction.

The method of claim 1,
The first electrode and the third electrode is connected to each other,
The first light emitting structure and the second light emitting structure,
Light emitting devices connected in parallel to each other in a parallel structure.

The method of claim 1,
The first conductivity type is n-type light emitting device.

The method of claim 1,
The first to fourth semiconductor layer,
A light emitting device comprising a nitride semiconductor.

The method of claim 1,
The first to fourth semiconductor layer,
A light emitting device comprising a zinc oxide semiconductor.

The method of claim 1,
Wherein the intermediate layer comprises:
Light emitting device comprising an oxide-based material.

The method of claim 1,
Wherein the intermediate layer comprises:
A light emitting device comprising at least one of ZnO, MgO, and TiO ₂ .

The method of claim 1,
Wherein the intermediate layer comprises:
A light emitting device comprising silicon doped with either the first conductive type or the second conductive type.

The method of claim 1,
Wherein the intermediate layer comprises:
A light emitting device having a thickness of 10 nm to 1 um.