KR101877396B1 - Light emitting device - Google Patents

Abstract

A light emitting device according to an 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 a second light emitting structure formed on the first light emitting structure A second semiconductor layer, a fourth semiconductor layer, and a second active layer formed between the third and fourth semiconductor layers; a first electrode connected to the first semiconductor layer; A second electrode connected to the third semiconductor layer, and a third electrode connected to the fourth semiconductor layer, wherein the first and third semiconductor layers are doped with the first conductivity type, And is doped with a 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.

In the prior art, a rectifier circuit portion for converting AC power into DC power and a smoothing circuit portion for regulating the size of the rectified power source and supplying the rectified power to the light emitting element portion is disclosed in Japanese Unexamined Patent Application Publication No. 10-2009-0082453 Emitting device according to the present invention.

However, in the prior art 1, since a rectifying circuit portion and a smoothing circuit portion are required for driving the light emitting element portion in the AC power source, the economical efficiency of the light emitting device can be impaired.

Embodiments provide a light emitting device that can be driven for both a forward voltage and a reverse voltage in an AC power source.

A light emitting device according to an 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 a second light emitting structure formed on the first light emitting structure A second semiconductor layer, a fourth semiconductor layer, and a second active layer formed between the third and fourth semiconductor layers; a first electrode connected to the first semiconductor layer; A second electrode connected to the third semiconductor layer, and a third electrode connected to the fourth semiconductor layer, wherein the first and third semiconductor layers are doped with the first conductivity type, And is doped with a second conductivity type.

The light emitting device according to the embodiment can be driven with both the forward voltage and the reverse voltage in the AC power source. Therefore, the AC power source can be used as the power source of the light emitting element without a separate rectifying circuit. Therefore, a rectifying circuit in an AC power source, or a separate element and apparatus such as an ESD element can be omitted.

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

In addition, since the forward voltage driving light emitting structure and the backward voltage driving light emitting structure are included in a single chip and can be grown in one process in the AC power source according to the embodiment, the manufacturing process of the light emitting device is simplified, The economic efficiency can be improved.

1 is a cross-sectional view of a light emitting device according to an 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,
FIG. 4 is a driving diagram of a forward voltage of a light emitting device according to an embodiment,
5 is a driving diagram of a light emitting device according to an embodiment of the present invention,
6 is a cross-sectional view of a light emitting device according to an embodiment,
7 is a cross-sectional view of a light emitting device according to an embodiment,
8 is a cross-sectional view of a light emitting device according to an embodiment,
9 is a cross-sectional view of a light emitting device according to an embodiment,
10 is a partially enlarged cross-sectional view of a light emitting device according to an embodiment,
11 is a cross-sectional view of a light emitting device according to an embodiment,
12 is a cross-sectional view of a light emitting device according to an embodiment,
13 is a cross-sectional view of a light emitting device according to an embodiment,
14 is a sectional view of a light emitting device according to an embodiment,
15 is a cross-sectional view of a light emitting device according to an embodiment,
16 is a cross-sectional view of a light emitting device according to an embodiment,
17 is a cross-sectional view of a light emitting device according to an embodiment,
18 is a cross-sectional view of a light emitting device according to an embodiment,
19 is a cross-sectional view of a light emitting device according to an embodiment,
20 is a sectional view of a light emitting device according to an embodiment,
21 is a partially enlarged cross-sectional view of a light emitting device according to an embodiment,
22 is a diagram showing an energy band diagram of a light emitting device according to an embodiment,
23 is an energy band diagram of a light emitting device according to an embodiment,
24 is a conceptual diagram showing a circuit diagram of an illumination system including a light emitting device according to an embodiment,
25 is a conceptual diagram showing a circuit diagram of an illumination system including a light emitting device according to an embodiment,
26 is a perspective view of a light emitting device package including the light emitting device according to the embodiment,
27 is a sectional view of a light emitting device package including the light emitting device according to the embodiment,
28 is a sectional view of a light emitting device package including a light emitting device according to the embodiment,
29 is a perspective view showing an illumination system including a light emitting device according to an embodiment,
30 is a cross-sectional view taken along line C-C 'of the illumination system of FIG. 27,
31 is an exploded perspective view of a liquid crystal display device including a light emitting device according to an embodiment, and
32 is an exploded perspective view of a liquid crystal display device including a light emitting device according to an embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter 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 specification.

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 inverting an element shown in the figures, an element described as "below" or "beneath" of another element may be placed "above" another element. Thus, the exemplary term "below" can include both downward and upward directions. The elements can also be oriented in different directions, so that spatially relative terms can be interpreted according to orientation.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present 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 defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. 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.

FIG. 1 is a cross-sectional view 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.

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

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

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 facilitate growth of the semiconductor layer. The buffer layer 112 can be formed in a low-temperature atmosphere and can be made of a material that can alleviate 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 can be grown as a single crystal on the substrate 110 and the buffer layer 112 grown with a single crystal can improve the crystallinity of the first light emitting structure 120 grown on the buffer layer 112.

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

The first semiconductor layer 122 may be located on the buffer layer 112. The first semiconductor layer 122 may be doped with a first conductivity type. At this time, the first conductivity type may be n-type. For example, the first semiconductor layer 122 may be formed of 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, the first semiconductor layer 122 may be a semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like. Meanwhile, the first semiconductor layer 122 may be a zinc oxide based 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 + The first semiconductor layer 122 may include at least one selected from the group consisting of Si, Ge, Sn, and the like. The first semiconductor layer 122 may include, for example, ZnO, AlO, AlZnO, InZnO, InO, InAlZnO, AlInO, Type dopant can be doped.

Further, although the first semiconductor layer 122 may further include an unshown semiconductor layer (not shown), the present invention is not limited thereto. The undoped semiconductor layer (not shown) is a layer formed for improving the crystallinity of the first semiconductor layer 122, and has a lower electrical conductivity than the first semiconductor layer 122 without being doped with the n- And may be the same as the first semiconductor layer 122.

A 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 Group 3-V group elements .

When the first active layer 124 is formed into a quantum well structure, the first active layer 124 may have a multiple quantum well structure. Further, 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 having a barrier layer having a compositional formula of _{Al b Ga 1 -a- b N (} 0≤a≤1, 0 ≤b≤1, 0≤a + b≤1) may have a single or multiple quantum well structure. 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), the barrier layer In _a Al _b Zn _1-ab O (0? A? 1, 0? B? 1, 0? A + b? 1), but the present invention is not limited thereto. On the other hand, the well layer may be formed of a material having a band gap smaller than the band gap of the barrier layer.

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

A conductive clad layer (not shown) may be formed on and / or below the first active layer 124. The conductive clad layer (not shown) may be formed of AlGaN-based or AlZnO-based semiconductor, for example, 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. At this time, 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, the second semiconductor layer 126 may be a semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like. On the other hand, the second semiconductor layer 126 may be a zinc oxide-based semiconductor layer. For example, the second semiconductor layer 126 may be formed of 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 + For example, ZnO, AlO, AlZnO, InZnO, InO, InAlZnO. The second semiconductor layer 126 may be doped with a p-type dopant such as Mg, Zn, Ca, Sr, Ba, or the like.

The first semiconductor layer 122, the first active layer 124 and the second semiconductor layer 126 may be formed using a metal organic chemical vapor deposition (MOCVD) method, a chemical vapor deposition A vapor deposition method, a vapor deposition method, a plasma enhanced chemical vapor deposition (PECVD) method, a molecular beam epitaxy (MBE) method, a hydride vapor phase epitaxy (HVPE) method or a sputtering method But the present invention 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 uniform or non-uniform. That is, the plurality of semiconductor layers may be formed to have various doping concentration distributions, but the invention is not limited thereto.

The first semiconductor layer 122 may be a p-type semiconductor layer, the second semiconductor layer 126 may be an n-type semiconductor layer, and the n-type or p-type semiconductor layer 126 may be 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 located on the second semiconductor layer 126. The third semiconductor layer 132 may be doped with a first conductivity type, such as the first semiconductor layer 122. For example, if 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. At this time, the first conductivity type may be n-type. For example, the third semiconductor layer 132 may be formed of 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 a semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like. On the other hand, the third semiconductor layer 132 may be a zinc oxide based semiconductor layer. For example, the third semiconductor layer 132 may be 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 + For example ZnO, AlO, AlZnO, InZnO, InO, InAlZnO. AlInO, and the like. The third semiconductor layer 132 may be doped with an n-type dopant such as Si, Ge or Sn.

A 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 Group 3-V group elements .

The second active layer 134 may be formed in a quantum well structure. Further, the second active layer 134 may be a nitride-based or zinc oxide-based semiconductor layer. For example, the second active layer 134 is _{In x Al y Ga 1-xy} N well layer having a composition formula of (0≤x≤1, 0 ≤y≤1, 0≤x + y≤1) and Al _a In _{b May} have a single or multiple quantum well structure with a barrier layer having a composition formula of Ga _{1 -a- b} N (0? A? ₁ , 0? B? ₁ , 0? A + b? 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), the barrier layer In _a Al _b Zn _{1 -a- b} O may be formed to have a composition formula of (0≤a≤1, 0≤b≤1, 0≤a + b≤1 ), it shall not be limited thereto. On the other hand, the well layer may be formed of a material having a band gap smaller than the band gap of the barrier layer.

Further, when the second active layer 134 has a multiple quantum well structure, each well layer (not shown) may have a different composition and a different band gap from each other, which will be described later.

A conductive clad layer (not shown) may be formed on and / or below the second active layer 134. The conductive clad layer (not shown) may be formed of AlGaN-based or AlZnO-based semiconductor, for example, and may have a band gap larger than the band gap 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, if the second semiconductor layer 126 is of the second conductivity type, the fourth semiconductor layer 136 may also be doped with the second conductivity type. At this time, 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 layer 136 may be a semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like. On the other hand, the fourth semiconductor layer 136 may be a zinc oxide based semiconductor layer. For example, the fourth semiconductor layer 136 may be 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 + For example, ZnO, AlO, AlZnO, InZnO, InO, InAlZnO. The fourth semiconductor layer 136 may be doped with a p-type dopant such as Mg, Zn, Ca, Sr, or Ba.

The third semiconductor layer 132, the second active layer 134 and the fourth semiconductor layer 136 may be formed by a method such as MOCVD (Metal Organic Chemical Vapor Deposition), CVD A vapor deposition method, a vapor deposition method, a plasma enhanced chemical vapor deposition (PECVD) method, a molecular beam epitaxy (MBE) method, a hydride vapor phase epitaxy (HVPE) method or a sputtering method But the present invention 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 can be uniformly or nonuniformly formed. That is, the plurality of semiconductor layers may be formed to have various doping concentration distributions, but the invention is not limited thereto.

The third semiconductor layer 132 may be a p-type semiconductor layer, the fourth semiconductor layer 136 may be an n-type semiconductor layer, and the n-type or p-type semiconductor layer 136 may be 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 and may be sequentially grown in a single growth process. And the second light emitting structure 130 may be formed of the same material, but the present invention is not limited thereto. Since the first and second light emitting structures 120 and 130 may have at least one of np, pn, npn, and pnp junction structures, the light emitting device 100 may include npnp, nppn, but is not limited to, at least one of npnpn, nppnp, pnnp, pnpn, pnnpn, pnpnp, npnnp, npnpn, npnnpn, npnpnp, pnpnp, pnppn, pnpnpn and pnppnp.

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

The first light emitting structure 120 and the second light emitting structure 130 may have different structures, materials, thicknesses, compositions, and sizes, but the present invention is not limited thereto.

1 and 2 illustrate that the light emitting device 100 includes the first light emitting structure 120 and the second light emitting structure 130 formed on the first light emitting structure 120, And the light emitting device 100 may include at least two light emitting structures (not shown).

A first electrode 142 may be formed on at least one surface of the first semiconductor layer 122. For example, the first and second light emitting structures 120 and 130 may be partially removed to expose a portion of the first semiconductor layer 122, and the first electrode 142 May be formed. 1, the first semiconductor layer 122 includes an upper surface facing the first active layer 124 and a lower surface facing the substrate 110, and an upper surface includes a region exposed at least one region, , The first electrode 142 may be disposed on the exposed region 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 semiconductor light-emitting structure 130 may be removed to expose a region of the third semiconductor layer 132, and a second electrode 144 may be formed at the exposed region. That is, as shown in FIG. 1, the three semiconductor layers 132 include an upper surface facing the fourth semiconductor layer 136 and a lower surface facing the substrate 110, and the upper surface includes a region in which at least one region is exposed , The second electrode 144 may be disposed on the exposed region of the upper surface. On the other hand, a hole penetrating one region of the third semiconductor layer 132 may be formed to expose a part 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 hole.

On the other hand, a 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 the corner region of the fourth semiconductor layer 136, but is not limited thereto.

A method of exposing the first semiconductor layer 122, the second semiconductor layer 126, and the third semiconductor layer 132 may be 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, the first mesa etching is performed on one region of 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.

A first electrode 142 is formed on the first semiconductor layer 122 and a second electrode 144 is formed on the second and third semiconductor layers 126 and 132 and on the fourth semiconductor layer 136 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 formed continuously as one member. Accordingly, power of the same polarity can be applied to the first semiconductor layer 122 and the fourth semiconductor layer 136 through the first electrode 142 and the third electrode 146.

The second electrode 144 is formed on the second semiconductor layer 126 and the third semiconductor layer 132 so that a power of the same polarity is applied to the second semiconductor layer 126 and the third semiconductor layer 132 A method of removing a part of the first and second light emitting structures 120 and 130 may use a predetermined etching method, but the present invention is not limited thereto. The etching method may be a wet etching method or a dry etching method.

The first to third electrodes 142, 144 and 146 may be formed of a conductive material such as In, Co, Si, Ge, Au, Pd, Pt, Ru, Re, Mg, Zn, Hf, And may include a metal selected from the group consisting of Ir, W, Ti, Ag, Cr, Mo, Nb, Al, Ni, Cu and WTi, , IGZO, IGTO, AZO, ATO, and the like, but the present invention is not limited thereto.

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

Hereinafter, the operation of the light emitting device 100 according to the embodiment will be described with reference to FIGS. 3 to 5. FIG. 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 the light emitting device 100 according to the embodiment.

The first electrode 142 is connected to the first semiconductor layer 122 and the second electrode 144 is connected to the second semiconductor layer 126 and the third semiconductor layer 132, 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, The device 100 may have a circuit structure in which two light emitting diodes are connected in an anti-parallel structure as shown in FIG.

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

4, in the AC power source, the positive voltage (+) is connected to the second electrode 144 and the negative voltage (-) is connected to the first and third electrodes 142 and 146 have. Accordingly, the first conduction direction power source can be applied to the light emitting element 100. [

A first current path A flowing from the second semiconductor layer 126 to the first semiconductor layer 124 through the active layer 124 is formed in the first light emitting structure 120. 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 and the first active layer 124 ). ≪ / RTI >

Meanwhile, the positive voltage (+) is connected to the third semiconductor layer 132 and the negative voltage (-) is connected to the fourth semiconductor layer 136, and the reverse voltage is applied to the second light emitting structure 130. Thus, the current path is not formed and the second light emitting structure 130 is turned off.

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

The negative voltage (-) may be supplied to the second electrode 144 and the positive voltage (+) may be supplied to the first and third electrodes 142 and 146, as shown in FIG. Accordingly, the second conduction direction power source can be applied to the light emitting element 100. [ On the other hand, the first energizing direction and the second energizing direction described above may be reversed.

A second current path B is formed in the second light emitting structure 130 from the fourth semiconductor layer 136 to the third semiconductor layer 134 through the second active layer 134. Since the fourth semiconductor layer 136 is a p-type semiconductor layer and the third semiconductor layer 132 is an n-type semiconductor layer, the second light emitting structure 130 is turned on and the second active layer 134 is turned on, Light can be generated.

In the first light emitting structure 120, a positive voltage (+) is connected to the first semiconductor layer 122, a negative voltage (-) is connected to the second semiconductor layer 126, and a reverse voltage is applied. Thus, the current path is not formed and the first light emitting structure 120 is turned off.

As shown in FIGS. 4 and 5, the light emitting device 100 according to the embodiment can emit light for both the forward bias and the reverse bias in the 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 are not required. Therefore, the light emitting device 100 according to the embodiment, and the light emitting device 100 according to the embodiment The economical efficiency of the used apparatus can be improved.

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

In addition, since the current path is formed for both the positive voltage and the negative voltage, damage of the light emitting device 100 by the ESD can be prevented, and a separate ESD protection device may not be required. In addition, since no separate ESD device is 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 can be reduced, Loss can be prevented.

Each of the light emitting structures 120 and 130 generating light for the reverse bias and the forward bias is included in one light emitting device 100 and each of the light emitting structures 120 and 13 is integrally formed, The first and second light emitting structures 120 and 130 may be grown. Therefore, the economical efficiency of the manufacturing process of the light emitting device 100 can be improved.

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

Referring to FIG. 6, a light emitting device 100 according to an embodiment includes a substrate 110, a first semiconductor layer 122, a second semiconductor layer 126, And a first active layer 124 formed between the first and second semiconductor layers 122 and 126. The first semiconductor layer 132 is formed on the first semiconductor layer 120, And a second active layer 134 formed between the third and fourth semiconductor layers 132 and 136. The first and second semiconductor layers 136 and 136 are formed on the substrate 110, The first irregular portion 114 may include a first irregular portion 114.

The first concavo-convex part 114 may be formed on at least one area of the surface of the substrate 110, but is not limited thereto. For example, in an area in contact with the buffer layer 112 as shown in FIG. 6, or in a lateral area of the substrate 110 as shown in FIG. 7, but is not limited thereto.

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

The first concave-convex portion 114 may be formed in a predetermined polygonal shape as shown in Figs. 6 and 7, or may be formed to have a curvature of a lens shape as shown in Fig. 8, but is not limited thereto.

The first concavo-convex part 114 may be formed by etching a region of the substrate 110 by a predetermined etching process in the process of manufacturing the substrate 110 or by etching the first and second light emitting structures 120 and 130 on the substrate 110. [ And then cutting the substrate 110 by a method such as a laser scribing process. However, the present invention is not limited thereto.

The first concavo-convex portion 114 is formed on the surface of the substrate 110 to prevent the light from being totally reflected from the interface between the substrate 110 and the buffer layer 112 or the outer surface of the substrate 110 . Therefore, the light extraction efficiency of the light emitting element 110 can be improved.

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

9, the light emitting device 100 according to the embodiment includes a first semiconductor layer 122, a second semiconductor layer 126, and a first semiconductor layer 122 formed between the first and second semiconductor layers 122 and 126 A first semiconductor layer 120 formed on the first light emitting structure 120 and having a third semiconductor layer 132, a fourth semiconductor layer 136, A second light emitting structure 130 including a second active layer 134 formed between the first and second semiconductor layers 132 and 136 and a second light emitting structure 130 formed between the first and second light emitting structures 120 and 130 150).

The intermediate layer 150 has a predetermined thickness and isolates the first and second light emitting structures 120 and 130 from each other. 9, one region of the intermediate layer 150 may be removed, and the second electrode 144 may be formed in contact with the second semiconductor layer 126 through the region.

The intermediate layer 150 may be, for example, an undoped undoped semiconductor layer. Thus, the intermediate layer 150 may have a low electrical conductivity because it is not doped with a p-type dopant or an n-type dopant. The dopant may have the same composition and structure as the respective semiconductor layers forming the first or second light emitting structure 120, except that the dopant is not doped.

The intermediate layer 150 is formed between the first and second light emitting structures 120 and 130 so that diffusion between the first and second light emitting structures 120 and 130 and leakage current Can be prevented.

Referring to FIG. 10, the intermediate layer 150 may have a multi-layer structure including several layers 151, 152, 153, 154 and 155. Although several layers 151, 152, 153, 154 and 155 are illustrated in FIG. 10, the present invention is not limited thereto, and at least two or more layers may be formed.

Each layer 151, 152, 153, 154, 155 may have at least two different band gaps. For example, the intermediate layer 150 may have a structure in which several layers 151, 152, 153, 154, and 155 having different band gaps are repeatedly stacked alternately, but the present invention is not limited thereto.

The difference in lattice constant between the substrate 110 and the first semiconductor layer 122 may be large. In particular, such crystal defects tend to increase with the growth direction. The intermediate layer 150 includes several layers 151, 152, 153, 154 and 155 having different band gaps from each other and is formed between the first and second light emitting structures 120 and 130, It is possible to prevent the propagation of crystal defects generated in the lower portion of the substrate 150. Therefore, crystal defects can be prevented from being transferred to the upper portion of the intermediate layer 150. Therefore, the reliability and luminous efficiency of the luminous means 100 can be improved.

On the other hand, the intermediate layer 150 may be formed of, for example, GaN, InN, InGaN, AlGaN, ZnO, AlO, AlZnO, InZnO, InO, InAlZnO. AlInO, and each of the layers may be arranged such that a layer having the smallest band gap and a layer having the smallest band gap are in contact with each other, of the layers forming the multilayer structure.

For example, since the band gap becomes larger as the composition of AlN becomes higher and the band gap becomes smaller as the composition of InN becomes higher, the band gap of the layer containing InN is the lowest and the band gap of the layer containing AlN is formed the largest have. Therefore, a layer including AlN having the largest bandgap and a layer containing InN having the smallest bandgap can be formed in contact with each other.

On the other hand, a layer containing AlN having a small lattice constant generates tensile stress, and a layer containing InN having a large lattice constant may cause compress stress. Therefore, when the layer including AlN and the layer including InN are alternately stacked, the stress between the layers can be relaxed.

The intermediate layer 150 may include a reflective material having reflectance. On the other hand, each of the layers 151, 152, 153, 154, and 155 may have at least two different refractive indices. The intermediate layer 150 can function as a DBR (Distributed Bragg Reflector) layer having a reflectivity, since the intermediate layer 150 includes several layers 151, 152, 153, 154, 155 having at least two different refractive indices.

Since the intermediate layer 150 has a reflectivity, light generated in the first and second light emitting structures 120 and 130 can be reflected by the intermediate layer 150. Therefore, the light generated in the first light emitting structure 120 can be reflected without passing through the second light emitting structure 130, and can proceed in the lateral direction. On the other hand, the light generated in the second light emitting structure 130 may be reflected without passing through the first light emitting structure 120 and proceed upward. Therefore, the light loss of the light emitting element 100 is reduced, and lateral light emission can be made possible.

11 and 12 are sectional views showing a light emitting device 100 according to an embodiment.

Referring to FIG. 11, a light emitting device 100 according to an embodiment includes a first semiconductor layer 122, a second semiconductor layer 126, and a first semiconductor layer 122 formed between the first and second semiconductor layers 122 and 126 A first semiconductor layer 120 formed on the first light emitting structure 120 and having a third semiconductor layer 132, a fourth semiconductor layer 136, And a second active layer 134 including a second active layer 134 formed between the first and second semiconductor layers 132 and 136. The first and second semiconductor layers 132 and 136 may include at least one region The second uneven portion 160 may be formed.

The second concavo-convex part 160 may be formed on at least one side of the side surfaces of the first and second light emitting structures 120 and 130, and may be formed in several or all areas, but is not limited thereto. The second concavo-convex 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 etching process and / or a dry etching process, but is not limited thereto.

The etching process may be performed by a wet etching process using an etchant such as photoelectrochemical (PEC) or a KOH solution.

As a result of the etching process, second irregularities 160 are formed on the side surfaces of the first and second light emitting structures 120 and 130, and the height of the second irregularities 160 may be 0.1 μm to 3 μm. The second concavo-convex part 160 may be irregularly formed in a random size, or may be formed to have a desired shape and arrangement, but the present invention is not limited thereto. The second concave-convex portion 160 may be at least one of a texture pattern, a concavo-convex pattern, and an uneven pattern as an uneven surface.

The shape of the second concave-convex portion 160 may be formed to have various shapes such as a cylinder, a polygonal column, a cone, a polygonal pyramid, a truncated cone, a polygonal pyramid, and the like.

The second concavo-convex part 160 prevents the light generated from the first and second active layers 124 and 134 from being totally reflected by the side surfaces of the first and second light emitting structures 120 and 130 to be reabsorbed or scattered To form a light extracting structure. That is, when the 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, the second concave- Can be formed.

The light generated from the first and second active layers 124 and 134 is incident on the first and second light emitting structures 120 and 130 as the second concave and convex portion 160 is formed on the side surfaces of the first and second light emitting structures 120 and 130, The light can be prevented from being totally reflected and reabsorbed or scattered by the side surfaces of the light emitting structures 120 and 130, thereby contributing to an improvement in the light extraction efficiency of the light emitting device 100.

Meanwhile, as shown in FIG. 12, the sides of the first and second light emitting structures 120 and 130 may have inclined angles. The side surfaces of the first and second light emitting structures 120 and 130 are formed to have an inclination angle so that the side surfaces of the first and second light emitting structures 120 and 130 are etched to form the second concave / 160 may be easily formed. In addition, the light traveling through the side surfaces of the first and second light emitting structures 120 and 130 travels in various directions including the lateral direction, thereby improving the light distribution pattern of the light emitting device 100.

On the other hand, when the inclination angle is excessively large or small, the size ratio of the first and second active layers 124 and 134 becomes smaller than the size of the light emitting device 100, and the luminous efficiency of the light emitting device 100 becomes smaller, The tilt angle may be between 50 [deg.] And 90 [deg.].

On the other hand, the growth planes of the first and second light emitting structures 120 and 130 may be non-polar or semi-polar crystal planes. For example, the C-plane {0001} of the GaN crystal 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, A Ga-face, or an 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 surface of the first and second light emitting structures 120 and 130 is a non-polar or semi-polar crystal plane, Ga-face or N-face is formed on the sides of the first and second light emitting structures 120 and 130 . Since the Ga-face and the N-face can be easily etched through the wet etching process, the side surfaces of the first and second light emitting structures 120 and 130 can be formed by the wet etching process have. In addition, since the first and second light emitting structures 120 and 130 are formed in a nonpolar or semi-polar crystal plane, the piezoelectric polarizations and the electrostatic fields due to the piezoelectric polarization are weakened, The recombination probability of electrons and holes in the second active layers 132 and 134 increases and the luminous efficiency of the light emitting device 100 can be improved.

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

Referring to FIG. 13, the light emitting device 100 according to the embodiment includes a first semiconductor layer 122, a second semiconductor layer 126, and a first semiconductor layer 122 formed between the first and second semiconductor layers 122 and 126 A first semiconductor layer 120 formed on the first light emitting structure 120 and having a third semiconductor layer 132, a fourth semiconductor layer 136, The first electrode 142 and the third electrode 146 are connected to each other and the first electrode 142 and the third electrode 146 are connected to each other, 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 and the second electrode 144 and the second light emitting structure A second insulating layer 149 may be formed between the first and second insulating layers 130 and 130.

The first electrode 142 and the third electrode 146 may be connected to each other, and may be formed continuously as shown in FIG. 13, for example. The first electrode 142 and the third electrode 146 are connected to each other to form an integral electrode.

The first insulating layer 148 is formed between the first and third electrodes 142 and 146 and the sides of the first and second light emitting structures 120 and 130 and includes first and third electrodes 142 and 146, It is possible to prevent the first and second light emitting structures 120 and 130 from being unnecessarily short-circuited.

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

The second insulating layer 149 may be formed on the side wall of the second light emitting structure 130 to prevent the second electrode 144 and the second light emitting structure 130 from being unnecessarily short-circuited.

That is, the second insulating layer 149 may be formed on the side wall of the second mesa-etched second light-emitting structure 130 described above.

First and second insulating layers (148, 149) is a material having electrical insulating properties, for example SiO _2, SiO _x, SiO _x N _y, Si ₃ N _4, Al ₂ O _3, TiO _x, TiO _2, Ti, Al , And Cr, but the present invention is not limited thereto.

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

Referring to FIG. 14, a light emitting device 100 according to an embodiment includes a first semiconductor layer 122, a second semiconductor layer 126, and a first semiconductor layer 122 formed between the first and second semiconductor layers 122 and 126 A first semiconductor layer 120 formed on the first light emitting structure 120 and having a third semiconductor layer 132, a fourth semiconductor layer 136, The first to third electrodes 142, 144, and 146 have a multi-layer structure, and the second light emitting structure 130 includes a second active layer 134 formed between the first and second semiconductor layers 132 and 136, .

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

Referring to FIG. 14, the third electrode 146 may include a bonding layer 146a, a reflective layer 146b, and a protective layer 146c. In addition, as described later, the wire bonding layer 146d may further include a wire bonding layer 146d so that a wire can be connected when a light emitting device package (not shown) is manufactured.

The reflective layer 146b may include an Ag alloy.

The reflectivity of the third electrode 146 can be improved and the luminous efficiency of the light emitting device 100 can be improved by including the silver (Ag) having high reflectivity on the reflection layer 146b. In addition, since silver is formed of an alloy, it is possible to prevent galvanic corrosion or the like from occurring due to an increase in Vf when the third electrode 146 is heat-treated and a contact potential difference.

On the other hand, when the fourth semiconductor layer 136 is formed of an n-type semiconductor layer and the reflection layer 146b is formed of simple silver, the third electrode 146 and the fourth semiconductor layer 136 may be difficult to form an ohmic contact have. However, as the reflective layer 146b includes a silver alloy, the third semiconductor layer 136 and the first third electrode 146 can form ohmic contact while securing high reflectivity by silver.

Meanwhile, the silver alloy may be formed of 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? 700? The alloy may be formed.

On the other hand, silver (Ag) may be contained in an amount of 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 to improve adhesion between the third electrode 146 and the third semiconductor layer 136, Thereby suppressing excessive diffusion and migration of silver contained in the silver. The protective layer 146c may be formed of at least one of Cr, Ti, Ni, Pd, Pt, W, Co, and Cu. The protective layer 146c suppresses excessive external oxygen injection and excessive external diffusion of silver particles, It can prevent aggregation and public phenomena.

On the other hand, the bonding layer 146a, the reflective layer 146b, and the protective layer 146c may be sequentially deposited, or may be formed at the same time, or may be subjected to an annealing process after forming, but are not limited thereto. On the other hand, only the bonding layer 146a and the reflective layer 146b may be sequentially deposited or formed at the same time, but the present invention is not limited thereto. On the other hand, when the bonding layer 146a and the reflective layer 146b are simultaneously formed and alloyed, one layer (Ag _x M _y A _z (1? X? 0.5)) may be formed.

When the third electrode 146 having such a structure is subjected to heat treatment, the third electrode 146 can be bonded to the fourth semiconductor layer 136 with a low contact resistance and a strong adhesive force.

Further, since galvanic corrosion or the like by heat treatment does not occur and diffusion of excess silver particles by the heat treatment is prevented by the bonding layer 146a and the protective layer 146c, the third electrode 146 is made of silver- The reflectivity characteristic can be maintained.

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

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

15 and 16 are sectional views of the light emitting device 100 according to the embodiment.

15, the light emitting device according to the embodiment includes a first semiconductor layer 122, a second semiconductor layer 126, and a first active layer 130 formed between the first and second semiconductor layers 122 and 126, A first semiconductor layer 120 formed on the first semiconductor layer 120 and a third semiconductor layer 132 formed on the first semiconductor layer 120; A second light emitting structure 130 including a second active layer 134 formed between the first and second light emitting structures 130 and 132 and a light transmitting electrode layer 170 formed on the second light emitting structure 130.

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

By forming the light-transmitting electrode layer 170 on the second light emitting structure 130, the current spreading can be improved. Therefore, the current provided to the second light emitting structure 130 is uniformly diffused, and the recombination rate between electrons and holes in the second active layer 134 can be increased.

16, at least one region of the light-transmitting electrode layer 170 is removed so that the fourth semiconductor layer 136 is exposed and the fourth semiconductor layer 136 and the third electrode 146 are formed in contact with each other But not limited to,

At this time, the fourth semiconductor layer 136 and the third electrode 146 may form a Schottky junction. At this time, 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 on the lower portion of the third electrode 146, Lt; RTI ID = 0.0 > current spreading < / RTI > can be improved.

17 is a sectional view of a light emitting device 100 according to the embodiment.

Referring to FIG. 17, a light emitting device 100 according to an embodiment includes a first semiconductor layer 122, a second semiconductor layer 126, and a first semiconductor layer 122 126 formed between the first and second semiconductor layers 122 126 A first semiconductor layer 120 formed on the first semiconductor layer 120 and a third semiconductor layer 132 formed on the first semiconductor layer 132 and a third semiconductor layer 136 formed on the first semiconductor layer 120; And a second light emitting structure 130 including a second active layer 134 formed between the semiconductor layers 132 and 136. The first light emitting structure 130 includes a plurality of light transmitting structures 172, The light transmitting electrode layer 170 may be formed on the structure 172. [

The translucent structure 172 may be formed such that several structures having translucency are arranged on the fourth semiconductor layer 136. The translucent structure 172 may include, but is not limited to, Al ₂ O ₃ , SiO ₂ , IZO, IZTO, IAZO, IGZO, IGTO, AZO and ATO.

The translucent structure 172 may be formed, for example, such that several particles having a predetermined size are scattered on the fourth semiconductor layer 136, or a layer having a predetermined thickness and roughness is formed on the fourth semiconductor layer 36 , But is not limited thereto. On the other hand, the light transmitting structure 172 may be arranged with a predetermined pattern, or may be randomly scattered, but is not limited thereto.

On the other hand, the translucent electrode layer 170 may be formed on the translucent structure 172 as shown in FIG. The formation of the light transmitting electrode layer 170 on the light transmitting structure 172 improves the current spreading and prevents the light transmitting structure 172 from separating from the fourth semiconductor layer 136 or damaging the light transmitting structure 172 .

A plurality of light transmitting structures 172 may be formed on the fourth semiconductor layer 136 so that a second concave and convex portion 174 having a predetermined roughness may be formed on the fourth semiconductor layer 136.

The second concave-convex portion 174 may be formed to have regular shapes and arrangements, and may be formed to have irregular shapes and arrangements, but the invention is not limited thereto. The second concave-convex portion 174 is an uneven upper surface, and a plurality of irregularly shaped irregularities are arranged or formed into a predetermined pattern to form at least one of a texture pattern, a concavo-convex pattern, and an uneven pattern But is not limited thereto.

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

The second concave-convex portion 174 forms a light extracting 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 incident angle smaller than the critical angle when the 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.

The second concave-convex portion 174 is formed on the upper surface of the second light emitting structure 130 so that light generated from the first and second active layers 124 and 134 is totally reflected from the upper surface of the second light emitting structure 130, And thus can be prevented from being reabsorbed or scattered, thereby contributing to improvement of the light extraction efficiency of the light emitting device 100.

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

Referring to FIG. 18, a light emitting device 100 according to an embodiment includes a first semiconductor layer 122, a second semiconductor layer 126, and a first semiconductor layer 122 formed between the first and second semiconductor layers 122 and 126 A first semiconductor layer 120 formed on the first light emitting structure 120 and having a third semiconductor layer 132, a fourth semiconductor layer 136, The first and second light emitting structures 120 and 130 include a second active layer 134 formed between the first and second semiconductor layers 132 and 136, EBL: Electron Blocking Layer (128, 138).

For example, as shown in FIG. 18, the first light emitting structure 120 may include a first electron confinement layer 128 and the second light emitting structure 130 may include a second electron confinement layer 138 .

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

On the other hand, the first and second electron confinement layers 128 and 138 may have a band gap larger than the band gap of the barrier layer included in the first and second active layers 124 and 134. For example, p-type AlGaN But it is not limited thereto.

The first and second electron confinement layers 128 and 138 are formed 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 . A first electron confinement layer 128 is formed between the second semiconductor layer 126 and the first active layer 124 and a second electron confinement layer 128 is formed between the fourth semiconductor layer 136 and the second active layer 134. In this case, The limiting layer 138 is formed, but is not limited thereto. 19, the first electron confinement 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 The second electron confinement layer 138 may be formed, but is not limited thereto.

FIG. 20 is a cross-sectional view of the light emitting device according to the embodiment, FIG. 21 is an enlarged cross-sectional view showing the region B in FIG. 20, and FIGS. 22 and 23 are energy band diagrams of the light emitting device according to the embodiment.

Referring to FIG. 20, the second active layer 134 of the light emitting device 100 may have a multiple quantum well structure. For example, the second active layer 134 may include first through third well layers Q1, Q2, Q3 and first through third barrier layers B1, B2, and B3.

Hereinafter, the multiple quantum well structure of the second active layer 134 will be described. However, the first active layer 124 may also have a multiple quantum well structure, and the following description also applies to the first active layer 124.

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

In FIG. 21, the first through third well layers Q1, Q2 and Q3 and the first through third barrier layers B1, B2 and B3 are formed and the first through third barrier layers B1, B2, B3 and the first to third well layers Q1, Q2 and Q3 are alternately stacked, but not limited thereto, the well layers Q1, Q2 and Q3 and the barrier layers B1, B2 and B3 ) May be formed to have any number, and the arrangement may also have any arrangement. In addition, as described above, the composition ratio, band gap, and thickness of the material forming each of the well layers Q1, Q2, and Q3 and the barrier layers B1, B2, and B3 may be different from each other, 21 as shown in Fig.

22 to 23, the band gap of the third well layer Q3 may be formed to be larger than the band gap 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 providing holes in the second active layer 134 is larger than the band gap 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, Q2) and the overall hole injection efficiency can be increased.

Since the band gap of the third well layer Q3 is larger than that of 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 The reliability of the light emitting device 100 can be further improved by mitigating the occurrence of the interlayer stress due to the band gap difference between the second semiconductor layer 126 and the second semiconductor layer 126 and the well layers Q1, Q2 and Q3 having a small band gap .

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) May have a composition formula. The bandgap of the well layers Q1, Q2 and Q3 becomes smaller as the In content of the well layers Q1, Q2 and Q3 becomes lower. On the contrary, the smaller the In content 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, Q2) of the bandgap of the third well layer (Q3) becomes large, and the crystallinity deteriorates. When the In content is 99% or more, there is no significant difference from the first and second well layers (Q1 and Q2), so that the injection of holes and improvement in hardness are not greatly affected. The ratio may be any of a molar ratio, a volume ratio, and a mass ratio, but is not limited thereto.

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

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) has a barrier layer (B1, B2, 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≤≤≤ The lattice constants of the well layers Q1, Q2 and Q3 become larger as the lattice constant of InN is larger than that of GaN and the In content of the well layers Q1, Q2 and Q3 becomes larger, The difference in lattice constant between the well layers Q1, Q2 and Q3 increases, and thus the strain between the layers becomes larger. By this strain, the above-mentioned polarization effect is further increased, the internal electric field is strengthened, Therefore, the band is bent according to the electric field and a triangular potential well is formed, and a shape in which electrons and holes are concentrated in the triangle potential well may occur, so that the recombination rate of electrons and holes may be lowered.

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

The third well layer Q3 adjacent to the fourth semiconductor layer 126 has a large bandgap and a high potential barrier so that carriers (e.g., holes) provided in the second semiconductor layer 126 By having resistivity, it is possible to bring about path diffusion of holes. The recombination of electrons and holes occurs in a wider range over the area of the second active layer 134 through path diffusion of the holes to improve the bonding ratio of electrons and holes and thus the luminous efficiency of the luminous means 100 is improved .

On the other hand, since crystal defects due to the difference in lattice constant between the substrate 110 and the first light emitting structure 120 formed on the substrate 110 tend to increase with the growth direction, The fourth semiconductor layer 136 formed at the position may have the largest crystal defects. 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 caused by the light emitting efficiency of the light emitting element 100 Can be reduced.

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

On the other hand, as shown in FIG. 23, the band gaps of the first through third well layers Q1, Q2, and Q3 may be sequentially increased

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

The well layers Q1, Q2 and Q3 are formed to have a larger bandgap as the fourth semiconductor layer 136 for injecting holes is formed so as to be closer to the fourth semiconductor layer 136 for injecting holes. Therefore, the holes of the first to third well layers Q1, Q2 and Q3 The injection efficiency can be improved, and therefore the luminous efficiency of the luminous means 100 can be improved.

As the bandgap increases sequentially from the first well layer Q1 to the third well layer Q3, the well layers Q1, Q2 and Q3 and the barrier layers B1, B2 and B3 and the third, The difference in lattice constant between the fourth semiconductor layers 132 and 134 can be alleviated and the generation of triangle potential wells can be reduced and thus the recombination rate of electrons and holes can be increased and the luminous efficiency of the light emitting device 100 can be improved .

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

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

Here, L corresponds to the thickness (d1, d2) of the well layer. Accordingly, as the thicknesses of the first through third well layers Q1, Q2 and Q3 increase, the energy level of light generated in the first through third well layers Q1, Q2 and Q3 becomes low.

The thickness of the well layer (not shown) of the first active layer 124 and the thicknesses of the first through third well layers Q1, Q2 and Q3 of the second active layer are different from each other, And the second light emitting structure 130 may generate light having a different wavelength from each other. For example, the first light emitting structure 120 may generate blue light and the second light emitting structure 130 may generate green light. Therefore, the light emitting device 100 can emit multicolored light, and it is possible to generate predetermined light such as white light without using a separate photocatalyst such as a phosphor (not shown) by superposing the multi-colored light.

24 and 25 are conceptual diagrams showing a circuit diagram of an illumination system 200 including the light emitting device 100 according to the embodiment.

24 and 25, an illumination system 200 including a light emitting device 100 according to an embodiment includes at least one light emitting device 100, and each light emitting device 100 is configured to be connected in series .

Each of the light emitting devices 100 may be connected to a substrate (not shown) through a predetermined circuit pattern to form a light emitting device array. The light emitting device 100 may be mounted on a light emitting device package 500 to be described later and the light emitting device package 500 may be mounted on a substrate or may be mounted on a substrate (COB: Chip on Board) type in which the semiconductor device 100 is mounted, but the present invention is not limited thereto.

In addition, the illumination system 200 including the light emitting device 100 according to the embodiment may include, but is not limited to, a lighting device such as a lamp, a streetlight, a backlight unit, and the like.

Since the light emitting device 100 according to the embodiment includes the first light emitting structure 120 and the second light emitting structure 130 capable of generating light in the reverse voltage and the constant voltage phase of the AC power, When the AC power source is connected to the system 200, the light emitting device 100 can emit light for both the reverse voltage and the constant voltage phase. Therefore, the flickering phenomenon of the lighting system 200 due to the phase change between the application of the reverse voltage and the application of the positive voltage Can be prevented.

In addition, each of the light emitting devices 100 can be driven in both the reverse voltage and the constant voltage phase, and corresponding current paths are formed. Therefore, for example, as shown in FIGS. 24 and 25, 100) may be configured to be connected in series to the AC power source. Accordingly, the connection of several light emitting devices 100 can be facilitated, and the output of the lighting system 200 can be improved and output can be adjusted.

26 to 28 are a perspective view and a cross-sectional view of a light emitting device package including the light emitting device according to the embodiment.

26 to 28, the light emitting device package 500 includes a body 510 having a cavity 520, first and second lead frames 540 and 550 mounted on the body 510, And a resin layer (not shown) filled in the cavity 520 so as to cover the light emitting device 530. The light emitting device 530 may include a light emitting device 530 electrically connected to the first and second lead frames 540 and 550,

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 element 530 is mounted on the first lead frame 540 and may be a light emitting element that emits light such as red, green, blue, or white, or a UV (Ultra Violet) However, the present invention 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 includes first and second light emitting structures (not shown), and the first and second light emitting structures (not shown) may be driven with reverse bias and 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, so that the luminous efficiency can be improved.

In addition, since no separate ESD device is required in the AC power source, optical loss due to the ESD device in the light emitting device package 500 can 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, or other resin material. The resin layer may be filled in the cavity 520 and then formed by ultraviolet ray or thermal curing.

In addition, the resin layer (not shown) may include a phosphor, and the phosphor may be selected to be a wavelength of light emitted from the light emitting device 530 so that the light emitting device package 500 may realize 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 element 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 element 530, And may be electrically connected through a conductive material such as a conductive material. 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.

28, 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 .

The base portion 582 is made of a transparent material having excellent thermal stability as a support for forming the prism pattern 584 and is made of, for example, polyethylene terephthalate, polycarbonate, polypropylene, polyethylene, polystyrene, But the present invention is not limited thereto.

Further, the base portion 582 may include a phosphor (not shown). For example, the base portion 582 can be formed by curing the fluorescent material (not shown) evenly dispersed in the material forming the base portion 582. When the base portion 582 is formed as described above, the phosphor (not shown) can be uniformly distributed throughout the base portion 582.

On the other hand, a three-dimensional prism pattern 584 for refracting and condensing 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 patterns 584 include a plurality of linear prisms arranged in parallel with one another along one direction on one side of the base portion 582 and the vertical section with respect to the axial direction of the linear prism 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 straightness of the light is improved and the luminance of light of the light emitting device package 500 can be improved have.

Meanwhile, the prism pattern 584 may include a phosphor (not shown).

The phosphors (not shown) are dispersed in the prism pattern 584 to form a prism pattern 584, for example, mixed with an acrylic resin to form a paste or a slurry state, .

When a phosphor (not shown) is included in the prism pattern 584, the uniformity and distribution of the light of the light emitting device package 500 is improved. In addition to the light focusing effect by the prism pattern 584, The orientation angle of the light emitting device package 500 can be improved.

A light guide plate, a prism sheet, a diffusion sheet, and the like, which are optical members, may be disposed on the light 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. Still another embodiment may be implemented as a display device, an indicating device, and a lighting system including the light emitting device or the light emitting device package described in the above embodiments. For example, the lighting system may include a lamp and a streetlight.

FIG. 29 is a perspective view illustrating a lighting device including a light emitting device package according to an embodiment, and FIG. 30 is a cross-sectional view taken along the line C-C 'of the lighting device of FIG. 29.

29 and 30, the lighting apparatus 600 may include a body 610, a cover 630 coupled to the body 610, and a finishing cap 650 positioned at opposite 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.

The light emitting device package 644 according to the embodiment includes a light emitting device (not shown), a light emitting device (not shown) includes first and second light emitting structures (not shown) The light emitting structure (not shown) can be driven in reverse bias and forward bias, respectively. Therefore, the illumination device 600 according to the embodiment can emit light in both the reverse bias and the forward bias in the AC power source, so that the flickering can be eliminated and the luminous efficiency can be improved.

The light emitting device package 644 may include an extended lead frame (not shown) so as to have an improved heat dissipation function, so that the reliability and efficiency of the light emitting device package 644 can be improved. The service life of the illumination device 600 including the element package 644 can 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.

Since the light generated in the light emitting device package 644 is emitted to the outside through the cover 630, the cover 630 must have a high light transmittance and sufficient heat resistance to withstand the heat generated in 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.

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

31, 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 in an edge-light manner.

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 a printed circuit board 718 on which a plurality of circuit components are mounted via a 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.

Meanwhile, the backlight unit 770 according to the embodiment includes a light emitting element (not shown), a light emitting element (not shown) includes first and second light emitting structures (not shown), and first and second light emitting elements The structures (not shown) can be driven 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, so that the flicker can be eliminated and the luminous efficiency can be improved.

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 enhancing vertical incidence by condensing the diffused light , And may include a protective film 764 for protecting the prism film 750.

32 is an exploded perspective view of a liquid crystal display device including a light emitting device according to an embodiment. However, the parts shown and described in Fig. 31 are not repeatedly described in detail.

32, 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 in a direct-down manner.

Since the liquid crystal display panel 810 is the same as that described with reference to FIG. 31, detailed description is 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. [

The light emitting device module 823 may include a PCB substrate 821 to mount a plurality of light emitting device packages 822 and a plurality of light emitting device packages 822 to form an array.

The backlight unit 870 includes a light emitting device (not shown), a light emitting device (not shown) includes first and second light emitting structures (not shown), and first and second light emitting devices The structures (not shown) can be driven 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, so that the flicker phenomenon can be solved 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.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention.

100: light emitting device 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

Claims (41)

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;
A second light emitting structure formed 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 disposed between the first light emitting structure and the second light emitting structure;
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,
Wherein the first and third semiconductor layers are doped with a first conductivity type,
The second and fourth semiconductor layers are doped with a second conductivity type,
Wherein the first and second light emitting structures each include first and second electron confinement layers,
Wherein the first and second electron confinement layers have band gaps greater than band gaps of respective barrier layers included in the first and second active layers,
A plurality of light-transmitting structures are formed on the second light-emitting structure, a light-transmitting electrode layer is formed on the second light-emitting structure and the light-
The intermediate layer has a multi-layer structure in which at least a first layer, a second layer, a third layer and a fourth layer having different band gaps are alternately stacked alternately. The layer having the largest band gap and the layer having the smallest band gap Emitting device. delete The method according to claim 1,
Wherein the first electrode and the third electrode are mutually connected,
The first light-emitting structure and the second light-
A light emitting device connected in antiparallel with each other. delete delete delete delete delete delete The method according to claim 1,
Wherein the amount of light emitted from the first light emitting structure and the amount of light emitted from the second light emitting structure are different from each other. The method according to claim 1,
The first light-emitting structure and the second light-
The light emitting element having a different thickness from each other. The method according to claim 1,
The first light emitting structure and the second light emitting structure are subjected to the first mesa etching to expose at least one region of the upper surface of the first semiconductor layer,
Wherein the first electrode is formed on an exposed region of the first semiconductor layer. The method according to claim 1,
The second light emitting structure is etched by a second mesa to expose at least one region of the upper surface of the third semiconductor layer,
And the second electrode is formed on an exposed region of the third semiconductor layer. The method according to claim 1,
Wherein the third electrode comprises:
And a light-emitting element formed on the transparent electrode layer. The method according to claim 1,
And a substrate formed under the first light emitting structure,
Wherein:
And a first concavo-convex portion formed on at least one region of the surface. delete The method according to claim 1,
Wherein the intermediate layer comprises:
A light emitting element which is an undoped semiconductor layer. delete delete 18. The method of claim 1 or 17,
The first layer, the second layer, the third layer,
And having different refractive indices from each other. 18. The method of claim 1 or 17,
Wherein the intermediate layer comprises:
A light emitting device comprising a reflective material. delete The method according to claim 1,
Wherein at least one of the first light emitting structure and the second light emitting structure comprises:
And a second concavo-convex portion formed on the side surface. The method according to claim 1,
At least one of the first light-emitting structure and the second light-
The side surface is formed to have an inclination angle,
The inclination angle,
50 DEG to 90 DEG. delete The method according to claim 1,
The first light emitting structure and the second light emitting structure may include a first light emitting structure,
Non-polar, or semi-polar growth surface,
Wherein the first light-emitting structure and the second light-emitting structure include GaN, and an N-face or a Ga-face is formed on a side surface. delete The method according to claim 1,
Wherein at least one of the first, second,
Layer structure,
Wherein at least one of the first, second,
A bonding layer, a reflective layer, and a protective layer. delete The method according to claim 1,
Wherein the first and second active layers are made of a single-
A multi-quantum well structure,
Wherein the first and second active layers comprise a well layer and a barrier layer,
Wherein the well layer comprises at least a first and a second well layer,
Wherein the barrier layer comprises at least a first and a second barrier layer,
Wherein the first well layer and the second well layer have different band gaps from each other. delete delete 31. The method of claim 30,
Wherein the first well layer and the second well layer have different In contents from each other. 31. The method of claim 30,
The first well layer, and the second well layer,
The light emitting element having a different thickness from each other. The method according to claim 1,
The first active layer generates light of a first wavelength,
The second active layer generates light of a second wavelength,
Wherein the first wavelength and the second wavelength are different from each other. A first light emitting structure that forms a first current path when a power is applied in a first energizing direction and generates a first light;
A second light-emitting structure formed on the first light-emitting structure and forming a second current path and generating a second light when the power is applied in the second energization direction; And
And an intermediate layer disposed between the first light emitting structure and the second light emitting structure,
Wherein the first energizing direction and the second energizing direction are opposite to each other,
Wherein the first light emitting structure includes a first semiconductor layer, a second semiconductor layer, and a first active layer formed between the first and second semiconductor layers,
The second light emitting structure includes a third active layer formed between the third semiconductor layer, the fourth semiconductor layer, and the third and fourth semiconductor layers,
Wherein the first and second light emitting structures each include first and second electron confinement layers,
Wherein the first and second electron confinement layers have band gaps greater than band gaps of respective barrier layers included in the first and second active layers,
A plurality of light-transmitting structures are formed on the second light-emitting structure, a light-transmitting electrode layer is formed on the second light-emitting structure and the light-
The intermediate layer has a multi-layer structure in which at least a first layer, a second layer, a third layer and a fourth layer having different band gaps are alternately stacked alternately. The layer having the largest band gap and the layer having the smallest band gap Emitting device. delete 37. The method of claim 36,
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,
Wherein 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. delete 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;
A second light emitting structure formed 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 disposed between the first light emitting structure and the second light emitting structure;
A first electrode for applying external power and connecting the first semiconductor layer and the fourth semiconductor layer;
A second electrode for applying external power and connecting the second semiconductor layer and the third semiconductor layer; / RTI >
Wherein the first and third semiconductor layers are doped with n-type and the second and fourth semiconductor layers are doped with p-type so that the first and second light emitting structures are connected in antiparallel structure,
The first current path is formed in the first light emitting structure to generate the first light when the power is applied in the first energization direction,
A second current path is formed in the second light emitting structure to generate a second light when the second power supply direction is applied,
Wherein the first energizing direction and the second energizing direction are opposite to each other,
Wherein the first and second light emitting structures each include first and second electron confinement layers,
Wherein the first and second electron confinement layers have band gaps greater than band gaps of respective barrier layers included in the first and second active layers,
A plurality of light-transmitting structures are formed on the second light-emitting structure, a light-transmitting electrode layer is formed on the second light-emitting structure and the light-
The intermediate layer has a multi-layer structure in which at least a first layer, a second layer, a third layer and a fourth layer having different band gaps are alternately stacked alternately. The layer having the largest band gap and the layer having the smallest band gap Emitting device. First, second, third and fourth semiconductor layers sequentially stacked;
A first light emitting layer formed between the first and second semiconductor layers;
A second light emitting layer formed between the third and fourth semiconductor layers;
An intermediate layer disposed between the second semiconductor layer and the third semiconductor layer;
A first trench exposing a part of the surface of the first semiconductor layer;
A second trench exposing a part of the surface of the third semiconductor layer;
A first hole exposing the second semiconductor layer to a part of a surface of the third semiconductor layer exposed by the second trench;
A first electrode formed in the first trench and electrically connected to the first semiconductor layer;
A second electrode formed in the second trench and the first hole, the second electrode electrically connected to the second and third semiconductor layers; And
And a third electrode electrically connected to the fourth semiconductor layer on the fourth semiconductor layer,
A plurality of light-transmitting structures are formed on the fourth semiconductor layer, a light-transmitting electrode layer is formed on the fourth semiconductor layer and the plurality of light-transmitting structures,
The intermediate layer has a multi-layer structure in which at least a first layer, a second layer, a third layer and a fourth layer having different band gaps are alternately stacked alternately. The layer having the largest band gap and the layer having the smallest band gap Emitting device.

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