KR20130056368A

KR20130056368A - Light emitting device

Info

Publication number: KR20130056368A
Application number: KR1020110121753A
Authority: KR
Inventors: 황성민
Original assignee: 엘지이노텍 주식회사
Priority date: 2011-11-21
Filing date: 2011-11-21
Publication date: 2013-05-30

Abstract

The light emitting device according to the embodiment includes a first electroluminescent structure including a first semiconductor layer, a second semiconductor layer, and a first active layer formed between the first and second semiconductor layers, and on the first electroluminescent structure. A second electroluminescent structure formed on and including a third semiconductor layer, a fourth semiconductor layer, and a second active layer formed between the third and fourth semiconductor layers, and a fifth semiconductor layer formed on the second electroluminescent structure. A photoluminescent structure including a sixth semiconductor layer and a third active layer formed between the fifth and sixth semiconductor layers, a first electrode connected to the first semiconductor layer, and a second and third semiconductor layers And a third electrode connected to the fourth semiconductor layer, wherein the first and third semiconductor layers are doped to the first conductivity type, and the second and fourth semiconductor layers are doped to the second conductivity type. The third active layer has a smaller bandgap than the first and second active layers.

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.

On the other hand, since the LED has a rectifying characteristic of a general diode, when connected to an AC power source is repeated on / off according to the direction of the current does not generate light continuously, there is a risk of being damaged by the reverse current.

Therefore, in recent years, various researches for using LEDs directly connected to AC power sources have been conducted.

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

In addition, the embodiment provides a light emitting device capable of implementing white light, or light of any color, including an electroluminescent structure and a photoluminescent structure.

The light emitting device according to the embodiment includes a first electroluminescent structure including a first semiconductor layer, a second semiconductor layer, and a first active layer formed between the first and second semiconductor layers, and on the first electroluminescent structure. A second electroluminescent structure formed on the second electroluminescent structure, and a second electroluminescent structure including a third semiconductor layer, a fourth semiconductor layer, and a second active layer formed between the third and fourth semiconductor layers. A photoluminescent structure comprising a layer, a sixth semiconductor layer, and a third active layer formed between the fifth and sixth semiconductor layers, a first electrode connected to the first semiconductor layer, and a second and third semiconductor layer And a third electrode connected to the fourth semiconductor layer, wherein the first and third semiconductor layers are doped to the first conductivity type, and the second and fourth semiconductor layers are to the second conductivity type. The doped third active layer has a smaller bandgap than the first and second active layers.

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

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

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

In addition, in the light emitting device according to the embodiment, the light emitting structure is disposed on the electroluminescent structure, thereby realizing white light or light having an arbitrary color.

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;
4 is a driving diagram when a forward voltage is applied to the light emitting device according to the embodiment;
5 is a driving diagram when applying a reverse voltage of the light emitting device according to the embodiment;
6 is a view illustrating driving of a light emitting device according to an embodiment when a voltage is applied according to FIG. 4;
7 is a view illustrating driving of a light emitting device according to an embodiment when a voltage is applied according to FIG. 5;
8 is an energy band diagram and driving principle of regions A and B of FIG. 6;
9 is a conceptual diagram illustrating a circuit diagram of a lighting system including a light emitting device according to an embodiment;
10 is a conceptual diagram illustrating a circuit diagram of a lighting system including a light emitting device according to an embodiment;
11 is a perspective view of a light emitting device package including a light emitting device according to the embodiment;
12 is a cross-sectional view of a light emitting device package including a light emitting device according to the embodiment;
13 is a cross-sectional view of a light emitting device package including a light emitting device according to the embodiment;
14 is a perspective view of a lighting system including a light emitting device according to the embodiment;
FIG. 15 is a cross-sectional view taken along the line CC ′ of the lighting system of FIG. 14;
16 is an exploded perspective view of a liquid crystal display device including the light emitting device according to the embodiment;
17 is an exploded perspective view of a liquid crystal display including the light emitting device according to the embodiment.

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

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

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

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

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size and area of each component do not entirely reflect actual size or area.

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

1 is a cross-sectional view of a light emitting device 100 according to the embodiment, and FIG. 2 is a plan view of the light emitting device 100 according to the embodiment.

1 and 2, a light emitting device 100 according to an embodiment may include a first semiconductor layer 122, a second semiconductor layer 126, and first and second semiconductor layers 122 and 126. A first electroluminescent structure 120 including a first active layer 124 formed on the first electroluminescent structure 120, a third semiconductor layer 132, a fourth semiconductor layer 136, And a second electroluminescent structure 130 including a second active layer 134 formed between the third and fourth semiconductor layers 132 and 136, and formed on the second electroluminescent structure 130 and being fifth. The photoluminescent structure 140 including the semiconductor layer 142, the sixth semiconductor layer 146, and the third active layer 134 formed between the fifth and sixth semiconductor layers 142 and 146, and the first semiconductor. A first electrode 152 connected to the layer 122, a second electrode 154 connected together with the second and third semiconductor layers 126 and 132, and a fourth electrode connected to the fourth semiconductor layer 136. A third electrode 156, wherein the first and third semiconductor layers 122, 132 have a first conductivity Doped, the second and fourth semiconductor layers 126 and 136 may be doped in a second conductivity type, and the third active layer 144 may have a smaller bandgap than the first and second active layers 124 and 134. have.

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

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

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

The first semiconductor layer 122 may be positioned on the buffer layer 112. The first semiconductor layer 122 may be doped with a first conductivity type. In this case, the first conductivity type may be n type. For example, the first semiconductor layer 122 may be implemented as an n-type semiconductor layer, and may provide electrons to the first active layer 124. The first semiconductor layer 122 may be a nitride based semiconductor layer. For example, the first semiconductor layer 122 may include a semiconductor material having a composition formula of InxAlyGa1-x-yN (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like may be included. Meanwhile, the first semiconductor layer 122 may be a zinc oxide semiconductor layer. For example, the first semiconductor layer 122 may include a semiconductor material having a composition formula of InxAlyZn1-x-yO (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). For example ZnO, AlO, AlZnO, InZnO, InO, InAlZnO. AlInO, and the like, but are not limited thereto. In addition, the first semiconductor layer 122 may be doped with n-type dopants such as Si, Ge, Sn, and the like.

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

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

When the first active layer 124 has a quantum well structure, the first active layer 124 may have a multi-quantum well structure. In addition, the first active layer 124 may be a nitride-based or zinc oxide-based semiconductor layer. For example, the first active layer 124 may include a well layer having a composition formula of InxAlyGa1-x-yN (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1) and InaAlbGa1-a-bN (0 ≦ It may have a single or multiple quantum well structure having a barrier layer having a composition formula of a ≦ 1, 0 ≦ b ≦ 1, 0 ≦ a + b ≦ 1. Meanwhile, the well layer has a composition formula of InxAlyZn1-x-yO (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), and the barrier layer is InaAlbZn1-a-bO (0 ≦ a ≦ 1 , 0 ≦ b ≦ 1, 0 ≦ a + b ≦ 1), but is not limited thereto. Meanwhile, the well layer may be formed of a material having a band gap smaller than the band gap of the barrier layer.

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

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

The second semiconductor layer 126 may be doped with a second conductivity type. In this case, the second conductivity type may be p-type. For example, the second semiconductor layer 126 may be implemented as a p-type semiconductor layer to inject holes into the first active layer 124. The second semiconductor layer 126 may be a nitride based semiconductor layer. For example, the second semiconductor layer 126 may include a semiconductor material having a composition formula of InxAlyGa1-x-yN (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like may be included. Meanwhile, the second semiconductor layer 126 may be a zinc oxide semiconductor layer. For example, the second semiconductor layer 126 may include a semiconductor material having a composition formula of InxAlyZn1-x-yO (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), and examples For example ZnO, AlO, AlZnO, InZnO, InO, InAlZnO. AlInO, and the like, but is not limited thereto. Meanwhile, the second semiconductor layer 126 may be doped with p-type dopants such as Mg, Zn, Ca, Sr, and Ba.

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

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

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

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

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

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

The third semiconductor layer 132 may be a nitride based semiconductor layer. For example, the third semiconductor layer 132 may include a semiconductor material having a composition formula of InxAlyGa1-x-yN (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), for example. For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like may be included. Meanwhile, the third semiconductor layer 132 may be a zinc oxide semiconductor layer. For example, the third semiconductor layer 132 may be a semiconductor material having a composition formula of InxAlyZn1-x-yO (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), for example, ZnO, AlO, AlZnO, InZnO, InO, InAlZnO. The third semiconductor layer 132 may be doped with an n-type dopant such as Si, Ge, Sn, or the like.

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

The second active layer 134 may be formed in a quantum well structure. In addition, the second active layer 134 may be a nitride-based or zinc oxide-based semiconductor layer. For example, the second active layer 134 may include a well layer having a composition formula of InxAlyGa1-x-yN (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1) and InaAlbGa1-a-bN (0 ≦ It may have a single or multiple quantum well structure having a barrier layer having a composition formula of a ≦ 1, 0 ≦ b ≦ 1, 0 ≦ a + b ≦ 1. Meanwhile, the well layer has a composition formula of InxAlyZn1-x-yO (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), and the barrier layer is InaAlbZn1-a-bO (0 ≦ a ≦ 1 , 0 ≦ b ≦ 1, 0 ≦ a + b ≦ 1), but is not limited thereto. Meanwhile, the well layer may be formed of a material having a band gap smaller than the band gap of the barrier layer.

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

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

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

The fourth semiconductor layer 136 may be a nitride based semiconductor layer. For example, the fourth semiconductor layer 136 may include a semiconductor material having a composition formula of InxAlyGa1-x-yN (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like may be included. Meanwhile, the fourth semiconductor layer 136 may be a zinc oxide semiconductor layer. For example, the fourth semiconductor layer 136 may include a semiconductor material having a composition formula of InxAlyZn1-x-yO (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), For example ZnO, AlO, AlZnO, InZnO, InO, InAlZnO. AlInO, and the like, but is not limited thereto. Meanwhile, the fourth semiconductor layer 136 may be doped with p-type dopants such as Mg, Zn, Ca, Sr, and Ba.

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

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

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

The photoluminescent structure 140 may be formed on the second electroluminescent structure 130.

The photoluminescent structure 140 may include a fifth semiconductor layer 142, a third active layer 144, and a sixth semiconductor layer 146.

The fifth semiconductor layer 142 may be doped with a first conductivity type or a second conductivity type. For example, the fifth semiconductor layer 142 may be implemented as an n-type semiconductor layer or a p-type semiconductor layer.

The fifth semiconductor layer 142 may be a nitride based semiconductor layer. For example, the fifth semiconductor layer 142 may include a semiconductor material having a composition formula of InxAlyGa1-x-yN (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), for example. For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like may be included. The fifth semiconductor layer 142 may be a zinc oxide semiconductor layer. For example, the fifth semiconductor layer 142 may be formed of a semiconductor material having InxAlyZn1-x-yO (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), for example, ZnO, AlO, AlZnO, InZnO, InO, InAlZnO. The fifth semiconductor layer 142 may be doped with n-type dopants, such as Si, Ge, Sn, or p, such as Mg, Zn, Ca, Sr, or Ba. Type dopants may be doped.

The third active layer 144 may be formed on the fifth semiconductor layer 142. The third active layer 144 may be formed of a single or multiple quantum well structure, a quantum-wire structure, a quantum dot structure, or the like using a compound semiconductor material of a group III-V group element. .

The third active layer 144 may be formed in a quantum well structure. In addition, the third active layer 144 may be a nitride-based or zinc oxide-based semiconductor layer. For example, the third active layer 144 may include a well layer having a composition formula of InxAlyGa1-x-yN (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1) and InaAlbGa1-a-bN (0 ≦ It may have a single or multiple quantum well structure having a barrier layer having a composition formula of a ≦ 1, 0 ≦ b ≦ 1, 0 ≦ a + b ≦ 1. Meanwhile, the well layer has a composition formula of InxAlyZn1-x-yO (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), and the barrier layer is InaAlbZn1-a-bO (0 ≦ a ≦ 1 , 0 ≦ b ≦ 1, 0 ≦ a + b ≦ 1), but is not limited thereto. Meanwhile, the well layer may be formed of a material having a band gap smaller than the band gap of the barrier layer.

In addition, when the third active layer 144 has a multi-quantum well structure, the composition of the third active layer 144 may have a different composition from that of the first and second active layers 124 and 134, which will be described later.

A conductive clad layer (not shown) may be formed on or under the third active layer 144. The conductive cladding layer (not shown) may be formed of, for example, an AlGaN-based or AlZnO-based semiconductor, and may have a band gap larger than that of the third active layer 144.

The sixth semiconductor layer 146 may be doped with a first conductivity type or a second conductivity type. For example, when the fifth semiconductor layer 142 is of the first conductivity type, the sixth semiconductor layer 146 may be doped into the second conductivity type. In this case, the second conductivity type may be p-type.

The sixth semiconductor layer 146 may be a nitride based semiconductor layer. For example, the sixth semiconductor layer 146 may include a semiconductor material having a composition formula of InxAlyGa1-x-yN (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), For example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like may be included. Meanwhile, the sixth semiconductor layer 146 may be a zinc oxide semiconductor layer. For example, the sixth semiconductor layer 146 may include a semiconductor material having a composition formula of InxAlyZn1-x-yO (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1), For example ZnO, AlO, AlZnO, InZnO, InO, InAlZnO. AlInO, and the like, but is not limited thereto. In addition, the sixth semiconductor layer 146 may be doped with an n-type dopant such as Si, Ge, Sn, or Mg, Zn, Ca, Sr, or Ba The p-type dopant may be doped.

The fifth semiconductor layer 142, the third active layer 144, and the sixth semiconductor layer 146 may be, for example, metal organic chemical vapor deposition (MOCVD) or chemical vapor deposition (CVD). Vapor Deposition), Plasma-Enhanced Chemical Vapor Deposition (PECVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), Sputtering It may be formed using, but is not limited thereto.

In addition, the doping concentrations of the conductive dopants in the fifth and sixth semiconductor layers 142 and 146 may be uniformly or non-uniformly formed. That is, the plurality of semiconductor layers may be formed to have various doping concentration distributions, but the invention is not limited thereto.

In addition, the fifth semiconductor layer 142 may be implemented as a p-type semiconductor layer, the sixth semiconductor layer 146 may be implemented as an n-type semiconductor layer, and the n-type or p-type semiconductor is formed on the sixth semiconductor layer 146. A semiconductor layer (not shown) including a layer may be formed. Accordingly, the photoluminescent structure 140 may have at least one of np, pn, npn, and pnp junction structures.

On the other hand, the light emitting structure 140 may be a photoluminescence (PL) light emitting structure. That is, the photoluminescent structure 140 may be a light emitting structure that absorbs light emitted from the outside to generate electrons and holes, and generates light by recombining the generated electrons and holes. This will be described later.

The first and second electroluminescent structures 120 and 130 and the photoluminescent structure 140 may be integrally formed, for example, may be sequentially grown in one growth process, but is not limited thereto. In addition, the first and second electroluminescent structures 120 and 130 and the photoluminescent structure 140 may be formed of the same material, but are not limited thereto. In addition, as described above, the first and second electroluminescent structures 120 and 130 and the photoluminescent structure 140 may each have at least one of an np, pn, npn, and pnp junction structure, thereby providing a light emitting device ( 100) may have any junction structure.

Meanwhile, the light generated by the first and second electroluminescent structures 120 and 130 and the light emitting structure 140 may have different wavelengths, and the amount of light generated may also be different from each other. For example, the amount of light generated in the first electroluminescent structure 120 is generated in the second electroluminescent structure 130 in consideration of the loss when passing through the second electroluminescent structure 130 and the photoluminescent structure 140. It may be greater than the amount of light.

In addition, the first and second electroluminescent structures 120 and 130 and the photoluminescent structure 140 may have different structures, materials, thicknesses, compositions, and sizes, but are not limited thereto.

In addition, although FIG. 1 shows that the light emitting device 100 includes the first and second electroluminescent structures 120 and 130 and the light emitting structure 140, the present invention is not limited thereto. It may include more than one light emitting structure (not shown).

The first electrode 152 may be formed on at least one surface of the first semiconductor layer 122. For example, a portion of the first and second electroluminescent structures 120 and 130 and the photoluminescent structure 140 may be removed to expose a portion of the first semiconductor layer 122, and the exposed first semiconductor layer 122 may be exposed. The first electrode 152 may be formed on the first electrode 152. That is, as shown in FIG. 1, the first semiconductor layer 122 includes a top surface facing the first active layer 124 and a bottom surface facing the substrate 110, and the top surface includes a region where at least one region is exposed. The first electrode 152 may be disposed on the exposed area of the upper surface.

The second electrode 154 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 electroluminescent structure 130 and the photoluminescent structure 140 may be removed to expose one region of the third semiconductor layer 132, and the second electrode 154 may be exposed to the exposed region. ) May be formed. That is, as shown in FIG. 1, the third semiconductor layer 132 includes an upper surface facing the fourth semiconductor layer 136 and a lower surface facing the substrate 110, and the upper surface includes a region where at least one region is exposed. The second electrode 154 may be disposed on the exposed area of the upper surface. Meanwhile, a hole penetrating a region of the third semiconductor layer 132 may be formed to expose a portion of the second semiconductor layer 126. The second electrode 154 may be connected to the second semiconductor layer 126 through the third semiconductor layer 132 through the hole.

The third electrode 156 may be formed on the fourth semiconductor layer 136. For example, at least one region of the photoluminescent structure 140 may be removed to expose one region of the fourth semiconductor layer 136, and a third electrode 156 may be formed in the exposed region. The third electrode 156 may be formed in at least one region on the fourth semiconductor layer 136, and may be formed in the center or corner region of the fourth semiconductor layer 136, but is not limited thereto.

Meanwhile, a method of exposing a part of the first semiconductor layer 122, the second semiconductor layer 126, and the fourth semiconductor layer 136 may use a predetermined etching method, but is not limited thereto. The etching method may be a wet etching method or a dry etching method.

For example, the etching method may be a mesa etching method. That is, the first mesa etching is performed on the first and second electroluminescent structures 120 and 130 and the one region of the photoluminescent structure 140 to expose one region of the first semiconductor layer 122, and the third semiconductor. A second mesa etching is performed on the second electroluminescent structure 130 and one region of the photoluminescent structure 140 so that one region of the layer 132 is exposed, and one region of the fourth semiconductor layer 136 is exposed. In this case, a third mesa etching may be performed on one region of the photoluminescent structure 140.

The first electrode 152 is formed on the first semiconductor layer 122, the second electrode 154 is formed on the second and third semiconductor layers 126 and 132, and the fourth semiconductor layer 136 is formed on the first semiconductor layer 122. As the third electrode 156 is formed, the first to third electrodes 152, 154, and 156 may be formed in the same direction.

The first electrode 152 and the third electrode 156 may be interconnected. For example, the first electrode 152 and the third electrode 156 may be continuously formed as one member. Meanwhile, a connection member (not shown) connecting the first electrode 152 and the third electrode 156 may be provided, but is not limited thereto. Accordingly, power having the same polarity may be applied to the first semiconductor layer 122 and the fourth semiconductor layer 136 through the first electrode 152 and the third electrode 156.

In addition, the second electrode 154 is formed on the second semiconductor layer 126 and the third semiconductor layer 132 to supply power having the same polarity to the second semiconductor layer 126 and the third semiconductor layer 132. Can be authorized. Meanwhile, a method of removing a part of the first and second electroluminescent structures 120 and 130 may use a predetermined etching method, but is not limited thereto. The etching method may be a wet etching method or a dry etching method.

Meanwhile, the first to third electrodes 152, 154, and 156 may be conductive materials, for example, In, Co, Si, Ge, Au, Pd, Pt, Ru, Re, Mg, Zn, Hf, Ta, Rh, It may include a metal selected from Ir, W, Ti, Ag, Cr, Mo, Nb, Al, Ni, Cu, and WTi, or may include an alloy thereof, and the metal material and IZO, IZTO, IAZO , IGZO, IGTO, AZO, ATO, and the like may include a transparent conductive material, but is not limited thereto.

In addition, at least one of the first to third electrodes 152, 154, and 156 may have a single layer or a multilayer structure, but is not limited thereto.

Meanwhile, at least one electrode of the first to third electrodes 152, 154, and 156 may be electrically connected to the photoluminescent structure 140, but is not limited thereto.

Hereinafter, an operation of the light emitting device 100 according to the embodiment will be described with reference to FIGS. 3 to 5. In the following description, it is assumed that the first and third semiconductor layers 122 and 132 are n-type semiconductor layers, and the second and fourth semiconductor layers 126 and 136 are p-type semiconductor layers. In addition, it is assumed that the photoluminescent structure 140 is not electrically connected to the first and second electroluminescent structures 120 and 130.

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

As described above, the first electrode 152 is connected to the first semiconductor layer 122, the second electrode 154 is connected to the second semiconductor layer 126, and the third semiconductor layer 132, and the third The electrode 156 may be connected to the fourth semiconductor layer 136, and the first electrode 152 and the third electrode 156 may be connected to each other. In this case, when the first and third semiconductor layers 122 and 132 are doped with the first conductivity type, and the second and fourth semiconductor layers 126 and 136 are doped with the second conductivity type, light emission according to an exemplary embodiment As shown in FIG. 3, the device 100 may have a circuit structure in which two light emitting diodes are connected in an anti-parallel structure.

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

As shown in FIG. 4, in an AC power source, a positive voltage (+) may be connected to the second electrode 154, and a negative voltage (−) may be connected to the first and third electrodes 142 and 146. have. Accordingly, the first energization direction power may be applied to the light emitting device 100.

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

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

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

As illustrated in FIG. 5, a negative voltage (−) may be supplied to the second electrode 154, and a positive voltage (+) may be supplied to the first and third electrodes 142 and 146. Accordingly, the second conduction direction power source may be applied to the light emitting device 100. On the other hand, the first conduction direction and the second conduction direction described above may be opposite.

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

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

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

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

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

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

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

Meanwhile, the photoluminescent structure 140 is formed on the first and second electroluminescent structures 120 and 130, and the first and second electroluminescent structures 120 and 130 are electroluminescent (EL) structures. The photoluminescent structure 140 may be a photoluminescence (PL) light emitting structure. Since the light emitting structure 140 is formed of a light emitting light emitting structure, the light emitting device 100 according to the embodiment may generate white light or light of a predetermined color. This will be described later.

Here, the electroluminescence is to emit light by recombination of electrons and holes supplied to the first and second active layers 124 and 134 by the applied current, and the photoluminescence is the first and second active layers 124 and 134. Emit light excited by the light emitted from

6 and 7 are diagrams illustrating a driving diagram of the light emitting device 100 according to the embodiment, and FIG. 8 is a diagram illustrating an energy band diagram and light generation principle in regions A and B of FIG. 6.

As described above, the photoluminescent structure 140 may be a photoluminescent light emitting structure. That is, electrons and holes may be generated as predetermined light having an energy greater than the energy band gap of the third active layer 144 is incident, and predetermined light may be generated as the generated electrons and holes are recombined. have.

According to an embodiment, the first electroluminescent structure 120 may generate the first light L1, and the second electroluminescent structure 130 may generate the second light L2. For example, as illustrated in FIG. 8, the first light L1 may be generated by recombination P1 between electrons and holes in the first active layer 124 of the first electroluminescent structure 120. And the second lights L1 and L2 include straight light beams S1 and S2 traveling upward, as shown in FIGS. 6 and 7, and reflected light beams R1 and R2 reflected after traveling downward. In this case, since the photoluminescent structure 140 is disposed on the traveling paths of the straight lights S1 and S2, at least a part of the straight lights S1 and S2 may be absorbed by the third active layer 144. On the other hand, a portion of the reflected light (R1, R2) may also be absorbed by the third active layer 144, a portion of the straight light (S1, S2) may also proceed without being absorbed by the third active layer 144, It is not limited.

For example, as described above, the first and second active layers 124 and 134 may have a multi-quantum well structure. For example, the first and second active layers 124 and 134 include first and second well layers W1, respectively, wherein the first and second well layers W1 are formed of Inx1Ga1-x1N (0.17 ≦ x1 ≦). 0.27). In addition, the third active layer 144 may also have a multi-quantum well structure. For example, the third active layer 144 may include a third well layer W3, and the third well layer W3 may have a composition formula of Inx2Ga1-x2N (0.3 ≦ x2 ≦ 0.4).

According to the composition as described above, the first and second light (L1, L2) generated in the first and second active layer (124, 134) is greater than the energy band gap of the well layer of the third active layer (144) It can have Therefore, as shown in FIG. 8, the first and second lights L1 and L2 generated in the first and second active layers 124 and 134 are absorbed in the third active layer 144 and thus, the third active layer ( At 144, electrons and holes may be generated (Q), and the third light L3 may be generated as the generated electrons and holes are recombined (P2).

In this case, as the third active layer 144 has a smaller bandgap than the first and second active layers 124 and 134, the third light L3 generated in the third active layer 144 may be the first and the second. It may have a wavelength different from the light (L1, L2). Meanwhile, wavelengths of the first and second lights L1 and L2 generated in the first and second active layers 124 and 134 and the third light L3 generated in the third active layer 144 are different from each other. The first light L1 and the third light L3 may be mixed, or the second light L2 and the third light L3 may be mixed to generate a fourth light (not shown), and thus, white light, Alternatively, the light having any color can be generated. Therefore, the color reproducibility of the light emitting device 100 may be improved, and the use of the phosphor for reproducing white light may be omitted.

For example, the first and second lights L1 and L2 may have a wavelength of 430 nm to 480 nm, and the third light L3 may have a wavelength of 530 nm to 600 nm. Accordingly, the first and second lights L1 and L2 may have a color of the blue region, and the third light L3 may have a color of the yellow region. Therefore, the white light may be generated as the first light L1 and the third light L3 or the second light L2 and the third light L3 are mixed.

9 and 10 are conceptual views illustrating a circuit diagram of an illumination system 200 including a light emitting device 100 according to an embodiment.

9 and 10, the lighting system 200 including the light emitting device 100 according to the embodiment includes at least one light emitting device 100, and each light emitting device 100 is configured to be connected in series. Can be.

Each light emitting device 100 may be connected to a substrate (not shown) through a predetermined circuit pattern to form a light emitting device array. In this case, the light emitting device 100 is mounted on, for example, a light emitting device package 500 to be described later, and the light emitting device package 500 is configured to be mounted on a substrate (not shown), or a light emitting device on a substrate (not shown). It may be configured in the form of (COB: Chip on Board) is mounted 100, but is not limited thereto.

In addition, the lighting system 200 including the light emitting device 100 according to the embodiment may include, for example, a lighting device such as a lamp, a street lamp, a backlight unit, but is not limited thereto.

Since the light emitting device 100 according to the embodiment includes a first electroluminescent structure 120 and a second electroluminescent structure 130 capable of generating light in a reverse voltage and a constant voltage phase of an AC power supply, respectively, When the AC power is connected to the lighting system 200, the light emitting device 100 may emit light for both the reverse voltage and the constant voltage phase, and thus the flicker of the lighting system 200 according to the phase switching between the reverse voltage application and the constant voltage application may occur. The phenomenon can be prevented.

In addition, each light emitting device 100 can drive in both a reverse voltage and a constant voltage phase, and a current path corresponding to each case is formed, and thus, for example, as shown in FIGS. 24 and 25, several light emitting devices ( 100 may be configured to be connected in series to an AC power source. Therefore, the connection of several light emitting devices 100 may be facilitated, and the output of the lighting system 200 may be improved and output may be adjusted.

11 to 13 are a perspective view and a cross-sectional view showing a light emitting device package including a light emitting device according to the embodiment.

11 to 13, 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 first one. And a light emitting device 530 electrically connected to the second lead frames 540 and 550, and a resin layer (not shown) filled in the cavity 520 to cover the light emitting device 530.

The body 510 is made of a resin material such as polyphthalamide (PPA), silicon (Si), aluminum (Al), aluminum nitride (AlN), photosensitive glass (PSG), polyamide 9T (PA9T) ), Neogeotactic polystyrene (SPS), a metal material, sapphire (Al2O3), beryllium oxide (BeO), and may be formed of at least one of a printed circuit board (PCB, Printed Circuit Board). The body 510 may be formed by injection molding, etching, or the like, but is not limited thereto.

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

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

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

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

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

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

In addition, the light emitting device 530 according to the embodiment includes a light emitting structure (not shown), and the light emitting structure (not shown) is a light emitting structure and has a different color from that of the first and second electroluminescent structures (not shown). By generating light, white light or light of any color can be generated.

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

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

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

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

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

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

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

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

On the other hand, according to the embodiment, as the light emitting device 530 includes a light emitting structure (not shown), the use of the phosphor may be omitted, but is not limited thereto.

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.

Meanwhile, referring to FIG. 13, the light emitting device package 500 according to the embodiment may include an optical sheet 580, and the optical sheet 580 may include a base portion 582 and a prism pattern 584. Can be.

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

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

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

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

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

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

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

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

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

14 is a perspective view illustrating a lighting apparatus including a light emitting device package according to an embodiment, and FIG. 15 is a cross-sectional view illustrating a C-C 'cross section of the lighting apparatus of FIG. 14.

Referring to FIGS. 14 and 15, the lighting device 600 may include a body 610, a cover 630 fastened to the body 610, and a closing cap 650 located at both ends of the body 610. have.

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

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

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

Meanwhile, according to the embodiment, as the light emitting device (not shown) includes the light emitting structure (not shown), the use of the phosphor may be omitted, but is not limited thereto.

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

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

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

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

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

FIG. 16 illustrates an edge-light method, and the liquid crystal display 700 may include a liquid crystal display panel 710 and a backlight unit 770 for providing light to the liquid crystal display panel 710.

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

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

The thin film transistor substrate 714 is electrically connected to 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.

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

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

17 is an exploded perspective view of a liquid crystal display including the light emitting device according to the embodiment. However, the parts illustrated and described in FIG. 16 will not be repeatedly described in detail.

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

Since the liquid crystal display panel 810 is the same as that described with reference to FIG. 16, a detailed description thereof will be omitted.

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

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

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

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

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

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

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

100 light emitting element 120 first electroluminescent structure
122: first semiconductor layer 124: first active layer
126: second semiconductor layer 130: second electroluminescent structure
132: third semiconductor layer 134: second active layer
140 photoluminescent structure 142 fifth semiconductor layer
144: third active layer 146: sixth semiconductor layer
152: first electrode 154: second electrode
156: third electrode

Claims

A first electroluminescent light emitting structure comprising a first semiconductor layer, a second semiconductor layer, and a first active layer formed between the first and second semiconductor layers;
A second electroluminescent structure formed on the first electroluminescent structure and including a third semiconductor layer, a fourth semiconductor layer, and a second active layer formed between the third and fourth semiconductor layers;
A photoluminescence light emitting structure on the second electroluminescent structure and including a fifth semiconductor layer, a sixth semiconductor layer, and a third active layer formed between the fifth and sixth semiconductor layers;
A first electrode electrically connected to the first semiconductor layer;
A second electrode electrically connected to the second and third semiconductor layers; And
And a third electrode electrically connected to the fourth semiconductor layer.
The first and third semiconductor layers are doped with a first conductivity type,
The second and fourth semiconductor layers are doped with a second conductivity type,
The third active layer has a smaller band gap than the first and second active layer.

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

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

The method of claim 1,
The first and second active layers include first and second quantum well layers,
The third active layer includes a third quantum well layer,
The first and second quantum well layers have a composition of Inx1Ga1-x1N (0.17 ≦ x1 ≦ 0.27),
The third quantum well layer has a composition of In x 2 Ga 1-x 2 N (0.3 ≦ x2 ≦ 0.4).

The method of claim 1,
The first and second active layers generate first and second light,
The first and second light has a wavelength of 430 nm to 480 nm.

The method of claim 1,
The third active layer generates a third light,
The third light has a wavelength of 530 nm to 600 nm.

A first electroluminescent structure for producing a first light;
A second electroluminescent structure formed on the first electroluminescent structure and generating a second light; and
And a photoluminescent structure formed on the second electroluminescent structure and generating a third light by the first and second light.
The first and second electroluminescent structure is a light emitting device that is inversely connected in parallel.

The method of claim 7, wherein
The first light has a wavelength of 430 nm to 480 nm.

The method of claim 7, wherein
The third light has a wavelength of 530 nm to 600 nm.