KR101983777B1 - Light emitting device - Google Patents

Abstract

A light emitting device capable of improving low current characteristics and optical output characteristics is disclosed.
A light emitting device according to an exemplary embodiment includes a first semiconductor layer doped with a first conductive dopant; A second semiconductor layer doped with a second conductive dopant; And an active layer between the first semiconductor layer and the second semiconductor layer, wherein the active layer includes a plurality of pair structures of a barrier layer and a well layer having a smaller energy band gap than the barrier layer, At least one of the barrier layers is doped with the first conductive dopant and Mg.

Description

[0001] LIGHT EMITTING DEVICE [0002]

An embodiment relates to a light emitting element.

BACKGROUND ART Light emitting devices such as light emitting diodes and laser diodes using semiconductor materials of Group 3-5 or 2-6 group semiconductors have been widely used for various colors such as red, green, blue, and ultraviolet And it is possible to realize white light rays with high efficiency by using fluorescent materials or colors, and it is possible to realize low energy consumption, semi-permanent life time, quick response speed, safety and environment friendliness compared to conventional light sources such as fluorescent lamps and incandescent lamps .

Therefore, a transmission module of the optical communication means, a light emitting diode backlight replacing a cold cathode fluorescent lamp (CCFL) constituting a backlight of an LCD (Liquid Crystal Display) display device, a white light emitting element capable of replacing a fluorescent lamp or an incandescent lamp Diode lighting, automotive headlights, and traffic lights.

A typical light emitting device includes a light emitting structure including a first semiconductor layer doped with a first conductive dopant, an active layer composed of a multiple quantum well structure, and a second semiconductor layer doped with a second conductive dopant. At this time, a stress relieving layer may be disposed between the first semiconductor layer and the active layer in order to relax the stress caused by the lattice mismatch between the first semiconductor layer and the active layer.

The stress relieving layer or the active layer contains In having a large lattice size and has a structure in which a barrier layer and a well layer having different lattice constants are alternately arranged, so that a pit due to lattice mismatching or the like may occur.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram schematically showing a semiconductor layer in which pits are formed. FIG. Referring to FIG. 1, a V-shaped pit 10 is formed in an arbitrary semiconductor layer 20. The optional semiconductor layer 1 may be a part of the stress relieving layer or the active layer in the light emitting element. The pit 10 is formed as a seed at most the threading dislocation TD and has an important influence on the crystallinity quality of the semiconductor layer thereafter so that if the pit 10 is not filled properly, It can cause defects.

The embodiment is intended to provide a light emitting device with improved low current and optical output characteristics.

A light emitting device according to an exemplary embodiment includes a first semiconductor layer doped with a first conductive dopant; A second semiconductor layer doped with a second conductive dopant; And an active layer between the first semiconductor layer and the second semiconductor layer, wherein the active layer includes a plurality of pair structures of a barrier layer and a well layer having a smaller energy band gap than the barrier layer, At least one of the barrier layers is doped with the first conductive dopant and Mg.

Wherein at least one barrier layer of the plurality of barrier layers comprises two first regions in contact with adjacent well layers and a second region between the two first regions, And the Mg may be doped in the second region.

A stress relaxation layer may be further disposed between the first semiconductor layer and the active layer and the stress relaxation layer may include a first layer and a second layer structure having a smaller energy band gap than the first layer, .

The stress relieving layer may be doped with the first conductivity type dopant and Mg together with the first layer closest to the active layer among the plurality of first layers.

Wherein the first layer closest to the active layer and the first barrier layer closest to the stress relieving layer among the active layer contact with each other in the stress relieving layer and the first conductive layer is formed on the last first layer and the first barrier layer, The dopant and Mg may be doped together.

The first conductive dopant and Mg may be doped in at least one barrier layer adjacent to the stress relieving layer among the plurality of barrier layers.

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

According to another embodiment, a light emitting device includes: a first semiconductor layer doped with a first conductive dopant; A second semiconductor layer doped with a second conductive dopant; And an active layer between the first semiconductor layer and the second semiconductor layer, the active layer comprising at least two adjacent well layers, an energy band which is in contact with the at least two well layers and which is greater than the energy band gap of the well layer, A first barrier layer having a gap, a second barrier layer disposed in the first barrier layer and having an energy bandgap between the first barrier layer and the well layer, wherein the second barrier layer is doped with Mg .

According to the embodiment, it is possible to prevent the occurrence of pits in the stress relieving layer or the active layer, thereby improving the low current characteristic and the light output characteristic of the light emitting element.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 schematically shows a semiconductor layer in which pits are formed. FIG.
2 is a side sectional view showing an example of a light emitting device according to an embodiment.
3 is a side sectional view showing another example of the light emitting device according to the embodiment.
4 is an energy band diagram of a light emitting device according to the first embodiment.
5 is a view for explaining the effect of the embodiment;
6 is an energy band diagram of a light emitting device according to a second embodiment.
7 is an energy band diagram of the light emitting device according to the third embodiment.
8 is an energy band diagram of the light emitting device according to the fourth embodiment.
9 is a view illustrating an embodiment of a light emitting device package including the light emitting device according to the embodiments.
10 is a view illustrating another embodiment of a light emitting device package including the light emitting device according to the embodiments.
11 is an exploded perspective view showing an embodiment of a lighting device including a light emitting device package according to embodiments.
12 is an exploded perspective view showing an embodiment of a display device in which a light emitting device package according to embodiments is disposed;

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

In the description of the embodiment according to the present invention, in the case of being described as being formed "on or under" of each element, the upper (upper) or lower (lower) or under are all such that two elements are in direct contact with each other or one or more other elements are indirectly formed between the two elements. Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

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

2 is a side sectional view showing an example of a light emitting device according to an embodiment.

Referring to FIG. 2, the light emitting device 100A includes a light emitting structure 120 including a first semiconductor layer 122, an active layer 124, and a second semiconductor layer 126. Referring to FIG.

The light emitting device 100A includes an LED (Light Emitting Diode) using a semiconductor layer of a plurality of compound semiconductor layers, for example, a Group III-V or a Group II-VI element, and the LED includes blue, green or red A colored LED emitting the same light, or a white LED or a UV LED. The emitted light of the LED may be implemented using various semiconductors, but is not limited thereto. For example, when the light emitting device 100A emits ultraviolet rays in the UV-A (ultraviolet-A) region, the emitted ultraviolet light may have a wavelength of about 315 to 400 nm.

The light emitting structure 120 may be formed using a metal organic chemical vapor deposition (MOCVD) method, a chemical vapor deposition (CVD) method, a plasma enhanced chemical vapor deposition (PECVD) method, (MBE), hydride vapor phase epitaxy (HVPE), or the like, but the present invention is not limited thereto.

The first semiconductor layer 122 may be formed of a semiconductor compound, and may be formed of a compound semiconductor, for example, a group III-V group or a group II-VI-VI. The first conductive type dopant may also be doped. When the first semiconductor layer 122 is an n-type semiconductor layer, the first conductivity type dopant may include Si, Ge, Sn, Se, Te, or the like as an n-type dopant, but is not limited thereto. When the first semiconductor layer 122 is a p-type semiconductor layer, the first conductive dopant may include Mg, Zn, Ca, Sr, and Ba as a p-type dopant, but is not limited thereto.

The first semiconductor layer 122 may include a semiconductor material having a composition formula of Al _x In _y Ga _(1-xy) N (0? X? 1, 0? _Y? 1, 0? _X + have. The first semiconductor layer 122 may be formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP and InP. When the light emitting device 100A is an ultraviolet light emitting device that emits light in the ultraviolet region, the first semiconductor layer 122 may include Al.

The second semiconductor layer 126 may be formed of a semiconductor compound, for example, a compound semiconductor such as a group III-V element or a group II-VI element. The second conductivity type dopant may also be doped. When the second semiconductor layer 126 is a p-type semiconductor layer, the second conductive dopant may include Mg, Zn, Ca, Sr, and Ba as a p-type dopant, but is not limited thereto. When the second semiconductor layer 126 is an n-type semiconductor layer, the second conductivity type dopant may include Si, Ge, Sn, Se, Te, or the like as the n-type dopant, but is not limited thereto.

The second semiconductor layer 126 may include a semiconductor material having a composition formula of Al _x In _y Ga _(1-xy) N (0? X? 1, 0? _Y? 1, 0? _X + have. The second semiconductor layer 126 may be formed of one or more of GaN, InN, AlN, InGaN, AlGaN, InAlGaN, AlInN, AlGaAs, InGaAs, AlInGaAs, GaP, AlGaP, InGaP, AlInGaP and InP. When the light emitting device 100A is an ultraviolet light emitting device that emits light in the ultraviolet region, the second semiconductor layer 126 may include Al.

Hereinafter, the case where the first semiconductor layer 122 is an n-type semiconductor layer and the second semiconductor layer 126 is a p-current semiconductor layer will be described as an example.

An n-type semiconductor layer (not shown) may be formed on the second semiconductor layer 126 when the semiconductor having the opposite polarity to the second conductivity type, for example, the second semiconductor layer 126 is a p-type semiconductor layer . Accordingly, the light emitting structure 120 may have any one of an n-p junction structure, a p-n junction structure, an n-p-n junction structure, and a p-n-p junction structure.

The active layer 124 is located between the first semiconductor layer 122 and the second semiconductor layer 126.

The active layer 124 is a layer in which electrons and holes meet each other to emit light having energy determined by the energy band inherent in the active layer (light emitting layer) material. When the first semiconductor layer 122 is an n-type semiconductor layer and the second semiconductor layer 126 is a p-type semiconductor layer, electrons are injected from the first semiconductor layer 122 and electrons are injected from the second semiconductor layer 126 Holes can be injected. When the light emitting device 100A is a UV LED, the active layer 124 may emit light having a wavelength of about 260 nm to 405 nm.

The active layer 124 may have a multi-well structure. For example, the active layer 124 may be formed with a multiple quantum well structure by injecting trimethylgallium gas (TMGa), ammonia gas (NH ₃ ), nitrogen gas (N ₂ ), and trimethyl indium gas (TMIn) But is not limited thereto.

InGaN / InGaN, InGaN / AlGaN, InAlGaN / GaN, InGaN / AlGaN, GaAs (InGaAs) / AlGaAs / InGaN / InGaN / InGaN / InGaN / InGaN / , GaP (InGaP) / AlGaP, but the present invention is not limited thereto. The well layer is formed of a material having an energy band gap smaller than that of the barrier layer.

The stress relieving layer 130 may be disposed between the first semiconductor layer 122 and the active layer 124. The stress relieving layer 130 is intended to alleviate the lattice mismatch between the first semiconductor layer 122 and the active layer 124. The stress relieving layer 130 may have a superlattice structure in which a plurality of well layers and barrier layers are alternately stacked. The well layer / barrier layer of the stress relieving layer 130 may be formed of any one or more of InGaN / GaN, InGaN / InGaN, GaN / AlGaN, InAlGaN / GaN, InGaN / AlGaN, GaAs (InGaAs) / AlGaAs, But the present invention is not limited thereto. The well layer of the stress relieving layer 130 may be formed of a material having an energy band gap larger than that of the well layer of the active layer 124.

The active layer 124 and the stress relieving layer 130 will be described later in more detail with reference to FIGS.

An electron blocking layer 135 may be disposed between the second semiconductor layer 126 and the active layer 124. According to an embodiment, the electron blocking layer 135 may be disposed adjacent to the active layer 124 in the second semiconductor layer 126. The electron blocking layer 135 has a high mobility of electrons provided in the first semiconductor layer 122 so that electrons do not contribute to light emission and pass through the active layer 124 to the second semiconductor layer 126 And serves as a potential barrier to prevent leakage current from being generated. The electron blocking layer 135 is formed of a material having a larger energy band gap than the active layer 124 and may be formed of a semiconductor material having a composition of In _x Al _y Ga _{1 -xy} N (0? _X <y <1) have. The electron blocking layer 135 may be doped with a second conductivity type dopant.

The light emitting structure 120 is disposed on the substrate 110.

The substrate 110 may be formed of a material having excellent thermal conductivity, which is suitable for semiconductor material growth. At least one of sapphire (Al ₂ O ₃ ), SiC, GaAs, GaN, ZnO, Si, GaP, InP, Ge, and Ga ₂ O ₃ may be used as the substrate 110. The substrate 110 may be wet-cleaned to remove impurities on the surface.

The light emitting structure 120 may be formed using a metal organic chemical vapor deposition (MOCVD) method, a chemical vapor deposition (CVD) method, a plasma enhanced chemical vapor deposition (PECVD) method, (MBE), hydride vapor phase epitaxy (HVPE), or the like, but the present invention is not limited thereto.

The buffer layer 112 may be positioned between the light emitting structure 120 and the substrate 110. The buffer layer 112 is intended to alleviate the difference in lattice mismatch and thermal expansion coefficient between the light emitting structure 120 and the substrate 110 material. The material of the buffer layer 112 may be at least one of a group III-V compound semiconductor or a group II-VI compound semiconductor such as GaN, InN, AlN, InGaN, InAlGaN and AlInN. The buffer layer 112 may be grown at a temperature lower than the growth temperature of the light emitting structure 120.

The undoped semiconductor layer 114 may be disposed between the substrate 110 and the first semiconductor layer 122. The undoped semiconductor layer 114 is formed to improve crystallinity of the first semiconductor layer 122 and may be formed of the same material as the first semiconductor layer 122 or a different material from the first semiconductor layer 122 . The undoped semiconductor layer 114 is not doped with the first conductive type dopant and thus exhibits lower electrical conductivity than the first semiconductor layer 122. The undoped semiconductor layer 114 may be disposed in contact with the first semiconductor layer 122 at an upper portion of the buffer layer 112. The undoped semiconductor layer 114 grows at a temperature higher than the growth temperature of the buffer layer 112 and exhibits better crystallinity than the buffer layer 112.

The light emitting structure 120 includes an exposed surface S that exposes a portion of the first semiconductor layer 122 by etching the second semiconductor layer 126, the active layer 124, and a portion of the first semiconductor layer 122 do. The first electrode 140 is disposed on the exposed surface S. The second electrode 145 is disposed on the un-etched second semiconductor layer 126.

The first electrode 140 and the second electrode 145 may be formed of a metal such as Mo, Cr, Ni, Au, Al, Layer structure including at least one of tungsten (V), tungsten (W), lead (Pd), copper (Cu), rhodium (Rh) or iridium (Ir).

The conductive layer 147 may be formed on the second semiconductor layer 126 before the second electrode 145 is formed. A portion of the conductive layer 147 may be partially opened to expose the second semiconductor layer 126 so that the second semiconductor layer 126 and the second electrode 145 can be in contact with each other. Alternatively, as shown in FIG. 2, the second semiconductor layer 126 and the second electrode 145 may be electrically connected to each other with the conductive layer 147 therebetween.

The conductive layer 147 is formed to improve the electrical characteristics of the second semiconductor layer 126 and to improve electrical contact with the second electrode 145, and may be formed in a layer or a plurality of patterns. The conductive layer 145 may be formed of a transparent electrode layer having transparency.

The conductive layer 145 may be formed of a transparent conductive layer and a metal. For example, the conductive layer 145 may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO) ), IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IZON TiO 2, Ag, Ni, Cr, Ti, Al, Rh, ZnO, IGZO (In-Ga ZnO), ZnO, IrOx, RuOx, NiO, RuOx / ITO, Ni / IrOx / Au, Pd, Ir, Sn, In, Ru, Mg, Zn, Pt, Au, and Hf.

The light emitting device 100A may be a horizontal light emitting device.

The lateral light emitting device means a structure in which the first electrode 140 and the second electrode 145 are formed in the same direction in the light emitting structure 120. Referring to FIG. 2, a first electrode 140 and a second electrode 145 are formed in an upper direction of the light emitting structure 120.

3 is a cross-sectional side view showing another example of the light emitting device according to the embodiment. The contents overlapping with the above-mentioned contents will not be described again, and the following description will focus on the differences.

Referring to FIG. 3, the light emitting device 100B includes a light emitting structure 120 including a first semiconductor layer 122, an active layer 124, and a second semiconductor layer 126. Referring to FIG. The stress relieving layer 130 may be disposed between the first semiconductor layer 122 and the active layer 124. The stress relieving layer 130 and the active layer 124 will be described later in more detail with reference to FIGS. 4 to 8. FIG.

The light extraction pattern R may be located in the first semiconductor layer 122. [ The light extraction pattern R can be formed by performing an etching process using a photo enhanced chemical (PEC) etching method or a mask pattern. The light extraction pattern R is for increasing the efficiency of extracting light generated in the active layer 124, and may be formed at regular intervals or irregularly.

A first electrode 140 is disposed on one surface of the first semiconductor layer 122 and a second electrode layer 150 is disposed on one surface of the second semiconductor layer 126. [ That is, the first electrode 140 is disposed on the upper surface of the light emitting structure 120, and the second electrode layer 150 is disposed on the lower surface of the light emitting structure 120.

The second electrode layer 150 may include at least one of a conductive layer 150a and a reflective layer 150b. The conductive layer 150a is provided to improve the electrical characteristics of the second semiconductor layer 126 and may be located in contact with the second semiconductor layer 126. [

The conductive layer 150a may be formed of a transparent electrode layer or an opaque electrode layer. For example, the conductive layer 150a may include indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO) , IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), IZON ), IGZO (In-Ga ZnO), ZnO, IrOx, RuOx, NiO, RuOx / ITO, Ni / IrOx / Au or Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, , Ir, Sn, In, Ru, Mg, Zn, Pt, Au, and Hf.

The reflective layer 150b may improve the external quantum efficiency of the light emitting device by reducing the amount of light that is emitted from the active layer 124 to thereby extinguish the light.

The reflective layer 150b may include at least one of Ag, Ti, Ni, Cr, and AgCu, but is not limited thereto. When the reflective layer 150b is formed of a material that makes an ohmic contact with the second semiconductor layer 126, the conductive layer 150a may not be formed separately.

The light emitting structure 120 is supported by the supporting substrate 160.

The supporting substrate 160 is formed of a material having high electrical conductivity and high thermal conductivity. For example, the supporting substrate 160 may be a base substrate having a predetermined thickness, such as molybdenum (Mo), silicon (Si), tungsten (W) (Au), a copper alloy (Cu Alloy), a nickel (Ni), a copper-tungsten (Cu-Al) alloy, or a material selected from the group consisting of copper (Cu) W), carrier wafer (for example, a GaN, Si, Ge, GaAs, ZnO, SiGe, SiC, SiGe, Ga 2 O 3 , etc.) or a conductive sheet or the like may optionally be included.

The light emitting structure 120 may be bonded to the supporting substrate 160 by a bonding layer 165. At this time, the second electrode layer 150 located under the light emitting structure 120 may be in contact with the bonding layer 165.

The bonding layer 165 may include a barrier metal or a bonding metal and may include at least one of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, It is not limited thereto.

The bonding layer 165 may include a diffusion preventing layer (not shown) adjacent to the light emitting structure 120 to prevent the metal or the like used in the bonding layer 165 from diffusing into the upper light emitting structure 120 have.

A passivation layer 170 may be disposed on at least a portion of the side and top surfaces of the light emitting structure 120.

The passivation layer 170 may be formed of an oxide or a nitride to protect the light emitting structure 120. As an example, the passivation layer 170 may comprise, but is not limited to, a silicon oxide (SiO ₂ ) layer, a silicon nitride layer, an oxynitride layer, or an aluminum oxide layer.

The light extraction pattern R may be formed on the passivation layer 170 when the passivation layer 170 is also located on the upper surface of the light emitting structure 120. [

The light emitting device 100B may be a vertical light emitting device.

The vertical light emitting device means a structure in which the first electrode 140 and the second electrode layer 150 are formed in different directions in the light emitting device 100. Referring to FIG. 3, a first electrode 140 is formed in an upper direction of the light emitting structure 120, and a second electrode layer 150 is formed in a lower direction of the light emitting structure 120.

The horizontal type light emitting device 100A and the vertical type light emitting device 100B may collectively be referred to as light emitting devices. In describing the embodiment, the light emitting element may be a horizontal light emitting element or a vertical light emitting element.

4 is an energy band diagram of the light emitting device according to the first embodiment. The contents overlapping with the above-mentioned contents will not be described again, and the following description will focus on the differences.

The light emitting device 100-1 according to the first embodiment includes a first semiconductor layer 122 doped with a first conductive dopant, a second semiconductor layer 126 doped with a second conductive dopant, And an active layer 124 between the layer 122 and the second semiconductor layer 126.

The active layer 124 includes a plurality of pairs of the well layers 124a and the barrier layers 124b and the well layer 124a has a smaller energy band gap than the barrier layer 124b. Although FIG. 4 illustrates a pair structure of four well layers 124a / barrier layer 124b as an example, the number of pair structures may vary according to the embodiment. The energy band gap of the barrier layer 124b is smaller than the energy band gap of the electron blocking layer 135 and the energy band gap of the first semiconductor layer 122 or the energy band gap of the second semiconductor layer 126 Band gap.

At least one barrier layer 124b of the plurality of barrier layers 124b belonging to the active layer 124 is doped with the first conductivity type dopant and Mg together. That is, the first conductive dopant and Mg are doped together for each of the barrier layers 124b and may be doped to all of the plurality of barrier layers 124b and the barrier layers 124b of some of the plurality of barrier layers 124b ). &Lt; / RTI &gt;

The active layer 124 alternately grows the well layer 124a and the barrier layer 124b having different lattice constants and in particular the well layer 124a contains a relatively large amount of In having a large crystal lattice, pit) may occur. Most of the pits are formed as seeds through which the threading dislocations progressed from the bottom of the active layer 124 and are formed in a shape depressed toward the substrate 110.

If Mg is doped into at least one of the barrier layers 124b of the plurality of barrier layers 124b as in the embodiment, the growth of the active layer 124 material is promoted by the Mg in the direction of the semi-polar crystal plane The occurrence of pits can be prevented in advance. In addition, when the pits have already been formed during the growth process of the active layer 124, the growth of the active layer 124 material in the direction of the semi-polar crystal plane is promoted, and the pits can be effectively filled by the semiconductor layer grown thereafter.

5 is a diagram for explaining the effect of the embodiment. FIG. 5 shows an arbitrary portion of the active layer 124. FIG.

5, there is a pit P depressed downward in the active layer 124, and Mg is doped into the barrier layer 124b. As a result, the active layer 124 is doped with Mg to form the active layer 124 in the semi- (124) growth of the material is promoted so that the pit (P) gradually fills the crystal quality. Therefore, the low current characteristic and the light output characteristic of the light emitting element can be improved.

In addition, according to the embodiment, by doping at least one of the barrier layers 124b with Mg as well as the first conductive type dopant, the series resistance between each layer constituting the active layer 124 can be reduced to lower the operating voltage It is possible to compensate for the increase of the operating voltage by the doping of Mg.

Referring again to FIG. 4, when a first conductive dopant and Mg are doped in a part of the barrier layer 124b of the plurality of barrier layers 124b, the barrier layer 124b doped with Mg is doped with the first conductive dopant, May be a barrier layer 124b adjacent to the first semiconductor layer 122. [ When Mg is doped in the barrier layer 124b adjacent to the first semiconductor layer 122, a high-quality semiconductor layer without pits can be grown from the initial growth of the active layer 124. [

According to the embodiment, Mg may not be separately doped in the last barrier layer 124b_last closest to the second semiconductor layer 126 during the growth of the active layer 124. When Mg is used as the second conductive type dopant in the second semiconductor layer 126 and / or the electron barrier layer 135, Mg may be present in the final barrier layer 124b_last by diffusion even if Mg is not separately doped. have.

The first conductive dopant doped to the barrier layer 124b may be the same as the first conductive dopant doped to the first semiconductor layer 122. [

Each of the plurality of barrier layers 124b may each include a first region 124b-1 contacting the adjacent well layer 124a and a second region 124b between the two first regions 124b-1 . Each of the barrier layers 124b includes two first regions 124b-1 that are in contact with both well layers 124a, since well layers 124a are located on both sides of one barrier layer 124b do. Exceptionally, the last barrier layer 124b has one first region 124b-1 because it is in contact with one well layer 124a on one side, and the one first region 124b-1 and the electron blocking layer 124b- And a second region 124b-2 between the first region 124b-2 and the second region 124b-2. Although not shown, when the active layer 124 starts from the barrier layer 124b in contact with the first semiconductor layer 122, the barrier layer 124b in contact with the first semiconductor layer 122 also has a first region 124b -1).

When the first conductive dopant and Mg are doped in at least one barrier layer 124b of the plurality of barrier layers 124b, the first conductive dopant is doped in the first region 124b-1, Mg may be doped in the second region 124b-2. When Mg is diffused into the well layer 124a, the efficiency of injecting holes may be lowered, causing a leakage current, and the efficiency of light emission may be lowered. Accordingly, the first region 124b-1 serves to prevent Mg present in the second region 124b-2 from diffusing into the well layer 124a.

6 is an energy band diagram of the light emitting device according to the second embodiment. The contents overlapping with the above-mentioned contents will not be described again, and the following description will focus on the differences.

The light emitting device 100-2 according to the second embodiment includes a first semiconductor layer 122 doped with a first conductive dopant, a second semiconductor layer 126 doped with a second conductive dopant, And an active layer 124 between the layer 122 and the second semiconductor layer 126.

At least one barrier layer 124b of the plurality of barrier layers 124b belonging to the active layer 124 may be doped with Mg or the first conductivity type dopant may be doped with Mg. May be doped to all of the plurality of barrier layers 124b and may be doped to some of the barrier layers 124b of the plurality of barrier layers 124b. When at least one barrier layer 124b of the plurality of barrier layers 124b belonging to the active layer 124 is doped with the first conductivity type dopant and Mg together with the first barrier layer 124b, Mg is doped together.

Each of the plurality of barrier layers 124b may each include a first region 124b-1 contacting the adjacent well layer 124a and a second region 124b between the two first regions 124b-1 . Each of the barrier layers 124b includes two first regions 124b-1 that are in contact with both well layers 124a, since well layers 124a are located on both sides of one barrier layer 124b do. Exceptionally, the last barrier layer 124b has one first region 124b-1 because it is in contact with one well layer 124a on one side, and the one first region 124b-1 and the electron blocking layer 124b- And a second region 124b-2 between the first region 124b-2 and the second region 124b-2. Although not shown, when the active layer 124 starts from the barrier layer 124b in contact with the first semiconductor layer 122, the barrier layer 124b in contact with the first semiconductor layer 122 also has a first region 124b -1).

When Mg is doped in at least one barrier layer 124b of the plurality of barrier layers 124b, the second region 124b-2 may be doped with Mg. The first region 124b-1 serves to prevent Mg present in the second region 124b-2 from diffusing into the well layer 124a. When Mg is diffused into the well layer 124a, the efficiency of injecting holes may be lowered, causing a leakage current, and the efficiency of light emission may be lowered.

When the first conductive dopant and the Mg are doped in at least one barrier layer 124b of the plurality of barrier layers 124b, the first conductive dopant is doped in the first region 124b-1, Mg may be doped in the second region 124b-2. As described above, the first region 124b-1 serves to prevent Mg present in the second region 124b-2 from diffusing into the well layer 124a. In addition, by doping the first region 124b-1 with the first conductive dopant, the series resistance between the respective layers constituting the active layer 124 can be reduced to lower the operating voltage, and the Mg of the second region 124b- It is possible to compensate for the increase of the operating voltage by doping.

In the barrier layer 124b in which the Mg doping or the doping of the first conductivity type dopant is performed in the plurality of barrier layers 124b, the first region 124b-1 has the energy band gap in the second region 124b- 2). &Lt; / RTI &gt; A part of Mg existing in the second region 124b-2 may be diffused into the well layer 124a beyond the first region 124b-1, so that the energy barrier of the first region 124b-1 is increased and Mg Can be prevented. The energy band gap of the second region 124b-2 is larger than the energy band gap of the well layer 124a.

6 shows that the first region 124b-1 and the second region 124b-2 have different energy band gaps in all of the plurality of barrier layers 124b belonging to the active layer 124, When the first conductive dopant and Mg are doped in a part of the barrier layer 124b of the plurality of barrier layers 124b, the first region 124b-1 belonging to the doped barrier layer 124b and the second region 124b- The energy band gap of the region 124b-2 may be different. When a first conductive dopant and Mg are doped in a part of the barrier layer 124b of the plurality of barrier layers 124b, the barrier layer 124b doped with the first conductive dopant and Mg may be formed on the first semiconductor layer 122 Or a barrier layer 124b adjacent to the barrier layer 124b. When Mg is doped in the barrier layer 124b adjacent to the first semiconductor layer 122, a high-quality semiconductor layer without pits can be grown from the initial growth of the active layer 124. [

6 shows that the energy band gap is also different in the portion of the active layer 124 that is in contact with the electron blocking layer 135 from the last barrier layer 124b_last. However, in the last barrier layer 124b_last, the electron blocking layer 135 ), The energy bandgap may be constant. That is, the last barrier layer 124b_last includes a first region 124b-2 contacting the well layer 124a and a second region 124b-2 between the first region 124b-2 and the electron blocking layer 135 And the energy band gap of the second region 124b-2 does not have to be constant because the Mg diffusion in the direction of the second semiconductor layer 126 is not required to be prevented in the second region 124b-2. .

The first region 124b-1 having a relatively large energy band gap in the barrier layer 124b may be referred to as a first barrier layer and the second region 124b-2 having a relatively small energy band gap may be referred to as a second barrier layer have. That is, the active layer 124 has at least two well layers 124a adjacent to each other, a first barrier layer 124a having an energy bandgap greater than the energy bandgap of the well layer 124a and in contact with the adjacent at least two well layers 124a, (First region, 124b-1) disposed in the first barrier layer (first region, 124b-1) and disposed between the first barrier layer (first region, 124b-1) and the well layer And a second barrier layer (second region, 124b-2) having an energy bandgap. The first barrier layer (first region, 124b-1) may be doped with a first conductive dopant and the second barrier layer (second region, 124b-2) may be doped with Mg.

7 is an energy band diagram of the light emitting device according to the third embodiment. The contents overlapping with the above-mentioned contents will not be described again, and the following description will focus on the differences.

The light emitting device 100-3 according to the third embodiment includes a first semiconductor layer 122 doped with a first conductive dopant, a second semiconductor layer 126 doped with a second conductive dopant, And an active layer 124 between the layer 122 and the second semiconductor layer 126.

At least one barrier layer 124b of the plurality of barrier layers 124b belonging to the active layer 124 is doped with the first conductivity type dopant and Mg together. That is, the first conductive dopant and Mg are doped together for each of the barrier layers 124b and may be doped to all of the plurality of barrier layers 124b and the barrier layers 124b of some of the plurality of barrier layers 124b ). &Lt; / RTI &gt;

Each of the plurality of barrier layers 124b may each include a first region 124b-1 contacting the adjacent well layer 124a and a second region 124b between the two first regions 124b-1 . Each of the barrier layers 124b includes two first regions 124b-1 that are in contact with both well layers 124a, since well layers 124a are located on both sides of one barrier layer 124b do. Exceptionally, the last barrier layer 124b has one first region 124b-1 since it is tangent to one well layer 124a. Although not shown, when the active layer 124 starts from the barrier layer 124b in contact with the first semiconductor layer 122, the barrier layer 124b in contact with the first semiconductor layer 122 also has a first region 124b -1).

When the first conductive dopant and Mg are doped in at least one barrier layer 124b of the plurality of barrier layers 124b, the first conductive dopant is doped in the first region 124b-1, Mg may be doped in the second region 124b-2. The first region 124b-1 serves to prevent Mg present in the second region 124b-2 from diffusing into the well layer 124a. When Mg is diffused into the well layer 124a, the efficiency of injecting holes may be lowered, causing a leakage current, and the efficiency of light emission may be lowered.

A stress relieving layer 130 is disposed between the first semiconductor layer 122 and the active layer 124. The crystallinity of the active layer 124 may be deteriorated by alternately growing the well layer 124a and the barrier layer 124b having a large difference in lattice constant and therefore the stress relieving layer 130 before growth of the active layer 124 The stress can be relaxed by growing first.

The stress relieving layer 130 includes a first layer 131 and a plurality of pairs of the second layers 132 having a smaller energy bandgap than the first layer 131. The second layer 132 may be formed of a material having a smaller energy band gap than the first and second semiconductor layers 122 and 126 or the barrier layer 124b of the active layer 124. [ The energy band gap of the first layer 131 may be larger than the energy band gap of the well layer 124a of the active layer 124. [

The stress relaxation layer 130 may be formed so that the first semiconductor layer 122 and the second layer 132 are in contact with each other and the first semiconductor layer 122 and the first layer 131 may be formed as shown in FIG. As shown in Fig. When the stress relaxation layer 130 is formed so that the first semiconductor layer 122 and the first layer 131 are in contact with each other, the difference in growth temperature between the first semiconductor layer 122 and the first layer 131 is small, It may also contribute to sexual quality.

The stress relieving layer 130 may be formed so that the active layer 124 and the second layer 132 are in contact with each other or may be formed so that the active layer 124 and the first layer 131 are in contact with each other have. When the stress relaxation layer 130 is formed so that the barrier layer 124b of the active layer 124 and the first layer 131 are in contact with each other, the difference in growth temperature between the barrier layer 124b and the first layer 131 is small It may contribute to crystallinity quality.

In the stress relieving layer 130, Mg may be doped in the first layer 131 adjacent to the active layer 124 among the plurality of first layers 131. Alternatively, the first conductive dopant and Mg may be doped in the first layer 131 adjacent to the active layer 124, according to an embodiment. When the stress relaxation layer 130 and the active layer 124 are grown, pits are generated mainly in the first first layer 131 of the stress relaxation layer 130 and extend to the active layer 124, Mg is doped in the layer 131, thereby preventing generation of pits and effectively filling the already generated pits.

The first first layer 131 of the stress relieving layer 130 and the first barrier layer 124b of the active layer 124 are in contact with each other, 124b may be doped with Mg as a single barrier layer, or Mg may be doped together with the first conductive dopant. Referring to FIG. 7, when the last first layer 131 of the stress relaxation layer 130 and the first barrier layer 124b of the active layer 124 are one barrier layer B, the barrier layer B is adjacent A region B-1 in contact with the second layer 132 of the stress relaxation layer 130, a region B-2 in contact with the well layer 124a of the adjacent active layer 124, a region B- The first B-3 region is doped with Mg, the B-1 region and the B-2 region are doped with a first conductive dopant, and the B-3 region is doped with Mg Lt; / RTI &gt; The region B-1 prevents Mg present in the region B-3 from diffusing into the second layer 132 of the stress relieving layer 130, while the region B-2 prevents Mg existing in the region B-3 from diffusing into the active layer To the well layer (124a) of the substrate (124).

When the first conductive dopant and Mg are doped in a part of the barrier layer 124b of the plurality of barrier layers 124b, the barrier layer 124b doped with the first conductive dopant and Mg is formed on the stress relieving layer 130, May be a barrier layer 124b adjacent to the barrier layer 124b. If Mg is doped in the barrier layer 124b adjacent to the stress relaxation layer 130, since the majority of pits are generated in the final barrier layer 131 of the stress layer 130, A high-quality semiconductor layer can be grown.

8 is an energy band diagram of the light emitting device according to the fourth embodiment. The contents overlapping with the above-mentioned contents will not be described again, and the following description will focus on the differences.

The light emitting device 100-4 according to the fourth embodiment includes a first semiconductor layer 122 doped with a first conductive dopant, a second semiconductor layer 126 doped with a second conductive dopant, And an active layer 124 between the layer 122 and the second semiconductor layer 126.

At least one barrier layer 124b of the plurality of barrier layers 124b belonging to the active layer 124 is doped with Mg or the first conductive dopant and Mg are doped together. May be doped to all of the plurality of barrier layers 124b and may be doped to some of the barrier layers 124b of the plurality of barrier layers 124b. When at least one barrier layer 124b of the plurality of barrier layers 124b belonging to the active layer 124 is doped with the first conductivity type dopant and Mg together with the first barrier layer 124b, Mg is doped together.

Each of the plurality of barrier layers 124b may each include a first region 124b-1 contacting the adjacent well layer 124a and a second region 124b between the two first regions 124b-1 . Each of the barrier layers 124b includes two first regions 124b-1 that are in contact with both well layers 124a, since well layers 124a are located on both sides of one barrier layer 124b do. Exceptionally, the last barrier layer 124b has one first region 124b-1 because it is in contact with one well layer 124a on one side, and the one first region 124b-1 and the electron blocking layer 124b- And a second region 124b-2 between the first region 124b-2 and the second region 124b-2. Although not shown, when the active layer 124 starts from the barrier layer 124b in contact with the first semiconductor layer 122, the barrier layer 124b in contact with the first semiconductor layer 122 also has a first region 124b -1).

When Mg is doped in at least one barrier layer 124b of the plurality of barrier layers 124b, the second region 124b-2 may be doped with Mg. The first region 124b-1 serves to prevent Mg present in the second region 124b-2 from diffusing into the well layer 124a. When Mg is diffused into the well layer 124a, the efficiency of injecting holes may be lowered, causing a leakage current, and the efficiency of light emission may be lowered.

When the first conductive dopant and the Mg are doped in at least one barrier layer 124b of the plurality of barrier layers 124b, the first conductive dopant is doped in the first region 124b-1, Mg may be doped in the second region 124b-2. As described above, the first region 124b-1 serves to prevent Mg present in the second region 124b-2 from diffusing into the well layer 124a. In addition, by doping the first region 124b-1 with the first conductive dopant, the series resistance between the respective layers constituting the active layer 124 can be reduced to lower the operating voltage, and the Mg of the second region 124b- It is possible to compensate for the increase of the operating voltage by doping.

In the barrier layer 124b in which the Mg doping or the doping of the first conductivity type dopant is performed in the plurality of barrier layers 124b, the first region 124b-1 has the energy band gap in the second region 124b- 2). &Lt; / RTI &gt; A part of Mg existing in the second region 124b-2 may be diffused into the well layer 124a beyond the first region 124b-1, so that the energy barrier of the first region 124b-1 is increased and Mg Can be prevented. The energy band gap of the second region 124b-2 is larger than the energy band gap of the well layer 124a.

8 shows that the first region 124b-1 and the second region 124b-2 have different energy bandgaps in all of the plurality of barrier layers 124b belonging to the active layer 124, When the first conductive dopant and Mg are doped in a part of the barrier layer 124b of the plurality of barrier layers 124b, the first region 124b-1 belonging to the doped barrier layer 124b and the second region 124b- The energy band gap of the region 124b-2 may be different. When a first conductive dopant and Mg are doped in a part of the barrier layer 124b of the plurality of barrier layers 124b, the barrier layer 124b doped with the first conductive dopant and Mg may be formed on the first semiconductor layer 122 Or a barrier layer 124b adjacent to the barrier layer 124b. When Mg is doped in the barrier layer 124b adjacent to the first semiconductor layer 122, a high-quality semiconductor layer without pits can be grown from the initial growth of the active layer 124. [

8 shows that the energy bandgap is different in the portion of the active layer 124 that is in contact with the electron blocking layer 135 in the last barrier layer 124b_last. However, in the last barrier layer 124b_last, the electron blocking layer 135 ), The energy bandgap may be constant. That is, the last barrier layer 124b_last includes a first region 124b-2 contacting the well layer 124a and a second region 124b-2 between the first region 124b-2 and the electron blocking layer 135 And the energy band gap of the second region 124b-2 does not have to be constant because the Mg diffusion in the direction of the second semiconductor layer 126 is not required to be prevented in the second region 124b-2. .

The first region 124b-1 having a relatively large energy band gap in the barrier layer 124b may be referred to as a first barrier layer and the second region 124b-2 having a relatively small energy band gap may be referred to as a second barrier layer have. That is, the active layer 124 has at least two well layers 124a adjacent to each other, a first barrier layer 124a having an energy bandgap greater than the energy bandgap of the well layer 124a and in contact with the adjacent at least two well layers 124a, (First region, 124b-1) disposed in the first barrier layer (first region, 124b-1) and disposed between the first barrier layer (first region, 124b-1) and the well layer And a second barrier layer (second region, 124b-2) having an energy bandgap. The first barrier layer (first region, 124b-1) may be doped with a first conductive dopant and the second barrier layer (second region, 124b-2) may be doped with Mg.

A stress relieving layer 130 is disposed between the first semiconductor layer 122 and the active layer 124.

In the stress relieving layer 130, Mg may be doped in the first layer 131 adjacent to the active layer 124 among the plurality of first layers 131. Alternatively, the first conductive dopant and Mg may be doped in the first layer 131 adjacent to the active layer 124, according to an embodiment. When the stress relaxation layer 130 and the active layer 124 are grown, pits are generated mainly in the first first layer 131 of the stress relaxation layer 130 and extend to the active layer 124, Mg is doped in the layer 131, thereby preventing generation of pits and effectively filling the already generated pits.

The first first layer 131 of the stress relieving layer 130 and the first barrier layer 124b of the active layer 124 are in contact with each other, 124b may be doped with Mg as a single barrier layer, or Mg may be doped together with the first conductive dopant. 8, when the last first layer 131 of the stress relaxation layer 130 and the first barrier layer 124b of the active layer 124 are one barrier layer B, the barrier layer B is adjacent A region B-1 in contact with the second layer 132 of the stress relaxation layer 130, a region B-2 in contact with the well layer 124a of the adjacent active layer 124, a region B- The first B-3 region is doped with Mg, the B-1 region and the B-2 region are doped with a first conductive dopant, and the B-3 region is doped with Mg Lt; / RTI &gt; The region B-1 prevents Mg present in the region B-3 from diffusing into the second layer 132 of the stress relieving layer 130, while the region B-2 prevents Mg existing in the region B-3 from diffusing into the active layer To the well layer (124a) of the substrate (124).

The energy band gap of each of the regions B-1 and B-2 is greater than the energy band gap of the region B-3. A part of Mg existing in the region B-3 diffuses to the second layer 132 of the stress relieving layer 130 beyond the region B-1 or the well layer 124a of the active layer 124 extends beyond the region B- It is possible to increase the energy barrier between the regions B-1 and B-2 and to prevent the diffusion of Mg. The energy band gap of the B-3 region is larger than the energy band gap of the well layer 124a of the active layer 124 and larger than the energy band gap of the second layer 132 of the stress relieving layer 130. [

When a barrier layer 124b of a plurality of barrier layers 124b is doped with Mg or a first conductive dopant and Mg is doped, the barrier layer 124b doped with Mg or the first conductive dopant and Mg The doped barrier layer 124b may be a barrier layer 124b adjacent to the stress relieving layer 130. [ If Mg is doped in the barrier layer 124b adjacent to the stress relaxation layer 130, since the majority of pits are generated in the final barrier layer 131 of the stress layer 130, A high-quality semiconductor layer can be grown.

The first layer 131 of the stress relaxation layer 130 adjacent to the barrier layer 124b of the active layer 124 or the barrier layer 124b of the active layer 124 and the first layer 131 of the stress relaxation layer 130 adjacent to the active layer 124 are formed of Mg It is possible to reduce the generation of pits to improve the low current characteristics and the light output characteristics of the light emitting device and to reduce the series resistance between the layers constituting the active layer 124 by doping the first conductivity type dopant and Mg together The operating voltage can be lowered and the increase of the operating voltage due to the doping of Mg can be compensated.

9 is a view illustrating an embodiment of a light emitting device package including a light emitting device according to embodiments.

The light emitting device package 200 according to an embodiment includes a body 210, a heat dissipation block 220 disposed in the body 210, and a light emitting device 100 disposed on the heat dissipation block 200 .

The body 210 may be embodied as a plurality of layers 211, 212, 213, 214. The number of layers constituting the body 210 may vary according to the embodiment.

When the light emitting device 100 is a UV LED that emits ultraviolet rays, the body 210 may be made of a material that is not deteriorated by ultraviolet rays, and may be made of, for example, a ceramic material. As an example, the body 210 may be implemented by a low temperature co-fired ceramic (LTCC) method. Also, the body 210 may be realized by a high temperature co-fired ceramic (HTCC) method. In addition, the body 210 may comprise a _{Si0 2, Si x O y,} Si 3 N 4, Si x N y, SiO x N y, Al 2 O 3, or AlN.

The body 210 may supply current to the light emitting device 100 through the conductive pattern located between the via holes formed through the respective layers 211 to 214 and the respective layers 211 to 214. [

A heat dissipation block 220 is disposed in the body 210. The heat dissipation block 220 effectively transmits heat generated from the light emitting device 100 to the outside. The heat dissipation block 220 may be formed of an alloy including Cu or Cu, but is not limited thereto.

10 is a view illustrating another embodiment of the light emitting device package including the light emitting device according to the embodiments.

10, a light emitting device package 300 according to an exemplary embodiment includes a body 310, first and second lead frames 321 and 322 disposed on the body 310, The light emitting device 100 according to the above embodiments is disposed on the body 310 and is electrically connected to the first lead frame 321 and the second lead frame 322. The molding part 340 ). A cavity may be formed in the body 310.

The body 310 may include a silicon material, a synthetic resin material, or a metal material. When the body 310 is made of a conductive material such as a metal material, an insulating layer is coated on the surface of the body 310 to prevent an electrical short between the first and second lead frames 321 and 322 .

The first lead frame 321 and the second lead frame 322 are electrically separated from each other and supply current to the light emitting device 100. The first lead frame 321 and the second lead frame 322 may increase the light efficiency by reflecting the light generated from the light emitting device 100. The heat generated from the light emitting device 100 To the outside.

The light emitting device 100 may be disposed on the body 310 or may be disposed on the first lead frame 321 or the second lead frame 322. The first lead frame 321 and the light emitting element 100 are directly energized and the second lead frame 322 and the light emitting element 100 are connected to each other through the wire 330 in this embodiment. The light emitting device 100 may be connected to the lead frames 321 and 322 by a flip chip method or a die bonding method in addition to the wire bonding method.

The molding part 340 may surround and protect the light emitting device 100. In addition, the phosphor 350 may be included on the molding part 340 to change the wavelength of light emitted from the light emitting device 100.

The phosphor 350 may include a garnet-based phosphor, a silicate-based phosphor, a nitride-based phosphor, or an oxynitride-based phosphor.

For example, the garnet-base phosphor is _{YAG (Y 3 Al 5 O 12} : Ce 3 +) or TAG: may be a _{(Tb 3 Al 5 O 12 Ce} 3 +), wherein the silicate-based phosphor is (Sr, Ba, Mg, Ca) ₂ SiO ₄ : Eu ^{2 +} , and the nitride phosphor may be CaAlSiN ₃ : Eu ^{2 +} containing SiN, and the oxynitride phosphor may be Si _{6 - x Al x O x N 8 -x:} Eu 2 + (0 <x <6) can be.

The light of the first wavelength range emitted from the light emitting device 100 is excited by the phosphor 350 to be converted into the light of the second wavelength range and the light of the second wavelength range passes through the lens (not shown) The light path can be changed.

A plurality of light emitting device packages according to embodiments may be arranged on a substrate, and a light guide plate, a prism sheet, a diffusion sheet, and the like may be disposed on the light path of the light emitting device package. 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, a lighting system including the semiconductor light emitting device or the light emitting device package described in the above embodiments, for example, the lighting system may include a lamp, a streetlight .

FIG. 11 is an exploded perspective view showing an embodiment of a lighting device including a light emitting device package according to embodiments.

The illumination device according to the embodiment includes a light emitting module 600 for projecting light, a housing 400 in which the light emitting module 600 is installed, a heat dissipating part 500 for emitting heat of the light emitting module 600, And a holder 700 for coupling the module 600 and the heat dissipating unit 500 to the housing 400.

The housing 400 includes a socket coupling part 410 coupled to an electric socket and a body part 420 connected to the socket coupling part 410 and having a light source 600 embedded therein. The body 420 may have one air flow hole 430 formed therethrough.

A plurality of air flow openings 430 are provided on the body portion 420 of the housing 400. The air flow openings 430 may be formed of one air flow openings or a plurality of flow openings may be radially arranged Various other arrangements are also possible.

The light emitting module 600 includes a plurality of light emitting device packages 650 disposed on a circuit board 610. The light emitting device package 650 may include the light emitting device according to the embodiment described above. The circuit board 610 may have a shape that can be inserted into the opening of the housing 400 and may be made of a material having a high thermal conductivity to transmit heat to the heat dissipating unit 500 as described later.

A holder 700 is provided under the light emitting module. The holder 700 may include a frame and another air flow port. Although not shown, an optical member may be provided under the light emitting module 600 to diffuse, scatter, or converge light projected from the light emitting module 650 of the light emitting module 600.

12 is an exploded perspective view illustrating a display device in which a light emitting device package according to embodiments is disposed.

12, the display device 800 according to the embodiment includes the light emitting modules 830 and 835, the reflection plate 820 on the bottom cover 810, and the reflection plate 820 disposed on the front side of the reflection plate 820, A first prism sheet 850 and a second prism sheet 860 disposed in front of the light guide plate 840 and a second prism sheet 860 disposed between the first prism sheet 850 and the second prism sheet 860. The light guiding plate 840 guides light emitted from the light- A panel 870 disposed in front of the panel 870 and a color filter 880 disposed in the front of the panel 870.

The light emitting module includes the above-described light emitting device package 835 on the circuit board 830. Here, the circuit board 830 may be a PCB or the like, and the light emitting device package 835 is as described above.

The bottom cover 810 may house the components in the display device 800. The reflection plate 820 may be formed as a separate component as shown in the drawing, or may be formed to be coated on the rear surface of the light guide plate 840 or on the entire surface of the bottom cover 810 with a highly reflective material Do.

Here, the reflection plate 820 can be made of a material having a high reflectance and can be used in an ultra-thin shape, and polyethylene terephthalate (PET) can be used.

The light guide plate 840 scatters light emitted from the light emitting device package module so that the light is uniformly distributed over the entire screen area of the LCD. Accordingly, the light guide plate 830 is made of a material having a good refractive index and transmittance. The light guide plate 830 may be formed of polymethyl methacrylate (PMMA), polycarbonate (PC), or polyethylene (PE). An air guide system is also available in which the light guide plate is omitted and light is transmitted in a space above the reflective sheet 820.

The first prism sheet 850 is formed on one side of the support film with a transparent and elastic polymeric material, and the polymer may have a prism layer in which a plurality of steric structures are repeatedly formed. As shown in the drawings, the plurality of patterns may be repeatedly provided with a stripe pattern.

In the second prism sheet 860, the edges and the valleys on one surface of the support film may be perpendicular to the edges and the valleys on one surface of the support film in the first prism sheet 850. This is to uniformly distribute the light transmitted from the light emitting module and the reflective sheet in all directions of the panel 870.

In the present embodiment, the first prism sheet 850 and the second prism sheet 860 form an optical sheet, which may be formed of other combinations, for example, a microlens array or a diffusion sheet and a microlens array Or a combination of one prism sheet and a microlens array, or the like.

A liquid crystal display (LCD) panel may be disposed on the panel 870. In addition to the liquid crystal display panel 860, other types of display devices requiring a light source may be provided.

In the panel 870, the liquid crystal is positioned between the glass bodies, and the polarizing plate is placed on both glass bodies to utilize the polarization of light. Here, the liquid crystal has an intermediate property between a liquid and a solid, and liquid crystals, which are organic molecules having fluidity like a liquid, are regularly arranged like crystals. The liquid crystal has a structure in which the molecular arrangement is changed by an external electric field And displays an image.

A liquid crystal display panel used in a display device is an active matrix type, and a transistor is used as a switch for controlling a voltage supplied to each pixel.

A color filter 880 is provided on the front surface of the panel 870 so that light projected from the panel 870 transmits only red, green, and blue light for each pixel.

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 embodiments, but, on the contrary, This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the equivalents of the claims, as well as the claims.

120: light emitting structure 122: first semiconductor layer
124: active layer 124a: well layer
124b: barrier layer 124b-1: first region
124b-2: second region 130: stress relaxation layer
131: first layer 132: second layer

Claims (10)

A first semiconductor layer doped with a first conductive dopant;
A second semiconductor layer doped with a second conductive dopant;
An active layer between the first semiconductor layer and the second semiconductor layer; And
A stress relieving layer between the first semiconductor layer and the active layer;
/ RTI &gt;
The active layer includes a plurality of pair structures of a barrier layer and a well layer having a smaller energy band gap than the barrier layer, and at least one barrier layer of the plurality of barrier layers is doped with Mg together with the first conductivity type dopant ,
Wherein at least one barrier layer of the plurality of barrier layers comprises two first regions in contact with adjacent well layers and a second region between the two first regions, And the Mg is doped in the second region,
The energy band gap of the first region is larger than the energy band gap of the second region,
The stress relieving layer includes a first layer and a second layer structure having a smaller energy band gap than the first layer, and the first layer closest to the active layer among the plurality of first layers is doped with Mg , And the first conductive type dopant and Mg are doped together. delete delete delete The method according to claim 1,
Wherein a first first layer closest to the active layer and a first barrier layer closest to the stress relieving layer among the active layer contact each other and Mg is doped together with the first first layer and the first barrier layer among the stress relieving layers , The first conductive type dopant and Mg are doped together,
And at least one barrier layer adjacent to the stress relieving layer among the plurality of barrier layers is doped with the first conductive dopant and Mg. delete delete A first semiconductor layer doped with a first conductive dopant;
A second semiconductor layer doped with a second conductive dopant;
An active layer between the first semiconductor layer and the second semiconductor layer; And
A stress relieving layer between the first semiconductor layer and the active layer;
/ RTI &gt;
The active layer comprising at least two adjacent well layers, a first barrier layer in contact with the at least two well layers and having an energy bandgap greater than an energy bandgap of the well layer, a second barrier layer disposed within the first barrier layer, And a second barrier layer having an energy bandgap between the layer and the well layer,
Wherein the stress relieving layer includes a first layer and a plurality of pairs of second layer structures having a smaller energy bandgap than the first layer,
The first layer closest to the active layer among the plurality of first layers is doped with Mg,
Wherein the first barrier layer is doped with the first conductive dopant,
And the second barrier layer is doped with Mg. delete delete

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