KR102237113B1 - Light emitting device - Google Patents

Abstract

The embodiment includes a first semiconductor layer, a second semiconductor layer, an active layer disposed between the first and second semiconductor layers, and a current dispersion injection layer disposed between the first semiconductor layer and the active layer; The dispersion injection layer is disposed on the first semiconductor layer, a current distribution layer having a first energy band gap, and a current disposed on the current distribution layer and having a second energy bed gap smaller than the first energy band gap. It provides a light emitting device including a current injection layer including an injection well layer and a current injection barrier layer disposed on the current injection well layer and having a third energy bad gap between the first and second energy band gaps.

Description

Light emitting device

The embodiment relates to a light emitting device.

Light Emitting Diode (LED) is a device that converts electrical signals into light by using the characteristics of compound semiconductors, and is used in home appliances, remote controls, electronic boards, indicators, and various automation devices. There is a trend.

When the forward voltage is applied, the electrons in the n-layer and the holes in the p-layer are combined to emit energy equivalent to the energy gap between the conduction band and the valence band. It is mainly emitted in the form of heat or light, and when it is emitted in the form of light, it becomes an LED.

Nitride semiconductors are attracting great interest in the development of optical devices and high-power electronic devices due to their high thermal stability and wide bandgap energy. In particular, a blue light emitting device, a green light emitting device, and an ultraviolet (UV) light emitting device using a nitride semiconductor have been commercialized and widely used.

An important issue is how efficiently the light-emitting device emits light generated from the semiconductor layer to the outside. Therefore, optical energy generated inside the light emitting device is not converted into thermal energy, and optical consideration is required to be emitted to the outside.

When electrons are injected from the n-type semiconductor layer, the light-emitting device must stably lose energy and contribute to light emission by being bound to the active layer.In general, a significant proportion of electrons do not contribute to light emission and are supplied to the p-type semiconductor layer. As a result, a leakage current is generated, and in recent years, research on a stacked structure of semiconductor layers that can prevent the occurrence of leakage current and prevent lattice mismatch occurring in the n-type semiconductor layer, the active layer, and the p-type semiconductor layer is in progress. .

An object of the embodiment is to provide a light emitting device capable of stably injecting electrons into an active layer and reducing lattice mismatch between the first semiconductor layer and the active layer, thereby improving luminous efficiency of the light emitting device.

The light emitting device according to the embodiment includes a first semiconductor layer, a second semiconductor layer, an active layer disposed between the first and second semiconductor layers, and a current distributing injection layer disposed between the first semiconductor layer and the active layer, , The current distribution injection layer is disposed on the first semiconductor layer, a current distribution layer having a first energy band gap, and a second energy bed gap disposed on the current distribution layer and smaller than the first energy band gap And a current injection layer including a current injection well layer having a current injection well layer and a current injection barrier layer disposed on the current injection well layer and having a third energy bad gap between the first and second energy band gaps.

In the light emitting device according to the embodiment, the active layer adjacent to the n-type semiconductor layer is provided by arranging a current dispersion injection layer to reduce lattice mismatch between the n-type semiconductor layer and the active layer and energy of electrons injected from the n-type semiconductor layer to the active layer. Electrons can be uniformly injected to one side of the active layer, and electrons injected into the active layer can stay in the active layer, thereby combining with holes injected from the p-type semiconductor layer to increase luminous efficiency.

1 is a perspective view showing a light emitting device according to an embodiment.
FIG. 2 is a perspective view showing the current dispersion injection layer shown in FIG. 1.
3 is a diagram showing an energy band diagram of a light emitting device according to the first embodiment.
4 is a diagram showing an energy band diagram of a light emitting device according to a second embodiment.
5 is a cross-sectional view illustrating a light emitting device package including a light emitting device according to an embodiment.
6 is an exploded perspective view of a display device including a light emitting device according to an exemplary embodiment.
7 is a cross-sectional view of the display device of FIG. 6.
8 is an exploded perspective view of a lighting device including a light emitting device according to an embodiment.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in a variety of different forms, and only these embodiments make the disclosure of the present invention complete, and are common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same elements throughout the specification.

Spatially relative terms "below", "beneath", "lower", "above", "upper", etc. It may be used to easily describe the correlation between the device or components and other devices or components. Spatially relative terms should be understood as terms including different directions of the device during use or operation in addition to the directions shown in the drawings. For example, if an element shown in the figure is turned over, an element described as “below” or “beneath” of another element may be placed “above” another element. Accordingly, the exemplary term “below” may include both directions below and above. The device may be oriented in other directions, and thus spatially relative terms may be interpreted according to the orientation.

The terms used in the present specification are for describing exemplary embodiments and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used herein, "comprises" and/or "comprising" refers to the presence of one or more other components, steps, actions and/or elements in which the recited component, step, operation and/or element is Or does not preclude additions.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used with meanings that can be commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not interpreted ideally or excessively unless explicitly defined specifically.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size and area of each component do not fully reflect the actual size or area.

In addition, the angles and directions mentioned in the process of describing the structure of the light emitting device in the embodiment are based on those described in the drawings. In the description of the structure constituting the light emitting device in the specification, when the reference point and the positional relationship with respect to the angle are not clearly stated, reference will be made to the related drawings.

Hereinafter, embodiments will be described in more detail with reference to the drawings.

1 is a perspective view showing a light emitting device according to an embodiment, and FIG. 2 is a perspective view showing a current distribution injection layer shown in FIG. 1.

1 and 2, the light emitting device 100 is disposed on the substrate 110 and the substrate 110, the first semiconductor layer 120, the current dispersion injection layer 125, the second semiconductor layer ( 140) and a light emitting structure 150 including an active layer 130 between the first and second semiconductor layers 120 and 140, a first electrode 162 and a second semiconductor electrically connected to the first semiconductor layer 120 A second electrode 164 electrically connected to the layer 140 may be included.

First, the light-emitting device 100 shown in FIG. 1 is illustrated and described as a horizontal type light-emitting device, but may be a vertical type light-emitting device, and the present invention is not limited thereto.

The substrate 110 may _{include any one of sapphire (Al 2} O ₃ ), GaN, ZnO, and AlO, but is not limited thereto.

In addition, the substrate 110 may be formed of a material suitable for semiconductor material growth, that is, a carrier wafer, may be formed of a material having excellent thermal conductivity, may include a conductive substrate or an insulating substrate, for example, sapphire (Al ₂ O ₃ ) At least one of SiC, Si, GaAs, GaP, InP, and Ga2O3 having higher thermal conductivity than the substrate may be used.

The substrate 110 may be wet cleaned to remove impurities from the surface, and the substrate 110 may have a light extraction pattern formed on the surface to improve the light extraction effect, but the present invention is not limited thereto.

In addition, the substrate 110 may be made of a material capable of improving thermal stability by facilitating heat dissipation.

Meanwhile, an antireflection layer (not shown) for improving light extraction efficiency may be disposed on the substrate 110.

A buffer layer 112 may be disposed on the substrate 110 to mitigate lattice mismatch between the substrate 110 and the light emitting structure 150 and allow the semiconductor layer to be easily grown.

The buffer layer 112 may be formed in a low temperature atmosphere, and may be made of a material capable of reducing a difference in lattice constants between the substrate 110 and the light emitting structure 150.

The buffer layer 112 may be grown as a single crystal on the substrate 110, and the buffer layer 112 grown as a single crystal may improve the crystallinity of the light emitting structure 150 grown on the buffer layer 112.

In addition, the buffer layer 112 may be formed in a low temperature atmosphere, and may include, for example, at least one of GaN, InN, AlN, AlInN, InGaN, AlGaN, and InAlGaN, but is not limited thereto.

That is, the buffer layer 112 may be formed in a structure such as an AlInN/GaN stacked structure, an InGaN/GaN stacked structure, or an AlInGaN/InGaN/GaN stacked structure.

The first semiconductor layer 120 included in the light emitting structure 150 may be disposed on the substrate 110 or the buffer layer 112, and may be implemented as an n-type semiconductor layer providing electrons to the active layer 130. .

The first semiconductor layer 120 is _{a semiconductor material having a composition formula of In x} Al _y Ga _1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1), for example, GaN, It may be selected from AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like, and for example, n-type dopants such as Si, Ge, Sn, Se, and Te may be doped.

An undoped semiconductor layer (not shown) that is not doped with a dopant may be disposed between the first semiconductor layer 120 and the substrate 110 or between the first semiconductor layer 120 and the buffer layer 112. The layer is a layer formed to improve the crystallinity of the first semiconductor layer 120, except that the n-type dopant is not doped and thus has a lower electrical conductivity than the first semiconductor layer 120. 120), but is not limited thereto.

The active layer 130 may be disposed on the first semiconductor layer 120, and the active layer 130 is a single or multiple quantum well structure, a quantum wire using a compound semiconductor material of a group 3-5 element. It may be formed in a structure or a quantum dot structure.

When the active layer 130 is formed in a quantum well structure, for example, In _x Ga _1-x N ( _{0≤x≤1), Al y} Ga _1-y N (0≤y≤1) or In _x Al _y Ga _{1- A well layer having a composition formula of xy} N (0≤x≤1, 0≤y≤1, 0≤x+y≤1), In _x Ga _1-x N (0≤x≤1), Al _y Ga _{1 -y N (0 ≤ y} ≤ 1) or In x Al y Ga _1-xy N (0 ≤ x ≤ 1, 0 ≤ y ≤ 1, 0 ≤ x + y ≤ 1) Or it can have a quantum well structure. The well layer may be formed of a material having an energy band gap smaller than the energy band gap of the barrier layer, and a detailed description thereof will be described later.

In addition, a conductive cladding layer (not shown) may be disposed above or/or below the active layer 130, and the conductive cladding layer may be formed of an AlGaN-based semiconductor, rather than the band gap of the active layer 130. It can have a large band gap.

The second semiconductor layer 140 may be disposed on the active layer 130, and the second semiconductor layer 140 may be implemented as a p-type semiconductor layer providing holes to the active layer 130.

The second semiconductor layer 140 is _{a semiconductor material having a composition formula of In x} Al _y Ga _1-xy N (0≤x≤1, 0≤y≤1, 0≤x+y≤1), for example, GaN, It may be selected from AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, and the like, and a p-type dopant such as Mg, Zn, Ca, Sr, Ba, etc. may be doped.

Meanwhile, an electron blocking layer is provided between the active layer 130 and the second semiconductor layer 140 in order to prevent electrons that are not recombined with the holes supplied from the active layer 130 from being supplied to the second semiconductor layer 140. layer, not shown), but is not limited thereto.

The first semiconductor layer 120, the active layer 130, and the second semiconductor layer 140 described above are, for example, metal organic chemical vapor deposition (MOCVD) and chemical vapor deposition (CVD). , Plasma-Enhanced Chemical Vapor Deposition (PECVD), Molecular Beam Epitaxy (MBE), Hydride Vapor Phase Epitaxy (HVPE), and sputtering. It may be formed, but is not limited thereto.

In addition, the doping concentration of the conductive dopant in the first and second semiconductor layers 120 and 140 may be formed uniformly or non-uniformly. That is, the plurality of semiconductor layers may be formed to have various doping concentration distributions, but the embodiment is not limited thereto.

In addition, the first semiconductor layer 120 may be implemented as a p-type semiconductor layer, the second semiconductor layer 140 may be implemented as an n-type semiconductor layer, and on the second semiconductor layer 140, an n-type or p-type semiconductor A third semiconductor layer (not shown) including a layer may be formed. Accordingly, the light emitting device 100 may have at least one of an np, pn, npn, and pnp junction structure.

Meanwhile, the active layer 130 and the second semiconductor layer 140 may be partially removed to expose a part of the first semiconductor layer 120, and the first electrode 162 on the exposed first semiconductor layer 120 Can be formed. That is, the first semiconductor layer 120 includes an upper surface facing the active layer 130 and a lower surface facing the substrate 110, the upper surface includes at least one exposed area, and the first electrode 162 is an upper surface Can be placed on the exposed area of the.

Meanwhile, a method of exposing a part of the first semiconductor layer 120 may use a predetermined etching method, but is not limited thereto. In addition, the etching method may be a wet etching method or a dry etching method.

Also, a second electrode 164 may be formed on the second semiconductor layer 140.

Meanwhile, the first and second electrodes 162 and 164 are conductive materials such as In, Co, Si, Ge, Au, Pd, Pt, Ru, Re, Mg, Zn, Hf, Ta, Rh, Ir, W , Ti, Ag, Cr, Mo, Nb, Al, Ni, Cu, and WTi may include a metal selected from, or may include an alloy thereof, may be formed in a single layer or multi-layer, limited thereto. Do not put it.

The current dispersion injection layer 125 may be disposed between the first semiconductor layer 120 and the active layer 130.

The current dispersion injection layer 125 is disposed on the first semiconductor layer 120 and is disposed on the current distribution layer 126 and the current distribution layer 126 having a first energy band gap, and the first energy band gap. A current injection barrier layer disposed on the current injection well layer 127a and the current injection well layer 127a having a smaller second energy bed gap and having a third energy bed gap between the first and second energy band gaps ( A current injection layer 127 including 127b) may be included.

The current distribution layer 126 may disperse electrons injected from the first semiconductor layer 120 in a horizontal direction.

The current distribution layer 126 _{is made of a composition of Al x} Ga _1-x N (0.1<x<0.2), and when the content (x) of Al is less than 0.1, the first energy band gap becomes too small and the first Electrons injected from the semiconductor layer 120 pass through so that electrons cannot be dispersed, and if the first energy band gap is greater than 0.2, the amount of electrons injected into the active layer 130 decreases because the first energy band gap becomes excessively large. This can be degraded.

At this time, the current distribution layer 126 is doped with at least one n-type dopant among i, Ge, Sn, Se, and Te, and the doping concentration of the n-type dopant may be 4 × 10 ¹⁸ to 5 × 10 ¹⁹ .

The thickness d1 of the current distribution layer 125 may be 30 Å to 70 Å, and when the thickness d1 is less than 30 Å, electrons injected from the first semiconductor layer 120 are tunneled and the electrons are not dispersed. If it is not injected into the active layer 130 and is thicker than 70 Å, tunneling of the electrons may be prevented, but the manufacturing process efficiency may be lowered.

In the current injection layer 127, a current injection well layer 127a and a current injection barrier layer 127b may be alternately stacked at least three times or more. That is, the current injection layer 127 may be stacked while the current injection well layer 127a and the current injection barrier layer 127b form a superlattice.

The current injection layer 127 is formed so that the current injection well layer 127a and the current injection barrier layer 127b lose the quantum confinement effect, so that the entire current injection layer 127 is formed by electrons or holes. To form an energy band.

Here, the current injection well layer 127a may be made of GaN, and as a result, may have the same second energy band gap as the energy band gap of the first semiconductor layer 120, but is not limited thereto.

The current injection barrier layer 127b _{is made of a composition of In a} Al _b Ga _1-ab N (0.03≤a≤0.05, 0.20≤b≤0.15), and at least one n of Si, Ge, Sn, Se, and Te The dopant is doped, and the doping concentration of the n-type dopant may be ^{1×10 18} to 3×10 ^18.

Here, the thickness (ds) of the current injection barrier layer 127b may be 15 Å to 30 Å, and if it is less than 15 Å, the electrons cannot be confined in the current injection well layer 127a, and if it is thicker than 30 Å, the electrons Since is not tunneled, the injection efficiency of the electrons may be lowered.

The thickness d2 of the current injection layer 127 including the current injection well layer 127a and the current injection barrier layer 127b may be 500 Å to 3000 Å. In an embodiment, the thickness d2 of the current injection layer 127 may be the thickness of a pair of the current injection well layer 127a and the current injection barrier layer 127b, or may be the entire thickness, but is not limited thereto.

3 is a diagram showing an energy band diagram of a light emitting device according to the first embodiment.

Referring to FIG. 3, the light emitting device 100 may include a first semiconductor layer 120, a current dispersion injection layer 125, an active layer 130, and a second semiconductor layer 140.

Here, the current distribution injection layer 125 may include a current distribution layer 126 and a current injection layer 127.

In this case, the current distribution layer 126 may have a first energy band gap E1 that is larger than the energy band gap of the first semiconductor layer 120.

The first energy band gap E1 is 3.7 eV to 3.8 eV, and may have an energy band gap greater than that of the current injection layer 127.

_{Here, the current distribution layer 126 is composed of a composition of Al x} Ga _1-x N (0.1<x<0.2) as described above in FIGS. 1 and 2, and the first energy according to the concentration (content) of Al The band gap E1 may increase or decrease.

The current distribution layer 126 allows electrons injected from the first semiconductor layer 120 to be distributed in a horizontal direction, thereby preventing the current path from being concentrated to one place by dispersing electrons to the current injection layer 127. .

The current injection layer 127 may include a current injection well layer 127a and a current injection barrier layer 127b, and the current injection well layer 127a and the current injection barrier layer 127b are alternately stacked to It consists of a lattice structure.

Here, the current injection well layer 127a may be formed of a second energy band gap E2 that is the same as the energy band gap of the first semiconductor layer 120. In the embodiment, the second energy band gap E2 is represented and described as being the same as the energy band gap of the first semiconductor layer 120, but may be smaller than the energy band gap of the first semiconductor layer 120, and is limited thereto. Do not put it.

The second energy band gap E2 may be 3.01 eV to 3.42 eV, and may be made of GaN as described above, but is not limited thereto.

The current injection barrier layer 127b may have a third energy band gap E3 between the first and second energy band gaps E1 and E2.

That is, the third energy band gap E3 may be 3.45 eV to 3.55 eV, and as described above _{, it is made of a composition of In a} Al _b Ga _1-ab N (0.03≦a≦0.05, 0.20≦b≦0.15). I can.

Here, the third energy band gap E3 may adjust the energy band gap by adjusting the concentration (content) of In and Al, but is not limited thereto.

The active layer 130 may have a multiple quantum well structure, and thus the active layer 130 includes first to third well layers Q1, Q2, Q3 and first to third barrier layers B1, B2, and B3. Can include.

In addition, the first to third well layers Q1, Q2, and Q3 and the first to third barrier layers B1, B2, and B3 may have a structure in which they are alternately stacked.

4 is a diagram showing an energy band diagram of a light emitting device according to a second embodiment.

4 illustrates the same configuration as that of FIG. 3 with the same reference numerals.

Referring to FIG. 4, the light emitting device 100 may include a first semiconductor layer 120, a current dispersion injection layer 125, an active layer 130, and a second semiconductor layer 140.

Here, the current distribution injection layer 125 may include a current distribution layer 126 and a current injection layer 127.

In this case, the current distribution layer 126 may include a current distribution well layer 126a and a current distribution barrier layer 126b.

The current distribution well layer 126a is made of a fourth energy band gap E4 that is smaller than the energy band gap of the first semiconductor layer 120 and can confine a certain amount of electrons injected from the first semiconductor layer 120. have.

The thickness of the current distribution well layer 126a may be 1.5 nm to 50 nm, and when the thickness is less than 1.5 nm, it may be difficult to confine electrons quantum mechanically, and when the thickness is 50 nm or more, the crystal quality of the light emitting device is deteriorated. Thus, the light efficiency can be lowered.

The current distribution barrier layer 126b is adjacent to the current distribution well layer 126a and may have a first energy band gap E1 that is larger than the energy band gap of the first semiconductor layer 120.

The first energy band gap E1 is 3.7 eV to 3.8 eV, and may have an energy band gap greater than that of the current injection layer 127.

Here, the current distribution barrier layer 126b _{is made of a composition of Al x} Ga _1-x N (0.1<x<0.2) as described above in FIGS. The energy band gap E1 may increase or decrease.

The above-described current distribution well layer 126a may be formed in the same manner as the current distribution barrier layer 126b, but the concentration (content) of Al may be formed differently.

The current distribution barrier layer 126b allows electrons injected from the first semiconductor layer 120 to be distributed in a horizontal direction, so that electrons are distributed to the current injection layer 127 to prevent the current path from being concentrated to one place. have.

The current injection layer 127 may include a current injection well layer 127a and a current injection barrier layer 127b, and the current injection well layer 127a and the current injection barrier layer 127b are alternately stacked to It consists of a lattice structure.

Here, the current injection well layer 127a may be formed of a second energy band gap E2 that is the same as the energy band gap of the first semiconductor layer 120. In the embodiment, the second energy band gap E2 is represented and described as being the same as the energy band gap of the first semiconductor layer 120, but may be smaller than the energy band gap of the first semiconductor layer 120, and is limited thereto. Do not put it.

The second energy band gap E2 may be 3.01 eV to 3.42 eV, and may be made of GaN as described above, but is not limited thereto.

The current injection barrier layer 127b may have a third energy band gap E3 between the first and second energy band gaps E1 and E2.

That is, the third energy band gap E3 may be 3.45 eV to 3.55 eV, and as described above _{, it is made of a composition of In a} Al _b Ga _1-ab N (0.03≦a≦0.05, 0.20≦b≦0.15). I can.

Here, the third energy band gap E3 may adjust the energy band gap by adjusting the concentration (content) of In and Al, but is not limited thereto.

The active layer 130 may have a multiple quantum well structure, and thus the active layer 130 includes first to third well layers Q1, Q2, Q3 and first to third barrier layers B1, B2, and B3. Can include.

In addition, the first to third well layers Q1, Q2, and Q3 and the first to third barrier layers B1, B2, and B3 may have a structure in which they are alternately stacked.

3 and 4, the current injection layer 127 includes at least three or more current injection well layers 127a and 127b as each of the second and third energy band gaps E2, Although shown and described as E3), each of the at least three or more current injection well layers 127a and 127b may be formed to have different energy band gaps, and the present invention is not limited thereto.

5 is a cross-sectional view illustrating a light emitting device package including a light emitting device according to an embodiment.

5, the light emitting device package 300 according to the embodiment includes a body 310 having a cavity, a light source unit 320 mounted in the cavity of the body 310, and a resin unit 350 filled in the cavity. can do.

The body 310 is made of a resin material such as polyphthalamide (PPA), silicon (Si), aluminum (Al), aluminum nitride (AlN), liquid crystal polymer (PSG, photo sensitive glass), polyamide 9T (PA9T). ), neo-geotactic polystyrene (SPS), metal material, sapphire (Al2O3), beryllium oxide (BeO), printed circuit board (PCB, Printed Circuit Board), it may be formed of at least one of ceramic.

The body 310 may be formed by injection molding, an etching process, or the like, but is not limited thereto.

The light source unit 320 is disposed on the bottom surface of the body 310, for example, the light source unit 320 may be any one of the light emitting devices illustrated and described in FIGS. 1 to 4. The light-emitting device may be, for example, a colored light-emitting device that emits red, green, blue, or white light or an ultra violet (UV) light-emitting device that emits ultraviolet rays, but is not limited thereto. In addition, one or more light-emitting elements may be mounted.

The body 310 may include a first electrode 330 and a second electrode 340. The first electrode 330 and the second electrode 340 may be electrically connected to the light source unit 320 to supply power to the light source unit 320.

In addition, the first electrode 330 and the second electrode 340 are electrically separated from each other, and reflect light generated from the light source unit 320 to increase light efficiency, and heat generated from the light source unit 320 Can be discharged to the outside.

5 shows that both the first electrode 330 and the second electrode 340 are bonded to the light source unit 320 by a wire 360, but the present invention is not limited thereto. In particular, in the case of a vertical light emitting device, the first electrode 330 and the second electrode 340 are bonded to each other. Any one of the electrode 330 and the second electrode 340 may be bonded to the light source unit 320 by a wire 360, and may be electrically connected to the light source unit 320 without a wire 360 by a flip-chip method. have.

The first electrode 330 and the second electrode 340 are made of metal, for example, titanium (Ti), copper (Cu), nickel (Ni), gold (Au), chromium (Cr), and tantalum ( Ta), platinum (Pt), tin (Sn), silver (Ag), phosphorus (P), aluminum (Al), indium (In), palladium (Pd), cobalt (Co), silicon (Si), germanium ( Ge), hafnium (Hf), ruthenium (Ru), iron (Fe) may include one or more materials or alloys. In addition, the first electrode 330 and the second electrode 340 may be formed to have a single-layer or multi-layer structure, but are not limited thereto.

The resin part 350 may be filled in the cavity and may include a phosphor (not shown). The resin part 350 may be formed of transparent silicone, epoxy, and other resin materials, and after filling the cavity, it may be formed by UV or thermal curing.

The type of the phosphor (not shown) may be selected according to the wavelength of light emitted from the light source unit 320 so that the light emitting device package 300 may implement white light.

The phosphor (not shown) included in the resin part 350 is a blue light-emitting phosphor, a cyan light-emitting phosphor, a green light-emitting phosphor, a yellow-green light-emitting phosphor, a yellow light-emitting phosphor, a yellow-red light-emitting phosphor, depending on the wavelength of light emitted from the light source unit 320. , An orange light-emitting phosphor, and a red light-emitting phosphor may be applied.

That is, the phosphor (not shown) may convert a wavelength of light generated from the light source unit 320. A type of light emitted from the light source unit 320 may be selected according to a wavelength so that the light emitting device package may implement white light. For example, when the light source unit 320 is a blue light emitting diode and a phosphor (not shown) is a yellow phosphor, the yellow phosphor is excited by blue light to emit yellow light, and blue light and blue light generated from the blue light emitting diode As yellow light generated by being excited by light is mixed, the light emitting device package 300 may provide white light.

The light emitting device according to the embodiment may be applied to a lighting system. The lighting system includes a structure in which a plurality of light emitting devices are arrayed, and includes the display device shown in FIGS. 6 and 7, the lighting device shown in FIG. 8, and may include a lighting lamp, a traffic light, a vehicle headlight, an electric sign, and the like.

6 is an exploded perspective view of a display device including a light emitting device according to an exemplary embodiment.

6, the display device 1000 according to the embodiment includes a light guide plate 1041, a light source module 1031 providing light to the light guide plate 1041, a reflective member 1022 under the light guide plate 1041, and , A bottom cover 1011 housing the optical sheet 1051 on the light guide plate 1041, the display panel 1061 on the optical sheet 1051, the light guide plate 1041, the light source module 1031, and the reflective member 1022 It may include, but is not limited thereto.

The bottom cover 1011, the reflective sheet 1022, the light guide plate 1041, and the optical sheet 1051 may be defined as a light unit 1050.

The light guide plate 1041 serves to diffuse light into a surface light source. The light guide plate 1041 is made of a transparent material, for example, among acrylic resins such as PMMA (polymethylmethacrylate), PET (polyethylene terephthalate), PC (polycarbonate), COC (cycloolefin copolymer), and PEN (polyethylene naphthalate) resins. It can contain one.

The light source module 1031 provides light to at least one side of the light guide plate 1041, and ultimately acts as a light source of the display device.

The light source module 1031 includes at least one, and may directly or indirectly provide light from one side of the light guide plate 1041. The light source module 1031 includes a substrate 1033 and a light emitting device 1035 according to the disclosed embodiment, and the light emitting devices 1035 may be arrayed on the substrate 1033 at predetermined intervals.

The substrate 1033 may be a printed circuit board (PCB) including a circuit pattern (not shown). However, the substrate 1033 may include not only a general PCB, but also a metal core PCB (MCPCB, Metal Core PCB), a flexible PCB (FPCB, Flexible PCB), and the like, but is not limited thereto. When the light emitting device 1035 is mounted on a side surface of the bottom cover 1011 or on a heat dissipation plate, the substrate 1033 may be removed. Here, a part of the heat dissipation plate may contact the upper surface of the bottom cover 1011.

In addition, the plurality of light emitting devices 1035 may be mounted on the substrate 1033 such that an emission surface from which light is emitted is spaced apart from the light guide plate 1041 by a predetermined distance, but the embodiment is not limited thereto. The light-emitting device 1035 may directly or indirectly provide light to a light-incident portion, which is one side of the light guide plate 1041, but is not limited thereto.

A reflective member 1022 may be disposed under the light guide plate 1041. The reflective member 1022 reflects light incident on the lower surface of the light guide plate 1041 and directs it upward, thereby improving the luminance of the light unit 1050. The reflective member 1022 may be formed of, for example, PET, PC, PVC resin, or the like, but is not limited thereto. The reflective member 1022 may be an upper surface of the bottom cover 1011, but is not limited thereto.

The bottom cover 1011 may accommodate the light guide plate 1041, the light source module 1031, the reflective member 1022, and the like. To this end, the bottom cover 1011 may be provided with a receiving portion 1012 having a box shape with an open top surface, but the embodiment is not limited thereto. The bottom cover 1011 may be coupled to the top cover, but the embodiment is not limited thereto.

The bottom cover 1011 may be formed of a metal material or a resin material, and may be manufactured using a process such as press molding or extrusion molding. In addition, the bottom cover 1011 may include a metal or non-metal material having good thermal conductivity, but is not limited thereto.

The display panel 1061 is, for example, an LCD panel, and includes first and second substrates made of transparent materials facing each other, and a liquid crystal layer interposed between the first and second substrates. A polarizing plate may be attached to at least one surface of the display panel 1061, and the structure of the polarizing plate is not limited thereto. The display panel 1061 displays information by light passing through the optical sheet 1051. The display device 1000 can be applied to various types of portable terminals, monitors of notebook computers, monitors of laptop computers, and televisions.

The optical sheet 1051 is disposed between the display panel 1061 and the light guide plate 1041, and includes at least one light-transmitting sheet. The optical sheet 1051 may include at least one of, for example, a diffusion sheet, a horizontal and vertical prism sheet, and a brightness enhancement sheet. The diffusion sheet diffuses incident light, the horizontal or/and vertical prism sheet condenses incident light to the display area, and the brightness enhancement sheet reuses lost light to improve brightness. In addition, a protective sheet may be disposed on the display panel 1061, but the embodiment is not limited thereto.

Here, on the light path of the light source module 1031, as an optical member, a light guide plate 1041 and an optical sheet 1051 may be included, but the embodiment is not limited thereto.

7 is a cross-sectional view of the display device of FIG. 6.

Referring to FIG. 7, the display device 1100 includes a bottom cover 1152, a substrate 1120 on which the light emitting devices 1124 disclosed above are arrayed, an optical member 1154, and a display panel 1155.

The substrate 1120 and the light emitting device 1124 may be defined as a light source module 1160. The bottom cover 1152, at least one light source module 1160, and the optical member 1154 may be defined as a light unit 1150. The bottom cover 1152 may include an accommodating part 1153, but the embodiment is not limited thereto. The light source module 1160 includes a substrate 1120 and a plurality of light emitting devices 1124 arranged on the substrate 1120.

Here, the optical member 1154 may include at least one of a lens, a light guide plate, a diffusion sheet, a horizontal and vertical prism sheet, and a brightness enhancement sheet. The light guide plate may be made of a PC material or a polymethyl methacrylate (PMMA) material, and the light guide plate may be removed. The diffusion sheet diffuses incident light, the horizontal and vertical prism sheets condens the incident light to the display area, and the luminance enhancement sheet reuses lost light to improve luminance.

The optical member 1154 is disposed on the light source module 1160, and performs a surface light source, diffusion, or condensation of light emitted from the light source module 1160.

8 is an exploded perspective view of a lighting device including a light emitting device according to an embodiment.

Referring to FIG. 8, the lighting device according to the embodiment includes a cover 2100, a light source module 2200, a radiator 2400, a power supply unit 2600, an inner case 2700, and a socket 2800. I can. In addition, the lighting device according to the embodiment may further include one or more of the member 2300 and the holder 2500. The light source module 2200 may include a light emitting device according to the embodiment.

For example, the cover 2100 may have a shape of a bulb or a hemisphere, and may be provided in a shape with a hollow and an open portion. The cover 2100 may be optically coupled to the light source module 2200. For example, the cover 2100 may diffuse, scatter, or excite light provided from the light source module 2200. The cover 2100 may be a kind of optical member. The cover 2100 may be coupled to the radiator 2400. The cover 2100 may have a coupling portion coupled to the radiator 2400.

A milky white paint may be coated on the inner surface of the cover 2100. The milky white paint may include a diffuser that diffuses light. The surface roughness of the inner surface of the cover 2100 may be larger than the surface roughness of the outer surface of the cover 2100. This is to allow the light from the light source module 2200 to be sufficiently scattered and diffused to be emitted to the outside.

The material of the cover 2100 may be glass, plastic, polypropylene (PP), polyethylene (PE), polycarbonate (PC), or the like. Here, polycarbonate is excellent in light resistance, heat resistance, and strength. The cover 2100 may be transparent or opaque so that the light source module 2200 can be seen from the outside. The cover 2100 may be formed through blow molding.

The light source module 2200 may be disposed on one surface of the radiator 2400. Accordingly, heat from the light source module 2200 is conducted to the radiator 2400. The light source module 2200 may include a light emitting device 2210, a connection plate 2230, and a connector 2250.

The member 2300 is disposed on the upper surface of the radiator 2400 and has guide grooves 2310 into which a plurality of light emitting elements 2210 and a connector 2250 are inserted. The guide groove 2310 corresponds to the substrate and the connector 2250 of the light emitting device 2210.

The surface of the member 2300 may be coated or coated with a light reflecting material. For example, the surface of the member 2300 may be coated or coated with a white paint. The member 2300 reflects light reflected on the inner surface of the cover 2100 and returning toward the light source module 2200 toward the cover 2100. Therefore, it is possible to improve the light efficiency of the lighting device according to the embodiment.

The member 2300 may be made of an insulating material, for example. The connection plate 2230 of the light source module 2200 may include an electrically conductive material. Accordingly, electrical contact may be made between the radiator 2400 and the connection plate 2230. The member 2300 is made of an insulating material to block an electrical short between the connection plate 2230 and the radiator 2400. The radiator 2400 receives heat from the light source module 2200 and heat from the power supply unit 2600 to radiate heat.

The holder 2500 blocks the receiving groove 2719 of the insulating part 2710 of the inner case 2700. Accordingly, the power supply unit 2600 accommodated in the insulating unit 2710 of the inner case 2700 is sealed. The holder 2500 has a guide protrusion 2510. The guide protrusion 2510 may have a hole through which the protrusion 2610 of the power supply unit 2600 passes.

The power supply unit 2600 processes or converts an electrical signal provided from the outside and provides it to the light source module 2200. The power supply unit 2600 is accommodated in the storage groove 2719 of the inner case 2700 and is sealed inside the inner case 2700 by the holder 2500.

The power supply unit 2600 may include a protrusion 2610, a guide part 2630, a base 2650, and a protrusion 2670.

The guide part 2630 has a shape protruding from one side of the base 2650 to the outside. The guide part 2630 may be inserted into the holder 2500. A number of components may be disposed on one surface of the base 2650. A number of components include, for example, a DC converter that converts AC power provided from an external power source into a DC power source, a driving chip that controls the driving of the light source module 2200, and an ESD (ElectroStatic) for protecting the light source module 2200. discharge) may include a protection element, but is not limited thereto.

The protrusion 2670 has a shape protruding outward from the other side of the base 2650. The protrusion 2670 is inserted into the connection part 2750 of the inner case 2700 and receives an electrical signal from the outside. For example, the protrusion 2670 may be provided equal to or smaller than the width of the connection part 2750 of the inner case 2700. Each end of the "+ wire" and the "- wire" may be electrically connected to the protrusion 2670, and the other end of the "+ wire" and the "- wire" may be electrically connected to the socket 2800.

The inner case 2700 may include a molding unit together with a power supply unit 2600 therein. The molding portion is a portion in which the molding liquid is solidified, and allows the power supply unit 2600 to be fixed inside the inner case 2700.

In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific embodiments described above, and without departing from the gist of the present invention claimed in the claims, the present invention belongs to the technical field to which the present invention belongs. Various modifications may be possible by those of ordinary skill in the art, and these modifications should not be understood individually from the technical spirit or prospect of the present invention.

Claims (14)

A first semiconductor layer;
A second semiconductor layer disposed on the first semiconductor layer;
An active layer disposed between the first and second semiconductor layers; And
Including; a current dispersion injection layer disposed between the first semiconductor layer and the active layer,
The current dispersion injection layer,
A current distribution layer disposed on the first semiconductor layer and having a first energy band gap; And
A current injection well layer disposed on the current distribution layer and having a second energy band gap smaller than the first energy band gap, and a third energy disposed on the current injection well layer and between the first and second energy band gaps Including; a current injection layer including a current injection barrier layer having a band gap,
The current injection well layer and the current injection barrier layer are alternately stacked at least three times,
The current distribution layer _{includes a composition of Al x} Ga _1-x N (0.1<x<0.2),
The current injection well layer contains a GaN composition,
The current injection barrier layer includes _a composition of In a Al _b Ga _1-ab N (0.03≤a≤0.05, 0.20≤b≤0.15),
The energy band gap of the first semiconductor layer is the same as the second energy band gap of the current injection well layer and is smaller than the third energy band gap of the current injection barrier layer. delete The method of claim 1,
The thickness of the current distribution layer is 30 Å to 70 Å,
The thickness of the current injection barrier layer is 15 Å to 30 Å,
A light emitting device having a thickness of the current injection layer of 500 Å to 3000 Å. The method of claim 1,
The current distribution layer is doped with at least one n-type dopant of Si, Ge, Sn, Se, and Te,
The doping concentration of the n-type dopant doped in the current distribution layer is 4 × 10 ¹⁸ to 5 × 10 ¹⁹ ,
The current injection barrier layer is doped with at least one n-type dopant of Si, Ge, Sn, Se, and Te,
A light emitting device ^{having a doping concentration of 1 × 10 18} to 3 × 10 ¹⁸ of the n-type dopant doped in the current injection barrier layer. The method of claim 1,
The first energy band gap is 3.7 eV to 3.8 eV,
The second energy band gap is 3.01 eV to 3.42 eV,
The third energy band gap is 3.45 eV to 3.55 eV light emitting device. delete delete delete delete delete delete delete delete The method of claim 1,
The current distribution layer,
A current distribution barrier layer having the first energy band gap; And
And a current distribution well layer having a fourth energy band gap between the second and third energy band gaps between the first semiconductor layer and the current distribution barrier layer.

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