KR20150087029A - A Light emitting device and A Fabrication method thereof - Google Patents

Abstract

A light emitting device according to an embodiment of the present invention includes a substrate; a light emitting structure which is arranged on the substrate and includes a first semiconductor layer, a second semiconductor layer arranged on the first semiconductor layer, and an active layer between the first semiconductor layer and the second semiconductor layer; and an insertion layer which is arranged between the substrate and the light emitting structure and includes an AlGaN layer and an InGaN layer. The second semiconductor layer includes an n-doped first layer and a p-doped second layer.

Description

TECHNICAL FIELD The present invention relates to a light emitting device and a fabrication method thereof,

The embodiments relate to a light emitting device and a method of manufacturing a light emitting device.

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

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

LED semiconductors are grown by a process such as MOCVD or molecular beam epitaxy (MBE) on a substrate such as sapphire or silicon carbide (SiC) having a hexagonal system structure.

LEDs can recombine holes and electrons in the active layer to generate light. This light can not be emitted from the inside to the outside of the LED, but can be converted into heat energy due to total internal reflection. Therefore, efforts are being made to reduce the light loss caused by the change of light energy into thermal energy.

In addition, due to the difference in the lattice constants between the inner layers of the light emitting device, defects are generated in the semiconductor layer during the growth process and the light efficiency may be lowered. Thus, researches on processes for minimizing the occurrence of defects have been actively conducted.

One embodiment of the present invention provides a light emitting device in which a plurality of layers having different doping densities are stacked to improve the current distribution to improve light extraction efficiency.

A light emitting device according to an embodiment of the present invention includes a substrate; A light emitting structure disposed on the substrate and including a first semiconductor layer, a second semiconductor layer disposed on the first semiconductor layer, and an active layer disposed between the first semiconductor layer and the second semiconductor layer; And an interlevel layer disposed between the substrate and the light emitting structure and including an aluminum gallium nitride layer (AlGaN) and an indium gallium nitride layer (InGaN), the second semiconductor layer comprising an n-doped first Layer and a p-doped second layer.

The light emitting device according to an exemplary embodiment of the present invention may include a first semiconductor layer including an n-doped first layer and a p-doped second layer to improve light efficiency by improving the current distribution of the light emitting structure.

A light emitting device according to an embodiment of the present invention includes an insertion layer including an aluminum gallium nitride layer (AlGaN) and an indium gallium nitride layer (InGaN) to improve crystal defects.

The light emitting device according to an embodiment of the present invention includes a plurality of p-doped second layers of the second semiconductor layer, and the doping densities of the second layers are different from each other, thereby enhancing the hole injection efficiency.

1 is a cross-sectional view illustrating a light emitting device according to an embodiment,
2 is a cross-sectional view of a light emitting device according to another embodiment,
3 is a cross-sectional view illustrating a light emitting device according to another embodiment,
4A and 4B are a perspective view and a cross-sectional view of a light emitting device package including a light emitting device according to an embodiment,
5 is an exploded perspective view of a display device including a light emitting device package according to an embodiment,
6 illustrates a display device including a light emitting device package according to an embodiment,
7 is an exploded perspective view of a lighting device including a light emitting device package according to an embodiment.

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

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

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

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

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

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

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

1 is a cross-sectional view illustrating a light emitting device according to an embodiment of the present invention.

Referring to FIG. 1, a light emitting device 100 according to an embodiment of the present invention includes a substrate 110, a first semiconductor layer 142, a first semiconductor layer 142, A light emitting structure 140 including a second semiconductor layer 146 disposed between the first semiconductor layer 142 and the second semiconductor layer 146 and an active layer 144 disposed between the first semiconductor layer 142 and the second semiconductor layer 146, (AlGaN) and an indium gallium nitride (InGaN) layer, which are disposed between the first electrode layer 140 and the second electrode layer 140. [

The substrate 110 may be disposed under the first semiconductor layer 142. The substrate 110 may support the first semiconductor layer 142. The substrate 110 may have optically transmissive properties. For example, the substrate 110 may include, but is not limited to, sapphire (Al ₂ O ₃ ).

The substrate 110 may have a light transmitting property when it is formed using a light transmitting material or a material having a certain thickness or less, but the present invention is not limited thereto. The refractive index of the substrate 110 is preferably smaller than the refractive index of the first semiconductor layer 142 for the purpose of light extraction efficiency, but is not limited thereto.

The substrate 110 may be formed of a semiconductor material, for example, Si, Ge, GaAs, ZnO, SiC, It can be implemented with a carrier wafer such as a silicon germanium (SiGe), gallium nitride (GaN), gallium (ⅲ) oxide (Ga ₂ O _3).

The substrate 110 may have a PSS (Patterned Substrate Sapphire) structure on its upper surface to enhance light extraction efficiency, but the present invention is not limited thereto. The substrate 110 facilitates the emission of heat generated in the light emitting device 100, thereby improving the thermal stability of the light emitting device 100. The light emitting device 100 may further include a buffer layer 120 that alleviates a difference in lattice constant between the substrate 110 and the first semiconductor layer 132. However, the present invention is not limited thereto.

The buffer layer 120 may mitigate lattice mismatch between the substrate 110 and the first semiconductor layer 142. The buffer layer 120 can facilitate the growth of the first semiconductor layer 142 on the upper surface. The buffer layer 120 can improve the crystallinity of the first semiconductor layer 142 disposed on the upper portion. The buffer layer 120 may be made of a material that can alleviate the lattice constant difference between the substrate 110 and the first semiconductor layer 142.

The insertion layer 130 may be disposed on the buffer layer 120. The intercalation layer 130 may comprise an aluminum gallium nitride layer (AlGaN) and an indium gallium nitride layer (InGaN).

The interlevel layer 130, together with the buffer layer 120, may mitigate lattice mismatch between the substrate 110 and the first semiconductor layer 142. The intercalation layer 130 may include, but is not limited to, a plurality of aluminum gallium nitride layers (AlGaN) and indium gallium nitride layers (InGaN).

The first semiconductor layer 142 may be disposed on the substrate 110. The first semiconductor layer 142 may be disposed on the buffer layer 120 or the interlayer 130 to match the lattice constant difference with the substrate 110. However, Although the first semiconductor layer 142 may be grown on the substrate 110, the first semiconductor layer 142 is not limited to the horizontal light emitting device and may be applied to the vertical light emitting device.

The first semiconductor layer 142 may be an n-type semiconductor layer. For example, when the light emitting device 100 emits blue light, the n-type semiconductor layer may include, for example, In _x Al _y Ga _1-xy N (0? X? 1, 0? _Y? (AlN), AlGaN (Indium Gallium Nitride), InGaN (Indium Gallium Nitride), InN (Indium Nitride), InAlGaN , AlInN, and the like. The first semiconductor layer 142 may be doped with an n-type dopant such as, for example, silicon (Si), germanium (Ge), tin (Sn), selenium (Se) or tellurium (Te).

The first semiconductor layer 142 may be supplied with power from the outside. The first semiconductor layer 142 may provide electrons to the active layer 144.

The active layer 144 may be disposed on the first semiconductor layer 142. The active layer 144 may be disposed between the second semiconductor layer 146 and the first semiconductor layer 142.

The active layer 144 may be formed of a semiconductor material. The active layer 144 may be formed of a single or multi-well structure or the like using a compound semiconductor material of Group 3-V group elements. The active layer 144 may be formed of a nitride semiconductor. For example, the active layer 144 may include gallium nitride (GaN), indium gallium nitride (InGaN), indium gallium nitride (InAlGaN), and the like.

In the case of emitting blue light, for example, the active layer 144 may have a composition formula of In _x Al _y Ga _{1 -x- y} N (0? X? 1, 0? _Y? 1, 0? _X + y? a barrier layer (not shown having the composition formula of the well layer (not shown) _{in a Al b Ga 1 -a- b} N (0≤a≤1, 0≤b≤1, 0≤a + b≤1) having upon ), But is not limited thereto. The well layer (not shown) may be formed of a material having a band gap smaller than the band gap of the barrier layer (not shown).

The active layer 144 may be formed by alternately stacking a plurality of well layers (not shown) and a barrier layer (not shown). The active layer 144 may include a plurality of well layers (not shown) to maximize optical efficiency.

The well layer (not shown) may have a smaller energy bandgap than the barrier layer (not shown). The well layer (not shown) may have a smaller energy bandgap than the first semiconductor layer 142. The well layer (not shown) may have a continuous energy level of the carrier.

The second semiconductor layer 146 may be formed on the active layer 144. The second semiconductor layer 146 may be formed of a p-type semiconductor layer doped with a p-type dopant. When the light emitting device emits light of a blue wavelength, the second semiconductor layer 146 may be formed of In _x Al _y Ga _{1 -x- y} N (0? _X? 1, 0? Y? (AlN), AlGaN (Indium Gallium Nitride), InGaN (indium gallium nitride), InN (indium nitride), InAlGaN, AlInN, or the like. And a p-type dopant such as magnesium (Mg), zinc (Zn), calcium (Ca), strontium (Sr), barium (Ba) or the like can be doped.

The first semiconductor layer 142, the active layer 144 and the second semiconductor layer 146 may be formed using a metal organic chemical vapor deposition (MOCVD) method, a chemical vapor deposition (CVD) method, a plasma May be formed by a method such as chemical vapor deposition (PECVD), molecular beam epitaxy (MBE), or hydride vapor phase epitaxy (HVPE) It is not limited.

The first semiconductor layer 142, the active layer 144 and the second semiconductor layer 146 may be formed using a metal organic chemical vapor deposition (MOCVD) method, a chemical vapor deposition (CVD) method, a plasma May be formed by a method such as chemical vapor deposition (PECVD), molecular beam epitaxy (MBE), or hydride vapor phase epitaxy (HVPE) It is not limited.

The doping concentration of the conductive dopant in the first semiconductor layer 142 and the second semiconductor layer 146 may be uniform or non-uniform, but is not limited thereto.

The first electrode (not shown) may be disposed on one region of the upper surface of the first semiconductor layer 142. A second electrode (not shown) may be disposed on the second semiconductor layer 146.

The first electrode (not shown) and the second electrode (not shown) may be formed of a conductive material such as indium (In), cobalt (Co), silicon (Si), germanium (Ge), gold (Au), palladium ), Platinum (Pt), ruthenium (Ru), rhenium (Re), magnesium (Mg), zinc (Zn), hafnium (Hf), tantalum (Ta), rhodium (Ti), Ag, Cr, Mo, Nb, Al, Ni, Cu, and WTi, Or a multi-layered structure using a metal or an alloy selected from the group consisting of a metal, a metal, and an alloy.

2 is a cross-sectional view illustrating a light emitting device 200 according to an embodiment of the present invention.

2, a light emitting device 200 according to another embodiment of the present invention includes a first semiconductor layer 146 and a second semiconductor layer 146. The second semiconductor layer 146 includes n-doped first layers 162 and 164 and p-doped second layers 151, 153 and 155 ).

The first layer 162, 164 may be n-doped. The first layers 162 and 164 may be plural. The first layer (162, 164) And the plurality of first layers 162 and 164 may have the same doping concentration with each other.

The first layer 162, 164 may be disposed between the plurality of second layers 151, 153, 155. The silicon (Si) doping concentration of the first layer 162, 164 may be between 10 ¹⁷ cm ^-3 and 10 ¹⁸ cm ^-3 . Two silicon (Si) dopant concentration of the first layer (162, 164) is 10 ¹⁷ cm ^-3 to 10 ¹⁸ cm ^{- 3} in the case where, it is possible to maximize the efficiency of injecting holes into the active layer 144.

The thickness of the first layer 162, 164 may be between 3 and 7 nm. When the first layer has a thickness of 3 to 7 nm, the second semiconductor layer 146 can maximize the efficiency of injecting holes into the active layer 142.

The second layer 151, 153, 155 may be p-doped. The second layers 151, 153, and 155 may be plural. The plurality of second layers 151, 153, and 155 may have different doping concentrations from each other. For example, the plurality of second layers 151, 153, 155 may be three.

The doping concentration of the second layers 151, 153, and 155 closer to the active layer 144 may be lower. The doping concentration of the second layers 151, 153, and 155 may be higher as the distance from the active layer 144 increases.

The thickness of the second layer 151 closest to the active layer 144 among the plurality of second layers 151, 153, and 155 may be 8 to 15 nm.

The thickness of the second layer 153 closest to the active layer 144 among the plurality of second layers 151, 153, and 155 may be 10 to 25 nm.

The thickness of the second layer 155 farthest from the active layer 144 among the plurality of second layers 151, 153, and 155 may be 20 to 40 nm.

The magnesium (Mg) doping concentration of the second layer 151 closest to the active layer 144 among the plurality of second layers 151, 153 and 155 may be 10 ¹⁷ cm ^-3 to 10 ¹⁸ cm ^-3 . The doping concentration of the second layer 153, which is the second closest to the active layer 144 among the plurality of second layers 151, 153 and 155, may be 10 ¹⁸ cm ^-3 to 10 ¹⁹ cm ^-3 . The magnesium (Mg) doping concentration of the second layer 155 farthest from the active layer 144 among the plurality of second layers 151, 153 and 155 may be 10 ¹⁹ cm ^-3 to 10 ²¹ cm ^-3 .

The plurality of second layers 151, 153, and 155 may have different doping densities depending on positions as described above, and holes may be easily injected into the active layer 144.

3 is a cross-sectional view illustrating a light emitting device 300 according to an embodiment of the present invention.

3, the light emitting device 300 according to an embodiment of the present invention may include a plurality of aluminum gallium nitride layers (AlGaN) and indium gallium nitride layers (InGaN) included in the insertion layer 130 .

For example, the aluminum gallium nitride layer 131, 133, 135 may be three. For example, the indium gallium nitride layers 137 and 139 may be two.

The indium gallium nitride layer 137, 139 may be disposed between the plurality of aluminum gallium nitride layers 131, 133, 135.

The indium (In) contents of the plurality of indium gallium nitride layers 137 and 139 may be equal to each other. The aluminum (Al) content of the plurality of aluminum gallium nitride layers (AlGaN) may be higher nearer to the substrate 110.

The indium gallium nitride layers 137 and 139 may have a thickness of 5 to 10 nm. The indium gallium nitride layers 137 and 139 can minimize crystal defects caused by the lattice constant difference between the light emitting structure 140 and the buffer layer 120 when the thickness is 5 to 10 nm.

4A and 4B are a perspective view and a cross-sectional view of a light emitting device package including a light emitting device according to an embodiment.

4A and 4B, the light emitting device package 300 according to the embodiment includes a body 310 having a cavity, first and second electrodes 340 and 350 mounted on the body 310, first and second electrodes 340 and 350, A light emitting device 320 electrically connected to the two electrodes, and an encapsulant 330 formed in the cavity. The encapsulant 330 may include a phosphor (not shown).

The body 310 is made of a resin material such as polyphthalamide (PPA), silicon (Si), aluminum (Al), aluminum nitride (AlN), liquid crystal polymer (PSG), polyamide 9T ), new geo-isotactic polystyrene (SPS), metal materials, sapphire (Al ₂ O _3), beryllium oxide (BeO), is a 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, etching, or the like, but is not limited thereto.

The inner surface of the body 310 may be formed with an inclined surface. The reflection angle of the light emitted from the light emitting device 320 can be changed according to the angle of the inclined surface, and thus the directivity angle of the light emitted to the outside can be adjusted.

The shape of the cavity formed in the body 310 may be circular, square, polygonal, elliptical, or the like, and may have a curved shape, but the present invention is not limited thereto.

The encapsulant 330 may be filled in the cavity and may include a phosphor (not shown). The encapsulant 330 may be formed of transparent silicone, epoxy, and other resin materials. The encapsulant 330 may be formed in such a manner that the encapsulant 330 is filled in the cavity and then cured by ultraviolet rays or heat.

The phosphor (not shown) may be selected according to the wavelength of the light emitted from the light emitting device 320, so that the light emitting device package 300 can realize white light.

The fluorescent material (not shown) included in the encapsulant 330 may be a blue light emitting phosphor, a blue light emitting fluorescent material, a green light emitting fluorescent material, a yellow green light emitting fluorescent material, a yellow light emitting fluorescent material, Fluorescent material, orange light-emitting fluorescent material, and red light-emitting fluorescent material may be applied.

The phosphor (not shown) may be excited by the light having the first light emitted from the light emitting device 320 to generate the second light. For example, when the light emitting element 320 is a blue light emitting diode and the phosphor (not shown) is a yellow phosphor, the yellow phosphor may be excited by blue light to emit yellow light, As the yellow light generated by excitation by blue light is mixed, the light emitting device package 300 can provide white light.

When the light emitting element 320 is a green light emitting diode, the magenta phosphor or the blue and red phosphors (not shown) are mixed. When the light emitting element 320 is a red light emitting diode, a cyan phosphor or a mixture of blue and green phosphors For example.

The phosphor (not shown) may be a known one such as YAG, TAG, sulfide, silicate, aluminate, nitride, carbide, nitridosilicate, borate, fluoride or phosphate.

The first electrode 340 and the second electrode 350 may be mounted on the body 310. The first electrode 340 and the second electrode 350 may be electrically connected to the light emitting device 320 to supply power to the light emitting device 320.

The first electrode 340 and the second electrode 350 are electrically separated from each other and reflect light generated from the light emitting device 320 to increase light efficiency. The first electrode 340 and the second electrode 350 may discharge heat generated from the light emitting device 320 to the outside.

The light emitting device 320 and the first electrode 340 and the second electrode 350 may be formed by wire bonding or the like, ) Method, a flip chip method, or a die bonding method.

The first electrode 340 and the second electrode 350 may be formed of a metal material such as titanium (Ti), copper (Cu), nickel (Ni), gold (Au), chromium (Cr), tantalum ), Platinum (Pt), tin (Sn), silver (Ag), phosphorous (P), aluminum (Al), indium (In), palladium (Pd), cobalt ), Hafnium (Hf), ruthenium (Ru), and iron (Fe). The first electrode 340 and the second electrode 350 may have a single-layer structure or a multi-layer structure, but the present invention is not limited thereto.

The light emitting device 320 is mounted on the first electrode 340 and may be a light emitting device that emits light such as red, green, blue, or white, or a UV (Ultra Violet) However, the present invention is not limited thereto. One or more light emitting elements 320 may be mounted.

The light emitting device 320 is applicable to both a horizontal type whose electrical terminals are all formed on the upper surface, a vertical type formed on the upper and lower surfaces, or a flip chip.

The light emitting device package 300 may include a light emitting device.

A light guide plate, a prism sheet, a diffusion sheet, and the like, which are optical members, may be disposed on a light path of the light emitting device package 300.

The light emitting device package 300, the substrate, and the optical member may function as a light unit. Another embodiment may be implemented as a display device, an indicating device, a lighting system including a light emitting device (not shown) or a light emitting device package 300, for example, the lighting system may include a lamp, a streetlight .

5 is an exploded perspective view of a display device having a light emitting device according to an embodiment.

5, a display device 1000 according to an exemplary embodiment of the present invention includes a light guide plate 1041, a light source module 1031 for providing light to the light guide plate 1041, and a reflection member 1022 An optical sheet 1051 on the light guide plate 1041 and a display panel 1061 on the optical sheet 1051 and the light guide plate 1041 and the light source module 1031 and the reflection member 1022 But is not limited to, a bottom cover 1011.

The bottom cover 1011, the reflective sheet 1022, the light guide plate 1041, and the optical sheet 1051 can 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 may be made of a transparent material, for example, acrylic resin such as polymethylmethacrylate (PET), polyethylene terephthalate (PET), polycarbonate (PC), cycloolefin copolymer (COC), and polyethylene naphtha late Resin. ≪ / RTI >

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 light source module 1031 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 embodiment described above and the light emitting devices 1035 may be arrayed at a predetermined interval on the substrate 1033 .

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), a flexible PCB (FPCB), and the like. When the light emitting element 1035 is mounted on the side surface of the bottom cover 1011 or on the heat radiation plate, the substrate 1033 can be removed. Here, a part of the heat radiating plate may be in contact with the upper surface of the bottom cover 1011.

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

The reflective member 1022 may be disposed under the light guide plate 1041. The reflection member 1022 reflects the light incident on the lower surface of the light guide plate 1041 so as to face upward, thereby improving the brightness of the light unit 1050. The reflective member 1022 may be formed of, for example, PET, PC, or PVC resin, 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 house 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 housing portion 1012 having a box-like shape with an opened upper surface, but the present invention is not limited thereto. The bottom cover 1011 may be coupled to the top cover, but 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 a non-metal material having good thermal conductivity, but the present invention is not limited thereto.

The display panel 1061 is, for example, an LCD panel, including first and second transparent substrates 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, but the present invention is not limited thereto. The display panel 1061 displays information by light passing through the optical sheet 1051. Such a display device 1000 can be applied to various types of portable terminals, monitors of notebook computers, monitors of laptop computers, televisions, and the like.

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 a sheet such as a diffusion sheet, a horizontal and vertical prism sheet, and a brightness enhancement sheet. The diffusion sheet diffuses incident light, and the horizontal and / or vertical prism sheet condenses incident light into a display area. The brightness enhancing sheet improves the brightness by reusing the lost light. A protective sheet may be disposed on the display panel 1061, but the present invention is not limited thereto.

Here, the optical path of the light source module 1031 may include the light guide plate 1041 and the optical sheet 1051 as an optical member, but the invention is not limited thereto.

6 is a view showing a display device having a light emitting device according to an embodiment.

6, the display device 1100 includes a bottom cover 1152, a substrate 1120 on which the above-described light emitting device 1124 is 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, the 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 a receiving portion 1153, but the present invention 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, and the horizontal and vertical prism sheets condense incident light into a display area. The brightness enhancing sheet enhances brightness by reusing the lost light.

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

7 is an exploded perspective view of a lighting device having a light emitting device according to an embodiment.

7, the lighting apparatus according to the embodiment includes a cover 2100, a light source module 2200, a heat discharger 2400, a power supply unit 2600, an inner case 2700, and a socket 2800 . Further, the illumination device according to the embodiment may further include at least one of the member 2300 and the holder 2500. The light source module 2200 may include a light emitting device according to an embodiment of the present invention.

For example, the cover 2100 may have a shape of a bulb or a hemisphere, and may be provided in a shape in which the hollow is hollow and a part is opened. 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 heat discharging body 2400. The cover 2100 may have an engaging portion that engages with the heat discharging body 2400.

The inner surface of the cover 2100 may be coated with a milky white paint. Milky white paints may contain a diffusing agent to diffuse 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 for sufficiently diffusing and diffusing the light from the light source module 2200 and emitting it to the outside.

The cover 2100 may be made of 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 so that the light source module 2200 is visible from the outside, and may be opaque. The cover 2100 may be formed by blow molding.

The light source module 2200 may be disposed on one side of the heat discharging body 2400. Accordingly, heat from the light source module 2200 is conducted to the heat discharger 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 heat discharging body 2400 and has guide grooves 2310 into which the plurality of light emitting elements 2210 and the connector 2250 are inserted. The guide groove 2310 corresponds to the substrate of the light emitting device 2210 and the connector 2250.

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 the light reflected by the inner surface of the cover 2100 toward the cover 2100 in the direction toward the light source module 2200. Therefore, the light efficiency of the illumination device according to the embodiment can be improved.

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. Therefore, electrical contact can be made between the heat discharging body 2400 and the connecting plate 2230. The member 2300 may be formed of an insulating material to prevent an electrical short circuit between the connection plate 2230 and the heat discharging body 2400. The heat discharger 2400 receives heat from the light source module 2200 and heat from the power supply unit 2600 to dissipate heat.

The holder 2500 blocks the receiving groove 2719 of the insulating portion 2710 of the inner case 2700. Therefore, the power supply unit 2600 housed in the insulating portion 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 the electrical signal to the light source module 2200. The power supply unit 2600 is housed in the receiving 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 unit 2630, a base 2650, and a protrusion 2670.

The guide portion 2630 has a shape protruding outward from one side of the base 2650. The guide portion 2630 may be inserted into the holder 2500. A plurality of components may be disposed on one side of the base 2650. The plurality of components include, for example, a DC converter for converting AC power supplied from an external power source into DC power, a driving chip for controlling driving of the light source module 2200, an ESD (ElectroStatic discharge) protective device, and the like, but the present invention 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 portion 2750 of the inner case 2700 and receives an external electrical signal. For example, the protrusion 2670 may be equal to or smaller than the width of the connection portion 2750 of the inner case 2700. One end of each of the positive wire and the negative wire is electrically connected to the protrusion 2670 and the other end of the positive wire and the negative wire are electrically connected to the socket 2800.

The inner case 2700 may include a molding part together with the power supply part 2600. The molding part is a hardened portion of the molding liquid so that the power supply unit 2600 can be fixed inside the inner case 2700.

The configuration and the method of the embodiments described above are not limitedly applied, but the embodiments may be modified so that all or some of the embodiments are selectively combined so that various modifications can be made. .

Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined.

It is to be understood that the terms "comprises", "comprising", or "having" as used in the foregoing description mean that the constituent element can be implanted unless specifically stated to the contrary, But should be construed as further including other elements.

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

110: substrate
120: buffer layer
130: insertion layer
140: Light emitting structure
142: first semiconductor layer
144:
146: second semiconductor layer

Claims (16)

Board;
A light emitting structure disposed on the substrate and including a first semiconductor layer, a second semiconductor layer disposed on the first semiconductor layer, and an active layer disposed between the first semiconductor layer and the second semiconductor layer; And
An interlevel layer disposed between the substrate and the light emitting structure and including an aluminum gallium nitride layer (AlGaN) and an indium gallium nitride layer (InGaN)
Wherein the second semiconductor layer comprises an n-doped first layer and a p-doped second layer. The method according to claim 1,
The second layer has a plurality of layers,
Wherein the plurality of second layers have different doping densities. 3. The method of claim 2,
Wherein the plurality of second layers are closer to the active layer and have a lower doping concentration. 3. The method of claim 2,
Wherein the first layer is disposed between the plurality of second layers. 5. The method of claim 4,
Wherein the first layer has a plurality of layers,
Wherein the plurality of first layers have the same doping concentration. The method according to claim 1,
The light emitting device ³ of silicon (Si) dopant concentration of the first layer is 10 ¹⁷ cm ^-3 to 10 ¹⁸ cm. The method according to claim 1,
The second layer has three,
The light emitting device ³ of magnesium (Mg) dopant concentration of the second layer closest to the active layer is 10 ¹⁷ cm ^-3 to 10 ¹⁸ cm. 8. The method of claim 7,
The light emitting device ³ of magnesium (Mg) dopant concentration of the second layer near the second time in the active layer is 10 ¹⁸ cm ^-3 to 10 ¹⁹ cm. 8. The method of claim 7,
A light emitting element ³ furthest magnesium (Mg) dopant concentration of the second layer in the active layer is 10 ¹⁹ cm ^-3 to 10 ²¹ cm. The method according to claim 1,
Wherein the first layer has a thickness of 3 to 7 nm. The method according to claim 1,
The second layer has three,
And the thickness of the second layer closest to the active layer is 8 to 15 nm. 12. The method of claim 11,
And the thickness of the second layer closest to the active layer is 10 to 25 nm. 12. The method of claim 11,
And the thickness of the second layer farthest from the active layer is 20 to 40 nm. The method according to claim 1,
And the thickness of the indium gallium nitride layer (InGaN) is 5 to 10 nm. The method according to claim 1,
The plurality of aluminum gallium nitride layers (AlGaN)
Wherein the plurality of aluminum gallium nitride layers (AlGaN) are closer to the substrate and have a higher content of aluminum (Al). 16. The method of claim 15,
A plurality of the indium gallium nitride layers (InGaN)
Wherein the plurality of indium gallium nitride layers (InGaN) have mutually different indium (In) contents.

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