KR20130053974A - Light emitting device - Google Patents

Abstract

PURPOSE: A light emitting device is provided to improve the reflection effect of light by using metal particles which is not oxidized in room temperature. CONSTITUTION: Metal particles(150) are arranged on a substrate. A light emitting structure(130) is arranged on the substrate and the metal particles. The light emitting structure includes a first semiconductor layer and a second semiconductor layer. An active layer(134) is arranged between the first semiconductor layer and the second semiconductor layer. The metal particles form a cluster.

Description

Light emitting device

An embodiment relates to 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 generate light by recombination of holes and electrons in the active layer. This light is not emitted from the inside of the LED to the outside but can turn into thermal energy due to total internal reflection. Therefore, efforts have been made to reduce the light loss caused by the change of light energy into thermal energy.

A patterned sapphire substrate (PSS) structure may be formed on the sapphire substrate to increase light extraction efficiency. When forming a PSS structure on a sapphire substrate, the amount of light lost due to total reflection inside the LED can be minimized. In addition to the PSS structure, efforts have been made to improve the light extraction structure by forming an uneven structure on the upper surface of the semiconductor layer.

The embodiment provides a light emitting device in which light extraction efficiency is improved by disposing light particles by disposing metal particles on a substrate.

The light emitting device according to the embodiment includes a substrate; Metal particles disposed on the substrate; And a light emitting structure disposed on the substrate and the metal particles, the light emitting structure including a first semiconductor layer, a second semiconductor layer, and an active layer disposed between the first semiconductor layer and the second semiconductor layer.

The light emitting device according to the embodiment may include metal particles on the substrate to improve light extraction efficiency through reflection of light.

The light emitting device according to the embodiment may increase the reflection effect of light by using a material that is not easily oxidized at room temperature as metal particles.

In the light emitting device according to the embodiment, the metal particles may be formed of a material having high thermal conductivity and may help to release thermal energy that may stay inside the semiconductor layer to the outside, thereby improving reliability.

In the light emitting device according to the embodiment, the metal particles may be formed of a material capable of causing surface plasmon resonance (Surface-plasmon resonance) to reflect light without absorbing the light generated in the active layer, thereby maximizing light extraction efficiency.

1 is a cross-sectional view showing the structure of a light emitting device according to the embodiment;
2 is a cross-sectional view showing a part of a light emitting device according to the embodiment;
3A is a perspective view showing a light emitting device package including a light emitting device of the embodiment;
3B is a cross-sectional view showing a light emitting device package including a light emitting device of the embodiment;
4A is a perspective view illustrating a lighting device including a light emitting device module according to an embodiment;
4B is a cross-sectional view showing a lighting apparatus including a light emitting device module according to an embodiment;
5 is an exploded perspective view illustrating a backlight unit including a light emitting device module according to an embodiment; and
6 is an exploded perspective view illustrating a backlight unit including a light emitting device module according to an embodiment.

Advantages and features of the embodiments, and methods of achieving them will become apparent with reference to the following detailed description in conjunction with the accompanying drawings. However, the embodiments are not limited to the matters disclosed below but may be embodied in various forms, and only the embodiments fully notify the person of ordinary skill in the art to which the embodiments belong. The scope of the rights is only defined by the scope of the claims. Thus, in some embodiments, well known process steps, well known device structures, and well known techniques are not described in detail in order to avoid unambiguous interpretation. Like reference numerals refer to like elements throughout.

In the description of the embodiments, when described as being formed on an "on or under" of each element, the on or under is It includes both the two elements are in direct contact with each other or one or more other elements are formed indirectly between the two elements. In addition, when expressed as "on" or "under", it may include not only an upward direction but also a downward direction based on one element.

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

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

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

Although the terms first, second, etc. may be used to describe various elements, components, regions, layers and / or regions, such elements. Ingredients. Areas. Layers and / or regions should not be limited by this term.

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 showing a structure of a light emitting device according to one embodiment, and FIG. 2 is a cross-sectional view showing a part of a light emitting device according to an embodiment.

Referring to FIG. 1, the light emitting device 100 according to the embodiment is disposed on the substrate 110, the metal particles 150 disposed on the substrate 110, and the substrate 110 and the metal particles 150. The light emitting structure includes a first semiconductor layer 132, a second semiconductor layer 136, and an active layer 134 disposed between the first semiconductor layer 132 and the second semiconductor layer 136.

The substrate 110 may be disposed under the first semiconductor layer 132. The substrate 110 may support the first semiconductor layer 132. The substrate 110 may receive heat from the first semiconductor layer 132. The substrate 110 may have a light transmissive property. The substrate 110 may have a light transmissive property when using a light transmissive material or formed below a predetermined thickness, but is not limited thereto. For example, the substrate may be formed of sapphire (Al ₂ O ₃ ). The refractive index of the substrate 110 is preferably smaller than the refractive index of the first semiconductor layer 132 for light extraction efficiency.

The substrate 110 may be formed of a semiconductor material according to an embodiment, for example, silicon (Si), germanium (Ge), gallium arsenide (GaAs), zinc oxide (ZnO), silicon carbide (SiC), It may be implemented as a carrier wafer such as silicon germanium (SiGe), gallium nitride (GaN), gallium (III) oxide (Ga ₂ O ₃ ).

The substrate 110 may be formed of a conductive material according to an embodiment. According to the embodiment, the metal may be formed of, for example, gold (Au), nickel (Ni), tungsten (W), molybdenum (Mo), copper (Cu), aluminum (Al), tantalum (Ta), or silver. It may be formed of any one selected from (Ag), platinum (Pt), chromium (Cr) or formed of two or more alloys, and may be formed by stacking two or more of the above materials. When the substrate 110 is formed of a metal, the thermal stability of the light emitting device may be improved by facilitating the emission of heat generated from the light emitting device.

The substrate 110 may include a patterned substrate (PSS) structure on an upper surface of the substrate 110 to increase light extraction efficiency.

Referring to FIG. 2 in which the top structure of the substrate 110 is enlarged, the substrate 110 may facilitate heat emission from the light emitting device 100, thereby improving thermal stability of the light emitting device 100. The substrate 110 may include a layer in which a difference between the first semiconductor layer 132 and the lattice constant exists so as to alleviate the lattice constant difference between the first semiconductor layer 132 and the first semiconductor layer 132.

The substrate 110 may have a recess 114 formed by recessing the protrusion 112 formed to protrude and have a PSS structure on an upper surface thereof. The substrate 110 may have a protrusion 112 and a recess 114 formed on the top surface thereof.

The metal particles 150 may be disposed on the upper surface of the substrate 110. The metal particles 150 may be disposed in the recesses 114 of the substrate 110. The metal particles 150 may be disposed between the protrusions 112. The metal particles 150 may be disposed in the buffer layer 120. The metal particles 150 may be surrounded by the buffer layer 120. Materials forming the buffer layer 120 may be disposed between the plurality of metal particles 150, but embodiments are not limited thereto.

The metal particles 150 may selectively absorb and absorb light of a specific wavelength band among the wavelength bands of the excitation light absorbed by the light emitting device 100. The metal particles 150 may induce surface plasmon resonance through resonance absorption of a specific wavelength. The metal particles 150 may be formed to have a resonance frequency corresponding to the same wavelength band as the excitation wavelength light of the light emitting device 100. The metal particles 150 may adjust the resonant frequency by adjusting the size and shape. The metal particles 150 may be formed of a material having a low degree of oxidation at room temperature.

The metal particles 150 may be one of gold (Au), silver (Ag), and copper (Cu). The metal particles 150 may be formed of one of gold (Au), silver (Ag), and copper (Cu) to cause surface plasmon resonance (SPR).

Surface plasmon resonance can occur due to the interaction of free electrons and light at the interface of materials with different dielectric constants with particles formed from metals, which are carried by photons of the dielectric material at the interface formed. It occurs when energy is transferred to the collective transition of free electrons present in the metal.

That is, the surface plasmon is a collective charge density oscillation of electrons occurring on the metal surface, and the surface plasmon wave generated by this is surface electromagnetic waves traveling along the interface of the material having a different dielectric constant from the metal particles 150.

On the other hand, the surface plasmon wave formed by being excited by light is characterized in that it does not propagate from the metal surface to the inside or the outside when the metal has a flat surface. Therefore, it is necessary to emit the surface plasmon wave to the outside, the metal particle 150 has a spherical shape, it can be easily emitted to the generated plasmon wave to the light.

The metal forming the metal particles 150 is preferably formed of at least one of gold, silver, and copper having an easy to release of electrons by an external magnetic pole and having a negative dielectric constant. The metal particle 150 may be a metal having a low oxidation degree at room temperature. The plurality of metal particles 150 may be spaced apart from each other to reflect light at various angles, but is not limited thereto. The metal particles 150 may be disposed between the PSS structures to exert synergistic effects with the PSS structures to maximize light extraction efficiency.

The metal particles 150 may form a cluster. The metal particles 150 may have a cluster size of 4 to 100 nm. When the width of the metal particles 150 is 4 nm or less, surface plasmon resonance may be generated with respect to the wavelength of light generated from the light emitting device 100. It is difficult to have a resonant frequency, and when the width of the metal particles 150 is 100 nm or more, it is difficult to arrange a large number of metal particles 150 in the depression 114, so that the effect of improving the light extraction efficiency can be reduced. Can be.

The metal particles 150 may be treated with an antioxidant, for example, hydrazine. The metal particles 150 may be pretreated with a strong antioxidant. The metal particles 150 may be reduced to an N ₂ H ₅ solution. That is, a metal film may be formed on the substrate 110 and rinsed with a N ₂ H ₅ solution to form the metal particles 150 from the metal film. The N ₂ H ₅ solution may be diluted in water (H ₂ 0). When the N ₂ H ₅ solution is diluted in water, the proportion of N ₂ H ₅ may be at least 58%. The metal particles 150 may be antioxidized to further improve reflection efficiency.

Since the metal particles 150 do not generate steam even under low pressure conditions, the material may be entangled in the MOCVD (Metal Organic Chemical Vapor Deposition) equipment, thereby eliminating the possibility of disruption in the manufacturing process of the light emitting device 100.

The buffer layer 120 may be disposed between the substrate 110 and the first semiconductor layer 132. The buffer layer 120 includes gallium nitride (GaN), indium nitride (InN), aluminum nitride (AlN), aluminum indium nitride (AlInN), indium gallium nitride (InGaN), aluminum gallium nitride (AlGaN), and indium aluminum It may be formed of one or more materials of gallium nitride (InAlGaN), but is not limited thereto. The buffer layer 120 may be grown as a single crystal on the substrate 110.

The buffer layer 120 may mitigate lattice mismatch between the substrate 110 and the first semiconductor layer 132. The buffer layer 120 may allow the first semiconductor layer 132 to be easily grown on the top surface. The buffer layer 120 may improve crystallinity of the first semiconductor layer 132 disposed on the top surface. 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 132.

The buffer layer 120 may be disposed in the recess 114 of the substrate. The buffer layer 120 may be disposed between the plurality of metal particles 150. The buffer layer 120 may be disposed between the metal particles 150 and the protrusion 112. That is, the buffer layer 120 may be formed to cover the metal particles 150. The buffer layer 120 may adjust the degree of spaced or concentrated metal particles 150 from each other. The buffer layer 120 may improve light extraction efficiency by reflecting light generated in the active layer in various directions by separating the plurality of metal particles 150 from each other.

The first semiconductor layer 132 may be disposed on the substrate 110. The first semiconductor layer 132 may be disposed on the buffer layer 120 to match the difference in lattice constant with the substrate 110, but is not limited thereto. The first semiconductor layer 132 may be grown on the substrate 110.

The light emitting structure 130 may be formed on the support substrate 110.

The light emitting structure 130 may include a first semiconductor layer 132, an active layer 134, and a second semiconductor layer 136, and an active layer between the first semiconductor layer 132 and the second semiconductor layer 136. 134 may be configured to be interposed.

The first semiconductor layer 132 may be implemented as an n-type semiconductor layer, and the n-type semiconductor layer may be, for example, In _x Al _y Ga _{1 -x- y} N (0≤x≤1, 0≤y≤1, A semiconductor material having a composition formula of 0 ≦ x + y ≦ 1, for example, gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), indium nitride (InN), InAlGaN, AlInN and the like can be selected. For example, the first semiconductor layer 132 may be doped with n-type dopants such as silicon (Si), germanium (Ge), tin (Sn), selenium (Se), and tellurium (Te).

The active layer 134 may be formed on the first semiconductor layer 132. The active layer 134 may be formed of a single or multiple quantum well structure, a quantum-wire structure, a quantum dot structure, or the like by using a compound semiconductor material of a group 3 to 5 element.

Well active layer 134 has a composition formula in this case formed of a quantum well structure, for _{example, In x Al y Ga 1 -x-} y N (0≤x≤1, 0≤y≤1, 0≤x + y≤1) It may have a single or quantum well structure having a layer and a barrier layer having a compositional formula of In _a Al _b Ga _{1 -a- b} N ( _{0≤a≤1, 0≤b≤1, 0≤a} + b≤1). have. The well layer may be formed of a material having a band gap smaller than the band gap of the barrier layer.

A conductive clad layer (not shown) may be formed on or under the active layer 134, and the conductive clad layer (not shown) may be formed of an AlGaN-based semiconductor, rather than a band gap of the active layer 134. It can have a large band gap.

The second semiconductor layer 136 may be formed on the active layer 134. The second semiconductor layer 136 may be implemented as a p-type semiconductor layer doped with a p-type dopant. The second semiconductor layer 136 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 ( Gallium nitride), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), indium nitride (InN), InAlGaN, AlInN, etc., and magnesium (Mg), zinc (Zn), calcium ( P-type dopants such as Ca), strontium (Sr), and barium (Ba) may be doped.

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

The light emitting structure 130 may have a uniform or non-uniform doping concentration of the conductive dopants in the first semiconductor layer 132 and the second semiconductor layer 136, but is not limited thereto. The interlayer structure of the light emitting structure 130 may be variously formed, but is not limited thereto.

The light emitting structure 130 may include a third semiconductor layer (not shown) having a polarity opposite to that of the second semiconductor layer 136 on the second semiconductor layer 136. In the light emitting structure 130, the first semiconductor layer 132 may be an n-type semiconductor layer, and the second semiconductor layer 136 may be implemented as a p-type semiconductor layer. Accordingly, the light emitting structure 130 may include at least one of an N-P junction, a P-N junction, an N-P-N junction, and a P-N-P junction structure.

The transparent electrode layer 140 may be disposed on the second semiconductor layer 136.

The transparent electrode layer 140 is formed of ITO, IZO (In-ZnO), GZO (Ga-ZnO), AZO (Al-ZnO), AGZO (Al-Ga ZnO), IGZO (In-Ga ZnO), IrO _x , RuO _x , RuO _x / ITO, Ni / IrO _x / Au, and Ni / IrO _x / Au / ITO, and may be formed, and formed on the second semiconductor layer 136 to prevent current grouping. can do.

A portion of the active layer 130, the second semiconductor layer 136, and the transparent electrode layer 140 are removed to expose a portion of the first semiconductor layer 120, and a first electrode is disposed on the exposed upper surface of the first semiconductor layer 120. 160 may be formed. The second electrode 170 may be formed on the upper surface of the second semiconductor layer 136. The second electrode 170 is connected to the second semiconductor layer 136 by removing a portion of the transparent electrode layer 140 and exposing a portion of the second semiconductor layer 136, or is connected to the transparent electrode layer 140. It may be electrically connected to the second semiconductor layer 136.

In addition, the second electrode 170 may be disposed on the second semiconductor layer 136. The second semiconductor layer 136 may receive a current from the second electrode 170. A light extraction structure may be formed on the top surface of the second semiconductor layer 136.

Meanwhile, the first and second electrodes 160 and 170 may be conductive materials, for example, In, Co, Si, Ge, Au, Pd, Pt, Ru, Re, Mg, Zn, Hf, Ta, Rh, Ir, W It may include a metal selected from Ti, Ag, Cr, Mo, Nb, Al, Ni, Cu, and WTi, or may include an alloy thereof, may be formed in a single layer or multiple layers, but is not limited thereto. .

3A is a perspective view illustrating a light emitting device package including a light emitting device according to an embodiment, and FIG. 3B is a cross-sectional view illustrating a cross section of a light emitting device package including a light emitting device according to an embodiment.

3A and 3B, a light emitting device package 300 according to an embodiment of the present invention includes a body 310 having a cavity formed therein, first and second electrodes 340 and 350 mounted on the body 310, 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 may be made of a resin material such as polyphthalamide (PPA), silicon (Si), aluminum (Al), aluminum nitride (AlN), photo sensitive glass (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 as viewed from above may be circular, rectangular, polygonal, elliptical, or the like, and in particular, may have a curved shape, but 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, and may be formed by filling in a cavity and then ultraviolet or thermal curing.

The phosphor (not shown) may be selected according to the wavelength of the light emitted from the light emitting device 320 to allow the light emitting device package 300 to 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.

That is, 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, and blue light emitted from the blue light emitting diode As the yellow light generated by excitation by blue light is mixed, the light emitting device package 300 can provide white light.

Similarly, when the light emitting device 320 is a green light emitting diode, a magenta phosphor or blue and red phosphors (not shown) are mixed, and when the light emitting device 320 is a red light emitting diode, a cyan phosphor or blue light is used. The case where a green fluorescent substance is mixed is mentioned as an example.

Such phosphors (not shown) may be known such as YAG-based, TAG-based, sulfide-based, silicate-based, aluminate-based, nitride-based, carbide-based, nitridosilicate-based, borate-based, fluoride-based, and phosphate-based compounds.

Meanwhile, 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 may reflect light generated from the light emitting device 320 to increase light efficiency, and also generate heat generated from the light emitting device 320. Can be discharged to the outside.

Although the light emitting device 320 is mounted on the first electrode 350 in FIG. 3B, the present invention is not limited thereto, and the light emitting device 320, the first electrode 340, and the second electrode 350 may be wire bonded. May be electrically connected by any one of the following methods, a flip chip method, and a die bonding method.

The first electrode 340 and the second electrode 350 are made of a metal material, 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 340 and the second electrode 350 may be formed to have a single layer or a multi-layer structure, but is not limited thereto.

The light emitting device 320 may be mounted on the first electrode 340 and may be, for example, a light emitting device emitting light of red, green, blue, white, or UV (ultraviolet) light emitting device emitting ultraviolet light. However, the present invention is not limited thereto. In addition, one or more light emitting devices 320 may be mounted.

Further, the light emitting device 320 may be a horizontal type in which all of its electrical terminals are formed on an upper surface, or a vertical type or flip chip formed on an upper and a lower surface. Applicable

On the other hand, the light emitting device 320 has a protrusion (not shown) and a depression (not shown) is formed on the upper surface of the substrate (not shown), the metal particles (not shown) are disposed on the depression (not shown) and the reflection of light Due to the effect and the effect of surface plasmon resonance, the light extraction efficiency may be improved, and the light emission efficiency of the light emitting device 320 and the light emitting device package 300 may be improved.

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 indicator device, or a lighting system including the light emitting device 100 or the light emitting device package 300 described in the above embodiments, for example, the lighting system may be a lamp, a street lamp. It may include.

4A is a perspective view illustrating a lighting system including a light emitting device according to an embodiment, and FIG. 4B is a cross-sectional view illustrating a cross-sectional view taken along line D-D 'of the lighting system of FIG. 4A.

4B is a cross-sectional view of the illumination system 400 of FIG. 4A cut in the longitudinal direction Z and the height direction X and viewed in the horizontal direction Y. FIG.

4A and 4B, the lighting system 400 may include a body 410, a cover 430 coupled to the body 410, and a finishing cap 450 positioned at opposite ends of the body 410 have.

The lower surface of the body 410 is fastened to the light emitting device module 440, the body 410 is conductive and so that the heat generated from the light emitting device package 444 can be discharged to the outside through the upper surface of the body 410 The heat dissipation effect may be formed of an excellent metal material, but is not limited thereto.

In particular, the light emitting device package 444 includes a light emitting device (not shown), and the light emitting device (not shown) is formed with a protrusion (not shown) and a recessed portion (not shown) on an upper surface of the substrate (not shown). Metal particles (not shown) may be disposed in the portion (not shown), and light extraction efficiency may be improved due to light reflection effects and surface plasmon resonance effects, and light emission of the light emitting device package 444 and the lighting system 400 may be performed. Efficiency can be improved.

The light emitting device package 444 may be mounted on the substrate 442 in multiple colors and in multiple rows to form a module. The light emitting device package 444 may be mounted at the same interval or may be mounted at various separation distances as necessary to adjust brightness. As the substrate 442, a metal core PCB (MCPCB) or a PCB made of FR4 may be used.

The cover 430 may be formed in a circular shape to surround the lower surface of the body 410, but is not limited thereto.

The cover 430 protects the light emitting device module 440 from the outside and the like. In addition, the cover 430 may include diffusing particles to prevent glare of the light generated from the light emitting device package 444 and to uniformly emit light to the outside, and may also include at least one of an inner surface and an outer surface of the cover 430. A prism pattern or the like may be formed on either side. In addition, a phosphor may be applied to at least one of an inner surface and an outer surface of the cover 430.

On the other hand, since the light generated from the light emitting device package 444 is emitted to the outside through the cover 430, the cover 430 should be excellent in the light transmittance, sufficient to withstand the heat generated in the light emitting device package 444 The cover 430 should be provided with heat resistance, and the cover 430 is made of a material including polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), or the like. It is preferably formed.

Closing cap 450 is located at both ends of the body 410 may be used for sealing the power supply (not shown). In addition, the closing cap 450 has a power pin 452 is formed, the lighting system 400 according to the embodiment can be used immediately without a separate device in the terminal from which the existing fluorescent lamps are removed.

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

5 is an edge-light method, and the liquid crystal display 500 may include a liquid crystal display panel 510 and a backlight unit 570 for providing light to the liquid crystal display panel 510.

The liquid crystal display panel 510 may display an image by using light provided from the backlight unit 570. The liquid crystal display panel 510 may include a color filter substrate 512 and a thin film transistor substrate 514 facing each other with a liquid crystal interposed therebetween.

The color filter substrate 512 may implement colors of an image displayed through the liquid crystal display panel 510.

The thin film transistor substrate 514 is electrically connected to the printed circuit board 518 on which a plurality of circuit components are mounted through the driving film 517. The thin film transistor substrate 514 may apply a driving voltage provided from the printed circuit board 518 to the liquid crystal in response to a driving signal provided from the printed circuit board 518.

The thin film transistor substrate 514 may include a thin film transistor and a pixel electrode formed of a thin film on another substrate of a transparent material such as glass or plastic.

The backlight unit 570 may convert the light provided from the light emitting device module 520, the light emitting device module 520 into a surface light source, and provide the light guide plate 530 to the liquid crystal display panel 510. Reflective sheet for reflecting the light emitted from the rear of the light guide plate 530 and the plurality of films 550, 566, 564 to uniform the luminance distribution of the light provided from the 530 and improve the vertical incidence ( 540.

The light emitting device module 520 may include a PCB substrate 522 so that a plurality of light emitting device packages 524 and a plurality of light emitting device packages 524 may be mounted to form a module.

In particular, the light emitting device package 524 includes a light emitting device (not shown), and the light emitting device (not shown) is formed with a protrusion (not shown) and a recessed portion (not shown) on an upper surface of the substrate (not shown). By disposing a metal particle (not shown) in the portion (not shown), the light extraction efficiency can be improved due to the reflection effect of light and the effect of surface plasmon resonance, and the light emission of the light emitting device package 524 and the backlight unit 570 Efficiency can be improved.

Meanwhile, the backlight unit 570 includes a diffusion film 566 for diffusing light incident from the light guide plate 530 toward the liquid crystal display panel 510, and a prism film 550 for condensing the diffused light to improve vertical incidence. ), And may include a protective film 564 to protect the prism film 550.

6 is an exploded perspective view of a liquid crystal display including the light emitting device according to the embodiment. However, the parts shown and described in Fig. 5 are not repeatedly described in detail.

6 illustrates a direct method, the liquid crystal display 600 may include a liquid crystal display panel 610 and a backlight unit 670 for providing light to the liquid crystal display panel 610.

Since the liquid crystal display panel 610 is the same as that described with reference to FIG. 5, detailed description is omitted.

The backlight unit 670 may include a plurality of light emitting device modules 623, a reflective sheet 624, a lower chassis 630 in which the light emitting device modules 623 and the reflective sheet 624 are accommodated, and an upper portion of the light emitting device module 623. It may include a diffusion plate 640 and a plurality of optical film 660 disposed in the.

LED Module 623 A plurality of light emitting device packages 622 and a plurality of light emitting device packages 622 may be mounted to include a PCB substrate 621 to form a module.

In particular, the light emitting device package 622 includes a light emitting device (not shown), and the light emitting device (not shown) is formed with a protrusion (not shown) and a depression (not shown) formed on an upper surface of the substrate (not shown). By disposing a metal particle (not shown) in the portion (not shown), the light extraction efficiency can be improved due to the reflection effect of light and the effect of surface plasmon resonance, and the light emission of the light emitting device package 622 and the backlight unit 670 Efficiency can be improved.

The reflective sheet 624 reflects the light generated from the light emitting device package 622 in the direction in which the liquid crystal display panel 610 is positioned to improve light utilization efficiency.

On the other hand, the light generated from the light emitting device module 623 is incident on the diffusion plate 640, the optical film 660 is disposed on the diffusion plate 640. The optical film 660 includes a diffusion film 666, a prism film 650, and a protective film 664.

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. .

Although the preferred embodiments have been illustrated and described above, the invention is not limited to the specific embodiments described above, and does not depart from the gist of the invention as claimed in the claims. Various modifications can be made by the person who has them, and these modifications should not be understood individually from the technical idea or the prospect of the present invention.

110: substrate 120: buffer layer
130: light emitting structure 132: first semiconductor layer
134: active layer 136: second semiconductor layer
140: translucent electrode layer 150: metal particles
160: first electrode 170: second electrode

Claims (10)

Board;
Metal particles disposed on the substrate; And
And a light emitting structure disposed on the substrate and the metal particles, the light emitting structure including a first semiconductor layer, a second semiconductor layer, and an active layer disposed between the first semiconductor layer and the second semiconductor layer. The method of claim 1,
The metal particle is a light emitting device of one of Au, Ag and Cu. The method of claim 1,
The metal particles may form a cluster (cluster), the size of the cluster is 4 to 100 nm light emitting device. The method of claim 1,
A light emitting device is provided with a protrusion and a depression on the upper surface of the substrate. 5. The method of claim 4,
The metal particles are disposed in the recess. The method of claim 1,
The light emitting device further comprises a buffer layer disposed between the light emitting structure and the substrate. The method of claim 1,
Protrusions and depressions are formed on the upper surface of the substrate,
The buffer layer is a light emitting device disposed between the electrode particles and the protrusion. The method of claim 1,
The metal particles are surrounded by the buffer layer. The method of claim 1,
The buffer layer is disposed in the recess. The method of claim 1,
The metal particle resonates with a specific wavelength of light generated in the active layer.

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