KR102252473B1 - Light emittng device - Google Patents

Abstract

Examples include a substrate; A plurality of protruding structures disposed on the substrate and including a first semiconductor layer; A second semiconductor layer formed in an upper region of at least a portion of each of the protruding structures; And an active layer and a third semiconductor layer disposed on side surfaces and upper surfaces of each of the protruding structures.

Description

Light emitting device {LIGHT EMITTNG DEVICE}

The embodiment relates to a light-emitting device, and more particularly, to a light-emitting device in which the quality of a light-emitting structure is improved and light is emitted from the entire area of an active layer.

Group 3-5 compound semiconductors such as GaN and AlGaN are widely used in optoelectronics and electronic devices due to their many advantages, such as having a wide and easily adjustable band gap energy.

In particular, light-emitting devices such as Ligit Emitting Diodes and laser diodes using semiconductor materials of Group 3-5 or Group 2-6 compound are developed in thin film growth technology and device materials, such as red, green, blue, and ultraviolet rays. Various colors can be implemented, and efficient white light can be realized by using fluorescent materials or by combining colors. Low power consumption, semi-permanent life, fast response speed, safety, and environment compared to conventional light sources such as fluorescent lamps and incandescent lamps. It has the advantage of affinity.

Therefore, the transmission module of the optical communication means, a light-emitting diode backlight that replaces the Cold Cathode Fluorescence Lamp (CCFL) that constitutes the backlight of the LCD (Liquid Crystal Display) display, and white light that can replace a fluorescent lamp or incandescent light bulb. Applications are expanding to diode lighting devices, automobile headlights and traffic lights.

In a light-emitting device, since the substrate and the light-emitting structure are heterogeneous materials, the lattice constant mismatch is very large, and the difference in the coefficient of thermal expansion between them is also very large. back), cracks, pits, and surface morphology defects may occur.

In order to solve the above-described problem, a buffer layer may be formed between the substrate and the light emitting structure, but the potential is still formed and the quality of the light emitting structure may be deteriorated. The efficiency of the light emitting device itself can be reduced.

In addition, there are attempts to suppress the growth of dislocations and the like by manufacturing a light emitting structure in a nanorod shape. However, when manufacturing a light emitting structure in the shape of a nanorod, current is concentrated on the upper portion of the nanorod, so that light may not be evenly emitted from all areas of the light emitting device.

1 is a view showing a conventional nano-rod-shaped light emitting device.

The conventional light emitting device 100 is provided on at least one nitride semiconductor layer 115 and at least one nitride semiconductor layer 115 on the substrate 112 and includes at least one through hole 116. It may include 117 and light-emitting nanorods 126 protruding from the through hole 116 of the mask layer 117 and formed to be spaced apart from each other.

The mask layer 17 may be formed by etching into a desired through-hole pattern by a lithography process, and the through-hole 116 may have a cross-sectional shape such as, for example, a circle, an ellipse, or a polygon.

Nanorods are not formed on the mask layer 117, and light emitting nanorods 126 may be formed through the through holes 116. The light-emitting nano-rod 126 includes a nano-core 120 grown through the through hole 116, a light-emitting layer 123 formed on the surface of the nano-core 120, and a semiconductor layer 125 formed on the surface of the light-emitting layer 123. Can include. The emission layer 123 may be radially grown from the nano core 120 to surround the surface of the nano core 120.

Electrons may be supplied to the emission layer 123 from the nano core 120, holes may be supplied to the emission layer 123 from the semiconductor layer 125, and light may be emitted by the combination of electrons and holes in the emission layer. Here, light is emitted through the surface area of the light-emitting nanorods, and the emission area of the light is wide, so that luminous efficiency may be high.

A first filling layer 130 may be formed on the mask between the light emitting nanorods 126. The first filling layer 130 may be formed to have a height smaller than the height of the light emitting nanorods 126. The first filling layer 130 may be formed of an insulator.

A first conductive layer 133 may be provided on the surfaces of the light emitting nanorods 126 and the first filling layer 130. In addition, a second filling layer 135 may be provided on the first conductive layer 133 between the light emitting nanorods. The second filling layer 135 may be formed of an insulator or a conductor.

The first electrode 137 may be provided on the first conductive layer 133 and the second filling layer 135. Current is injected through the first electrode 137 and flows through the first conductive layer 133 to the light emitting nanorods, thereby increasing current injection efficiency. A protective layer 127 may be further provided between the mask layer 117 and the first filling layer 130 and between the semiconductor layer 125 and the first filling layer 130.

When the current injected from the first electrode 137 flows through the first conductive layer 133, the first filling layer 130 may prevent leakage to other places without flowing to the light emitting layer 123. In addition, the protective layer 127 can further increase the current leakage prevention rate by allowing the first filling layer 130 to be well attached to the mask layer 117 or the semiconductor layer 125, and the first filling layer 130 The over-protective layer 127 may contribute to increase the electron-hole bonding rate in the light-emitting layer 123.

However, the conventional nanorod-shaped light emitting device described above has the following problems.

In the above-described light emitting device, the conductive layer is not evenly distributed over the entire area of the nanorods, so there is a limitation in increasing the light emitting area. In addition, since the current tends to travel to the shortest distance with a small resistance, most of the carriers injected on the top of the nanorod on which the first electrode is formed remain, and it is difficult to expect even light emission over the entire area of the nanorod.

The embodiment is intended to increase the light-emitting area of the light-emitting device and, in particular, to generate light evenly over the entire area of the light-emitting structure.

Examples include a substrate; A plurality of protruding structures disposed on the substrate and including a first semiconductor layer; A second semiconductor layer formed in an upper region of at least a portion of each of the protruding structures; And an active layer and a third semiconductor layer disposed on side surfaces and upper surfaces of each of the protruding structures.

The resistance of the second semiconductor layer may be greater than that of the first semiconductor layer.

The thickness of the second semiconductor layer may be at least 100 angstroms to 100 nanometers.

The light emitting device may further include a conductive layer disposed along the circumference of the third semiconductor layer.

Another embodiment is a substrate; A plurality of protruding structures disposed on the substrate and including a first semiconductor layer; An active layer and a third semiconductor layer disposed on side surfaces and upper surfaces of each of the protruding structures; And a conductive layer disposed around the third semiconductor layer, wherein the conductive layer includes a first conductive layer disposed in a lower region of the protruding structure and a second conductive layer disposed in an upper region of the protruding structure. It provides a light emitting device including.

The resistance of the first conductive layer may be smaller than that of the second conductive layer.

The thickness of the first conductive layer may be thicker than that of the second conductive layer.

The light emitting device may further include a gap filling layer filling a gap between each of the third semiconductor layers.

The light emitting device may further include a mask disposed on the substrate and dividing the plurality of protruding structures.

The substrate may be made of glass, and a metal layer disposed between the substrate and the protruding structure may be disposed.

In the light emitting device according to the present embodiment, a second semiconductor layer having high resistance is disposed on the top of the protruding structure of the size, so that electrons and holes are actively combined in the active layer disposed on the side surface than the active layer disposed on the top of the protruding structure. Light can be emitted. Accordingly, it is possible to solve a problem in which light emission is concentrated in the upper region of the protruding structure in the related art.

1 is a view showing a conventional nano-rod-shaped light emitting device,
2A is a view showing a first embodiment of a light emitting device,
FIG. 2B is a diagram showing in detail area'A' of FIG. 2A,
2C is a view showing a second embodiment of a light emitting device,
3A is a view showing a third embodiment of a light emitting device,
FIG. 3B is a diagram showing in detail area'B' of FIG. 3A,
3C is a view showing a fourth embodiment of a light emitting device,
3D is a view showing a fifth embodiment of a light emitting device,
3E is a diagram showing a sixth embodiment of a light emitting device,
4 is a view showing an embodiment of a light emitting device package in which the light emitting device is arranged,
5 is a diagram showing an embodiment of an image display device in which a light emitting device is disposed,
6 is a view showing an embodiment of a lighting device in which a light emitting device is disposed.

Hereinafter, embodiments of the present invention capable of realizing the above object will be described with reference to the accompanying drawings.

In the description of the embodiment according to the present invention, in the case where it is described as being formed in "on or under" of each element, the upper (upper) or lower (lower) (on or under) includes both elements in direct contact with each other or in which one or more other elements are indirectly formed 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.

FIG. 2A is a diagram illustrating a first embodiment of a light emitting device, and FIG. 2B is a diagram illustrating a region'A' in FIG. 2A in detail.

In the light emitting device 200a according to the embodiment, a light emitting structure 220 is disposed on a substrate 210, and the light emitting structure 220 includes a first semiconductor layer 222, a second semiconductor layer 223, and an active layer ( 224 and a third semiconductor layer 226.

The first semiconductor layer 222 is composed of a base 222a and a protruding structure 222b on the substrate 210, and a second semiconductor layer 223 is disposed in an upper region of each protruding structure 222b, respectively. The mask 280 is disposed between the protruding structures 222b of, and the conductive layer 240 is disposed along the circumference of the third semiconductor layer 226, and the third semiconductor around each protruding structure 222b A gap filling layer 250 fills the gap between the layers 226, a transparent electrode 260 is disposed on the gap filling layer 250 and the conductive layer 240, and the first semiconductor layer ( A first electrode 290 and a second electrode 295 are disposed on the 222 and the transparent electrode 260, respectively.

The substrate 210 may be formed of a material suitable for growth of a semiconductor material or a carrier wafer, may be formed of a material having excellent thermal conductivity, and may include a conductive substrate or an insulating substrate. For example, at least one of sapphire (Al ₂ O ₃ ), SiO ₂ , SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge, Ga ₂ 0 ₃ may be used.

When the substrate 210 is formed of sapphire or the like, and the light emitting structure 220 including GaN or AlGaN is disposed on the substrate 210, the lattice mismatch between GaN or AlGaN and sapphire is very large. Since the difference in the coefficient of thermal expansion between them is also very large, dislocation, melt-back, crack, pit, and surface morphology defects that deteriorate crystallinity occur. Therefore, a buffer layer (not shown) may be formed of AlN or the like.

Although not shown, an undoped GaN layer or an AlGaN layer is disposed between the buffer layer (not shown) and the light emitting structure 220, so that the above-described electric potential or the like can be prevented from being transferred into the light emitting structure 220.

The light emitting structure 220 includes a first semiconductor layer 222, an active layer 224, and a third semiconductor layer 226.

The first semiconductor layer 222 includes a base layer 222a and a protruding structure 222b, and the base layer 222a may be formed as a thin film on the entire surface of the substrate 210, and the protruding structure 222b A plurality of protruding structures are grown on the silver base layer 222a.

As shown, the side surface of the protruding structure 222b is disposed in a vertical direction from the base layer 222a, and the upper surface is disposed at an obtuse angle with the side surface. In addition, as will be described later, the upper surface of the protruding structure 222b is flat and may be provided at a right angle to the side surface, as in the embodiment illustrated in FIG. 2C.

The protruding structure 222b has a size R in the horizontal direction on a nano scale, but may have a scale of about 10 micrometers in some cases. The size R of the protruding structure 222b in the horizontal direction may be greater than the distance d between the adjacent masks 280, for example, R may be twice or more than d. The above-described distance (d) may be a diameter of an opening between adjacent masks 280 through which the protruding structure 222b can be grown from the base layer 222a.

_{The height h 1} of the base layer 222a in the first semiconductor layer 222 may be 100 nanometers to 10 micrometers, but if it is less than 100 nanometers, it may not be sufficient for the growth of the first semiconductor layer 222. If it is larger than 10 micrometers, the thickness of the light emitting structure 220 may increase too much.

The height h ₂ of the protruding structure 222b and the pitch P between the protruding structure 222b may vary depending on the wavelength and amount of light emitted from the light emitting structure 220.

The protruding structure may have a hexagonal column, circular or polygonal cross section, and each protruding structure may be arranged irregularly in addition to a regular arrangement, and the size or shape of each protruding structure may be the same, but may be different.

In FIG. 2A, although the base layer 222a and the protruding structure 222b are partitioned by a dotted line, they may be made of the same material, and may be grown before and after using the mask 280, respectively.

Each of the masks 280 may be made of an insulating material, may divide the base layer 222a and the protruding structure 222b, and may also divide each protruding structure 222b. The mask 280 may prevent current from leaking to other places when the current flows through the conductive layer 240.

The first semiconductor layer 222 may be implemented as a compound semiconductor such as Group III-V or Group II-VI, and may be a semiconductor layer of a first conductivity type by doping with a first conductivity type dopant. The first semiconductor layer 222 is _{a semiconductor material having a composition formula of Al x} In _y Ga _(1-xy) N (0≤x≤1, 0≤y≤1, 0≤x+y≤1), AlGaN, GaN , InAlGaN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP may be formed of any one or more.

When the first semiconductor layer 222 is an n-type semiconductor layer, the first conductivity-type dopant may include an n-type dopant such as Si, Ge, Sn, Se, and Te. The first semiconductor layer 222 may be formed as a single layer or multiple layers, but is not limited thereto.

The second semiconductor layer 223 may be disposed on the protruding structure 222a, and may be disposed to have a thickness of at least 100 angstroms. The second semiconductor layer 223 may block current from flowing in the upper portion of the protruding structure 222a or allow a smaller amount of current to flow than the side surface, so that current can be evenly supplied through the side surface of the protruding structure 222a. have. _{The thickness (t 1} ) of the second semiconductor layer 230 must be at least 100 angstroms or more to achieve the above-described current blocking effect. Considering the size of the protruding structure 222b, the thickness may not exceed 100 nanometers. have.

The second semiconductor layer 223 may be implemented as a compound semiconductor such as Group III-V, Group II-VI, etc., may be non-conductive, or may be doped with a first conductivity type dopant to form a first conductivity type semiconductor layer or A dopant of the second conductivity type may be doped so that the semiconductor layer of the second conductivity type may have higher resistance. The second semiconductor layer 223 is _{a semiconductor material having a composition formula of Al x} In _y Ga _(1-xy) N (0≤x≤1, 0≤y≤1, 0≤x+y≤1), AlGaN, GaN. , InAlGaN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP may be formed of any one or more, and the resistance of the second semiconductor layer 223 may be greater than the resistance of the first semiconductor layer 222.

The active layer 224 and the third semiconductor layer 226 may be formed as thin films on the upper surface of the second semiconductor layer 223 and the side surface of the protruding structure 222b, and on a partial region of the mask 280, respectively. .

The active layer 224 is disposed on the side surface of the first semiconductor layer 222 and the upper surface of the second semiconductor layer 223, and is a single well structure, a multiple well structure, a single quantum well structure, and a multiple quantum well. It may include any one of a (MQW: Multi Quantum Well) structure, a quantum dot structure, or a quantum line structure.

The active layer 224 is a well layer and a barrier layer, such as AlGaN/AlGaN, InGaN/GaN, InGaN/InGaN, AlGaN/GaN, InAlGaN/GaN, GaAs (InGaAs), using a compound semiconductor material of group III-V element /AlGaAs, GaP (InGaP) / AlGaP may be formed in any one or more pair structure, but is not limited thereto. The well layer may be formed of a material having an energy band gap smaller than the energy band gap of the barrier layer.

The third semiconductor layer 226 may be formed of a semiconductor compound on the surface of the active layer 224. The third semiconductor layer 226 may be implemented as a compound semiconductor such as Group III-V or Group II-VI, and may be doped with a second conductivity type dopant. The third semiconductor layer 226 is, for example, _{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), AlGaN, GaN AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP may be formed of any one or more, for example, the third semiconductor layer 226 may be made _{of Al x} Ga _{(1-x) N.}

The third semiconductor layer 226 may be a second conductivity type semiconductor layer doped with a second conductivity type dopant. When the third semiconductor layer 226 is a p type semiconductor layer, the second conductivity type dopant is Mg, Zn, Ca , Sr, Ba, etc. may be a p-type dopant. The third semiconductor layer 226 may be formed as a single layer or multiple layers, but is not limited thereto.

Although not shown, an electron blocking layer may be disposed between the active layer 224 and the third semiconductor layer 226. The electron blocking layer may have a superlattice structure, for example, AlGaN doped with a second conductivity type dopant may be disposed, and GaN having a different composition ratio of aluminum is formed as a layer. A plurality of them may be arranged alternately with each other.

A conductive layer 240 may be disposed on the mask 280 and around each of the third semiconductor layers 226, and the conductive layer 240 is a transparent conductive material, for example, Indium-Tin-Oxide (ITO). ), etc.

A gap filling layer 250 is disposed while filling a gap between the conductive layers 240 disposed around each of the protruding structures 222b, and the gap filling layer 250 is made of an insulating material or a conductive material. If the gap filling layer 250 is made of an insulating material, the insulating material may be made of a non-conductive oxide or nitride, and more specifically, a silicon oxide (SiO ₂ ) layer, an oxynitride layer, and an aluminum oxide layer. In this case, the current supplied from the second electrode 295 may be concentrated to the surface of the third semiconductor layer 226 through the conductive layer 240.

A transparent conductive layer 260 is disposed on the gap filling layer 250, and a part of the transparent conductive layer 260 may contact the conductive layer 240 disposed on the protruding structure 222b. That is, a side surface of the conductive layer 240 may contact the gap filling layer 260, but a portion of the conductive layer 240, particularly an upper region, may contact the transparent conductive layer 260.

A gap-filling layer 250 is formed between the protruding structures 222b to stably support a nano-scale or micro-scale protruding structure, and a transparent conductive layer 260 on top of the protruding structure 222b and the gap-filling layer 250 Is formed to stably support the second electrode 295.

The first electrode 290 may be formed in a region of the first semiconductor layer 222 in which a part of the base layer 222a is exposed. The first electrode 290 and the second electrode 295 include at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au). Alternatively, it may be formed in a multi-layered structure, and each may be connected to a wire (not shown).

When forming an electrode on the protruding structure, due to the aspect ratio of the protruding structure, it is difficult to supply current to the entire area of the protruding structure, especially because current is concentrated from the second electrode to the upper part of the protruding structure.

In the light emitting device according to the present embodiment, a second semiconductor layer having high resistance is disposed on the top of the protruding structure, and as shown in FIG. The combination is active and light can be emitted. Accordingly, it is possible to solve a problem in which light emission is concentrated in the upper region of the protruding structure in the related art.

The light emitting device 200b according to the embodiment shown in FIG. 2C is similar to the embodiment shown in FIG. 2A, but the upper surface of the protruding structure 222b is flat and is provided at a right angle to the side surface.

FIG. 3A is a view showing a third embodiment of a light emitting device, and FIG. 3B is a view showing a region'B' of FIG. 3A in detail.

The light emitting device 200c according to the present embodiment is similar to the embodiment shown in FIG. 2A, but the second semiconductor layer is omitted, and the conductive layer 240 is formed of the first conductive layer 240a and the second conductive layer 240b. It is different in that it consists of ).

Since the second semiconductor layer is omitted, the active layer 224 is disposed on the side surface and the upper surface of the protruding structure 222b of the first semiconductor layer 222. In addition, the first conductive layer 240a may be disposed to correspond to the lower region of the protruding structure 222b, and the second conductive layer 240b may be disposed to correspond to the upper region of the protruding structure 222b. That is, the first conductive layer 240a is disposed to correspond to the side surface of the third semiconductor layer 226, and the second conductive layer 240b is disposed to correspond to an inclined region above the third semiconductor layer 226. Can be.

The first conductive layer 240a is disposed in contact with the gap filling layer 250, and the second conductive layer 240b is disposed in contact with the gap filling layer 250 and the transparent electrode 260, respectively.

The first conductive layer 240a and the second conductive layer 240b may be made of a transparent conductive material, for example, Indium-Tin-Oxide (ITO), and the resistance of the first conductive layer 240a is the second conductive layer. It may be smaller than the resistance of the layer 240b, and more conductive dopants may be included in the first conductive layer 240a.

Therefore, more current may flow to the side of the protruding structure than the upper side of the protruding structure, and as shown in FIG. 3B, light is emitted because electrons and holes are actively combined in the active layer disposed on the side rather than the active layer disposed on the top of the protruding structure. Can be. Accordingly, it is possible to solve a problem in which light emission is concentrated in the upper region of the protruding structure in the related art.

3C is a view showing a fourth embodiment of a light emitting device.

The light emitting device 200d according to the embodiment shown in FIG. 3C is similar to the embodiment shown in FIG. 3A, but the top surface of the protruding structure 222b is flat and is provided at a right angle to the side surface, and the first conductive layer ( 240a) corresponds to the side surface of the protruding structure 222b perpendicular to the base layer 222a and is disposed in contact, and the second conductive layer 240b corresponds to the flat upper surface of the protruding structure 2220b and is disposed in contact. Has become. In addition, the first conductive layer 240a may be disposed in contact with the gap filling layer 250 and the transparent electrode 260, and the second conductive layer 240b may be disposed in contact with the transparent electrode 260. .

3D is a view showing a fifth embodiment of a light emitting device.

The light emitting device 200e according to the embodiment shown in FIG. 3D is similar to the embodiment shown in FIG. 3A, except that the first conductive layer 240a and the second conductive layer 240b are made of the same material. In addition, since the thickness t _{1 of} the first conductive layer 240a is thicker than the thickness t ₂ of the second conductive layer 240b, the resistance of the first conductive layer 240a is May be less than the resistance.

Accordingly, as in the above-described embodiment shown in FIGS. 3A and 3C, more current may flow toward the side of the protruding structure, and the bonding of electrons and holes in the active layer disposed on the side rather than the active layer disposed on the protruding structure. This is done actively so that more light can be emitted.

3E is a diagram showing a light emitting device according to a sixth embodiment.

The light emitting device 200f according to this embodiment is similar to the embodiment shown in FIG. 3A, but there is a difference in that the metal layer 215 is disposed between the substrate 210 and the base layer 222a. That is, a non-conductive glass can be used as the substrate 210, and at this time, a metal layer 215 is formed on the substrate 210 and the light emitting structure 220 is grown as a nitride-based semiconductor layer on the metal layer 215. I can make it. In this embodiment, the non-conductive glass is used as the substrate 210 and the metal layer 215 is formed between the substrate 210 and the light emitting structure 220. Can be applied.

In the above-described embodiments, the protruding structure may have a hexagonal column or a circular or polygonal cross section, and each protruding structure may be arranged irregularly in addition to a regular arrangement, and the size or shape of each protruding structure may be the same. However, it may be different.

4 is a view showing an embodiment of a light emitting device package in which the light emitting device is disposed.

The light emitting device package 300 according to the embodiment includes a body 310 including a cavity, a first lead frame 321 and a second lead frame 322 installed on the body 310, and the body The light emitting device 200 according to the above-described embodiments installed on the first lead frame 321 and the second lead frame 322 and electrically connected to the first lead frame 321 and the second lead frame 322, and a molding part 350 formed in the cavity. ).

The body 310 may be formed of a silicon material, a synthetic resin material, or a metal material. When the body 310 is made of a conductive material such as a metal material, although not shown, an insulating layer is coated on the surface of the body 310 to prevent an electrical short between the first and second lead frames 321 and 322. I can.

The first lead frame 321 and the second lead frame 322 are electrically separated from each other and supply current to the light emitting device 200. In addition, the first lead frame 321 and the second lead frame 322 may reflect light generated from the light emitting device 200 to increase light efficiency, and transfer heat generated from the light emitting device 200 to the outside. It can also be discharged.

The light emitting device 200 may be a light emitting device according to the embodiment shown in 200a to 200f described above.

The light emitting device 200 may be fixed to the first lead frame 321 with a conductive paste 330 or the like, and the electrode of the light emitting device 200 may be bonded to the second lead frame with a wire 290.

The molding part 350 may surround and protect the light emitting device 200. In addition, a phosphor 360 may be included on the molding part 350. In this structure, since the phosphors 360 are distributed, the wavelength of light emitted from the light emitting device 200 can be converted in the entire area where the light is emitted from the light emitting device package 300.

The light emitting device package 300 may be mounted as one or a plurality of light emitting devices according to the above-described embodiments, but is not limited thereto.

Hereinafter, as an embodiment of a lighting system in which the above-described light emitting device package is disposed, an image display device and a lighting device will be described.

5 is a diagram showing an embodiment of an image display device in which a light emitting device is disposed.

As shown, the image display device 500 according to the present embodiment includes a light source module, a reflector 520 on the bottom cover 510, and light emitted from the light source module disposed in front of the reflector 520. The first prism sheet 550 and the second prism sheet 560 and the second prism sheet 560 disposed in front of the light guide plate 540 to guide the image display device in front of the light guide plate 540 It includes a panel 570 disposed in front and a color filter 580 disposed in the entirety of the panel 570.

The light source module includes a light emitting device package 535 on the circuit board 530. Here, the circuit board 530 may be a PCB or the like, and the light emitting device of the light emitting device package 535 is as described above.

The bottom cover 510 may accommodate components in the image display device 500. The reflector 520 may be provided as a separate component as shown in this drawing, or may be provided in a form coated with a material having high reflectivity on the rear surface of the light guide plate 540 or the front surface of the bottom cover 510.

The reflector 520 may use a material that has high reflectivity and can be used in an ultra-thin type, and may use polyethylene terephtalate (PET).

The light guide plate 540 scatters light emitted from the light emitting device package module so that the light is uniformly distributed over the entire screen area of the liquid crystal display. Accordingly, the light guide plate 530 is made of a material having a good refractive index and transmittance, and may be formed of polymethylmethacrylate (PMMA), polycarbonate (PC), or polyethylene (PolyEthylene; PE). In addition, when the light guide plate 540 is omitted, an air guide type display device may be implemented.

The first prism sheet 550 is formed of a light-transmitting and elastic polymer material on one surface of the support film, and the polymer may have a prism layer in which a plurality of three-dimensional structures are repeatedly formed. Here, the plurality of patterns may be repeatedly provided in a stripe type of floors and valleys as shown.

In the second prism sheet 560, a direction of a floor and a valley on one side of the support film may be perpendicular to a direction of a floor and a valley on one surface of the support film in the first prism sheet 550. This is to evenly distribute the light transmitted from the light source module and the reflective sheet in all directions of the panel 570.

In this embodiment, the first prism sheet 550 and the second prism sheet 560 form an optical sheet, and the optical sheet is formed of a different combination, for example, a microlens array, or a diffusion sheet and a microlens array. It may be made of a combination or a combination of a single prism sheet and a micro lens array.

The panel 570 may include a liquid crystal display. In addition to the liquid crystal display panel 560, other types of display devices requiring a light source may be provided.

The panel 570 is in a state in which a liquid crystal is placed between the glass bodies and a polarizing plate is placed on both glass bodies in order to utilize the polarization of light. Here, the liquid crystal has an intermediate characteristic between a liquid and a solid, and the liquid crystal, which is an organic molecule having fluidity like a liquid, has a state that is regularly arranged like a crystal, and the molecular arrangement is changed by an external electric field. Display an image.

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

A color filter 580 is provided on the front surface of the panel 570 to transmit light projected from the panel 570 and transmit only red, green, and blue light for each pixel, thereby displaying an image.

6 is a view showing an embodiment of a lighting device in which a light emitting device is disposed.

The lighting device according to the present embodiment may include a cover 1100, a light source module 1200, a radiator 1400, a power supply unit 1600, an inner case 1700, and a socket 1800. In addition, the lighting device according to the embodiment may further include any one or more of the member 1300 and the holder 1500, and the light source module 1200 may include a light emitting device package according to the above-described embodiments. .

The cover 1100 has a shape of a bulb or a hemisphere, is hollow, and may be provided in an open shape. The cover 1100 may be optically coupled to the light source module 1200. For example, the cover 1100 may diffuse, scatter, or excite light provided from the light source module 1200. The cover 1100 may be a kind of optical member. The cover 1100 may be coupled to the radiator 1400. The cover 1100 may have a coupling portion coupled to the radiator 1400.

A milky white paint may be coated on the inner surface of the cover 1100. The milky white paint may include a diffuser that diffuses light. The surface roughness of the inner surface of the cover 1100 may be greater than the surface roughness of the outer surface of the cover 1100. This is to allow the light from the light source module 1200 to be sufficiently scattered and diffused to be emitted to the outside.

The material of the cover 1100 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 1100 may be transparent or opaque so that the light source module 1200 can be seen from the outside. The cover 1100 may be formed through blow molding.

The light source module 1200 may be disposed on one surface of the radiator 1400. Accordingly, heat from the light source module 1200 is conducted to the radiator 1400. The light source module 1200 may include a light emitting device package 1210, a connection plate 1230, and a connector 1250.

The member 1300 is disposed on the upper surface of the radiator 1400 and has guide grooves 1310 into which a plurality of light emitting device packages 1210 and a connector 1250 are inserted. The guide groove 1310 corresponds to the substrate and the connector 1250 of the light emitting device package 1210.

The surface of the member 1300 may be coated or coated with a light reflective material. For example, the surface of the member 1300 may be coated or coated with a white paint. The member 1300 reflects light reflected on the inner surface of the cover 1100 and returned toward the light source module 1200 toward the cover 1100. Therefore, it is possible to improve the light efficiency of the lighting device according to the embodiment.

The member 1300 may be made of an insulating material, for example. The connection plate 1230 of the light source module 1200 may include an electrically conductive material. Accordingly, electrical contact may be made between the radiator 1400 and the connection plate 1230. The member 1300 is made of an insulating material to block an electrical short between the connection plate 1230 and the radiator 1400. The radiator 1400 receives heat from the light source module 1200 and heat from the power supply unit 1600 to radiate heat.

The holder 1500 blocks the receiving groove 1919 of the insulating part 1710 of the inner case 1700. Accordingly, the power supply unit 1600 accommodated in the insulating unit 1710 of the inner case 1700 is sealed. The holder 1500 has a guide protrusion 1510. The guide protrusion 1510 has a hole through which the protrusion 1610 of the power supply unit 1600 passes.

The power supply unit 1600 processes or converts an electrical signal provided from the outside and provides it to the light source module 1200. The power supply unit 1600 is accommodated in the storage groove 1719 of the inner case 1700 and is sealed inside the inner case 1700 by the holder 1500. The power supply unit 1600 may include a protrusion 1610, a guide unit 1630, a base 1650, and an extension 1670.

The guide part 1630 has a shape protruding outward from one side of the base 1650. The guide part 1630 may be inserted into the holder 1500. A number of parts may be disposed on one surface of the base 1650. A number of components include, for example, a DC converter that converts AC power provided from an external power source to DC power, a driving chip that controls driving of the light source module 1200, and an ESD for protecting the light source module 1200. (ElectroStatic discharge) may include a protection element, but is not limited thereto.

The extension part 1670 has a shape protruding outward from the other side of the base 1650. The extension part 1670 is inserted into the connection part 1750 of the inner case 1700 and receives an electrical signal from the outside. For example, the extension part 1670 may be provided equal to or smaller than the width of the connection part 1750 of the inner case 1700. Each end of the "+ wire" and "- wire" may be electrically connected to the extension part 1670, and the other end of the "+ wire" and "- wire" may be electrically connected to the socket 1800. .

The inner case 1700 may include a molding unit together with the power supply unit 1600 therein. The molding part is a part where the molding liquid is hardened, and allows the power supply part 1600 to be fixed inside the inner case 1700.

Although the embodiments have been described above, these are only examples and do not limit the present invention, and those of ordinary skill in the field to which the present invention belongs are not exemplified above without departing from the essential characteristics of the present embodiment. It will be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention defined in the appended claims.

100, 200, 200a~200f: light emitting device 210: substrate
115: metal layer 220: light emitting structure
222: first semiconductor layer 222a: base layer
222b: protruding structure 223: second semiconductor layer
224: active layer 226: third semiconductor layer
240: conductive layer 240a: first conductive layer
240b: second conductive layer 250: gap filling layer
260: transparent electrode 280: mask
290: first electrode 295: second electrode
400: light emitting device package 500: image display device

Claims (10)

Board;
A plurality of protruding structures disposed on the substrate and including a first semiconductor layer;
A second semiconductor layer formed in an upper region of at least a portion of each of the protruding structures;
An active layer and a third semiconductor layer disposed on side surfaces and upper surfaces of each of the protruding structures; And
Including a conductive layer disposed along the circumference of the third semiconductor layer,
The resistance of the second semiconductor layer is greater than the resistance of the first semiconductor layer,
The side surface of the first semiconductor layer directly contacts the active layer, the upper surface of the first semiconductor layer directly contacts the lower surface of the second semiconductor layer, and the upper surface and the side surface of the second semiconductor layer directly contact the active layer and,
The thickness of the second semiconductor layer in the vertical direction is constant,
A light emitting device in which a height of a central region of the upper surface of the first semiconductor layer is higher than that of an edge region. delete The method of claim 1,
The second semiconductor layer has a thickness of at least 100 angstroms to 100 nanometers. delete delete delete delete The method according to claim 1 or 3,
A light emitting device further comprising a gap filling layer filling a gap between each of the third semiconductor layers. delete The method according to claim 1 or 3,
The substrate is made of glass and further comprises a metal layer disposed between the substrate and the protruding structure.

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