KR101904044B1 - Light-emitting device - Google Patents

Abstract

The light emitting device includes a substrate including m-plane sapphire, a light emitting structure including m-plane GaN formed on m-plane sapphire, a light emitting structure formed between m-plane sapphire and m-plane GaN, ) ≪ / RTI > nitride layer.

Description

Light-emitting device

An embodiment relates to a light emitting element.

Light-emitting diodes (LEDs) are semiconductor light-emitting devices that convert current into light.

Semiconductor light emitting devices are widely used as light sources for displays, light sources for automobiles, and light sources because they can obtain light having high luminance.

The light emitting device is made by growing a semiconductor layer on a substrate, which causes defects due to lattice mismatch between the substrate and the semiconductor layer.

The embodiment provides a light emitting device capable of mitigating lattice mismatch to prevent defects.

The embodiment provides a light emitting device capable of stably growing a light emitting structure.

Embodiments provide a light emitting device having improved physical and electrical characteristics.

The embodiment provides a light emitting device having improved internal light emitting efficiency.

According to an embodiment, the luminous means comprises a substrate comprising m-plane sapphire; A light emitting structure including m-plane GaN formed on the m-plane sapphire; And a buffer layer formed between the m-plane sapphire and the m-plane GaN and including a nitride series having a salt structure (NaCl).

In the embodiment, a buffer layer made of a nitride-based nitride structure is formed between a substrate including m-plane sapphire and a light-emitting structure including m-plane GaN, so that defects are not generated in the semiconductor layer, and stable growth is possible.

1 is a cross-sectional view illustrating a light emitting device according to an embodiment.
2 is a diagram showing a crystal structure of sapphire used as a substrate.
3 is a diagram showing a crystal structure of GaN used as a light emitting structure.
4 is a diagram showing lattice constants of m-plane GaN.
5A and 5B are views showing an embodiment of a rock salt structure.
6 is a diagram showing the lattice mismatch between the substrate, the buffer layer and the light emitting structure.
7 is a cross-sectional view illustrating a horizontal light emitting device according to an embodiment.
8 is a cross-sectional view illustrating a flip-type light emitting device according to an embodiment.
9 is a cross-sectional view illustrating a vertical light emitting device according to an embodiment.
10 is an exploded perspective view of a display device according to an embodiment.
11 is a view showing a display device having a light emitting element according to an embodiment.
12 is a perspective view of a lighting apparatus according to an embodiment.

In describing an embodiment according to the invention, in the case of being described as being formed "above" or "below" each element, the upper (upper) or lower (lower) Directly contacted or formed such that one or more other components are disposed between the two components. Also, in the case of "upper (upper) or lower (lower)", it may include not only an upward direction but also a downward direction based on one component.

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

Referring to FIG. 1, a light emitting device 1 according to an embodiment may include a substrate 11 and a light emitting structure 20 formed on the substrate 11.

The light emitting structure 20 may include a first conductive semiconductor layer 15, an active layer 17, and a second conductive semiconductor layer 19.

The substrate 11 may be formed of a material having excellent thermal conductivity and / or transparency, but the present invention is not limited thereto. For example, the substrate 11 may be formed of at least one selected from the group consisting of sapphire (Al ₂ O ₃ ), SiC, Si, GaAs, GaN, ZnO, Si, GaP, InP and Ge .

A difference in lattice constant occurs between the substrate 11 and the light emitting structure 20 and cracks, voids, grains, and the like are generated due to lattice mismatch due to the difference in lattice constant. And defects such as bowing may occur.

In an embodiment, a buffer layer 12 may be formed between the substrate and the light emitting structure 20, specifically, the first conductivity type semiconductor layer 15 to mitigate such lattice mismatch.

The buffer layer 12 may be formed of a material having a lattice constant between the lattice constant of the substrate and the lattice constant of the light emitting structure 20.

The light emitting structure 20 may be formed of a Group III and V compound semiconductor material, but the present invention is not limited thereto. The compound semiconductor material may include, for example, Al, In, Ga, and N, but is not limited thereto.

The light emitting structure 20 may be formed by a metal organic chemical vapor deposition (MOCVD) method, a chemical vapor deposition (CVD) method, a plasma enhanced chemical vapor deposition (PECVD) method, a molecular beam epitaxy (Molecular Beam Epitaxy) and HVPE (Hydride Vapor Phase Epitaxy).

The first conductivity type semiconductor layer 15, the active layer 17 and the second conductivity type semiconductor layer 19 are successively grown on the buffer layer 12 by MOCVD to form a light emitting structure (20) may be formed.

When the light emitting structure 20 is grown without defects by the buffer layer 12, the electrical and optical characteristics of the light emitting device 1 manufactured by the light emitting structure 20 are improved and the light efficiency is increased have.

Therefore, in order to grow the light emitting structure 20 having a good crystallinity on the substrate 11, it is very important to reduce the difference in lattice constant with respect to the substrate 11 preferentially.

As shown in Fig. 2, sapphire is most stable in a hexagonal wurtzite crystal structure. These crystal structures have three base planes axes (a1, a2, a3) that are 120 ㅀ rotational symmetry with respect to each other and are all perpendicular to the vertical c-axis.

The c-plane 110 is formed along the c-axis, and the a-plane 130 and the m-plane 120 are formed perpendicular to the c-plane.

In addition, the r-plane 140, which is tilted diagonally in contact with the m-plane 120 at the base, may be formed.

As shown in Fig. 3, GaN is also stable in a wurtzite crystal structure.

The c-plane 210 may be formed along the c-axis and the a-plane 230 and the m-plane 220 may be formed perpendicular to the c-plane 210.

In the embodiment, the substrate may be formed of, for example, m-plane sapphire whose upper surface has an m-plane, and the light emitting structure 20, that is, the first conductive semiconductor layer 15, the active layer 17, The two-conductivity-type semiconductor layer 19 may be formed of m-plane GaN grown in the m-plane on the m-plane of the sapphire, but the invention is not limited thereto.

The m-plane sapphire can have a lattice constant of 4.765A in the a-axis direction and a lattice constant of 13.001A in the c-axis direction.

On the other hand, as shown in FIG. 4, the m-plane GaN can have a lattice constant of 3.189 angstroms in the a-axis direction and a lattice constant of 5.189 angstroms in the c-axis direction.

In this case, between the m-plane GaN and the m-plane sapphire, the m-plane GaN has a lattice mismatch of 8.23% with respect to the a-axis direction of the m-plane sapphire, Lt; / RTI > may have a lattice mismatch of -1.92%.

Therefore, since the lattice mismatch between the m-plane GaN and the m-plane sapphire is relatively small, the light emitting structure 20 including the m-plane GaN grown on the substrate including the m-plane sapphire can be stably grown , Electrical and optical characteristics and light efficiency can be improved.

However, the electrical and optical characteristics and the light efficiency are still not remarkably improved.

The embodiment is characterized in that the buffer layer 12 made of a nitride series of a salt structure is formed between the substrate including the m-plane sapphire and the light emitting structure 20 including the m-plane GaN so that the electrical and optical characteristics and the light efficiency Can be remarkably improved.

5A and 5B are views showing an embodiment of a rock salt structure.

The ceramic structure has the same number of cations and anions, and these materials are called AX type compounds. A represents a cation, and X represents an anion.

There are various crystal structures in the AX compound. The rock salt structure is a structure in which the anion forms an FCC structure and all the octahedral sites are filled with cations as shown in FIG. 5A.

As shown in FIG. 5B, the rock salt structure is a structure in which an octahedron composed of a cation forms the edge of the octahedron.

In the FCC structure formed by anions, the number of octahedral sites is the number of anions, and the formula is defined as AX.

The compound having a salt structure may include NaCl, KCl, LiF, MgO, CaO, SrO, NiO, CoO, MnO, PbO, LaN, ThN, PrN, NdN, SmN and the like.

The embodiment can form the buffer layer 12 in the nitride system among the compounds having the salt salt structure.

For example, the buffer layer 12 may be formed to include one selected from the group consisting of LaN, ThN, PrN, NdN, and SmN, but is not limited thereto.

Table 1 shows the sizes of the compounds of the salt salt structure.

compound Cell size (Å) a / 2 ^ 0.5 LaN 5.301 3.74894 ThN 5.2 3.67751 PrN 5.155 3.64569 NdN 5.151 3.64286 SmN 5.0481 3.57008

When the buffer layer 12 is formed with such a compound, the lattice mismatch between the substrate including m-sapphire and the light-emitting structure 20 including m-plane GaN can be remarkably reduced by the buffer layer 12 have.

6 is a diagram showing the lattice mismatch between the substrate, the buffer layer and the light emitting structure.

The substrate 11 is an m-plane sapphire whose top surface is m-plane and the light emitting structure 20 is an m-plane GaN crystal grown on the m-plane of the m-plane sapphire, But is not limited thereto.

As the buffer layer 12, a nitride series of a salt structure including one selected from the group consisting of LaN, ThN, PrN, NdN, and SmN may be used.

The size of each nitride series may range from 5.0481 A (SmN) to 5.301 A (LaN).

In this case, the lattice mismatch between the substrate, the buffer layer 12 and the light emitting structure 20 is as follows.

When LaN is used as the buffer layer 12, LaN may have a lattice mismatch at 10.24% in the a-axis direction with m-plane sapphire, and a lattice mismatch at 8.05% in the c-axis direction. The m-plane GaN can have a lattice mismatch of 0.26% in the a-axis direction with LaN and a lattice mismatch of -2.24% in the c-axis direction.

When ThN is used as the buffer layer 12, ThN may have lattice mismatch of 8.5% in the a-axis direction with m-plane sapphire and 6.26% lattice mismatch in the c-axis direction. The m-plane GaN can have a lattice mismatch of 2.16% in the a-axis direction with ThN and a lattice mismatch of -0.29% in the c-axis direction.

When PrN is used as the buffer layer 12, PrN can have a lattice mismatch of 7.44% in the a-axis direction with m-plane sapphire and a lattice mismatch of 5.44% in the c-axis direction. The m-plane GaN can have a lattice mismatch of 3.01% in the a-axis direction with PrN and a lattice mismatch of 0.58% in the c-axis direction.

When NdN is used as the buffer layer 12, NdN can have a lattice mismatch of 7.62% in the a-axis direction with m-plane sapphire and a lattice mismatch of 5.37% in the c-axis direction. The m-plane GaN can have a lattice mismatch of 3.08% in the a-axis direction with NdN and a lattice mismatch of 0.66% in the c-axis direction.

When SmN is used as the buffer layer 12, SmN may have a lattice mismatch of 5.44% in the a-axis direction with m-plane sapphire and a lattice mismatch of 3.44% in the c-axis direction. The m-plane GaN can have a lattice mismatch of 5.02% in the a-axis direction with SmN and a lattice mismatch of 2.64% in the c-axis direction.

As described above, since the buffer layer 12 including nitride is formed between the substrate including the m-plane sapphire and the light emitting structure 20 including the m-plane GaN, Direction and the lattice mismatch of 8% or less in the c-axis direction.

In particular, the lattice mismatch of the m-plane GaN-containing light emitting structure 20 with respect to the buffer layer 12 is 5.02% or less in the a-axis direction and 2.64% or less in the c-axis direction. This is because the lattice mismatch of the m-plane GaN light emitting structure 20 on the buffer layer 12 is very low, so that the crystal growth is remarkably excellent and the electrical and optical characteristics and the light efficiency can be remarkably improved.

The light emitting structure 20 may include a first conductive semiconductor layer 15, an active layer 17, and a second conductive semiconductor layer 19.

Although the first conductivity type semiconductor layer 15, the active layer 17, and the second conductivity type semiconductor layer 19 may be grown to have m-planes on their upper surfaces, the present invention is not limited thereto.

The first conductive semiconductor layer 15 may be formed on the buffer layer 12. The first conductivity type semiconductor layer 15 may be, for example, an n-type semiconductor layer including an n-type dopant. The n-type semiconductor layer may be formed of 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, InAlGaN, GaN, AlGaN, InGaN, AlN, InN and AlInN, and may be doped with an n-type dopant such as Si, Ge or Sn.

The first conductive semiconductor layer 15 serves as a conductive layer for supplying a first carrier such as electrons to the active layer 17 and a second carrier of the active layer 17, (not shown) to prevent the holes from being transferred to the buffer layer 12.

By doping the first conductivity type semiconductor layer 15 with a high-concentration dopant, electrons can act as a conductive layer which can move freely.

The first conductive semiconductor layer 15 is formed of a compound semiconductor material having a bandgap equal to or larger than that of the active layer 17 so that the barrier layer 12 prevents the holes of the active layer 17 from being transferred to the buffer layer 12. [ And the like.

The first conductive semiconductor layer 15 may be grown from the buffer layer 12 so that the upper surface thereof has an m-plane, but the present invention is not limited thereto.

The active layer 17 may be formed on the first conductive semiconductor layer 15.

The active layer 17 may emit light by recombining electrons supplied from the first conductivity type semiconductor layer 15 and holes supplied from the second conductivity type semiconductor layer 19, for example. The active layer 17 must have at least a wide band gap for the generation of light.

The active layer 17 may include any one of a single quantum well structure (SQW), a multiple quantum well structure (MQW), a quantum dot structure, and a quantum wire structure.

The active layer 17 may be formed of one or a periodic repetition of one selected from GaN, InGaN, AlGaN, and AlInGaN.

The active layer 17 may be grown from the first conductivity type semiconductor layer 15 so that its top surface has an m-plane, but the present invention is not limited thereto.

The second conductive semiconductor layer 19 may be formed on the active layer 17. The second conductive semiconductor layer 19 may be, for example, a p-type semiconductor layer including a p-type dopant. The p-type semiconductor layer may be 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, InAlGaN, GaN, AlGaN, InGaN, AlN, InN and AlInN, and may be doped with a p-type dopant such as Mg, Zn, Ca, Sr or Ba.

The second conductivity type semiconductor layer 19 is doped with a high concentration dopant, so that the second conductivity type semiconductor layer 19 can serve as a conductive layer capable of moving the holes freely.

The second conductive semiconductor layer 19 may be grown from the active layer 17 so that the upper surface thereof has an m-plane, but the present invention is not limited thereto.

The light emitting structure 20 may be formed of the first conductive semiconductor layer 15, the active layer 17, and the second conductive semiconductor layer 19.

Although not shown, a transparent electrode layer may be formed on the second conductive semiconductor layer 19. The transparent electrode layer may be formed of ITO, IZO (In-ZnO), GZO (Ga-ZnO), AZO (Al- ZnO) , Ni / IrOx / Au, and Ni / IrOx / Au / ITO.

A reflective electrode layer (not shown) may be formed instead of the transparent electrode layer. The reflective electrode layer may include at least one selected from the group consisting of silver (Ag), aluminum (Al), platinum (Pt), and palladium (Pd) having high reflection efficiency.

7 is a cross-sectional view illustrating a horizontal light emitting device according to an embodiment.

7, the horizontal light emitting device 10A according to the embodiment may be mesa etched until the first conductive semiconductor layer 15 in the light emitting device 1 of FIG. 1 has a predetermined depth . Thus, the first conductivity type semiconductor layer 15 can be exposed.

A transparent electrode layer 27 is formed on the second conductivity type semiconductor layer 19 for current spreading and a first electrode 31 is formed on the first conductivity type semiconductor layer 15, The second electrode 33 may be formed on the second electrode 27.

If current spreading is not required, the transparent electrode layer 27 may not be formed. In this case, the second electrode 33 may be formed on the second conductive semiconductor layer 19.

The transparent electrode layer 27 may be formed of a material having excellent transparency so that light is emitted to the outside. The transparent electrode layer 27 may be formed of a material such as ITO, IZO (In - ZnO), GZO (Ga - ZnO), AZO (Al - ZnO), AGZO (Al - Ga ZnO), IGZO RuOx, RuOx / ITO, Ni / IrOx / Au, and Ni / IrOx / Au / ITO. However, the present invention is not limited thereto.

The first and second electrodes 31 and 33 may be formed of a material having excellent electrical conductivity. The first and second electrodes 31 and 33 may include at least one selected from the group consisting of Au, Ti, Ni, Cu, Al, Cr, Ag, and Pt or an alloy thereof.

In order to mitigate lattice mismatch, the horizontal light emitting device 10A according to the embodiment is formed with a buffer layer 12 including a nitride-based nitride structure, and a light emitting structure 20 including m-plane GaN is formed thereon It is possible to improve the crystallinity of the light emitting structure 20 including the first conductivity type semiconductor layer 15, the active layer 17 and the second conductivity type semiconductor layer 19 to improve the light efficiency, The characteristics can be improved.

8 is a cross-sectional view illustrating a flip-type light emitting device according to an embodiment.

As shown in Fig. 8, the flip-type light emitting device 10B according to the embodiment is obtained by inverting the horizontal light emitting device 1 of Fig. 7 by 180 degrees and replacing the transparent electrode layer 27 of the horizontal light emitting device 10B By forming the reflective electrode layer 29, its fabrication can be completed.

When the light generated in the active layer 17 propagates downward, the reflective electrode layer 29 reflects the light and proceeds in the upward direction to improve the light extraction efficiency.

The reflective electrode layer 29 may be formed of a metal material having excellent conductivity and reflectivity and may be selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Or alloys thereof, but are not limited thereto.

In the flip-type light emitting device 10B according to the embodiment, a buffer layer 12 including a nitride-based nitride structure is formed to relieve lattice mismatch, and a light emitting structure 20 including m-plane GaN is formed thereon It is possible to improve the crystallinity of the light emitting structure 20 including the first conductivity type semiconductor layer 15, the active layer 17 and the second conductivity type semiconductor layer 19 to improve the light efficiency and improve the electrical characteristics and optical characteristics Can be improved.

9 is a cross-sectional view illustrating a vertical light emitting device according to an embodiment.

A channel layer 43, a reflection electrode layer 45, a bonding layer 47, and a conductive support member (not shown) are formed on the second conductivity type semiconductor layer 19 in the light emitting element 1 of Fig. 49 are formed and turned 180 degrees, and then the substrate 11 can be removed. Then, the side surface of the light emitting structure 20 may be formed obliquely through the mesa etching. A protective layer 51 is formed on the side surface of the light emitting structure 20 and the upper surface of the channel layer 43 and on the upper surface of the light emitting structure 20 to protect the light emitting structure 20, Electrodes 53 may be formed on the semiconductor layer 15. In this way, the vertical light emitting device 10C according to the embodiment can be manufactured.

The reflective electrode layer 45 may be formed of a material having a conductive property to supply power to the light emitting structure 20 while having a reflection characteristic for reflecting light.

The reflective electrode layer 45 may be formed of at least one selected from the group consisting of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au and Hf, It is not limited.

The conductive support member 49 is formed of a conductive material through which electricity can flow, and may be formed of at least one selected from the group consisting of Cu, Au, Ni, Mo, and Cu-W, but the present invention is not limited thereto.

The protective layer 51 may be formed of the same material as the channel layer 43, but is not limited thereto.

The channel layer 43 and the passivation layer 51 may be formed of one of oxide, nitride, and insulating material. The channel layer 43 and the protective layer 51 is, for example, ITO, IZO, IZTO, IAZO , IGZO, IGTO, AZO, ATO, GZO, SiO 2, SiO x, SiO x N y, Si 3 N 4, Al ₂ O ₃ , and TiO ₂ .

The electrode 53 may be formed of a material having excellent electrical conductivity. The electrode 53 may include at least one selected from the group consisting of Au, Ti, Ni, Cu, Al, Cr, Ag, and Pt, or an alloy thereof.

On the other hand, the current blocking layer 41 may be formed to overlap with the electrode 53 in the vertical direction to prevent concentration of the current in the vertical direction.

The current blocking layer 41 may be formed of the same material as the protective layer 51 and the channel layer 43, but the present invention is not limited thereto.

Although the buffer layer 12 is not shown in the vertical light emitting device 10C according to the embodiment. This is because the buffer layer 12 is also removed when the substrate 11 is removed to fabricate the vertical light emitting device 10C as described above.

In order to minimize the lattice mismatching, the buffer layer 12 is formed on the buffer layer 12 including the nitride based nitride layer to minimize the lattice mismatch. Thus, the first conductive semiconductor layer The light emitting structure 20 including the first conductive semiconductor layer 15, the active layer 17, and the second conductive semiconductor layer 19 can be improved in crystallinity to improve light efficiency and improve electrical characteristics and optical characteristics.

The light emitting device 10 according to the embodiment can be applied to a light unit. The light unit includes a structure in which a plurality of light emitting elements 10 are arrayed. The light unit includes the display apparatus shown in Figs. 8 and 9 and the illumination apparatus shown in Fig. 10, and includes a lighting lamp, a traffic light, a vehicle headlight, , And an indicator light.

10 is an exploded perspective view showing a display device according to an embodiment.

10, the display apparatus 1000 according to the first embodiment includes a light guide plate 1041, a light emitting module 40 for providing light to the light guide plate 1041, An optical sheet 1051 on the light guide plate 1041, a display panel 1061 on the optical sheet 1051, the light guide plate 1041, a light emitting module 40, and a reflection member 1022 But the present invention is not limited thereto.

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 diffuses the light from the light emitting module 40 to convert the light into a surface light source. The light guide plate 1041 may be made of a transparent material such as acrylic resin such as polymethyl methacrylate (PET), polyethylene terephthalate (PET), polycarbonate (PC), cycloolefin copolymer (COC), and polyethylene naphthalate Resin. ≪ / RTI >

The light emitting module 40 is disposed on at least one side of the light guide plate 1041 to provide light to at least one side of the light guide plate 1041 and ultimately to serve as a light source of the display device.

At least one light emitting module (40) is disposed in the bottom cover, and may directly or indirectly provide light from one side of the light guide plate (1041). The light emitting module 40 includes a module substrate 43 and a light emitting package 10 according to the embodiment described above and the light emitting package 10 can be arrayed on the module substrate 43 at a predetermined interval have. When the light emitting package 10 is mounted on the side surface of the bottom cover 1011 or on the heat radiation plate, the module substrate 43 can be removed. A part of the heat radiation plate may be in contact with the upper surface of the bottom cover 1011. Therefore, the heat generated in the light emitting package 10 can be emitted to the bottom cover 1011 via the heat radiation plate.

The plurality of light emitting packages 10 may be mounted on the module substrate 43 such that the light emitting surface of the plurality of light emitting packages 10 is spaced apart from the light guiding plate 1041 by a predetermined distance. The light emitting package 10 may directly or indirectly provide light to the light-incident portion, which is one side 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 reflective member 1022 reflects the light incident on the lower surface of the light guide plate 1041 and supplies the reflected light to the display panel 1061 to improve the brightness of the display panel 1061. 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 emitting module 40, 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 a top cover (not shown), 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 transmits or blocks light provided from the light emitting module 40 to display information. The display device 1000 can be applied to video display devices such as portable terminals, monitors of notebook computers, monitors of laptop computers, and televisions.

The optical sheet 1051 is disposed between the display panel 1061 and the light guide plate 1041 and includes at least one light-transmitting sheet. The optical sheet 1051 may include at least one of a sheet such as a diffusion sheet, a horizontal / vertical prism sheet, a brightness enhanced sheet, and the like. The diffusion sheet diffuses incident light, and the horizontal and / or vertical prism sheet concentrates incident light on the display panel 1061. The brightness enhancing sheet reuses the lost light to improve the brightness I will. A protective sheet may be disposed on the display panel 1061, but the present invention is not limited thereto.

The optical path of the light emitting module 40 may include the light guide plate 1041 and the optical sheet 1051 as an optical member, but the present invention is not limited thereto.

11 is a sectional view showing a display device according to the embodiment.

11, the display device 1100 according to the second embodiment includes a bottom cover 1152, a module substrate 43 on which the above-described light emitting package 10 is arrayed, an optical member 1154, (1155).

The module substrate 43 and the light emitting package 10 may be defined as a light emitting module 40. The bottom cover 1152, the at least one light emitting module 40, and the optical member 1154 may be defined as a light unit (not shown).

The bottom cover 1152 may include a receiving portion 1153, but the present invention is not limited thereto.

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 PMMA (poly methy methacrylate) material, and such a light guide plate may be removed. The diffusion sheet diffuses the incident light, and the horizontal and vertical prism sheets condense incident light onto the display panel 1155. The brightness enhancing sheet reuses the lost light to improve the brightness .

The optical member 1154 is disposed on the light emitting module 40 and performs surface light source, diffusion, and light condensation on the light emitted from the light emitting module 40.

12 is a perspective view showing a lighting apparatus according to an embodiment.

12, a lighting apparatus according to an embodiment of the present invention includes a case 1510, a light emitting module 1530 installed in the case 1510, a connection terminal 1530 installed in the case 1510, Lt; RTI ID = 0.0 > 1520 < / RTI >

The case 1510 is preferably formed of a material having a good heat dissipation property, and may be formed of, for example, a metal material or a resin material.

The light emitting module 50 may include a module substrate 55 and a light emitting package 10 mounted on the module substrate 55. A plurality of the light emitting packages 10 may be arrayed in a matrix or spaced apart at a predetermined interval.

The module substrate 55 may have a printed circuit pattern on an insulator. For example, the module substrate 55 may be a printed circuit board (PCB), a metal core PCB, a flexible PCB, a ceramic PCB , FR-4 substrate, and the like.

In addition, the module substrate 55 may be formed of a material that efficiently reflects light, or may be a coating layer such as a white color, a silver color, or the like whose surface is efficiently reflected by light.

At least one light emitting package 10 may be mounted on the module substrate 55. Each of the light emitting packages 10 may include at least one light emitting diode (LED) chip. The LED chip may include a light emitting diode in a visible light band such as red, green, blue or white, or a UV light emitting diode that emits ultraviolet (UV) light.

The light emitting module 50 may be arranged to have a combination of various light emitting packages 10 to obtain color and brightness. For example, a white light emitting diode, a red light emitting diode, and a green light emitting diode may be arranged in combination in order to secure a high color rendering index (CRI).

The connection terminal 1520 may be electrically connected to the light emitting module 50 to supply power. The connection terminal 1520 is connected to the external power source by being inserted in a socket manner, but the present invention is not limited thereto. For example, the connection terminal 1520 may be formed in a pin shape and inserted into an external power source or may be connected to an external power source through wiring.

1: light emitting element 10A: horizontal light emitting element
10B: Flip type light emitting device 10C: Vertical type light emitting device
11: substrate 12: buffer layer
15: first conductivity type semiconductor layer 17: active layer
19: second conductivity type semiconductor layer 20: light emitting structure
27: transparent electrode layer 29, 45: reflective electrode layer
31: first electrode 33: second electrode
41: current blocking layer 43: channel layer
47: bonding layer 49: conductive supporting member
51: protective film 53: electrode

Claims (5)

a substrate comprising m-plane sapphire;
A light emitting structure including m-plane GaN formed on the m-plane sapphire; And
And a buffer layer formed between the m-plane sapphire and the m-plane GaN and including a nitride series having a salt structure (NaCl). The method according to claim 1,
Wherein the buffer layer comprises one selected from the group consisting of LaN, ThN, PrN, NdN and SmN. The method according to claim 1,
And the buffer layer is formed on the m-plane of the substrate. The method according to claim 1,
The light-
A first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer. 5. The method of claim 4,
The first conductivity type semiconductor layer may include a first conductivity type semiconductor layer,
And m-plane GaN formed on the buffer layer such that the upper surface thereof has an m-plane.

Images