WO2017074095A1 - Light-emitting element comprising wavelength conversion structure - Google Patents

Abstract

Provided is a light-emitting element comprising a wavelength conversion structure. Particularly, the light-emitting element comprises a wavelength conversion structure comprising a filter layer, a wavelength conversion layer, and a reflective layer such that a part of light, which has been emitted from a light-emitting structure, is selectively transmitted through the filter layer, and the transmitted light is absorbed by the wavelength conversion layer, is emitted as light that has a wavelength domain, which has been changed through down-conversion of energy, and is mixed with the light emitted from the light-emitting structure, thereby making it possible to easily implement various colors of light, including white light.

Description

Light emitting device comprising a wavelength conversion structure

The present invention relates to a light emitting device, and more particularly to a light emitting device that can implement a variety of colors through a wavelength conversion structure.

The light emitting device is an optoelectronic device that emits light based on a bandgap energy caused by recombination of electrons and holes in the compound semiconductor layers when a voltage is applied. The light emitting device is excellent in light efficiency due to its fast processing speed and low power consumption, and has a feature that can be miniaturized. In recent years, it is expected that the light emitting device can replace an illumination light source such as a fluorescent lamp or an incandescent lamp. Accordingly, the development of applying a light emitting device as a high power and high efficiency light source for a back light of a lighting device or a display device is being actively conducted.

In general, one light emitting device emits monochromatic light having a predetermined wavelength. Thus, in order to realize white light, white light is obtained by combining R (red, red), G (green, green), and B (blue, blue), or a phosphor The technique of converting into white light by using is introduced. However, when applying the conventional techniques to implement light of various colors including white light, the brightness of the light is reduced, or the final color is uneven due to the arrangement of a plurality of phosphors having different specific gravity and particle size, The process is complicated.

In order to solve the above problems, the present invention is to provide a light emitting device that can easily implement a light of various colors, including white light.

To solve the above problems, the present invention includes a light emitting structure in which a plurality of semiconductor laminates including light emitting layers positioned between semiconductor layers having different conductivity types are stacked, and a wavelength conversion structure disposed on one surface of the light emitting structure. The wavelength conversion structure may include a filter layer disposed on one surface of the light emitting structure to transmit only a portion of the light emitted from the light emitting structure, and disposed on one surface of the filter layer to absorb light transmitted through the filter layer. Light emission comprising a wavelength conversion layer for changing and emitting a wavelength region of light and a reflection layer disposed on one surface of the wavelength conversion layer, reflecting the light emitted from the wavelength conversion layer and the light emitting structure to the outside An element can be provided.

The light emitting layers included in the light emitting structures may emit light having different wavelength regions. In one embodiment of the present invention, the light emitting structure is a first semiconductor laminate for emitting green light and a second semiconductor laminate for emitting blue light are sequentially stacked, the wavelength conversion layer absorbs the green light or the blue light It may be to be excited. In another embodiment of the present invention, the light emitting structure includes a first semiconductor laminate emitting near-uv light, a second semiconductor laminate emitting green light, and a third semiconductor laminate emitting blue light. The sieves are sequentially stacked, and the wavelength conversion layer may be excited by absorbing any light selected from the near ultraviolet light, the green light, or the blue light.

The filter layer selectively transmits light having a first wavelength region in the light emitting structure, and the wavelength conversion layer absorbs light having the first wavelength region that has passed through the filter layer to down-convert energy of light. ) To emit light having the second wavelength region.

On the other side of the light emitting structure, an upper filter for selectively transmitting the light emitted from the light emitting structure and the wavelength conversion layer may be further provided.

The light emitting device of the present invention can easily implement light of a desired color including white light through a light emitting structure and a wavelength conversion structure in which a plurality of semiconductor laminates are multi-bonded.

In addition, the upper filter disposed on the top of the light emitting structure may increase the amount of light reaching the wavelength converting structure, thereby improving conversion efficiency of the wavelength converting structure.

However, the effects of the invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1A to 1C are cross-sectional views illustrating a structure of a light emitting device and a flow of light emitted from the light emitting device according to an embodiment of the present invention.

2A to 2B are cross-sectional views illustrating a light emitting device and a flow of light emitted from the light emitting device according to another embodiment of the present invention.

3A to 3B are cross-sectional views illustrating a light emitting device and a flow of light emitted from the light emitting device according to another embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. While the invention allows for various modifications and variations, specific embodiments thereof are illustrated by way of example in the drawings and will be described in detail below. However, it is not intended to be exhaustive or to limit the invention to the precise forms disclosed, but rather the invention includes all modifications, equivalents, and alternatives consistent with the spirit of the invention as defined by the claims. Like reference numerals denote like elements throughout the specification. In the drawings, the thicknesses of layers and regions may be exaggerated or reduced for clarity. Like reference numerals denote like elements throughout the specification.

The present invention relates to a light emitting device including a light emitting structure in which a plurality of semiconductor laminates including light emitting layers positioned between semiconductor layers having different conductivity types are stacked, and a wavelength conversion structure disposed on one surface of the light emitting structure. The wavelength conversion structure is disposed on one surface of the light emitting structure, the filter layer for transmitting only a portion of the light emitted from the light emitting structure, disposed on one surface of the filter layer, absorbs the light transmitted through the filter layer to change the wavelength region of the light It may include a wavelength conversion layer for emitting and a reflective layer disposed on one surface of the wavelength conversion layer, reflecting the light emitted from the wavelength conversion layer and the light emitting structure to the outside. Specifically, when the first conductive semiconductor layer is n-type, the second conductive semiconductor layer has a p-type, so that the light emitting layer is an n-type semiconductor layer and a p-type semiconductor layer. It can mean to be located between.

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

Referring to FIG. 1A, a first light emitting layer 113 may be disposed between semiconductor layers having different conductivity types (a first conductive semiconductor layer 111 and a second conductive semiconductor layer 115). 1 The semiconductor laminate 110 may be provided. In addition, on the first semiconductor laminate 110, a second layer disposed between semiconductor layers having different conductivity types (first conductive semiconductor layer 121 and second conductive semiconductor layer 125). The second semiconductor laminate 120 including the light emitting layer 123 may be stacked to form the light emitting structure 100. That is, in one embodiment of the present invention, the light emitting structure 100 is n-type semiconductor layer / light emitting layer / p-type semiconductor layer / n-type semiconductor layer / light-emitting layer / p-type semiconductor layer /. It may have a structure arranged in.

1B is a view schematically illustrating a light emitting device according to another embodiment of the present invention. Specifically, this is another embodiment having a structure different from that of the light emitting structure of FIG. 1A.

Referring to FIG. 1B, a first light emitting layer 113 may be disposed between semiconductor layers having different conductivity types (the first conductive semiconductor layer 111 and the second conductive semiconductor layer 115). A first semiconductor laminate 110 is provided, a second light emitting layer 123 is disposed on the second conductive semiconductor layer 115, and a second conductive semiconductor layer (top) is disposed on the second light emitting layer 123. A first conductivity type semiconductor layer 121 having a different conductivity type from 115 may be disposed. That is, the light emitting structure 100 of Fig. 1B is n-type semiconductor layer / light emitting layer / p-type semiconductor layer / light emitting layer / n-type semiconductor layer. It may have a structure arranged in. The first conductivity type semiconductor layers 111 and 121 and the second conductivity type semiconductor layers 115 and 125 may be compound semiconductor layers implanted with dopants that may exhibit conductive properties. Specifically, for example, the first conductive semiconductor layers 111 and 121 may be nitride-based oxides or oxides implanted with n-type impurities such as silicon (Si), nitrogen (N), phosphorus (P), or boron (B). Zinc-based or gallium arsenide-based compound semiconductor materials. In addition, the second conductivity type semiconductor layers 115 and 125 may include magnesium (Mg), nitrogen (N), phosphorus (P), arsenic (As), zinc (Zn), lithium (Li), copper (Cu), and the like. It may include a nitride, zinc oxide or gallium arsenide compound semiconductor material implanted with a p-type impurity. In addition, the type and concentration of impurities included in the conductive semiconductor layers of each of the semiconductor stacks 110 and 120 may be variously applied according to embodiments.

The light emitting layers 113 and 123 convert bandgap energy emitted by recombination of electrons and holes between the first conductive semiconductor layers 111 and 121 and the second conductive semiconductor layers 115 and 125 as light. By performing the role of emitting, a conventional light emitting layer material can be used. Specifically, the light emitting layers 113 and 123 are made of an InAlGaN layer having In _x Al _y Ga _(1-xy) N (0 ≦ x <1, 0 ≦ y <1 and 0 ≦ x + y <1) as wells, _{in a Al b Ga (1-} ab) N (0≤a <1, 0≤b <1 and 0≤a + b <1) of the InAlGaN barrier layer multiple quantum well (multi-quantum well, as MQW Or a single quantum well structure. Here, a and b are irrelevant to x and y and are intended to form a barrier structure. Alternatively, the light emitting layers 113 and 123 may include a zinc oxide-based material such as ZnMgO or ZnCdO. In some embodiments, the light emitting layers 113 and 123 may be formed of a doped compound semiconductor. The emission layers 113 and 123 may emit light of various colors having different wavelength ranges according to the composition ratio of the constituent materials. In general, the wavelength region of near ultraviolet light is about 300nm to 410nm, the wavelength range of blue light is about 440nm to 460nm, the wavelength range of green light is about 525nm to 535nm, the wavelength range of yellow light is about 550nm to 600nm, and the red light is about The wavelength of is about 615nm to 630nm.

Referring to FIG. 1A, first and second electrodes 117 and 127 and second and second electrodes 119 and 129 are respectively formed on the first and second conductive semiconductor layers 111 and 121 and 115 and 125, respectively. This can be formed. In addition, referring to FIG. 1B, first electrodes 117 and 127 and second electrodes 119 are formed on the first conductive semiconductor layers 111 and 121 and the second conductive semiconductor layer 115, respectively. Can be. The first electrodes 117 and 127 and the second electrodes 119 and 129 may be formed of an electrode material of a conventional light emitting device. For example, nickel (Ni), copper (Cu), titanium (Ti), It may be at least one selected from the group consisting of a metal such as aluminum (Al) or gold (Au) or a transparent electrode material such as ITO, IZO, TiO ₂ , ZnO, CaO, or WO ₃ having excellent light transmittance and electrical conductivity. . A voltage may be applied to the first semiconductor stack 110 and the second semiconductor stack 120 through the first electrodes 117 and 127 and the second electrodes 119 and 129. The light emitting layers 113 and 123 included in each of the semiconductor stacks 110 and 120 may emit light having different wavelength regions due to voltage.

1A to 1B, a reflective layer 251 and a wavelength conversion layer on one surface of the light emitting structure 100 in which the first semiconductor laminate 110 and the second semiconductor laminate 120 are sequentially stacked. The wavelength conversion structure 200 in which the 231 and the filter layer 211 are sequentially stacked may be disposed. In detail, a filter layer 211 that transmits only a portion of the light emitted from the light emitting structure 100 is disposed below the light emitting structure 100, and passes through the filter layer 211 under the filter layer 211. A wavelength conversion layer 231 is disposed to absorb the light and change the wavelength region of the light. The wavelength conversion layer 231 is disposed below the wavelength conversion layer 231 and is emitted from the light emitting structure 100. A reflective layer 251 may be disposed to reflect light and emit it to the outside.

In detail, the filter layer 211 transmits only light having a wavelength region that is a target target to be wavelength converted among light having different wavelength regions emitted from each of the semiconductor stacks 110 and 120 of the light emitting structure 100. To reach the wavelength conversion layer 231 disposed under the filter layer 211. In addition, the filter layer 211 may perform a role of selectively transmitting the light emitted from the wavelength conversion layer 231 into the changed wavelength region and emitting the light to the upper portion of the light emitting structure. Through this, the present invention can emit light having a wavelength region that can implement a desired color to the outside of the light emitting device.

The filter layer 211 may use a conventional color filter material including a pigment and a pigment carrier or resin (transparent resin, epoxy resin, silicone resin). For example, the filter layer 211 may be formed of a dichroic filter, a long pass filter, a short pass filter, a band pass filter, or a notch. Dielectric filters, such as notch filters, may be used, but are not limited thereto.

The wavelength conversion layer 231 may be formed of a wavelength conversion material and may be excited by absorbed light to change and emit a wavelength range of light. Specifically, when the filter layer 211 selectively transmits light having the first wavelength region emitted from the light emitting structure 100, the wavelength conversion layer 231 passes through the filter layer 211. Absorbs light having the wavelength region and down-converts the energy of the light having the first wavelength region to convert the second wavelength region, the wavelength region being higher than the wavelength of the first wavelength region according to the energy downconversion. It can emit by changing the wavelength range by the light which has. The first wavelength region and the second wavelength region may be set to a predetermined range according to the light to be implemented.

The wavelength conversion material may be a wavelength conversion material that can be converted so that the wavelength region of the light emitted by the conversion may have at least one wavelength range selected from the group consisting of red, yellow, green, and blue, At least one known wavelength converting material selected from among quantum dots (QD), quantum well (QW) phosphors, and pigments may be used according to a wavelength range of light. For example, the quantum dot (QD) may be a group II-VI compound or a group III-V compound, and more specifically, may be a CdSe quantum dot, a ZnSe quantum dot, an InGaAs quantum dot, or an InGaN quantum dot, and the quantum well QQ is It may be an InGaN quantum well layer, but is not limited thereto. The quantum dot and the quantum well may be formed using a conventional epitaxy method.

For example, as the red wavelength converting material, sulfide-based phosphors such as SrS: Eu or CaS: Eu, nitride-based phosphors such as SrSiN: Eu, CaSiN: Eu or LaSiN: Eu or iron oxide (Fe ₂ O ₃ ), Pigments such as lead oxide (Pb ₃ O ₄ ) or mercury sulfide (HgS) may be included, but are not limited thereto. Specifically, for example, a yellow wavelength converting material is a yttrium aluminum garnet (YAG) -based phosphor such as YAG: Ce, TbYAG: Ce, GdYAG: Ce or GdTbYAG: Ce, methyl silicate, ethyl silicate, or magnesium Silicate-based phosphors such as aluminum silicate, or pigments such as cadmium sulfide-zinc sulfide (CdS-ZnS), zinc chromate (ZnCrO ₄ ), or lead chromate (PbCrO ₄ ), but are not limited thereto. Specifically, for example, the green wavelength converting material is a phosphor of BaSiO: Eu, SrSiO: Eu, SrAlO: Eu, SrAlO: Eu, SrGaS: Eu, SrSiAlON: Eu, YSiON: Tb, YSiON: Tb or GdSiON: Tn, or Chromium oxide (Cr ₂ O ₃ ), chromium hydroxide (Cr ₂ O (OH) ₄ ) or basic copper acetate (Cu (C ₂ H ₃ O ₂ ) -2Cu (OH) ₂ ), cobalt chrome green (Cr ₂ O ₃ Pigments such as -Al ₂ O ₃ -CoO), but are not limited thereto. Specifically, for example, the blue wavelength converting material is a phosphor such as Sr (PO) Cl: Eu, SrMgSiO: Eu, BaMgSiO: Eu, BaMgAlO: Eu, SrPO: Eu or SrSiAlON: Eu, or ferric ferrocyanide (Fe _4). Pigments such as [Fe (CN) ₆ ] ₃ ) or cobalt blue (CoO-Al ₂ O ₃ ), but are not limited thereto.

The wavelength conversion layer 231 may be formed by a known method of depositing a phosphor or a pigment, and for example, a dispensing method, a spin coating method, a physical vapor deposition method, PVD) method, etc. can be used.

Referring to FIG. 1A, the reflective layer 251 is disposed on one surface of the wavelength conversion layer 231 to reflect light emitted from the wavelength conversion layer 231 and the light emitting structure 100 to the outside of the light emitting device. And a portion of the light that has passed through the wavelength conversion layer 231 but is not converted may be reflected. The reflective layer 251 may be a reflective layer material used in a conventional lighting device, for example, a metal layer for reflecting light such as aluminum (Al) thin film may be used, but is not limited thereto.

As described above, the present invention includes a wavelength conversion structure on one surface of a light emitting structure to which a plurality of semiconductor laminates are bonded, thereby converting a part of the light emitted from the light emitting structure through the wavelength converting structure into light having a desired wavelength region. The light emitting device may emit light having various colors together with light emitted from the light emitting structure.

1C is a cross-sectional view schematically illustrating the flow of light emitted from the light emitting device having the structure of FIGS. 1A to 1B described above. Referring to FIG. 1C, a portion of the light emitted from the first semiconductor laminate 110 is emitted to the upper portion of the light emitting structure 100, and a portion of the light passes through the filter layer 211 to transmit the wavelength conversion layer 231. ) Is reached. Light emitted from the first semiconductor laminate 110 reaching the wavelength conversion layer 231 is converted into a wavelength region of light by the wavelength conversion layer 231 to emit light from the first semiconductor laminate 110. Light having a wavelength region different from that of the city may be emitted, and the light may be emitted to the upper portion of the light emitting structure 100 by the reflective layer 251. Thus, the light emitted from the upper portion of the light emitting structure 100 is the light emitted from the second semiconductor stack 120, the light emitted from the first semiconductor stack 110 and the wavelength conversion layer 231 As the light emitted from is mixed, various colors can be realized according to the wavelength range of each light.

As described above, the present invention arranges a filter layer between the light emitting structure and the wavelength conversion layer and passes only a part of the light emitted from the light emitting structure, thereby converting the light into a light having a desired wavelength region so as not to pass through the converted light and filter layer. Since all the reflected light can be utilized, the wavelength region of the light finally emitted from the light emitting device can be easily controlled.

In one embodiment of the present invention, the light emitting structure 100 is a first semiconductor laminate 110 for emitting green light and a second semiconductor laminate 120 for emitting blue light are sequentially stacked, the wavelength conversion The layer 231 may be absorbed by absorbing the green light or the blue light. The green light or the blue light absorbed by the wavelength conversion layer 231 may be converted into red light, yellow light or green light and emitted according to the composition of wavelength change materials such as phosphors and pigments constituting the wavelength conversion layer 231. . For example, YAG in which green light of the first semiconductor laminate 110 is transmitted through the filter layer 211 to reach the wavelength conversion layer 231, and the wavelength conversion layer 231 emits yellow light. In the case of including the phosphor, the blue light reaching the wavelength conversion layer 231 is generated by the yellow-green fluorescence by exciting the wavelength conversion layer 231 made of the YAG-based phosphor to the outside of the light emitting structure 100 Can be released. Accordingly, the light emitting device is composed of green light emitted from the first semiconductor laminate 110, blue light emitted from the second semiconductor laminate 120, and yellow-green light converted and emitted from the wavelength conversion layer 231. White light can be realized.

2A is a cross-sectional view schematically illustrating a light emitting device according to another embodiment of the present invention.

Referring to FIG. 2A, a first semiconductor including a light emitting layer 133 disposed between semiconductor layers having different conductivity types (first conductive semiconductor layer 131 and second conductive semiconductor layer 135). The laminate 130 may be provided. On the first semiconductor laminate 130, a light emitting layer 143 positioned between semiconductor layers having different conductivity types (first conductive semiconductor layer 141 and second conductive semiconductor layer 145). A second semiconductor laminate 140 may be provided. On the second semiconductor laminate 140, a light emitting layer 153 positioned between semiconductor layers having different conductivity types (first conductive semiconductor layer 151 and second conductive semiconductor layer 155). The third semiconductor laminate 150 including a stack may be stacked to form the light emitting structure 100. In addition, the first and second conductive semiconductor layers 131, 141, and 151 and the second and second conductive semiconductor layers 135, 145, and 155, respectively, have a first electrode 137, 147, 157, and a second electrode 139, respectively. 149 and 159 may be formed.

Referring to FIG. 2A, a filter layer 213 is formed at a lower portion of the light emitting structure 100 to which the three semiconductor laminates 130, 140, and 150 are bonded to transmit only a part of the light emitted from the light emitting structure 100. The wavelength conversion layer 233 is disposed under the filter layer 213 to absorb the light transmitted through the filter layer 213 to change the wavelength region of the light, and is disposed below the wavelength conversion layer 233. The reflective layer 253 reflecting the light emitted from the wavelength conversion layer 233 to be emitted to the outside may be disposed. Description of the functions and features of each component described above is the same as that disclosed in Figure 1a, for a detailed description thereof may refer to Figure 1a.

FIG. 2B is a cross-sectional view schematically illustrating the flow of light emitted from the light emitting device having the structure of FIG. 2A described above. FIG.

Referring to FIG. 2B, a portion of the light emitted from the first semiconductor laminate 130 is emitted to the upper portion of the light emitting structure 100, and a portion of the light passes through the filter layer 213 to transmit the wavelength conversion layer 233. ) Is reached. The light emitted from the first semiconductor laminate 130 reaching the wavelength conversion layer 233 is converted into a wavelength region of the light by the wavelength conversion layer 233, so that the first semiconductor laminate 130 The light may be light having a wavelength region different from that at the time of light emission, and the light may be emitted to the upper portion of the light emitting structure 100 by the reflective layer 253. Accordingly, the light emitted from the upper portion of the light emitting structure 100 may be light emitted from the second semiconductor laminate 140, light emitted from the third semiconductor laminate 150, or the first semiconductor laminate ( The light emitted from 130 and the light emitted from the wavelength conversion layer 233 are mixed, and various colors may be implemented according to the wavelength range of each light.

In one embodiment of the present invention, the light emitting structure 100, the first semiconductor laminate 130 for emitting near ultraviolet light, the second semiconductor laminate 140 for emitting green light and the third light emitting blue light The semiconductor laminate 150 is sequentially stacked, and the wavelength conversion layer 233 may be excited by absorbing any one of the near ultraviolet light, the green light, and the blue light. For example, near-ultraviolet light of the first semiconductor laminate 130 is transmitted through the filter layer 213 to reach the wavelength conversion layer 233, and the wavelength conversion layer 233 emits red light. In the case of including a sulfide-based phosphor, near-ultraviolet light that reaches the wavelength conversion layer 233 is generated as red light by exciting the wavelength conversion layer 233 made of the sulfide-based phosphor to the outside of the light emitting structure 100. Can be released. Accordingly, the light emitting device may include blue light emitted from the third semiconductor stack 150, green light emitted from the second semiconductor stack 140, near ultraviolet light emitted from the first semiconductor stack 130, and The red light converted and emitted by the wavelength conversion layer 233 may be synthesized to implement white light.

As described above with reference to FIGS. 2A and 2B, the present invention may easily implement various colors of light by synthesizing the light emitted from the semiconductor stacks by multi-bonding the semiconductor stacks. Through this structural feature, the present invention can improve the problem that the luminance is lowered and the color is uneven when a plurality of various phosphors are disposed in one semiconductor laminate in order to realize light of various colors. The wavelength conversion structure can be used to easily control the color of light. Accordingly, the light emitting device of the present invention can be actively used in pixels or related fields of a display device such as a display.

In another embodiment of the present invention, the other surface of the light emitting structure, the upper filter for selectively transmitting the light emitted from the light emitting structure and the wavelength conversion layer may be further provided.

3A is a cross-sectional view schematically illustrating a light emitting device according to still another embodiment of the present invention. Specifically, in the structure of FIG. 2A, the upper filter may be further disposed on the other surface of the light emitting structure.

Referring to FIG. 3A, a first light emitting layer 163 may be disposed between semiconductor layers having different conductivity types (a first conductive semiconductor layer 161 and a second conductive semiconductor layer 165). 1 The semiconductor laminate 160 may be provided. The second light emitting layer 173 is disposed on the first semiconductor laminate 160, and the second conductive semiconductor layer 165 of the first semiconductor laminate 160 is disposed on the second light emitting layer 173. The first conductive semiconductor layer 171 having another conductivity type may be disposed to form the second semiconductor laminate 170. A third light emitting layer 183 is disposed on the second semiconductor laminate 170, and a first conductive semiconductor layer 171 of the second semiconductor laminate 170 is disposed on the third light emitting layer 183. A second conductive semiconductor 185 having a conductivity type different from that of the first semiconductor laminate 180 is formed to form the first semiconductor laminate 160, the second semiconductor laminate 170, and the second semiconductor laminate 180. The light emitting structure 100 including the third semiconductor laminate 180 may be formed. In addition, first and second electrodes 167 and 177 and 179 and 189 may be formed in the first and second conductive semiconductor layers 161 and 171 and 165 and 185, respectively. have.

A filter layer 215 for transmitting only a part of the light emitted from the light emitting structure 100 is disposed under the light emitting structure 100 to which the three semiconductor laminates 160, 170, and 180 are bonded to each other. A wavelength conversion layer 235 is disposed below the wavelength conversion layer 235 to absorb light transmitted through the filter layer 215 to change the wavelength region of the light. The reflective layer 255 may be disposed to reflect the light emitted from the 235 to the outside. Description of the functions and features of each component described above is the same as that disclosed in Figure 1a, a detailed description thereof may be referred to Figure 1a.

Referring to FIG. 3A, an upper filter 310 may be further disposed on the other surface of the light emitting structure 100, that is, the uppermost part of the light emitting structure 100. The upper filter 310 selectively transmits the light emitted from each of the semiconductor stacks 160, 170, and 180 constituting the light emitting structure 100 and the light emitted from the wavelength conversion layer 235. By performing the role, the filter function may finally select a wavelength region of the light emitted from the light emitting device according to the color of the light to be implemented. Through this, the present invention can be easily controlled to implement various colors of light, including white light.

3B is a cross-sectional view schematically illustrating the flow of light emitted from the light emitting device having the structure of FIG. 3A described above.

Referring to FIG. 3B, a portion of the light emitted from the first semiconductor laminate 160 is emitted toward an upper direction of the light emitting structure 100, and a portion of the other light is disposed below the first semiconductor laminate 160. The light emitted to the filter layer 215 but emitted to the upper portion of the light emitting structure 100 is reflected by the upper filter 310 disposed on the light emitting structure 100 and finally emitted to the outside of the light emitting device. Can be controlled to prevent The reflected light passes through the filter layer 215 disposed under the first semiconductor laminate 160, reaches the wavelength conversion layer 235 disposed under the filter layer 215, and converts the wavelength into the upper filter 310. ) Can be penetrated. That is, as described above, by providing the filter layer 310 on the light emitting structure 100, it is possible to reach the wavelength conversion layer 235 through the filter layer 215 without losing the light to be converted. The filter layer disposed on the top of the light emitting structure may increase the amount of light reaching the wavelength converting structure, thereby improving the conversion efficiency of the wavelength converting structure. For example, a material of the upper filter 310 may include a dichroic filter, a long pass filter, a short pass filter, and a band pass filter. Or a dielectric filter such as a notch filter, but is not limited thereto.

On the other hand, the embodiments of the present invention disclosed in the specification and drawings are merely presented specific examples to aid understanding, and are not intended to limit the scope of the present invention. It is apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

Claims (6)

1. And a light emitting structure in which a plurality of semiconductor laminates including light emitting layers positioned between semiconductor layers having different conductivity types are stacked, and a wavelength conversion structure disposed on one surface of the light emitting structure,

   The wavelength conversion structure,

   A filter layer disposed on one surface of the light emitting structure and transmitting only a part of the light emitted from the light emitting structure;

   A wavelength conversion layer disposed on one surface of the filter layer to absorb the light passing through the filter layer and change the wavelength region of the light to emit the light; And

   And a reflective layer disposed on one surface of the wavelength conversion layer to reflect light emitted from the wavelength conversion layer and the light emitting structure to be emitted to the outside.
2. The method of claim 1,

   The light emitting device of claim 1, wherein the light emitting layers included in the plurality of light emitting structures emit light having different wavelength regions.
3. The method of claim 1,

   The light emitting structure is

   A first semiconductor laminate for emitting green light; And

   The second semiconductor laminate that emits blue light is sequentially stacked,

   And the wavelength conversion layer absorbs the green light or the blue light and is excited.
4. The method of claim 1,

   The light emitting structure,

   A first semiconductor laminate for emitting near ultraviolet light;

   A second semiconductor laminate for emitting green light; And

   The third semiconductor laminate that emits blue light is sequentially stacked,

   The wavelength conversion layer is a light emitting device, characterized in that the absorption of any one selected from the near ultraviolet light, the green light or the blue light is excited.
5. The method of claim 1,

   The filter layer selectively transmits light having a first wavelength region in the light emitting structure,

   And the wavelength conversion layer absorbs light having the first wavelength region passing through the filter layer, and down-converts energy of light to emit light having the second wavelength region.
6. The method of claim 1,

   And an upper filter on the other surface of the light emitting structure, for selectively transmitting the light emitted from the light emitting structure and the wavelength conversion layer.

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