WO2021166785A1

WO2021166785A1 - Light-emitting element, light-emitting element array, and display device

Info

Publication number: WO2021166785A1
Application number: PCT/JP2021/005146
Authority: WO
Inventors: 幹夫滝口; 大畑　豊治; 享宏小山
Original assignee: ソニーグループ株式会社
Priority date: 2020-02-19
Filing date: 2021-02-12
Publication date: 2021-08-26
Also published as: JPWO2021166785A1

Abstract

[Problem] To provide a light-emitting element, a light-emitting element array, and a display device, which have high reliability and high light extraction efficiency. [Solution] A light-emitting element according to the present invention is provided with: a base material; a fluorescent body layer; a first sealing film; a second sealing film; and an excitation light source. The base material has a first main surface and a second main surface opposite to the first main surface, and a through-hole is provided between the first main surface and the second main surface. The fluorescent body layer contains a fluorescent body and is housed in the through-hole. The first sealing film has a gas barrier property, and is provided to the first main surface side of the fluorescent body layer. The second sealing film has a gas barrier property, and is provided to the second main surface side of the fluorescent body layer. The excitation light source is joined to the first main surface side of the base material, and causes excitation light to enter the fluorescent body layer.

Description

Light emitting element, light emitting element array and display device

The present technology relates to a light emitting element, a light emitting element array, and a display device including an excitation light source and a phosphor.

A light emitting element equipped with an excitation light source such as an LED (Light Emitting Diode) and a phosphor is used in a display device or the like. In recent years, QD (Quantum Dot) has been attracting attention as a phosphor, but since QD is deteriorated by oxygen and water, how to seal it is important.

For example, Patent Documents 1 and 2 disclose a configuration in which a QD layer is sandwiched between barrier films in a QD sheet used in a liquid crystal display device. Further, Patent Document 3 discloses a configuration in which the QD layer is sealed with a glass frit for each LED.

Further, Patent Documents 4 and 5 have a configuration in which an LED is embedded in a reflector together with a QD layer. Patent Document 6 discloses a configuration in which QD particles are individually sealed, or a plurality of QD particles are collectively sealed with a sealing film such as _{SiO 2.}

Japanese Unexamined Patent Publication No. 2018-13724 JP-A-2017-121745 Special Table 2018-532256 Japanese Unexamined Patent Publication No. 2018-186232 Japanese Unexamined Patent Publication No. 2015-220330 Japanese Patent Application Laid-Open No. 2013-505347

However, as described in Patent Documents 1 and 2, when a QD sheet in which a QD layer is sandwiched between barrier films is used in a method of driving for each pixel, the QD sheet is not separated for each pixel, so that cross talk (adjacent). Mixing of light between light emitting elements) occurs. Further, as described in Patent Document 3, if the QD layer is sealed with a glass frit for each LED, the thickness of the glass needs to be 100 μm or more, which makes miniaturization difficult. Further, since the mirror structure cannot be formed on the side wall of the QD layer, crosstalk cannot be suppressed between the light emitting elements, and the light extraction efficiency is low.

Further, as described in Patent Documents 4 and 5, in the configuration in which the LED is embedded in the reflector together with the QD layer, the size of the light emitting element becomes larger than that of the LED, and the excitation light source is independently driven for each subpixel. Not suitable for display devices. Further, as described in Patent Document 6, in the configuration in which the QD is sealed for each particle, the volume density of the sealing film is larger and the volume density of the QD is smaller than that in the method of sealing the entire QD layer. Therefore, it is not suitable for miniaturization of the element.

As described above, a QD sealing method that achieves both miniaturization of a light emitting element and high light extraction efficiency, which is suitable for a display device that independently drives an excitation light source for subpixels, has not been proposed. In addition, there are many fluorescent materials other than QD that need to be sealed to prevent deterioration, and an appropriate fluorescent material sealing method is required.

In view of the above circumstances, an object of the present technology is to provide a light emitting element, a light emitting element array, and a display device having high reliability and light extraction efficiency.

In order to achieve the above object, the light emitting device according to one embodiment of the present technology includes a base material, a phosphor layer, a first sealing film, a second sealing film, and an excitation light source.
The base material has a first main surface and a second main surface opposite to the first main surface, and a through hole is provided between the first main surface and the second main surface. Is provided.
The phosphor layer is housed in the through hole and contains a fluorescent substance.
The first sealing film has a gas barrier property and is provided on the first main surface side of the phosphor layer.
The second sealing film has a gas barrier property and is provided on the second main surface side of the phosphor layer.
The excitation light source is bonded to the first main surface side of the base material, and the excitation light is incident on the phosphor layer.

According to this configuration, the phosphor layer is sealed by the first sealing film and the second sealing film, and it is possible to prevent deterioration of the phosphor due to oxygen and moisture. Further, the excitation light source can be arranged close to the phosphor layer, and the light extraction efficiency can be improved. Further, the phosphor layer is housed in a through hole provided in the base material, and the base material can prevent crosstalk with an adjacent light emitting element.

The first sealing film may be further provided on the inner peripheral surface of the through hole and may cover the entire circumference of the phosphor layer together with the second sealing film.

The light emitting element may further include a light reflecting film provided between the inner peripheral surface and the first sealing film.

The light emitting element has a gas barrier property, is provided on the inner peripheral surface, and has a light reflecting film that covers the entire circumference of the phosphor layer together with the first sealing film and the second sealing film. Further may be provided.

The base material has a gas barrier property, and may cover the entire circumference of the phosphor layer together with the first sealing film and the second sealing film.

The surface of the base material forming the inner peripheral surface may have light reflectivity.

The through hole may have a shape in which the distance between the inner peripheral surfaces gradually increases from the first main surface toward the second main surface.

The phosphor may be a quantum dot.

The phosphor layer may be formed by dispersing the phosphor and the scatterer in a light-transmitting resin.

The light emitting element may further include an etching stop layer provided between the base material and the light reflecting film.

The first sealing film has a thickness that transmits the excitation light and reflects the fluorescence.
The second sealing film may have a thickness that transmits the fluorescence and reflects the excitation light.

The light emitting element may further include a lens bonded to the second main surface side of the base material.

The light emitting element array according to one embodiment of the present technology has a first main surface and a second main surface opposite to the first main surface, and has the first main surface and the second main surface. A base material having through holes provided between the main surfaces, a phosphor layer contained in the through holes and containing a phosphor, and having gas barrier properties, on the first main surface side of the phosphor layer. The first sealing film provided, the second sealing film having gas barrier properties and provided on the second main surface side of the phosphor layer, and the first main of the base material. A plurality of light emitting elements joined to the surface side and provided with an excitation light source for incidenting excitation light on the phosphor layer are arranged.

The light emitting element has a first light emitting element including a first phosphor in which the phosphor layer emits fluorescence of the first color, and a second light emitting element in which the phosphor layer has a second color different from the first color. A second light emitting element containing a second phosphor that emits fluorescence may be included.

The light emitting element includes a first phosphor in which the phosphor layer emits fluorescence of a first color, and a second phosphor in which a second color different from the first color is emitted.
The light emitting element array is bonded to the second main surface side of the base material, and is attached to the first color filter that transmits light of the first color and the second main surface side of the base material. A second color filter that is joined and transmits light of the second color may be further provided.

A display device according to an embodiment of the present technology includes a light emitting element array and a drive circuit.
The light emitting element array has a first main surface and a second main surface opposite to the first main surface, and penetrates between the first main surface and the second main surface. A first base material provided with pores, a phosphor layer contained in the through holes and containing a phosphor, and a first main surface side of the phosphor layer having gas barrier properties. The sealing film and the second sealing film having a gas barrier property and provided on the second main surface side of the phosphor layer are bonded to the first main surface side of the base material. A plurality of light emitting elements including an excitation light source for incidenting excitation light on the phosphor layer are arranged.
The drive circuit drives the excitation light source.

It is sectional drawing of the light emitting element which concerns on embodiment of this technique. It is a top view of the light emitting element. It is a bottom view of the light emitting element. It is sectional drawing of the light emitting part included in the said light emitting element. It is sectional drawing of the base material provided in the said light emitting part. It is a schematic diagram which shows the operation of the said light emitting element. It is a schematic diagram which shows the operation of the said light emitting element. It is a schematic diagram which shows the operation of the said light emitting element. It is a schematic diagram which shows the manufacturing method of the said light emitting element. It is a schematic diagram which shows the manufacturing method of the said light emitting element. It is a schematic diagram which shows the manufacturing method of the said light emitting element. It is a schematic diagram which shows the manufacturing method of the said light emitting element. It is a top view which shows the shape of the through hole provided in the light emitting element. It is a top view which shows the shape of the through hole provided in the light emitting element. It is sectional drawing of the light emitting element having another structure which concerns on embodiment of this technique. It is sectional drawing of the light emitting element having another structure which concerns on embodiment of this technique. It is sectional drawing of the light emitting element having another structure which concerns on embodiment of this technique. It is sectional drawing of the light emitting element having another structure which concerns on embodiment of this technique. It is a schematic diagram which shows the manufacturing method of the said light emitting element. It is sectional drawing of the light emitting element having another structure which concerns on embodiment of this technique. It is sectional drawing of the light emitting element array which concerns on embodiment of this technique. It is sectional drawing of the light emitting element array which concerns on the comparative example of this technique. It is sectional drawing of the light emitting element array which has other configurations which concerns on embodiment of this technique. It is sectional drawing of the display device which concerns on embodiment of this technique.

The light emitting element according to the embodiment of the present technology will be described.

[Structure of light emitting element]
FIG. 1 is a cross-sectional view of the light emitting element 100 according to the present embodiment, FIG. 2 is a top view of the light emitting element 100, and FIG. 3 is a bottom view of the light emitting element 100. Note that FIG. 1 is a cross-sectional view taken along the line AA in FIGS. 2 and 3.

As shown in these figures, the light emitting element 100 includes a light emitting unit 110 and an excitation light source 130. The excitation light source 130 is bonded to the light emitting portion 110 by the adhesive layer 140. FIG. 4 is a cross-sectional view showing the light emitting unit 110. As shown in the figure, the light emitting unit 110 includes a base material 111, a phosphor layer 112, a first sealing film 114, a second sealing film 115, and a light reflecting film 113.

The base material 111 is a film-like or plate-like member that houses the phosphor layer 112. The base material 111 may be made of a resin film made of a resin such as polyimide, a metal foil, a glass plate, a semiconductor substrate such as a silicon substrate, or the like. FIG. 5 is a cross-sectional view showing the base material 111. In the following description, the thickness direction of the base material 111 is defined as the Z direction, and the two directions perpendicular to the Z direction are defined as the X direction and the Z direction.

As shown in the figure, the base material 111 has a first main surface 111a and a second main surface 111b. The first main surface 111a and the second main surface 111b are main surfaces on opposite sides of the base material 111, and both can be surfaces parallel to the XY plane. The base material 111 is provided with a through hole 111c formed between the first main surface 111a and the second main surface 111b and communicating with the first main surface 111a and the second main surface 111b.

As shown in FIG. 5, the peripheral surface of the through hole 111c is defined as the inner peripheral surface 111d. The inner peripheral surface 111d is a surface inclined with respect to the thickness direction (Z direction) of the base material 111, and the through hole 111c has a shape in which the opening gradually increases from the first main surface 111a to the second main surface 111b. Can be. As shown in FIG. 5, the distance D between the inner peripheral surfaces 111d can be gradually increased from the first main surface 111a to the second main surface 111b. The shape of the through hole 111c may be various shapes described later in addition to those shown here.

As shown in FIG. 4, the phosphor layer 112 is a layer that is housed in the through hole 111c and emits fluorescence by the excitation light incident from the excitation light source 130. Specifically, the phosphor layer 112 is a layer composed of a phosphor 121, a scatterer 122, and a filler 123, and has a structure in which the particulate phosphor 121 and the scatterer 122 are dispersed in the filler 123. Can be.

The fluorescent substance 121 is fine particles made of a fluorescent material. The phosphor 121 can be QD (Quantum Dot), and the material thereof can be InP, CdSe, CdSeS, CdS, ZnSe, ZnS, GaAs, GaN or perovskite. Further, the phosphor 121 is not limited to QD, and may be an organic phosphor or an inorganic phosphor.

The scatterer 122 scatters the fluorescence emitted from the phosphor 121 and makes the fluorescence orientation pattern Lambertian. The scatterer 122 can be fine particles composed _{of SiO 2} , Al ₂ O ₃ , TIO ₂ or Ta ₂ O _3. The filler 123 is filled around the phosphor 121 and the scatterer 122. The filler 123 is a light-transmitting resin, and can be a UV (ultraviolet) curable resin or a thermosetting resin.

In addition, the filler 123 includes acrylic resin, polypropylene, polyethylene, polystyrene, AS (Styrene AcryloNitrile copolymer) resin, ABS (Acrylonitrile Butadiene Styrene) resin, methacrylic resin, polyvinyl chloride, polyacetal, polyamide, polycarbonate, and modified polyphenylene ether. , Polybutylene terephthalate, polyethylene terephthalate, polysulfone, polyether sulfone, polyphenylene sulfide, polyamideimide, polymethylpentene, liquid crystal polymer, epoxy resin, phenol resin, urea resin, melanin resin, diallyl phthalate resin, unsaturated polyester resin, polyimide , Polyurethane, silicone resin or a mixture thereof.

The phosphor layer 112 is not limited to the one composed of the phosphor 121, the scatterer 122 and the filler 123, and may include at least the phosphor 121. That is, the phosphor layer 112 may be composed of only the phosphor 121 and the filler 123 without containing the scatterer 122. Further, the phosphor layer 112 may not contain the filler 123, and the fine particles of the phosphor 121 and the filler 123 may be present in a freely movable state. Further, the phosphor layer 112 may exist in a state in which only the phosphor 121 can move freely.

The light reflecting film 113 is formed between the inner peripheral surface 111d and the first sealing film 114 and between the second main surface 111b and the first sealing film 114, and emits light emitted from the phosphor layer 112 to the second. It reflects toward the main surface 111b. The light reflecting film 113 can be, for example, a metal film such as Al, Au, or Ag, and the thickness can be, for example, 100 nm. Further, the light reflecting film 113 may be a dielectric multilayer film.

The first sealing film 114 and the second sealing film 115 seal the phosphor layer 112. As shown in FIG. 4, the first sealing film 114 is provided inside the through hole 111c on the inner peripheral surface 111d via the light reflecting film 113 and on the first main surface 111a side of the phosphor layer 112. Further, the first sealing film 114 is provided on the second main surface 111b via the light reflecting film 113 outside the through hole 111c.

The second sealing film 115 is provided inside the through hole 111c on the second main surface 111b side of the phosphor layer 112, and is provided on the opposite side of the first sealing film 114 with the phosphor layer 112 interposed therebetween. .. Further, the second sealing film 115 is provided on the second main surface 111b via the light reflecting film 113 and the first sealing film 114 outside the through hole 111c. As a result, the entire circumference of the phosphor layer 112 is covered and sealed by the first sealing film 114 and the second sealing film 115.

The first sealing film 114 and the second sealing film 115 are films having light transmittance and gas barrier properties, and are made of, for example, SiO ₂ , SiN, AlN, ZrO ₂ , Ta ₂ O ₃ or Zn O. Can be done. The first sealing film 114 and the second sealing film 115 may be made of the same material or may be made of different materials. The thickness of the first sealing film 114 and the second sealing film 115 can be, for example, 100 nm. The light emitting unit 110 has the above configuration.

The excitation light source 130 is bonded to the first main surface 111a side of the base material 111, and emits excitation light to the phosphor layer 112. The excitation light source 130 may be an LED (Light Emitting Diode), and may include an n-type layer 131, a p-type layer 132, an active layer 133, an n electrode 134, and a p electrode 135 as shown in FIG. can. In the excitation light source 130, the n-type and the p-type may be reversed.

The n-type layer 131, the p-type layer 132, and the active layer 133 can be made by doping a semiconductor material such as GaN, AlGaInN, AlGaInAs, AlGaInP, ZnSe, or ZnO with a dopant. The n-electrode 134 and the p-electrode 135 are made of a conductive material such as AuGe / Ni / Au, Ti / Pt / Au, Pd, Ni / Au or ITO (Indium Tin Oxide).

The excitation light source 130 is a light source capable of emitting monochromatic excitation light, and the emission wavelength can be the wavelength of blue light or ultraviolet light. Further, the excitation light source 130 may be any one capable of emitting excitation light, and may be an OLED (Organic Light Emitting Diode), a laser diode, a VCSEL (Vertical Cavity Surface Emitting LASER), or the like, in addition to the LED.

The adhesive layer 140 adheres the excitation light source 130 to the light emitting unit 110. The adhesive layer 140 is not particularly limited as long as it has light transmission with respect to the emission wavelength of the excitation light source 130. Further, the excitation light source 130 may be bonded to the light emitting unit 110 by another method instead of bonding by the adhesive layer 140.

[Operation of light emitting element]
6 to 8 are schematic views showing the operation of the light emitting element 100. When electric power is supplied to the excitation light source 130, light emission is generated in the active layer 133 as shown by an arrow in FIG. This light (hereinafter referred to as excitation light) passes through the adhesive layer 140 and the first sealing film 114 from the excitation light source 130 and enters the phosphor layer 112.

When the excitation light is incident on the phosphor 121, fluorescence is generated in the phosphor 121 as shown by an arrow in FIG. 7. The fluorescence is scattered by the scatterer 122, passes through the second sealing film 115, and is emitted to the front of the light emitting element 100 (the side opposite to the excitation light source 130). Further, as shown in FIG. 8, of the fluorescence, the light traveling toward the inner peripheral surface 111d of the through hole 111c is reflected by the light reflecting film 113 and transmitted through the second sealing film 115 to the light emitting element 100. It is emitted forward.

[Effect of light emitting element]
In the light emitting element 100, as shown in FIG. 4, the entire circumference of the phosphor layer 112 is covered with the first sealing film 114 and the second sealing film 115, and each light emitting element 100 is sealed. The first sealing film 114 and the second sealing film 115 have a gas barrier property, and prevent oxygen and moisture from reaching the phosphor layer 112. As a result, deterioration of the phosphor 121 due to oxygen and moisture can be prevented, and the reliability of the light emitting element 100 can be maintained.

Further, conventionally, a structure in which an excitation light source is embedded in a phosphor layer is known, but in the light emitting element 100, the phosphor layer 112 is arranged away from the excitation light source 130 which is a heat source. As a result, deterioration of the phosphor 121 due to heat can be prevented, and the reliability of the light emitting element 100 can be maintained in this respect as well.

As described above, since the light emitting element 100 can prevent the deterioration of the phosphor 121 due to oxygen, moisture, and heat, high reliability can be realized even for a phosphor that can cause deterioration such as QD and an organic phosphor. Can be done.

Further, in the light emitting element 100, the thickness of the first sealing film 114 and the second sealing film 115 can be reduced, and the excitation light source 130 can be arranged close to the phosphor layer 112. It is possible to reduce the size of the light emitting element 100. Further, if the distance between the excitation light source 130 and the phosphor layer 112 is small, the light diffused and emitted from the excitation light source 130 also enters the phosphor layer 112, so that the efficiency of the light emitting element 100 can be improved. ..

Further, in the light emitting element 100, the light reflecting film 113 is provided on the inner peripheral surface 111d of the through hole 111c. As a result, among the fluorescence, the light traveling in the direction of the inner peripheral surface 111d is also emitted in front of the light emitting element 100, so that the efficiency can be improved. Further, in the light emitting element 100, the phosphor layer 112 is separated between the adjacent light emitting elements 100, and it is possible to prevent light mixing (crosstalk) as described later.

[Manufacturing method of light emitting element]
A method of manufacturing the light emitting element 100 will be described. 9 to 12 are schematic views showing a method of manufacturing the light emitting element 100.

As shown in FIG. 9A, the support layer 151 is formed on the first main surface 111a of the base material 111. The support layer 151 is made of, for example, Ni, and can be formed by a sputtering method and plating. The thickness of the support layer 151 is, for example, about 500 μm. Further, the mask layer 152 is formed on the second main surface 111b of the base material 111. The mask layer 152 is made of, for example, Cu and can be formed by a sputtering method.

Subsequently, the mask layer 152 is patterned as shown in FIG. 9 (b). This patterning can be performed by forming a resist pattern on the mask layer 152 by photolithography and removing the material of the mask layer 152 by wet etching using the resist pattern.

Subsequently, the base material 111 is patterned as shown in FIG. 9 (c). This patterning can be performed by using the mask layer 152 as a hard mask and removing the material of the base material 111 by wet etching. As a result, the through hole 111c is formed.

At this time, by using an isotropic etchant, it is possible to form a through hole 111c having an inclined inner peripheral surface 111d as shown in FIG. 9C. Further, through holes 111c having an inner peripheral surface 111d perpendicular to the XY plane may be formed by dry etching.

Subsequently, as shown in FIG. 10A, the mask layer 152 is removed. At this time, an etchant that is selective for the material of the support layer 151 is used so that the support layer 151 is not removed.

Subsequently, as shown in FIG. 10B, the light reflecting film 113 is formed on the support layer 151, the inner peripheral surface 111d, and the second main surface 111b. The light reflective film 113 can be formed by, for example, a sputtering method. Further, the first sealing film 114 is formed on the light reflecting film 113. The first sealing film 114 can be formed, for example, by a sputtering method.

Subsequently, as shown in FIG. 10 (c), the phosphor layer 112 is formed in the through hole 111c. The phosphor layer 112 can be formed by filling the through hole 111c with a filler 123 in which the phosphor 121 and the scatterer 122 are dispersed and curing the mixture.

Subsequently, as shown in FIG. 11A, the second sealing film 115 is formed on the phosphor layer 112 and the first sealing film 114. The second sealing film 115 can be formed by, for example, a sputtering method. As a result, the phosphor layer 112 is sealed by the first sealing film 114 and the second sealing film 115.

Subsequently, as shown in FIG. 11B, the support substrate 153 is bonded onto the second sealing film 115. The support substrate 153 is, for example, a glass substrate, and can be adhered to the second sealing film 115 by the adhesive 154.

Subsequently, as shown in FIG. 11 (c), the support layer 151 is removed. The support layer 151 can be removed by wet etching. At this time, an etchant having selectivity for the light reflecting film 113 is used.

Subsequently, as shown in FIG. 12A, the light reflecting film 113 is removed on the first main surface 111a. The light-reflecting film 113 can be removed by wet etching using the resist pattern after forming a resist pattern having an opening that exposes only the light-reflecting film 113 on the first main surface 111a by photolithography or the like.

Subsequently, the support substrate 153 is removed as shown in FIG. 12 (b). As a result, the light emitting unit 110 is formed. Further, as shown in FIG. 12 (c), the excitation light source 130 can be bonded to the light emitting portion 110 by the adhesive layer 140 to manufacture the light emitting element 100.

The excitation light source 130 is manufactured by growing crystals on a sapphire substrate by the MOCVD (Metal Organic Chemical Vapor Deposition) method, and after the electrode forming process, peeling off the sapphire substrate using a laser lift-off (LLO) method. Can be done. If the sapphire substrate remains, the distance between the active layer 133 of the excitation light source 130 and the phosphor layer 112 becomes long, and in a display device that independently drives the excitation light source 130 for each subpixel, it is necessary to reduce the pitch for each subpixel. Not suitable because it exists. Therefore, it is preferable to peel off the crystal growth substrate.

The light emitting element 100 can be manufactured as described above. Although the manufacturing process of one light emitting element 100 is shown here, it is actually possible to manufacture a light emitting element array (described later) including a large number of light emitting elements 100 at a time by the above manufacturing process.

[About the 1st sealing film and the 2nd sealing film]
The thickness of the first sealing film 114 and the second sealing film 115 can be set to a thickness close to the wavelength of light in the vicinity of 100 nm, and the reflectance for each wavelength can be controlled by adjusting the refractive index and the thickness. Is possible. As shown in FIG. 4, the thickness T1 of the first sealing film 114 is preferably a thickness that transmits excitation light and reflects fluorescence. As a result, the fluorescence incident on the first sealing film 114 is reflected by the first sealing film 114, and the light extraction efficiency is improved.

Further, the thickness T2 of the second sealing film 115 is preferably a thickness that reflects excitation light and transmits fluorescence. As a result, the excitation light is prevented from passing through the phosphor layer 112, and the excitation light can be used for exciting the phosphor 121, so that the light extraction efficiency is improved. Further, increasing the reflectance of the excitation light of the second sealing film 115 suppresses the excitation of the phosphor layer 112 by the external light and contributes to the improvement of the external light contrast.

Since the first sealing film 114 has, for example, the refractive index of the adhesive layer 140 of about 1.5, a material having a large difference in refractive index is preferable, and the first sealing film 114 is made of a high refractive index material such as _{TiO 2.} Can be. Further, the first sealing film 114 and the second sealing film 115 can be formed as a multilayer film in which a plurality of layers having a low refractive index layer and a plurality of layers having a high refractive index are alternately laminated, whereby the light of the phosphor layer 112 can be obtained. The extraction efficiency can be improved. The low refractive index layer may be made of, for example, SiO ₂ , and the high refractive index layer may be made of, for example, TiO ₂ .

[About the shape of the through hole]
As shown in FIG. 5, the through hole 111c provided in the base material 111 has an inner circumference such that the distance D between the inner peripheral surfaces 111d gradually increases from the first main surface 111a side toward the second main surface 111b side. It is preferable that the surface 111d has an inclined structure. Since the light reflecting film 113 is provided on the inner peripheral surface 111d as described above, by inclining the inner peripheral surface 111d, the incident light is reflected toward the front of the element (see FIG. 8), and the light utilization efficiency. Can be improved.

The inner peripheral surface 111d is not limited to an inclined flat surface as shown in FIG. 5, and the inner peripheral surface 111d is gradually separated from the first main surface 111a side toward the second main surface 111b side. It may be a curved curved surface. Further, the inner peripheral surface 111d is a plane parallel to the thickness direction (Z direction) of the base material 111, and the distance D may be constant from the first main surface 111a side to the second main surface 111b side.

Further, the shapes of the upper surface and the lower surface of the through hole 111c are not limited to the square shape as shown in FIGS. 2 and 3. 13 and 14 are schematic views showing other shapes of the through hole 111c, and FIGS. 13 (a) and 14 (a) are plan views, FIGS. 13 (b) and 14 (a) of the light emitting element 100 as viewed from above. 14 (b) is a plan view of the light emitting element 100 as viewed from the lower surface.

As shown in FIGS. 13 (a) and 13 (b), the through hole 111c may be circular on the first main surface 111a and the second main surface 111b. Further, as shown in FIGS. 14A and 14B, the through hole 111c may be hexagonal on the first main surface 111a and the second main surface 111b. In addition to this, the through hole 111c can have various shapes such as a rectangle, an ellipse, or a polygon on the first main surface 111a and the second main surface 111b. Further, the through hole 111c may have different shapes on the first main surface 111a and the second main surface 111b, such as a square on the first main surface 111a and a circle on the second main surface 111b.

[About other configurations of light emitting elements]
The configuration of the light emitting element 100 is not limited to the above, and the following configuration is also possible. 15 to 20 are schematic views of a light emitting element 100 having another configuration.

As shown in FIG. 15, the first sealing film 114 may not be provided on the inner peripheral surface 111d of the through hole 111c, but may be provided on the first main surface 111a side of the phosphor layer 112 and the base material 111. .. In this case, by using the light reflecting film 113 as a film having a gas barrier property, the light reflecting film 113 can be used for sealing the phosphor layer 112. That is, the entire circumference of the phosphor layer 112 can be covered with the light reflecting film 113, the first sealing film 114, and the second sealing film 115, and the phosphor layer 112 can be sealed.

Further, as shown in FIG. 16, the light emitting element 100 may not have the light reflecting film 113. The first sealing film 114 may not be provided on the inner peripheral surface 111d of the through hole 111c, but may be provided on the first main surface 111a side of the phosphor layer 112 and the base material 111. In this case, by making the base material 111 have a gas barrier property, the base material 111 can be used for sealing the phosphor layer 112. That is, the entire circumference of the phosphor layer 112 can be covered with the base material 111, the first sealing film 114, and the second sealing film 115, and the phosphor layer 112 can be sealed.

Further, in this configuration, by making the surface of the base material 111 constituting the inner peripheral surface 111d have light reflectivity, the light incident on the inner peripheral surface 111d is reflected to the front of the light emitting element 100, that is, the light. It is possible to realize the same function as the reflective film 113.

Further, as shown in FIG. 17, the light emitting element 100 may have a light-shielding portion 141. The light-shielding portion 141 is formed by removing the first sealing film 114 and the second sealing film 115 around the through hole 111c on the second main surface 111b and arranging a material having no light transmission. Can be done. By providing the light-shielding portion 141, it is possible to suppress the reflection of external light in the region between the light-emitting elements 100 and improve the external light contrast ratio of the display device having the light-emitting element 100 as a pixel.

Further, by removing the first sealing film 114 and the second sealing film 115 and providing the light-shielding portion 141, the first sealing film 114 and the second sealing film 115 can be separated from the adjacent light emitting element 100. It is possible to prevent the propagation of light through the film, that is, to suppress crosstalk. The light-shielding portion 141 can be arranged on the second sealing film 115 without removing the first sealing film 114 and the second sealing film 115.

Further, as shown in FIG. 18, the light emitting element 100 may have an etching stop layer 142. The etching stop layer 142 is made of a material of the support layer 151 (see FIG. 11B) and a material having etching selectivity, and is provided between the base material 111 and the light reflecting film 113. The etching stop layer 142 can be, for example, _{a dielectric film such as SiO 2} , AlN, SiN, TIO ₂ , Al ₂ O ₃ , ZnO or Ta ₂ O ₃ , or a metal film such as Ti, Cr, Au or Ag. ..

FIG. 19 is a schematic view showing a part of the manufacturing process of the light emitting element 100 including the etching stop layer 142, and is a schematic view showing a step of removing the support layer 151 (see FIGS. 11B and 11C). .. As shown in FIGS. 19A and 19B, the light reflecting film 113 is coated on the etching stop layer 142 in the step of removing the support layer 151 to protect it from etching.

When the etching stop layer 142 is not provided as shown in FIGS. 11B and 11C, the light-reflecting film 113 is attached to the support layer 151 so that the light-reflecting film 113 is not removed when the support layer 151 is removed. On the other hand, it is necessary to use materials having different etching selectivity. However, the material of the light reflecting film 113 is limited because it needs to have a high reflectance with respect to excitation light and fluorescence.

On the other hand, when the etching stop layer 142 is provided as shown in FIG. 19, since the light reflecting film 113 is protected from etching, the material of the support layer 151 is selected without considering the etching selectivity with the light reflecting film 113. It becomes possible to do. The etching stop layer 142 may be provided between the base material 111 and the light reflecting film 113 even when the first sealing film 114 is not provided on the inner peripheral surface 111 as shown in FIG.

Further, as shown in FIG. 20, the light emitting element 100 may include a lens 143. The lens 143 is made of resin, glass, or the like, and can be adhered to the second main surface 111b side of the base material 111 with the adhesive 144. In the structure of FIG. 1, since the fluorescence is isotropically emitted from the phosphor 121, it is refracted into the air from the second sealing film 115 and has an orientation characteristic close to that of Lambertian when emitted. On the other hand, by providing the lens 143 as shown in FIG. 20, the emitted light of the light emitting element 100 is concentrated at a narrow angle in front, and the light distribution characteristics can be optimized in the required direction, so that the light utilization efficiency is improved. It is possible.

[About light emitting element array]
The light emitting element 100 can be arrayed. FIG. 21 is a cross-sectional view of a light emitting element array 150 in which a plurality of light emitting elements 100 are arrayed. As shown in the figure, the light emitting element array 150 includes a red light emitting element 100R, a green light emitting element 100G, and a blue light emitting element 100B.

The red light emitting element 100R has the configuration of the above light emitting element 100, and the phosphor layer 112 includes a red phosphor 121R that emits red fluorescence. The green light emitting element 100G has the configuration of the above light emitting element 100, and the phosphor layer 112 includes a green phosphor 121G that emits green fluorescence. The blue light emitting element 100B has a configuration in which the phosphor 121 is not included in the light emitting element 100. The red light emitting element 100R, the green light emitting element 100G, and the blue light emitting element 100B can be formed by separately coating the phosphor layer 112 by the ink jot method.

In each light emitting element 100, the excitation light source 130 emits blue excitation light. In the red light emitting element 100R, when blue excitation light is incident on the light emitting unit 110, red fluorescence is emitted from the red phosphor 121R. In the green light emitting element 100G, when blue excitation light is incident on the light emitting unit 110, green fluorescence is emitted from the green phosphor 121G. In the blue light emitting element 100B, when blue light is incident on the light emitting unit 110, it is scattered by the scatterer 122 and the blue light is emitted.

In the light emitting element array 150, the red light emitting element 100R, the green light emitting element 100G, and the blue light emitting element 100B can emit red, green, and blue light in this way, and each light emitting element 100 is a pixel as a subpixel. Can be configured.

In the light emitting element array 150, each excitation light source 130 emits blue excitation light and is converted into red light and green light by the red phosphor 121R and the green phosphor 121G, but the present invention is not limited to this. A second part of the light emitting element 100 constituting the light emitting element array 150 includes a first phosphor 121 that emits fluorescence of the first color, and another part of the light emitting element 100 emits fluorescence of the second color. It can contain the phosphor 121 of.

Further, the light emitting element array 150 may further include a third phosphor that emits fluorescence of a third color. For example, the blue light emitting element 100B contains a blue phosphor that emits blue fluorescence to the phosphor layer 112. Including, each excitation light source 130 may emit ultraviolet rays as excitation light. Further, the light emitted by the light emitting element array 150 is not limited to three colors, and may be a single color, two colors, or four or more colors. Further, the light emitting element 100 constituting the light emitting element array 150 may be a light emitting element 100 having any of the configurations disclosed in the present disclosure.

The light emitting element array 150 can prevent crosstalk (mixing) of light. FIG. 22 is a schematic view of a light emitting device array 500 having a conventional structure, which is shown as a comparison. As shown in the figure, in the light emitting element array 500, the front and back surfaces of the phosphor layer 511 are respectively sealed by the sealing film 512, and the first film 513 and the second film 514 are provided on the outside of the sealing film 512. Has been done.

A red color filter 515R, a green color filter 515G, and a blue color filter 515B are provided on the first film 513. A light source 520R for red light, a light source 520G for green light, and a light source 520B for blue light are provided on the second film 514.

The phosphor layer 511 contains a red phosphor 516R and a green phosphor 516G. When the blue excitation light is emitted from the light source 520R, the red fluorescence is emitted from the red phosphor 516R, and the red light is emitted from the red color filter 515R. Further, when the blue excitation light is emitted from the light source 520G, the green fluorescence is emitted from the green phosphor 516G, and the red light is emitted from the green color filter 515G. Further, when blue light is emitted from the light source 520B, it passes through the phosphor layer 511 as it is and is emitted as blue light from the blue color filter 515B.

Here, when for example wants causing green light, (in the figure, _{L E)} emitting light source 520G when is, (in the _{figure, L f1)} green fluorescence from the green phosphor 516G is released from the green color filter 515G green light _{L G} is emitted. In addition to this, _{a part of the fluorescence L f1} excites the red phosphor 516 near the red color filter 515R. As a result, red fluorescence (L _{f2 in the} figure) is emitted from the red phosphor 516R, and a small amount of red light _LR is emitted from the red color filter 515R.

Therefore, even if only the light source 520G is emitted, the red light _LR is not emitted, and crosstalk occurs. Similarly, when the light source 520R or the light source 520B is made to emit light, fluorescence or scattered light excites a nearby phosphor, and crosstalk occurs. On the other hand, in the light emitting element array 150, as shown in FIG. 21, since the phosphor layer 112 of each color is separated by the base material 111, it is possible to suppress crosstalk.

Further, in the light emitting element array 500, the light traveling in the lateral direction (XY directions) is wasted, but in the light emitting element array 150, the light traveling in the lateral direction is also reflected by the light reflecting film 113 and is effectively used. Therefore, the light extraction efficiency is also improved.

FIG. 23 is a cross-sectional view of a light emitting element array 160 having another configuration. As shown in the figure, the light emitting element array 160 is composed of a red light emitting element 100R, a green light emitting element 100G, and a blue light emitting element 100B.

The red light emitting element 100R has the configuration of the light emitting element 100, and the phosphor layer 112 includes a red phosphor 121R that emits red fluorescence and a green phosphor 121G that emits green fluorescence. A red color filter 145R is bonded to the second main surface 111b side of the red light emitting element 100R.

The green light emitting element 100G has the configuration of the light emitting element 100, and the phosphor layer 112 includes a red phosphor 121R that emits red fluorescence and a green phosphor 121G that emits green fluorescence. A green color filter 145G is bonded to the second main surface 111b side of the green light emitting element 100G.

The blue light emitting element 100B has the configuration of the light emitting element 100, and the phosphor layer 112 includes a red phosphor 121R that emits red fluorescence and a green phosphor 121G that emits green fluorescence. A blue color filter 145B is bonded to the second main surface 111b side of the blue light emitting element 100B.

In each light emitting element 100, the excitation light source 130 emits blue excitation light. In the red light emitting element 100R, when blue excitation light is incident on the light emitting unit 110, red fluorescence is emitted from the red phosphor 121R, and green fluorescence is emitted from the green phosphor 121G. The red component of fluorescence passes through the red color filter 145R, and red light is emitted from the red light emitting element 100R.

In the green light emitting element 100G, when blue excitation light is incident on the light emitting unit 110, red fluorescence is emitted from the red phosphor 121R, and green fluorescence is emitted from the green phosphor 121G. The green component of fluorescence passes through the green color filter 145G, and green light is emitted from the green light emitting element 100G.

In the blue light emitting element 100B, when blue excitation light is incident on the light emitting unit 110, red fluorescence is emitted from the red phosphor 121R, and green fluorescence is emitted from the green phosphor 121G. The blue excitation light passes through the blue color filter 145B, and the blue light is emitted from the green light emitting element 100G.

In this configuration, since the phosphor layers 112 of the red light emitting element 100R, the green light emitting element 100G, and the blue light emitting element 100B have the same structure, it is not necessary to separately paint the phosphor layer 112, and the manufacturing cost can be reduced. Can be done.

In the light emitting element array 160, each excitation light source 130 emits blue excitation light and is converted into red light and green light by the red phosphor 121R and the green phosphor 121G, but the present invention is not limited to this. Each light emitting element 100 may include a first phosphor 121 that emits fluorescence of a first color and a second phosphor 121 that emits fluorescence of a second color. Further, some light emitting elements may be provided with a color filter that transmits the fluorescence of the first color, and other light emitting elements may be provided with a color filter that transmits the fluorescence of the second color.

Further, the light emitting element array 160 may further include a third phosphor 121 that emits fluorescence of the third color, and each light emitting element 100 has a blue phosphor that emits blue fluorescence to the phosphor layer 112. Including, each excitation light source 130 may emit ultraviolet rays as excitation light. Further, the light emitted by the light emitting element array 160 is not limited to three colors, and may be a single color, two colors, or four or more colors. Further, the light emitting element 100 constituting the light emitting element array 160 may be a light emitting element 100 having any of the configurations disclosed in the present disclosure.

[Display device]
A display device using the light emitting element array 150 will be described. FIG. 24 is a cross-sectional view showing a display device 170 using the light emitting element array 150. As shown in the figure, the display device 170 includes a light emitting element array 150 and a drive circuit 180.

The drive circuit 180 individually drives the light emitting elements 100 included in the light emitting element array 150. The drive circuit 180 is a TFT (thin-film-transistor) or CMOS (Complementary Metal Oxide Semiconductor), and may be made of a material such as Si, GaN, or SiC. The drive circuit 180 includes an n-terminal 181 and a p-terminal 182, the n-terminal 181 is connected to the n-electrode 134 of the excitation light source 130 by a lead wire 183, and the p-terminal 182 is connected to the p-electrode 135 of the excitation light source 130 by a lead wire 184. There is. The conductor 183 and the conductor are, for example, Au bumps, but may be Cu-Cu bonded or the like.

By driving the excitation light source 130 included in the red light emitting element 100R, the green light emitting element 100G, and the blue light emitting element 100B by the drive circuit 180, it is possible to emit red, green, and blue, respectively, and display the display device. It is possible to achieve it. Further, by integrating the light emitting element array 150 and the drive circuit 180, it is possible to reduce the size of the display device. Although the display device using the light emitting element array 150 has been described here, the light emitting element array 160 and the drive circuit 180 may be connected to form a display device.

The display device according to this embodiment can be used as a display device for a video wall, a smartphone, a television, a notebook PC, an AR (Augmented Reality) device, a VR (Virtual Reality) device, a projector, a head-up display, a wearable device, and the like. .. Further, the light emitting element and the light emitting element array according to the present embodiment can also be used as a lighting device.

Note that this technology can have the following configurations.

(1)
A group having a first main surface and a second main surface opposite to the first main surface, and a through hole is provided between the first main surface and the second main surface. Wood and
A phosphor layer contained in the through hole and containing a phosphor,
A first sealing film having a gas barrier property and provided on the first main surface side of the phosphor layer,
A second sealing film having a gas barrier property and provided on the first main surface side of the phosphor layer, and
A light emitting device provided with an excitation light source bonded to the first main surface side of the base material and causing excitation light to be incident on the phosphor layer.
(2)
The light emitting element according to (1) above.
A light emitting element that is further provided on the inner peripheral surface of the through hole and covers the entire circumference of the phosphor layer together with the second sealing film.
(3)
The light emitting element according to (2) above.
A light emitting element further comprising a light reflecting film provided between the inner peripheral surface and the first sealing film.
(4)
The light emitting element according to (1) above.
A light emitting device having a gas barrier property, which is provided on the inner peripheral surface and further includes a light reflecting film which covers the entire circumference of the phosphor layer together with the first sealing film and the second sealing film. ..
(5)
The light emitting element according to (1) above.
The light emitting element according to claim 1.
A light emitting element having a gas barrier property and covering the entire circumference of the phosphor layer together with the first sealing film and the second sealing film.
(6)
The light emitting element according to (5) above.
The surface of the base material forming the inner peripheral surface is a light emitting element having light reflectivity.
(7)
The light emitting device according to any one of (3), (4) and (6) above.
The through hole is a light emitting element having a shape in which the distance between the inner peripheral surfaces gradually increases from the first main surface toward the second main surface.
(8)
The light emitting device according to any one of (1) to (7) above.
The phosphor is a light emitting element that is a quantum dot.
(9)
The light emitting device according to any one of (1) to (8) above.
The phosphor layer is a light emitting element in which the phosphor and the scatterer are dispersed in a light-transmitting resin.
(10)
The light emitting device according to (3) or (4) above.
A light emitting element further comprising an etching stop layer provided between the base material and the light reflecting film.
(11)
The light emitting device according to any one of (1) to (10) above.
The first sealing film has a thickness that transmits the excitation light and reflects the fluorescence.
The second sealing film is a light emitting element having a thickness that transmits the fluorescence and reflects the excitation light.
(12)
The light emitting device according to any one of (1) to (11) above.
A light emitting element further comprising a lens bonded to the second main surface side of the base material.
(13)
A group having a first main surface and a second main surface opposite to the first main surface, and a through hole is provided between the first main surface and the second main surface. A material, a phosphor layer contained in the through hole and containing a phosphor, a first sealing film having a gas barrier property and provided on the first main surface side of the phosphor layer, and a gas barrier. It is bonded to the second sealing film provided on the second main surface side of the phosphor layer and the first main surface side of the base material, and is excited by the phosphor layer. A light emitting element array in which a plurality of light emitting elements including an excitation light source for incident light are arranged.
(14)
The light emitting element array according to (13) above.
The light emitting element has a first light emitting element including a first phosphor in which the phosphor layer emits fluorescence of the first color, and a second light emitting element in which the phosphor layer has a second color different from the first color. A light emitting element array containing a second light emitting element containing a second phosphor that emits fluorescence.
(15)
The light emitting element array according to (13) above.
The light emitting element includes a first phosphor in which the phosphor layer emits fluorescence of a first color, and a second phosphor in which a second color different from the first color is emitted.
A first color filter bonded to the second main surface side of the base material and transmitting light of the first color, and a first color filter.
A light emitting element array further comprising a second color filter bonded to the second main surface side of the base material and transmitting light of the second color.
(16)
A group having a first main surface and a second main surface opposite to the first main surface, and a through hole is provided between the first main surface and the second main surface. A material, a phosphor layer contained in the through hole and containing a phosphor, a first sealing film having a gas barrier property and provided on the first main surface side of the phosphor layer, and a gas barrier. It is bonded to the second sealing film provided on the second main surface side of the phosphor layer and the first main surface side of the base material, and is excited by the phosphor layer. A light emitting element array in which a plurality of light emitting elements including an excitation light source for incident light are arranged, and
A display device including a drive circuit for driving the excitation light source.

100 ... Light emitting element 110 ... Light emitting part 111 ... Base material 111a ... First main surface 111b ... Second main surface 111c ... Through hole 111d ... Inner peripheral surface 112 ... Fluorescent layer 113 ... Light reflecting film 114 ... First sealing film 115 ... Second encapsulant film 121 ... Fluorescent material 122 ... Scatterer 123 ... Filler 130 ... Excitation light source 141 ... Light-shielding part 142 ... Etching stop layer 143 ... Lens 145R ... Red color filter 145G ... Green color filter 145B ...

Blue color filter

150, 160 ... Light emitting element array 160 ... Light emitting element array 170 ... Display device 180 ... Drive circuit

Claims

A group having a first main surface and a second main surface opposite to the first main surface, and a through hole is provided between the first main surface and the second main surface. Wood and
A phosphor layer contained in the through hole and containing a phosphor,
A first sealing film having a gas barrier property and provided on the first main surface side of the phosphor layer,
A second sealing film having a gas barrier property and provided on the second main surface side of the phosphor layer,
A light emitting device including an excitation light source bonded to the first main surface side of the base material and causing excitation light to be incident on the phosphor layer.
The light emitting element according to claim 1.
A light emitting device that is further provided on the inner peripheral surface of the through hole and covers the entire circumference of the phosphor layer together with the second sealing film.
The light emitting element according to claim 2.
A light emitting element further comprising a light reflecting film provided between the inner peripheral surface and the first sealing film.
The light emitting element according to claim 1.
A light emitting device having a gas barrier property and further provided with a light reflecting film provided on the inner peripheral surface and covering the entire circumference of the phosphor layer together with the first sealing film and the second sealing film. ..
The light emitting element according to claim 1.
A light emitting device having a gas barrier property and covering the entire circumference of the phosphor layer together with the first sealing film and the second sealing film.
The light emitting element according to claim 5.
The surface of the base material forming the inner peripheral surface is a light emitting element having light reflectivity.
The light emitting device according to any one of claims 3, 4 and 6.
The through hole is a light emitting element having a shape in which the distance between the inner peripheral surfaces gradually increases from the first main surface toward the second main surface.
The light emitting element according to claim 1.
The phosphor is a light emitting element which is a quantum dot.
The light emitting element according to claim 1.
The phosphor layer is a light emitting element in which the phosphor and the scatterer are dispersed in a light-transmitting resin.
The light emitting element according to claim 3 or 4.
A light emitting element further comprising an etching stop layer provided between the base material and the light reflecting film.
The light emitting element according to claim 1.
The first sealing film has a thickness that transmits the excitation light and reflects the fluorescence.
The second sealing film is a light emitting element having a thickness that transmits the fluorescence and reflects the excitation light.
The light emitting element according to claim 1.
A light emitting element further comprising a lens bonded to the second main surface side of the base material.
A group having a first main surface and a second main surface opposite to the first main surface, and a through hole is provided between the first main surface and the second main surface. A material, a phosphor layer contained in the through hole and containing a phosphor, a first sealing film having a gas barrier property and provided on the first main surface side of the phosphor layer, and a gas barrier. It has a property and is bonded to the first main surface side of the base material with a second sealing film provided on the second main surface side of the phosphor layer and excited to the phosphor layer. A light emitting element array in which a plurality of light emitting elements including an excitation light source for incident light are arranged.
The light emitting element array according to claim 13.
The light emitting element has a first light emitting element including a first phosphor in which the phosphor layer emits fluorescence of the first color, and a second light emitting element in which the phosphor layer has a second color different from the first color. A light emitting element array containing a second light emitting element containing a second phosphor that emits fluorescence.
The light emitting element array according to claim 13.
The light emitting element includes a first phosphor in which the phosphor layer emits fluorescence of a first color, and a second phosphor in which a second color different from the first color is emitted.
A first color filter bonded to the second main surface side of the base material and transmitting light of the first color, and a first color filter.
A light emitting element array further comprising a first color filter bonded to the second main surface side of the base material and transmitting light of the second color.
A group having a first main surface and a second main surface opposite to the first main surface, and a through hole is provided between the first main surface and the second main surface. A material, a phosphor layer contained in the through hole and containing a phosphor, a first sealing film having a gas barrier property and provided on the first main surface side of the phosphor layer, and a gas barrier. It has a property and is bonded to the first main surface side of the base material with a second sealing film provided on the second main surface side of the phosphor layer and excited to the phosphor layer. A light emitting element array in which a plurality of light emitting elements including an excitation light source for incident light are arranged, and
A display device including a drive circuit for driving the excitation light source.