Light emitting device and method for manufacturing the same

Abstract

A first light-emitting device according to an aspect of the present disclosure includes a color conversion layer formed by mixing a quantum dot phosphor in a resin. The color conversion layer has a shading region having a concentration distribution of the quantum dot phosphor in at least a portion thereof.

Description

[Technical field]

[0001] The present disclosure relates, for example, to light emitting devices having quantum dot phosphors and methods of making light emitting devices. [Background technology]

[0002] In recent years, lighting devices and image display devices that are configured by assembling a number of light-emitting diodes (LEDs) have become widespread. For example, an LED display has been proposed in which three LEDs that emit red (R), green (G), and blue (B) light are arranged in a two-dimensional matrix as one pixel, and development is underway of a color conversion type light-emitting device that uses a phosphor placed on an LED as a light source for the LED display to obtain a desired color by color conversion using the phosphor (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2017-538290 Summary of the Invention

[0004] However, in a color conversion type light emitting device using quantum dots as a phosphor, it is required to improve the light extraction efficiency in the forward direction. Therefore, it is desirable to provide a light emitting device capable of improving the light extraction efficiency in the forward direction and a method for manufacturing the light emitting device.

[0005] A first light emitting device according to one aspect of the present disclosure includes a color conversion layer having a quantum dot phosphor mixed in a resin, the color conversion layer having a light and dark region with a distribution in the concentration of the quantum dot phosphor in at least a portion of the color conversion layer.

[0006] A second light emitting device according to one aspect of the present disclosure includes a plurality of pixels arranged two-dimensionally. Each pixel has a color conversion layer formed by mixing a quantum dot phosphor in a resin. The color conversion layer has a light and dark region having a distribution in the concentration of the quantum dot phosphor in at least a portion of the color conversion layer.

[0007] A method for producing a light emitting device according to one aspect of the present disclosure includes the following two steps. (A) applying a color conversion layer made by mixing a quantum dot phosphor in a resin to the inside of a recess of a substrate having a recess with a reflective film provided at least on a side surface thereof; (B) forming a light-shade region in which the concentration of the quantum dot phosphor changes in at least a portion of the color conversion layer by irradiating the color conversion layer with light in a manner that causes optical interference in the color conversion layer;

[0008] In the first and second light-emitting devices according to one aspect of the present disclosure, and in the manufacturing method of the light-emitting device according to one aspect of the present disclosure, a light and dark region in which the concentration of the quantum dot phosphor changes is formed in at least a part of the color conversion layer. This makes it possible to form a reflection structure in the color conversion layer having the same angle as the reflection film on the side wall, so that the excitation light and fluorescence are reflected in front of the reflection film, thereby reducing the effect of loss when reflected by the reflection film. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of a cross-sectional configuration of a light-emitting device according to a first embodiment of the present disclosure. [Diagram 2] 2 is a diagram illustrating an example of a top view configuration of the light emitting device of FIG. 1. [Diagram 3] 2 is a diagram illustrating an example of the rear surface configuration of the light emitting device in FIG. 1. [Figure 4] 1. FIG. 4 is a diagram illustrating a modification of the top view of the light-emitting device of FIG. [Diagram 5] 1. FIG. 4 is a diagram illustrating a modification of the top view of the light-emitting device of FIG. [Figure 6] 4A to 4C are cross-sectional views illustrating an example of a method for manufacturing the light-emitting device of FIG. [Figure 7] 7A to 7C are cross-sectional views illustrating an example of a manufacturing process following FIG. 6. [Figure 8] 8A to 8C are cross-sectional views illustrating an example of a manufacturing process following FIG. 7. [Figure 9] 9A to 9C are cross-sectional views illustrating an example of a manufacturing process following FIG. 8. [Figure 10] 10A to 10C are cross-sectional views illustrating an example of a manufacturing process following FIG. [Figure 11] 11A to 11C are cross-sectional views illustrating an example of a manufacturing process following FIG. [Figure 12] 12 is a cross-sectional view showing an example of a manufacturing process following FIG. 11. [Figure 13] 13 is a cross-sectional view showing an example of a manufacturing process following FIG. 12. [Figure 14] 14A to 14C are cross-sectional views illustrating an example of a manufacturing process following FIG. 13. [Figure 15] 15 is a cross-sectional view showing an example of a manufacturing process following FIG. 14. [Figure 16] 16 is a cross-sectional view showing an example of a manufacturing process following FIG. 15. [Figure 17] 17A to 17C are cross-sectional views illustrating an example of a manufacturing process following FIG. 16. [Figure 18] 18 is a cross-sectional view illustrating an example of a manufacturing process following FIG. 17. [Figure 19] 2 is a diagram for explaining the operation of the light emitting device of FIG. 1. FIG. [Figure 20] 2 is a diagram illustrating a modified example of the cross-sectional configuration of the light-emitting device in FIG. [Figure 21] 21A to 21C are cross-sectional views illustrating an example of a method for manufacturing the light-emitting device of FIG. [Figure 22] 21 is a diagram for explaining the operation of the light emitting device in FIG. 20. FIG. [Diagram 23] 2 is a diagram illustrating a modified example of the cross-sectional configuration of the light-emitting device in FIG. [Figure 24] 24A to 24C are cross-sectional views illustrating an example of a method for manufacturing the light-emitting device of FIG. [Diagram 25] 24 is a diagram for explaining the operation of the light emitting device of FIG. 23. FIG. [Figure 26]2 is a diagram illustrating a modified example of the cross-sectional configuration of the light-emitting device in FIG. [Figure 27] 27A to 27C are cross-sectional views illustrating an example of a method for manufacturing the light-emitting device of FIG. 26. [Figure 28] 27 is a diagram for explaining the operation of the light emitting device in FIG. 26. FIG. [Figure 29] 2 is a diagram illustrating a modified example of the cross-sectional configuration of the light-emitting device in FIG. [Diagram 30] 30A to 30C are cross-sectional views illustrating an example of a method for manufacturing the light-emitting device of FIG. 29. [Diagram 31] 30 is a diagram for explaining the operation of the light emitting device in FIG. 29. FIG. [Diagram 32] FIG. 4 is a diagram illustrating an example of a cross-sectional configuration of a light-emitting device according to a second embodiment of the present disclosure. [Diagram 33] 33 is a diagram illustrating a modified example of the cross-sectional configuration of the light-emitting device in FIG. 32. [Diagram 34] 33 is a diagram illustrating a modified example of the cross-sectional configuration of the light-emitting device in FIG. 32. [Diagram 35] FIG. 13 is a perspective view illustrating an example of a configuration of an image forming apparatus according to a third embodiment of the present disclosure. [Diagram 36] FIG. 36 is a diagram illustrating an example of a circuit layout in the drive substrate of FIG. 35. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiment of the present disclosure will be described in detail with reference to the drawings. The following description is one specific example of the present disclosure, and the present disclosure is not limited to the following embodiment. Furthermore, the present disclosure is not limited to the arrangement, dimensions, and dimensional ratios of each component shown in each drawing. The description will be given in the following order. 1. First embodiment (light emitting device) Examples of shading on the side: Figures 1 to 19 2. Modification of the First Embodiment (Light Emitting Device) Modifications A, B, and C: Examples of providing a shading area in the center...Figures 20 to 28 Modification D: Example of randomly providing light and dark areas on the whole surface...Figures 29 to 31 3. Second embodiment (light-emitting device) Example of multiple pixels: Figures 32 to 34 4. Third embodiment (image display device)...FIG. 35, FIG. 36

[0011] <1. First embodiment> [composition] A light-emitting device 1 according to a first embodiment of the present disclosure will be described. Fig. 1 shows an example of a cross-sectional configuration of the light-emitting device 1. Fig. 2 shows an example of a top configuration of the light-emitting device 1 of Fig. 1. Fig. 3 shows an example of a back configuration of the light-emitting device 1 of Fig. 1. This light-emitting device 1 is suitably used as a display pixel of an image display device known as an LED display.

[0012] The light emitting device 1 includes a reflective structure 20 on the light emitting surface side of the light emitting element 10 via, for example, an adhesive layer 30. The adhesive layer 30 is made of, for example, a UV curing adhesive or a heat curing adhesive that is highly transparent in the visible range. The reflective structure 20 has a substrate 21 having an opening 21A at a position facing the light emitting element 10. The reflective structure 20 has a reflective film 22 on the side of the opening 21A, and further has a color conversion layer 23 within the opening 21A. The reflective film 22 and the color conversion layer 23 are accommodated within the opening 21A. The color conversion layer 23 is made by mixing quantum dot phosphor 231 into resin.

[0013] The light-emitting device 1 corresponds to a specific example of a "light-emitting device" in the present disclosure. The light-emitting element 10 corresponds to a specific example of a "light-emitting element" in the present disclosure. The reflective structure 20 corresponds to a specific example of a "reflective structure" in the present disclosure. The substrate 21 corresponds to a specific example of a "substrate" in the present disclosure. The opening 21A corresponds to a specific example of an "opening" in the present disclosure. The reflective film 22 corresponds to a specific example of a "reflective film" in the present disclosure. The color conversion layer 23 corresponds to a specific example of a "color conversion layer" in the present disclosure. The quantum dot phosphor 231 corresponds to a specific example of a "quantum dot phosphor" in the present disclosure.

[0014] In the light-emitting element 10, the top surface refers to the surface on the reflective structure 20 side, and refers to the light extraction surface. In the light-emitting element 10, the bottom surface or back surface refers to the surface opposite the reflective structure 20. In the reflective structure 20, the top surface refers to the surface opposite the light-emitting element 10, and refers to the light emission surface S of the light-emitting device 1. In the reflective structure 20, the bottom surface or back surface refers to the surface on the light-emitting element 10 side.

[0015] (Light emitting element 10) The light emitting element 10 is a solid-state light emitting element that emits light of a predetermined wavelength band from the top surface, for example, an LED (Light Emitting Diode) chip. The LED chip refers to an LED chip cut from a wafer used for crystal growth, and is not a package type covered with molded resin or the like. The LED chip has a size of, for example, 5 μm to 100 μm, and is called a micro LED. The light emitting element 10 emits excitation light to the color conversion layer 23.

[0016] The light emitting element 10 has, for example, a semiconductor layer formed by sequentially stacking a first conductive type layer 12, an active layer 13, and a second conductive type layer 14, with the second conductive type layer 14 serving as a light extraction surface. A columnar mesa portion 10A including the first conductive type layer 12 and the active layer 13 is provided in this semiconductor layer. The first conductive type layer 12 is exposed at the top of the mesa portion 10A, and a part of the second conductive type layer 14 is exposed at the base of the mesa portion 10A. The light emitting element 10 further has, for example, a first electrode 11 electrically connected to the first conductive type layer 12 and a second electrode 15 electrically connected to the second conductive type layer 14. The first electrode 11 and the second electrode 15 are provided on the back side of the light emitting element 10, respectively.

[0017] The first conductive type layer 12, the active layer 13, and the second conductive type layer 14 are made of materials corresponding to the wavelength band required for the light emitted from the light emitting element 10. The first conductive type layer 12, the active layer 13, and the second conductive type layer 14 are made of, for example, III-V compound semiconductors. The first conductive type layer 12, the active layer 13, and the second conductive type layer 14 are made of, for example, semiconductors capable of emitting ultraviolet light having an emission wavelength of 360 nm or more and 430 nm or less, or light in the blue band having an emission wavelength of 430 nm or more and 500 nm or less. In this case, the active layer 13 is preferably made of, for example, a GaInN-based material.

[0018] The first electrode 11 is in contact with the first conductive type layer 12 and is electrically connected to the first conductive type layer 12. The first electrode 11 is in ohmic contact with the first conductive type layer 12. The first electrode 11 is, for example, a metal electrode, and is made of, for example, a multilayer film (Ni / Au) of nickel (Ni) and gold (Au). The first electrode 11 may be made of, for example, a transparent conductive material such as indium tin oxide (ITO).

[0019] The second electrode 15 is in contact with the second conductive type layer 14 and is electrically connected to the second conductive type layer 14. The second electrode 15 is in ohmic contact with the second conductive type layer 14. The second electrode 15 is, for example, a metal electrode, and is made of, for example, a multilayer film (Ti / Al) of titanium (Ti) and aluminum (Al) or a multilayer film (Cr / Au) of chromium (Cr) and gold (Au). The second electrode 15 may be made of a transparent conductive material, for example, ITO.

[0020] (Reflection structure 20) The reflection structure 20 absorbs light (excitation light) emitted from the light emitting element 10 and extracts wavelength-converted light (e.g., fluorescence) upward. The reflection structure 20 has a light emission surface S. The light emission surface S is a light extraction surface for the wavelength-converted light. The reflection structure 20 has a substrate 21 that supports the light emitting element 10 via an adhesive layer 30. The substrate 21 is made of, for example, a polyimide film. The substrate 21 may be made of, for example, metal, glass, a semiconductor such as Si, or a resist. The substrate 21 has an opening 21A at a position facing the light emitting element 10. In the opening 21A, the opening diameter on the light emission surface S side is larger than the opening diameter on the opposite side to the light emission surface S. That is, the opening 21A has a tapered side surface (inclined surface) whose inner diameter increases toward the light emission surface S side. The side surface of the opening 21A is preferably inclined at 45° with respect to the normal line of the substrate 21. In this case, however, there is a possibility that the size of opening 21A will become too large if the thickness of color conversion layer 23 is to be set to a desired thickness. Therefore, the side surface of opening 21A may be inclined at an angle of less than 45° with respect to the normal line of substrate 21.

[0021] A reflective film 22 is provided on the side of the opening 21A. The reflective film 22 is provided at a location facing at least a part of the side of the color conversion layer 23. The reflective film 22 is provided on the side of the opening 21A and is formed in a plane having a normal in a direction that obliquely intersects with the normal direction of the substrate 21. The reflective film 22 reflects, for example, excitation light emitted from the light emitting element 10 and having a shallow internal angle, or fluorescence emitted from the quantum dot phosphor 231, into the color conversion layer 23. The reflective film 22 is preferably made of a metal material that has a high reflectance in the visible range and a small angle dependency. The reflective film 22 may be made of, for example, Al that has a high average reflectance in the visible range, or may be made of a metal material such as Ag or Au. The reflective film 22 may be made of a dielectric multilayer film. The dielectric multilayer film may be, for example, TiO 2 ,Ta 2 O 5 ,SiO 2 ,Al 2 O 3 It is composed of materials such as:

[0022] A color conversion layer 23 and a sealing film 24 are provided in the opening 21A. The sealing film 24 is provided between the color conversion layer 23 and the reflective film 22. The sealing film 24 serves to protect the surface of the reflective film 22 and to seal the color conversion layer 23 from oxygen and moisture. A sealing film 25 is provided on the light emission surface S side of the color conversion layer 23. The sealing film 25 is provided in contact with the surface of the color conversion layer 23 on the light emission surface S side. The sealing film 25 serves to seal the color conversion layer 23 from oxygen and moisture. The sealing films 24, 25 are made of, for example, SiN, Al 2 O 3 , AlN, ZrO 2 , Ta 2 O 3 , TiO 2 , ZnO, etc.

[0023] Color conversion layer 23 absorbs and converts the wavelength of excitation light emitted from light emitting element 10. Color conversion layer 23 is formed by mixing a plurality of quantum dot phosphors 231 in a resin.

[0024] The quantum dot phosphor 231 absorbs the excitation light emitted from the light emitting element 10 and emits fluorescence. The quantum dot phosphor 231 is a particulate phosphor that emits fluorescence with a blue wavelength of 430 nm to 500 nm, a green wavelength of 500 nm to 550 nm, or a red wavelength of 610 nm to 780 nm. The quantum dot phosphor 231 is configured to include one or more types of materials selected from, for example, CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, InP, GaN, GaAs, GaP, AlN, AlP, AlSb, InN, InAs, InSb, and perovskite-based materials.

[0025] The most important factor in determining the fluorescent wavelength (fluorescent color) of the quantum dot phosphor 231 is the band gap energy of the material constituting the quantum dot. For this reason, it is desirable to select a material according to the desired fluorescent color. For example, in order to obtain red fluorescence, the quantum dot phosphor material is preferably selected from, for example, InP, GaInP, InAsP, CdSe, CdZnSe, CdTeSe, and CdTe. In order to obtain green fluorescence, the quantum dot phosphor material is preferably selected from, for example, InP, GaInP, ZnSeTe, ZnTe, CdSe, CdZnSe, CdS, and CdSeS. In order to obtain blue fluorescence, the quantum dot phosphor material is preferably selected from, for example, ZnSe, ZnTe, ZnSeTe, CdSe, CdZnSe, CdS, CdZnS, and CdSeS. It should be noted that the quantum dot phosphor material is not limited to the above, and may be, for example, CuInSe 2 , CuInS 2 , CuInGaS and AgInS 2 Other examples include CsPb(Cl / Br) 3 , CsPbBr 3 , CsPb(I / Br) 3 and CsPbI 3 A perovskite nanophosphor made of the above may also be used.

[0026] In addition, the fluorescent color of the quantum dot phosphor 231 can be controlled by its particle size. For example, the fluorescent wavelength becomes shorter as the particle size becomes smaller. In order to obtain fluorescent light with high color purity, it is desirable to select phosphor particles with a controlled particle size.

[0027] The quantum dot phosphor 231 preferably has a core / shell structure consisting of a core part that emits light and has an average particle size of, for example, about 2 to 10 nm, and a shell layer that covers and protects the core part. The shell layer is composed of one or more layers. The shell layer may further include silicon oxide (SiO 2 ) and aluminum oxide (Al 2 O 3The quantum dot phosphor 231 may be covered with an inorganic film such as a polyaniline film. A large number of organic ligands are coordinated to the surface of the quantum dot phosphor 231, and the organic ligands suppress the aggregation of the quantum dot phosphor 231 when the quantum dot phosphor is mixed with a solvent, and improve the dispersibility.

[0028] For filling the quantum dot phosphor 231, for example, an inkjet type or needle type dispenser is used to eject or apply the resin mixed with the quantum dot phosphor 231 depending on the viscosity of the resin. This is classified as a plateless printing method, and since the quantum dot phosphor 231 can be selectively filled only in the barrier, it is possible to improve the utilization efficiency of the quantum dot phosphor 231. The resin containing the quantum dot phosphor 231 may be applied to a predetermined location using screen printing or gravure printing technology, which are plate-based printing methods. In addition, the resin containing the quantum dot phosphor 231 may be applied to the entire substrate, such as with a spin coater.

[0029] The resin mixed with the quantum dot phosphor 231 is for dispersing the quantum dot phosphor 231 uniformly, and is preferably formed using a material that is optically transparent to the excitation light. Specific examples of the resin material include ultraviolet curing resin and thermosetting resin. Sol-gel glass and the like may also be used.

[0030] The opening 21A has a rectangular shape, for example, as shown in Fig. 2. The opening 21A is not limited to a rectangular shape, and may have a polygonal shape, for example, as shown in Fig. 4, or a circular shape, as shown in Fig. 5.

[0031] Incidentally, the color conversion layer 23 has a shading region 23a having a distribution in the concentration of the quantum dot phosphor 231 in at least a part of the color conversion layer 20. The shading region 23a is provided in a position close to the reflective film 22 as shown in FIG. 1, for example, and has shading at a predetermined period (for example, 100 nm to several μm) in the normal direction of the reflective film 22. The quantum dot phosphor 231 has a relatively high refractive index with respect to the resin mixed with the quantum dot phosphor 231. Therefore, in the color conversion layer 23, the refractive index is relatively high in the region where the concentration of the quantum dot phosphor 231 is relatively high, and the refractive index is relatively low in the region where the concentration of the quantum dot phosphor 231 is relatively low. For this reason, by alternately stacking the region where the concentration of the quantum dot phosphor 231 is high and the region where the concentration of the quantum dot phosphor 231 is low, the region where the refractive index is relatively high and the region where the refractive index is relatively low are alternately stacked. Therefore, the light and shade region 23a can reflect the fluorescent light and the excitation light.

[0032] The structure in which the concentration of the quantum dot phosphor 231 changes periodically on the order of the wavelength of light can be produced, for example, by utilizing the effect of light interference when UV-curing a UV-curable resin in which the quantum dot phosphor 231 is dispersed. For example, a standing wave is generated by interfering with two types of UV light with different travel directions, and the interference creates areas with strong and weak light intensity at a certain period. By using this interference light to cure a UV-curable resin in which the quantum dot phosphor 231 is dispersed, a structure in which the quantum dot phosphor 231 has a shading on the order of the wavelength of light can be formed. Since a standing wave is generated in the direction of the difference in wave vectors of the two types of UV light with different travel directions, the shading of the quantum dot phosphor 231 also occurs along the direction of the standing wave. For this reason, by controlling the travel directions of the two types of UV light, the shading of the quantum dot phosphor 231 can be formed in any direction. The shading period d of the quantum dot phosphor 231 is expressed by the period of interference of the two types of UV light as shown in formula (1). In formula (1), n ​​is the refractive index of the resin in which the quantum dot phosphor 231 is dispersed. From formula (1), the period of the shading of the quantum dot phosphor 231 can be controlled by the wavelength λ of the UV light and the angle θ between the two types of UV light. This makes it possible to control the period to reflect light of a desired wavelength. d = (λ / n) / (2sinθ) ... Equation (1)

[0033] Two kinds of UV light with different travel directions can be realized by branching one UV light and irradiating it at different angles with the optical path length aligned. However, it can be realized more easily by using the reflection of the side wall of the container in which the quantum dot phosphor 231 is filled. When collimated UV light is irradiated from above during UV curing, the travel direction of the component of light reflected by the side wall changes. Standing waves can be generated by the interference between the incident light traveling in the vertical direction and the reflected light at the side wall. At this time, standing waves are generated in the normal direction of the side wall, so the shading of the quantum dot phosphor 231 is also formed in the normal direction of the side wall. As a result, when a reflective film is provided on the side wall, it is possible to form a reflective structure having the same angle as the reflective film on the side wall in the color conversion layer 23. As a result, by reflecting the excitation light and fluorescence in front of the reflective film, the effect of loss when reflected by the reflective film can be reduced, and the light extraction efficiency is improved.

[0034] [Manufacturing method] Next, a method for manufacturing the light emitting device 1 according to the present embodiment will be described. Figures 6 to 18 show an example of a manufacturing process for the light emitting device 1.

[0035] First, one side of the substrate 21 made of a 10 μm thick polyimide film is plated with Cu, and the other side is plated with Ni. As a result, a Cu layer 110 is formed on the upper surface of the substrate 21, and a Ni layer 100 is formed on the rear surface of the substrate 21 (FIG. 6). Next, a part of the Cu layer 110 is patterned using a general photolithography technique and development technique, and a part of the Cu layer 110 is removed. As a result, an opening 110A is formed in the Cu layer 110 (FIG. 7). Next, a part of the substrate 21 is removed by wet etching using the Cu layer 110 as a mask. As a result, an opening 21A is formed in the substrate 21 (FIG. 8).

[0036] Next, the Cu layer 110 is removed using a weak alkaline etchant that is selective to Ni (FIG. 9). Next, Al and SiO 2are successively formed by sputtering (FIG. 10). As a result, a reflective film 22 and a sealing film 24 are formed. At this time, the reflective film 22 and the sealing film 24 are provided on the side surface of the opening 21A, and are formed in a plane having a normal line in a direction that diagonally intersects with the normal line direction of the substrate 21. Next, the color conversion layer 23 made by mixing quantum dot phosphor 231 in resin is applied (filled) into the opening 21A using an inkjet method (FIG. 11). Next, if the resin mixed with the quantum dot phosphor 231 is a UV curable resin, a collimated mercury lamp is used as a light source when curing the resin.

[0037] Light is irradiated onto the color conversion layer 23 in such a manner that optical interference occurs within the color conversion layer 23. For example, collimated UV light L is irradiated vertically from above onto the color conversion layer 23 to harden the resin (FIG. 12). At this time, standing waves are generated by the UV light L incident in the vertical direction and the UV light reflected by the reflective film 22 provided on the side wall of the opening 21A interfering with each other, and a structure (shade region 23a) in which the shading of the quantum dot phosphor 231 changes periodically in the normal direction of the reflective film 22 on the order of the wavelength of light can be obtained in at least a part of the color conversion layer 23 (FIG. 13). At this time, the shade region 23a having a predetermined period of shading in the normal direction of the reflective film 22 can be formed in a position close to the reflective film 22.

[0038] The wavelength of the most intense emission line of the mercury lamp is 365 nm, and the spectral width is sufficiently smaller than 1 nm. Since the smaller the spectral width, the longer the coherence length, it is preferable to use a light source with a narrow spectral width. The wavelength of the UV light is preferably in the range of 300 nm to 400 nm, and the full width at half maximum is preferably 5 nm or less. An LD (Laser Diode) or a solid-state laser may be used instead of the mercury lamp. Next, SiO 2 is deposited by a sputtering method. As a result, sealing film 25 is formed on color conversion layer 23 (FIG. 14). As a result, the entire surface of color conversion layer 23 is covered with a dense inorganic film, which makes it possible to suppress the effects of deterioration of quantum dot phosphors 231 due to oxygen and water.

[0039] Next, the glass substrate 130 is bonded to the sealing film 25 side using the adhesive layer 120 (FIG. 15). Next, the Ni layer 100 on the back surface is removed by an etchant selective to Al (FIG. 16). Next, a photoresist having an opening only in a portion facing the reflective film 22 exposed on the back surface is formed, and then a part of the reflective film 22 is removed by wet etching using the photoresist as a mask (FIG. 17). As a result, an opening 22A is formed in the reflective film 22. Then, the photoresist is removed. Next, the adhesive layer 30 is applied to the opening 22A, and the light emitting element 10 is bonded to the substrate 21 via the adhesive layer 30 (FIG. 18). Finally, the glass substrate 130 and the adhesive layer 120 are removed. In this manner, the light emitting device 1 is manufactured.

[0040] [effect] Next, effects of the light emitting device 1 according to the present embodiment will be described.

[0041] In this embodiment, a shaded region 23a in which the concentration of the quantum dot phosphor 231 changes is formed in at least a portion of the color conversion layer 23. This allows a reflection structure having the same angle as the reflection film 22 on the side wall to be formed in the color conversion layer 23, so that, for example, as shown in Fig. 19, by reflecting the excitation light or fluorescence in front of the reflection film 22, the effect of loss caused when reflected by the reflection film 22 can be reduced. Therefore, the light extraction efficiency can be improved.

[0042] In this embodiment, the quantum dot phosphor 231 is configured to include one or more types of materials selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, InP, GaN, GaAs, GaP, AlN, AlP, AlSb, InN, InAs, InSb, and perovskite-based materials. This makes it possible to obtain, for example, red fluorescence, green fluorescence, and blue fluorescence. In this way, in this embodiment, full-color light can be generated by selecting the material of the quantum dot phosphor 231. Therefore, the light-emitting device 1 can be suitably used as a display pixel of an image display device called a so-called LED display.

[0043] In this embodiment, the reflective film 22 is provided at a location facing at least a part of the side surface of the color conversion layer 23. This allows the excitation light and fluorescence transmitted through the light and shade region 23a to be reflected by the reflective film 22, thereby improving the light extraction efficiency.

[0044] In this embodiment, a substrate 21 having an opening 21A in which a color conversion layer 23 and a reflective film 22 are housed is provided, and further, a light emitting element 10 is provided that is supported by the substrate 21 and emits excitation light to the color conversion layer 23. This makes it possible to manufacture a large number of light emitting devices 1 at once by mounting the light emitting element 10 on the substrate 21 using, for example, a transfer technique. Therefore, it is possible to provide light emitting devices 1 at low cost.

[0045] In this embodiment, the shading region 23a is provided in a position close to the reflective film 22, and has shading at a predetermined period in the normal direction of the reflective film 22. This makes it possible to form a reflective structure in the color conversion layer 23 having the same angle as the reflective film 22 on the side wall, so that by reflecting the excitation light and fluorescence just before the reflective film 22, it is possible to reduce the effect of loss caused when reflected by the reflective film 22. Therefore, it is possible to improve the light extraction efficiency.

[0046] In this embodiment, the reflective film 22 is formed in a plane having a normal in a direction that obliquely intersects with the deposition direction of the color conversion layer 23. This makes it possible to easily extract light (e.g., fluorescent light) that has been wavelength-converted by absorbing light (excitation light) emitted from the light emitting element 10 upwards. This makes it possible to improve the light extraction efficiency.

[0047] <2. Modification of the First Embodiment> Next, a modification of the light emitting device 1 according to the above embodiment will be described.

[0048] [Variation A] Fig. 20 shows a modified cross-sectional configuration of the light-emitting device 1 according to the above embodiment. In the above embodiment, the shading region 23a may be provided in the central portion of the color conversion layer 23, for example, as shown in Fig. 20, and may have shading at a predetermined period in a direction parallel to the deposition direction of the color conversion layer 23.

[0049] In this case, in the manufacturing process, for example, as shown in FIG. 21, the color conversion layer 23 is irradiated with collimated UV light L obliquely from above to harden the resin. At this time, the obliquely incident UV light L and the UV light reflected by the reflective film 22 provided on the bottom surface of the opening 21A interfere with each other to generate standing waves, and a structure (shade region 23a) in which the shading of the quantum dot phosphor 231 periodically changes on the order of the wavelength of light in the normal direction of the reflective film 22 (normal direction of the substrate 21) can be obtained in at least a part of the color conversion layer 23. As a result, for example, as shown in FIG. 22, by reflecting the excitation light and fluorescence in front of the reflective film 22, the effect of loss when reflected by the reflective film 22 can be reduced. Therefore, the light extraction efficiency can be improved.

[0050] [Variation B] Fig. 23 shows a modified cross-sectional configuration of the light-emitting device 1 according to the above embodiment. In the above embodiment, the shading region 23a may be provided in the central portion of the color conversion layer 23, for example, as shown in Fig. 23, and may have shading at a predetermined period in a direction perpendicular to the deposition direction of the color conversion layer 23.

[0051] In this case, in the manufacturing process, for example, as shown in FIG. 24, two kinds of collimated UV light L are irradiated onto the color conversion layer 23 at an incident angle of ±30° from different directions to harden the resin. At this time, the two kinds of UV light L incident at an incident angle of ±30° from different directions interfere with each other to generate standing waves, and a structure (shade region 23a) in which the shading of the quantum dot phosphor 231 periodically changes on the order of the wavelength of light in the normal direction of the reflective film 22 (normal direction of the substrate 21) can be obtained in at least a part of the color conversion layer 23. At this time, in order to reduce reflection at the bottom surface, for example, as shown in FIG. 24, an opening 22A may be provided in the reflective film 22 at a position corresponding to the bottom surface of the opening 21A, and a relatively thick adhesive layer 140 may be provided in the gap between the Ni layer 100 and the substrate 21 including the opening 22A. 25, for example, by reflecting the excitation light or fluorescence in front of the reflective film 22, it is possible to reduce the influence of loss caused by reflection at the reflective film 22. Therefore, it is possible to improve the light extraction efficiency.

[0052] [Variation C] Fig. 26 shows a modified cross-sectional configuration of the light-emitting device 1 according to the above embodiment. In the above embodiment, the shading region 23a may be provided in the center of the color conversion layer 23, for example, as shown in Fig. 26, and may have shading in a direction parallel to the deposition direction of the color conversion layer 23 and in a direction intersecting a direction perpendicular to the deposition direction of the color conversion layer 23. In this case, the reflective film 22 is formed in a plane having a normal in a direction perpendicular to the deposition direction of the color conversion layer 23, for example.

[0053] In this case, in the manufacturing process, for example, as shown in FIG. 27, two kinds of collimated UV light L are irradiated to the color conversion layer 23 at incident angles of 30° and 60° from a common direction, thereby hardening the resin. At this time, the two kinds of UV light L incident at incident angles of 30° and 60° from a common direction interfere with each other, generating a standing wave in the 45° direction, and a structure (shade region 23a) in which the shading of the quantum dot phosphor 231 periodically changes in the order of the wavelength of light in the normal direction of the reflective film 22 (normal direction of the substrate 21) can be obtained in at least a part of the color conversion layer 23. At this time, in order to reduce reflection at the bottom surface, for example, as shown in FIG. 27, an opening 22A may be provided in the reflective film 22 at a position corresponding to the bottom surface of the opening 21A, and a relatively thick adhesive layer 140 may be provided in the gap between the Ni layer 100 and the substrate 21, including the opening 22A. 28, for example, by reflecting the excitation light or fluorescence in front of the reflective film 22, it is possible to reduce the influence of loss caused by reflection at the reflective film 22. Therefore, it is possible to improve the light extraction efficiency.

[0054] In this modification, for example, as shown in Fig. 26, the reflective film 22 may be formed in a plane having a normal in a direction perpendicular to the deposition direction of the color conversion layer 23. Even in this case, for example, as shown in Fig. 28, the light refracted in the light and dark region 23a often travels in a direction that obliquely intersects with the normal to the substrate 21, so that the light reflected by the reflective film 22 can be extracted to the outside. Therefore, even if the reflective film 22 is formed in a plane having a normal in a direction perpendicular to the deposition direction of the color conversion layer 23, the light extraction efficiency can be improved.

[0055] [Variation D] FIG. 29 shows a modified example of the cross-sectional structure of the light-emitting device 1 according to the above embodiment. In this modified example, a color conversion layer 26 is provided instead of the color conversion layer 23. In the color conversion layer 26, shading regions having a distribution in the concentration of the quantum dot phosphor 231 are provided throughout the color conversion layer 26, and have random shading in all directions. For example, as shown in FIG. 29, the color conversion layer 26 has a plurality of high-concentration regions 26a in which the concentration of the quantum dot phosphor 231 is relatively high, and a plurality of low-concentration regions 26b in which the concentration of the quantum dot phosphor 231 is relatively low. The plurality of high-concentration regions 26a are randomly distributed throughout the color conversion layer 26.

[0056] In this case, in the manufacturing process, for example, as shown in FIG. 30, collimated UV light L is obliquely irradiated from above to the color conversion layer 26D, which is made by mixing the quantum dot phosphor 231 in the resin, through the diffusion plate 200, to harden the resin. At this time, the light scattered by the diffusion plate 200 generates a random speckle pattern in the color conversion layer 26D, and the resin is hardened under the condition that the light intensity of the UV light is spatially randomly modulated. As a result, for example, as shown in FIG. 31, the effective optical path length of the excitation light is longer than that in the case where the multiple high concentration regions 26a are not provided, and the absorption rate can be increased. By isotropically scattering the fluorescence, a light distribution pattern close to Lambertian is obtained when it is radiated from the color conversion layer 26 into the air. The same effect as that when not only the quantum dot phosphor 231 but also the scatterer is dispersed in the color conversion layer 26 can be obtained. Therefore, the light extraction efficiency can be improved.

[0057] In addition, in this modification, since no scatterer is provided in addition to the multiple high-concentration regions 26a, the concentration of the quantum dot phosphor 231 in the color conversion layer 26 can be increased. If a scatterer is used, it becomes difficult to increase the concentration of the quantum dot phosphor 231 by the amount of the scatterer. Therefore, in this modification, the concentration of the quantum dot phosphor 231 can be increased, and the effective optical path length can be lengthened by scattering. This increases the absorptance of the quantum dot phosphor 231, and thus the color conversion layer 26 can be made thinner and the amount of the quantum dot phosphor 231 used can be reduced without decreasing the light extraction efficiency.

[0058] <3. Second embodiment> Next, an example in which the light emitting device 1 according to the above embodiment and its modified example is used as a pixel will be described. Fig. 32 shows an example of a cross-sectional configuration of a light emitting device 2 according to a second embodiment of the present disclosure. The light emitting device 2 includes a plurality of pixels 1R, 1G, and 1B (first pixels) arranged two-dimensionally.

[0059] The pixels 1R, 1G, and 1B emit light of different wavelengths. The pixel 1R is configured by the light-emitting device 1 according to the above embodiment and its modified example, and is a pixel in which the color conversion layer 23 is configured to emit red fluorescence. In this embodiment, the color conversion layer 23 in the pixel 1R is referred to as the color conversion layer 23R. The color conversion layer 23R includes a quantum dot phosphor 231 made of a material that emits red fluorescence. In the color conversion layer 23R, the quantum dot phosphor 231 is made of a material selected from, for example, InP, GaInP, InAsP, CdSe, CdZnSe, CdTeSe, and CdTe.

[0060] The pixel 1G is constituted by the light emitting device 1 according to the above embodiment and its modified example, and is a pixel in which the color conversion layer 23 is configured to emit green fluorescence. In the present embodiment, the color conversion layer 23 in the pixel 1G is referred to as the color conversion layer 23G. The color conversion layer 23G includes a quantum dot phosphor 231 made of a material that emits green fluorescence. In the color conversion layer 23G, the quantum dot phosphor 231 is made of a material selected from, for example, InP, GaInP, ZnSeTe, ZnTe, CdSe, CdZnSe, CdS, CdSeS, and the like.

[0061] The pixel 1B is a pixel in which, instead of the color conversion layer 23 in the light emitting device 1 according to the above embodiment and its modifications, a scattering layer 23B formed by mixing a scatterer 232 in a resin is provided.

[0062] The scatterer 232 preferably has an average particle size larger than that of the quantum dot phosphor 231 and a refractive index larger than that of the resin. The scatterer 232 preferably uses a dielectric substance having a particle size of, for example, 100 nm or more and 1000 nm or less. A specific material for the scatterer 232 is, for example, silicon oxide (SiO 2 ), titanium dioxide (TiO 2 ), aluminum oxide (Al 2 O 3 ), aluminum nitride (AlN), boron nitride (BN), zinc oxide (ZnO), etc. The pixel 1B is configured to emit light of the same wavelength as the light emitted from the light emitting element 10. When the light emitting element 10 emits ultraviolet light having an emission wavelength of 360 nm or more and 430 nm or less, or light in the blue band having an emission wavelength of, for example, 430 nm or more and 500 nm or less (that is, when the pixel 1B is provided with a light emitting element 10 that emits light common to the light emitting elements 10 provided in the pixels 1R and 1G), the pixel 1B emits ultraviolet light or light in the blue band.

[0063] The reflection structures 20 in the pixels 1R, 1G, and 1B are formed on a common substrate 21. A microlens array 28 may be bonded to the substrate 21 on which the pixels 1R, 1G, and 1B are formed via an adhesive layer 27, as shown in FIG. 33, for example. In this case, each of the pixels 1R, 1G, and 1B is assigned to one microlens included in the microlens array 28. A drive substrate 40 provided with a drive circuit for driving the light-emitting elements 10 included in the pixels 1R, 1G, and 1B may be bonded to the substrate 21 on which the pixels 1R, 1G, and 1B are formed, as shown in FIG. 34, for example. In this case, a pad electrode 41 on the drive substrate 40 is electrically connected to the second electrode 15 of the light-emitting element 10 via a bump 43 provided on the pad electrode 41. In addition, a pad electrode 42 on the drive substrate 40 is electrically connected to the first electrode 11 of the light-emitting element 10 via a bump 44 provided on the pad electrode 42.

[0064] In this embodiment, a set of pixels 1R, 1G, and 1B can be a unit pixel when displaying a color image. In this embodiment, a pixel that emits a single color light (for example, white light) other than red, green, and blue may be provided.

[0065] In this embodiment, the light emitting device 1 according to the above embodiment and its modified example is used for a pixel, thereby realizing a high brightness image display device.

[0066] <4. Third embodiment> Next, an example in which the light emitting device 2 according to the second embodiment is used as a unit pixel when displaying a color image will be described. Fig. 35 shows a perspective configuration example of an image display device 3 according to a third embodiment of the present disclosure. The image display device 3 is a so-called LED display, in which LEDs are used as display pixels.

[0067] 35, the image display device 3 includes a display panel 50 and a drive circuit (not shown) that drives the display panel 50. The display panel 50 is, for example, a mounting substrate 50A and a transparent substrate 50B that are stacked on top of each other. The surface of the transparent substrate 50B serves as an image display surface, and has a display area in the center and a frame area, which is a non-display area, around the display area.

[0068] Fig. 36 shows an example of the layout of a region corresponding to the display region on the surface of the mounting substrate 50A on the transparent substrate 50B side. In the region corresponding to the display region on the surface of the mounting substrate 50A, a plurality of data lines DTL are formed extending in a predetermined direction and arranged in parallel at a predetermined pitch, for example, as shown in Fig. 36. In the region corresponding to the display region on the surface of the mounting substrate 50A, a plurality of scan lines SCL are further formed extending in a direction intersecting (for example, perpendicular to) the data lines DTL and arranged in parallel at a predetermined pitch. The data lines DTL and the scan lines SCL are made of a conductive material such as Cu (copper).

[0069] The scan line SCL is formed, for example, on the outermost layer, for example, on an insulating layer (not shown) formed on the surface of a substrate. The substrate of the mounting substrate 50A is made of, for example, a glass substrate or a resin substrate, and the insulating layer on the substrate is made of, for example, SiNx, SiOx, or AlxOy. On the other hand, the data line DTL is formed in a layer (for example, a layer below the outermost layer) different from the outermost layer including the scan line SCL, for example, in an insulating layer on the substrate. In addition to the scan line SCL, for example, a black is provided on the surface of the insulating layer as needed. The black is for enhancing contrast and is made of a light absorbing material. The black is formed, for example, in at least an area of ​​the surface of the insulating layer where the pad electrodes 53 and 54 described below are not formed. The black can be omitted as needed.

[0070] The vicinity of the intersection of the data line DTL and the scan line SCL constitutes a display pixel 51, and a plurality of display pixels 51 are arranged in a matrix within the display area. A light-emitting device 2 is mounted on each display pixel 51. Note that the image display device 3 shown in Fig. 36 is an example of a passive matrix type image display device, and the light-emitting device 2 can also be applied to an active matrix type image display device.

[0071] In this embodiment, the light emitting device 2 according to the second embodiment is used in the display pixel 51. This makes it possible to realize an image display device 3 with high brightness.

[0072] Although the present disclosure has been described above by way of an embodiment, the present disclosure is not limited to the above embodiment and various modifications are possible. Note that the effects described in this specification are merely examples. The effects of the present disclosure are not limited to the effects described in this specification. The present disclosure may have effects other than those described in this specification.

[0073] Furthermore, for example, the present disclosure can have the following configuration. (1) A color conversion layer is provided in which a quantum dot phosphor is mixed in a resin, The color conversion layer has a light and dark region having a distribution in concentration of the quantum dot phosphor in at least a part of the color conversion layer. Light emitting device. (2) The quantum dot phosphor is composed of one or more types of materials selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, InP, GaN, GaAs, GaP, AlN, AlP, AlSb, InN, InAs, InSb, and perovskite-based materials. The light-emitting device according to (1). (3) A reflective film is further provided at a location facing at least a portion of the side surface of the color conversion layer. A light-emitting device according to (1) or (2). (4) a substrate having an opening in which the color conversion layer and the reflective film are housed; a light-emitting element supported by the substrate and configured to emit excitation light toward the color conversion layer; Further equipped (3) A light-emitting device according to (3). (5) The light and dark area is provided in the vicinity of the reflective film and has light and dark patterns at a predetermined interval in the normal direction of the reflective film. A light-emitting device according to (3) or (4). (6) The light and dark region is provided in the center of the color conversion layer and has light and dark shading at a predetermined interval in a direction parallel to the deposition direction of the color conversion layer. A light-emitting device according to (3) or (4). (7) The light and dark region is provided in the center of the color conversion layer and has light and dark shading at a predetermined interval in a direction perpendicular to the deposition direction of the color conversion layer. A light-emitting device according to (3) or (4). (8) The light and dark areas are provided over the entire color conversion layer and have random light and dark areas in all directions. A light-emitting device according to (3) or (4). (9) The reflective film is formed in a plane having a normal line in a direction obliquely intersecting with the deposition direction of the color conversion layer. A light-emitting device according to any one of (5) to (8). (10) The shading region is provided in a central portion of the color conversion layer, and has shading in a direction parallel to a deposition direction of the color conversion layer and a direction perpendicular to the deposition direction of the color conversion layer. A light-emitting device according to (3) or (4). (11) The reflective film is formed in a plane having a normal line perpendicular to the deposition direction of the color conversion layer. The light-emitting device according to (10). (12) A plurality of first pixels arranged two-dimensionally, Each of the first pixels has a color conversion layer formed by mixing a quantum dot phosphor in a resin, The color conversion layer has a light and dark region having a distribution in concentration of the quantum dot phosphor in at least a part of the color conversion layer. Light emitting device. (13) Further comprising a plurality of second pixels arranged two-dimensionally and having a scattering layer formed by mixing a scattering body in a resin, Each of the first pixels further includes a first light-emitting element that emits excitation light to the color conversion layer, Each of the second pixels further includes a second light-emitting element that emits light common to the first light-emitting element and the first light-emitting element toward the scattering layer. The light-emitting device according to (12). (14) Each of the first pixels and each of the second pixels further includes a microlens on a light exit surface. The light-emitting device according to (13). (15) The light emitting element may further include a drive circuit that drives the first light emitting element included in each of the first pixels and the second light emitting element included in each of the second pixels. The light-emitting device according to (13). (16) A substrate has a recess with a reflective film on at least a side surface thereof, and a color conversion layer formed by mixing a quantum dot phosphor in a resin is applied to the recess; forming a light-shade region in which the concentration of the quantum dot phosphor changes in at least a part of the color conversion layer by irradiating the color conversion layer with light in a manner that causes optical interference in the color conversion layer; Includes A method for manufacturing a light-emitting device. (17) the reflective film is provided on a side surface of the recess and is provided in a plane having a normal line in a direction obliquely intersecting a normal line direction of the substrate, The light is irradiated onto the color conversion layer in a direction parallel to the normal direction of the substrate, thereby forming the light and shade region having a predetermined period in the normal direction of the reflective film at a position close to the reflective film. Includes A method for producing a light-emitting device according to (16). (18) the reflective film is provided on a bottom surface of the recess, The light is irradiated onto the color conversion layer from a direction obliquely intersecting a normal direction of the substrate, thereby forming the light and shade region having a predetermined period in the normal direction of the bottom surface. Includes A method for producing a light-emitting device according to (16). (19) The light is scattered light, and the light-and-shade area having random light and shade in all directions is formed by irradiating the color conversion layer with the light. Includes A method for producing a light-emitting device according to (16).

[0074] According to the first light-emitting device and the second light-emitting device according to one aspect of the present disclosure, and the manufacturing method of the light-emitting device according to one aspect of the present disclosure, a shading region in which the concentration of the quantum dot phosphor changes is formed in at least a part of the color conversion layer, so that a reflection structure having the same angle as the reflection film of the side wall can be formed in the color conversion layer. As a result, by reflecting the excitation light or fluorescence in front of the reflection film, the influence of the loss when reflected by the reflection film is reduced, so that the light extraction efficiency can be improved. Note that the effects of the present disclosure are not necessarily limited to the effects described here, and may be any of the effects described in this specification.

[0075] This application claims priority based on Japanese Patent Application No. 2020-026367, filed on February 19, 2020 in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0076] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur to those skilled in the art depending on design requirements and other factors, and that such modifications are within the scope of the appended claims and their equivalents.

Claims

1. A color conversion layer formed by mixing a quantum dot phosphor in a resin; a reflective film provided at a position facing at least a part of a side surface of the color conversion layer; Equipped with the color conversion layer has a light and dark region having a distribution in concentration of the quantum dot phosphor in at least a portion of the color conversion layer, The light and dark region is provided in the center of the color conversion layer and has light and dark shading at a predetermined interval in a direction parallel to the deposition direction of the color conversion layer. Light emitting device.

2. A color conversion layer comprising a quantum dot phosphor mixed in a resin; a reflective film provided at a position facing at least a part of a side surface of the color conversion layer; Equipped with the color conversion layer has a light and dark region having a distribution in concentration of the quantum dot phosphor in at least a portion of the color conversion layer, The shading region is provided in a central portion of the color conversion layer, and has shading in a direction parallel to a deposition direction of the color conversion layer and a direction perpendicular to the deposition direction of the color conversion layer. Light emitting device.

3. The quantum dot phosphor is composed of one or more types of materials selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, InP, GaN, GaAs, GaP, AlN, AlP, AlSb, InN, InAs, InSb, and perovskite-based materials. A light emitting device according to claim 1 or 2.

4. a substrate having an opening in which the color conversion layer and the reflective film are housed; a light-emitting element supported by the substrate and configured to emit excitation light toward the color conversion layer; Further equipped A light emitting device according to claim 1 or 2.

5. The reflective film is formed in a plane having a normal line perpendicular to the deposition direction of the color conversion layer. The light emitting device of claim 2.

6. A plurality of first pixels arranged two-dimensionally, Each of the first pixels is A color conversion layer formed by mixing a quantum dot phosphor in a resin; a reflective film provided at a position facing at least a part of a side surface of the color conversion layer; having the color conversion layer has a light and dark region having a distribution in concentration of the quantum dot phosphor in at least a portion of the color conversion layer, The light and dark region is provided in the center of the color conversion layer and has light and dark shading at a predetermined interval in a direction parallel to the deposition direction of the color conversion layer. Light emitting device.

7. A method for detecting a pixel value comprising: Each of the first pixels includes a color conversion layer formed by mixing a quantum dot phosphor in a resin, a reflective film provided at a position facing at least a part of a side surface of the color conversion layer; having the color conversion layer has a light and dark region having a distribution in concentration of the quantum dot phosphor in at least a portion of the color conversion layer, The shading region is provided in a central portion of the color conversion layer, and has shading in a direction parallel to a deposition direction of the color conversion layer and a direction perpendicular to the deposition direction of the color conversion layer. Light emitting device.

8. The liquid crystal display further includes a plurality of second pixels that are two-dimensionally arranged and have a scattering layer formed by mixing a scattering body in a resin, Each of the first pixels further includes a first light-emitting element that emits excitation light to the color conversion layer, Each of the second pixels further includes a second light-emitting element that emits light common to the first light-emitting element and the second light-emitting element toward the scattering layer. A light emitting device according to claim 6 or claim 7.

9. Each of the first pixels and each of the second pixels further includes a microlens on a light exit surface.

9. The light emitting device of claim 8.

10. The light emitting element may further include a drive circuit that drives the first light emitting element included in each of the first pixels and the second light emitting element included in each of the second pixels.

9. The light emitting device of claim 8.

11. A substrate has a recess with a reflective film on at least a side surface thereof, and a color conversion layer formed by mixing a quantum dot phosphor in a resin is applied to the recess; forming a light-shade region in which the concentration of the quantum dot phosphor changes in at least a part of the color conversion layer by irradiating the color conversion layer with light in a manner that causes optical interference in the color conversion layer; Including, the reflective film is provided on a side surface of the recess and is provided in a plane having a normal line in a direction obliquely intersecting a normal line direction of the substrate, The light is irradiated onto the color conversion layer in a direction parallel to the normal direction of the substrate, thereby forming the light and shade region having a predetermined period in the normal direction of the reflective film at a position close to the reflective film. Further includes A method for manufacturing a light-emitting device.

12. A substrate having a recess with a reflective film on at least a side surface, the recess being coated with a color conversion layer formed by mixing a quantum dot phosphor in a resin; forming a light-shade region in which the concentration of the quantum dot phosphor changes in at least a part of the color conversion layer by irradiating the color conversion layer with light in a manner that causes optical interference in the color conversion layer; Including, the reflective film is provided on a bottom surface of the recess, The light is irradiated onto the color conversion layer from a direction obliquely intersecting a normal direction of the substrate, thereby forming the light and shade region having a predetermined period in the normal direction of the bottom surface. Further includes A method for manufacturing a light-emitting device.

13. A substrate having a recess with a reflective film on at least a side surface, the recess being coated with a color conversion layer formed by mixing a quantum dot phosphor in a resin; forming a light-shade region in which the concentration of the quantum dot phosphor changes in at least a portion of the color conversion layer by irradiating the color conversion layer with light in a manner that causes optical interference in the color conversion layer; forming the light and shade region having light and shade randomly in all directions by irradiating the color conversion layer with scattered light as the light; Includes A method for manufacturing a light-emitting device.

Images