Light-emitting element and display device

Abstract

The present invention provides a light-emitting element and a display device that can extract more wavelength-converted light. [Solution] A light-emitting element comprising: a light source that emits light in a first wavelength range; a wavelength conversion material that converts the light in the first wavelength range into light in a second wavelength range; and a wavelength conversion layer that includes a plurality of single-crystal silicon particles that scatter the light in the first wavelength range.

Description

[Technical Field]

[0001] The present invention relates to a light-emitting element and a display device. [Background technology]

[0002] In recent years, the development of light-emitting elements with wavelength conversion layers has progressed. In such light-emitting elements, the wavelength of light emitted from a light source is converted by the wavelength conversion layer and extracted externally. The wavelength conversion layer contains, for example, titanium oxide particles along with quantum dots (e.g., Patent Document 1). Light-emitting elements are applied, for example, to display devices. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2024-93715 [Overview of the project] [Problems that the invention aims to solve]

[0004] In light-emitting and display devices having a wavelength conversion layer, it is desirable to extract as much wavelength-converted light as possible.

[0005] This invention has been made in view of the above circumstances, and aims to provide a light-emitting element and a display device that can extract more wavelength-converted light. [Means for solving the problem]

[0006] The above problem can be solved by any of the following means (1) to (11).

[0007] (1) A light-emitting element comprising: a light source that emits light in a first wavelength range; a wavelength conversion material that converts the light in the first wavelength range into light in a second wavelength range; and a wavelength conversion layer that includes a plurality of single-crystal silicon particles that scatter the light in the first wavelength range.

[0008] (2) The light-emitting element according to (1) above, wherein the second wavelength range is the red wavelength range and the size of the single crystal silicon particles is 90 nm or more and 130 nm or less.

[0009] (3) The light-emitting element according to (1) or (2) above, wherein the second wavelength range is the green wavelength range and the size of the single crystal silicon particles is 80 nm or more and 110 nm or less.

[0010] (4) The light-emitting element according to any of (1) to (3) above, wherein the first wavelength range is the blue wavelength range.

[0011] (5) The wavelength conversion material is a light-emitting element according to any one of (1) to (4) above, comprising at least one of a quantum dot and a phosphor.

[0012] (6) A display device comprising: a light source provided in each of the first and second pixels that emits light in a first wavelength range; a first wavelength conversion layer provided in the first pixel and containing a first wavelength conversion material that converts light in the first wavelength range into light in a second wavelength range and a plurality of first single-crystal silicon particles that scatter light in the first wavelength range; and a second wavelength conversion layer provided in the second pixel and containing a second wavelength conversion material that converts light in the first wavelength range into light in a third wavelength range different from the second wavelength range and a plurality of second single-crystal silicon particles that scatter light in the first wavelength range.

[0013] (7) The display device according to (6) above, wherein the particle size D1 corresponding to the peak of the particle size distribution of a plurality of first single-crystal silicon particles is different from the particle size D2 corresponding to the peak of the particle size distribution of a plurality of second single-crystal silicon particles.

[0014] (8) The display device according to (7) above, wherein the peak wavelength of the third wavelength range is shorter than the peak wavelength of the second wavelength range, and the magnitude D2 is smaller than the magnitude D1.

[0015] (9) The display device according to (8) above, wherein the first wavelength range is the blue wavelength range, the second wavelength range is the red wavelength range, and the third wavelength range is the green wavelength range.

[0016] (10) The display device according to any one of the above (6) to (9), wherein the light source further comprises a plurality of third single-crystal silicon particles provided in a third pixel, the plurality of third single-crystal silicon particles being provided in the third pixel and scattering light in the first wavelength range.

[0017] (11) The display device according to any one of the above (6) to (10), wherein the light source includes a micro LED (Light Emitting Diode).

Effects of the Invention

[0018] In the light-emitting element and the display device according to one embodiment of the present invention, the wavelength conversion layer includes single-crystal silicon particles. The single-crystal silicon particles selectively scatter light in the first wavelength range. In other words, since scattering of light in the second wavelength range in the wavelength conversion layer is suppressed, self-absorption of light in the second wavelength range can be suppressed. Therefore, it is possible to extract a larger amount of wavelength-converted light.

Brief Description of Drawings

[0019] [Figure 1] It is a cross-sectional view illustrating an example of a configuration of a display device according to one embodiment. [Figure 2A] It is a cross-sectional view illustrating an example of a configuration of the red conversion layer shown in FIG. 1. [Figure 2B] It is a cross-sectional view illustrating an example of a configuration of the green conversion layer shown in FIG. 1. [Figure 3A] It is a diagram for explaining light extracted from the red conversion layer shown in FIG. 1. [Figure 3B] It is a diagram for explaining light extracted from a red conversion layer according to a comparative example. [Figure 4] It is a diagram illustrating an example of scattering spectra of the first single-crystal silicon particles shown in FIG. 3A and the titanium oxide particles shown in FIG. 3B. [Figure 5] It is a diagram illustrating another example of scattering spectra of the first single-crystal silicon particles shown in FIG. 3A and the titanium oxide particles shown in FIG. 3B. [Figure 6]This is a cross-sectional view showing an example of the configuration of the transparent layer in a modified display device. [Modes for carrying out the invention]

[0020] Embodiments of the present invention will be described in detail below with reference to the attached drawings. In the following drawings, the same reference numerals refer to the same components, and the size of each component in the drawings is exaggerated for clarity and convenience of explanation. On the other hand, the embodiments described below are merely illustrative, and various modifications are possible from such embodiments.

[0021] In the following, "upper part" or "top" may include not only items that are directly above and in contact, but also items that are above but not in contact. Similarly, "lower part" or "bottom" may include not only items that are directly below and in contact, but also items that are below but not in contact.

[0022] A singular expression includes plural expressions unless the context clearly indicates that it is singular. Furthermore, when a part is said to "include," "possess," or "have" a component, it does not exclude other components, but rather may include other components, unless otherwise specified.

[0023] Unless explicitly stated otherwise, the steps constituting the method shall be performed in the appropriate order. This order is not necessarily limited to the order in which the steps are described. All examples or illustrative terms are used solely to illustrate the technical idea and are not limited in scope to the claims.

[0024] In the following explanations, when ordinal numbers such as "1st" and "2nd" are used, they are for convenience only and do not prescribe any particular order unless otherwise specified.

[0025] [Embodiment] Figure 1 shows an example of a cross-sectional configuration of a display device (display device 100) according to one embodiment. The display device 100 has, for example, a first structure 110, a second structure 120, and a joint 130. In the display device 100, for example, the second structure 120 and the first structure 110 are stacked, with the joint 130 provided between them. The second structure 120 includes a light source 122. Light emitted from the light source 122 passes through the joint 130 and the first structure 110 in that order and is taken out to the outside of the display device 100. The light source 122 emits, for example, light in the blue wavelength range (for example, 430 nm to 495 nm).

[0026] This display device 100 has multiple red pixels 10r, multiple green pixels 10g, and multiple blue pixels 10b arranged in a matrix. Light in the red wavelength range (e.g., 600nm to 750nm) is extracted from the red pixels 10r, light in the green wavelength range (e.g., 495nm to 570nm) is extracted from the green pixels 10g, and light in the blue wavelength range is extracted from the blue pixels 10b. In the following description, the stacking direction of the second structure 120 and the first structure 110 may be referred to as the Z direction, and the arrangement directions of the red pixels 10r, green pixels 10g, and blue pixels 10b may be referred to as the X direction and Y direction.

[0027] <Configuration of display device 100> (first structure 110) The first structure 110 includes, for example, a transparent substrate 111, a light-shielding matrix 112, a color filter 113, an overcoat layer 114, a partition wall 116, a color conversion layer 117, and a transparent layer 118. The color filter 113 includes, for example, a red color filter 113r, a green color filter 113g, and a blue color filter 113b. The color conversion layer 117 includes, for example, a red conversion layer 117r and a green conversion layer 117g.

[0028] In the red pixel 10r, the transparent substrate 111, red color filter 113r, overcoat layer 114, and red conversion layer 117r are arranged in this order along the Z direction. In the green pixel 10g, the transparent substrate 111, green color filter 113g, overcoat layer 114, and green conversion layer 117g are arranged in this order along the Z direction. In the blue pixel 10b, the transparent substrate 111, blue color filter 113b, overcoat layer 114, and transparent layer 118 are arranged in this order along the Z direction.

[0029] The transparent substrate 111 is, for example, a plate-shaped member having a rectangular planar (XY plane) shape. The transparent substrate 111 is light-transmitting. The transparent substrate 111 contains, for example, a glass material or a resin material. The resin material is, for example, polyimide. The transparent substrate 111 may be flexible.

[0030] The light-shielding matrix 112 is a so-called black matrix. The light-shielding matrix 112 is provided, for example, together with the color filter 113, between one main surface of the transparent substrate 111 and the overcoat layer 114. The light-shielding matrix 112 plays a role in preventing the mixing of light emitted from the red pixel 10r, the green pixel 10g, and the blue pixel 10b, respectively. The light-shielding matrix 112 is provided, for example, between the red color filter 113r and the green color filter 113g, between the green color filter 113g and the blue color filter 113b, and between the blue color filter 113b and the red color filter 113r. The edges of the light-shielding matrix 112 may overlap with the edges of the color filters 113. The light-shielding matrix 112 is made of a patternable light-shielding material.

[0031] The color filter 113 selectively transmits light in a predetermined wavelength range. The red color filter 113r selectively transmits light in the red wavelength range. The green color filter 113g selectively transmits light in the green wavelength range. The blue color filter 113b selectively transmits light in the blue wavelength range. By providing such color filters 113, the color purity of the light extracted from the red pixel 10r, green pixel 10g, and blue pixel 10b can be increased. The color filter 113 contains, for example, a resin material.

[0032] The overcoat layer 114 is provided between the color filter 113, the color conversion layer 117, and the transparent layer 118. The overcoat layer 114 is further provided between the light-shielding matrix 112 and the partition wall 116. This overcoat layer 114 flattens the main surface side of the transparent substrate 111 on which the light-shielding matrix 112 and the color filter 113 are provided, and also protects the color filter 113. The overcoat layer 114 contains, for example, a photosensitive acrylic resin. The refractive index of the overcoat layer 114 is, for example, about 1.5.

[0033] The partition wall 116 separates the red pixels 10r, green pixels 10g, and blue pixels 10b. The height (size in the Z direction) of the partition wall 116 is approximately the same as the thickness of the red conversion layer 117r, the green conversion layer 117g, and the transparent layer 118. The height of the partition wall 116 is, for example, 5 μm or more and 50 μm or less. It is preferable that the partition wall 116 has light reflection properties for light in the wavelength range emitted from the light source 122 and light in the wavelength range converted by the red conversion layer 117r and the green conversion layer 117g. As a result, light that is emitted directly from the light source 122, or that passes from the light source 122 through the red conversion layer 117r and the green conversion layer 117g and heads toward the partition wall 116, is reflected by the partition wall 116. Therefore, the utilization efficiency of the light emitted from the light source 122 is increased, and the light extraction efficiency can be improved. The partition wall 116 contains, for example, a white pigment and a resin material. Suitable resin materials include, for example, photosensitive resin materials such as acrylic resins, epoxy resins, silicone resins, and polyimide resins.

[0034] The color conversion layers 117 provided on the red pixels 10r and green pixels 10g convert the wavelength of light incident from the second structure 120 side and transmit it to the transparent substrate 111 side.

[0035] Figure 2A shows an example of the configuration of the red conversion layer 117r, and Figure 2B shows an example of the configuration of the green conversion layer 117g. The red conversion layer 117r provided in the red pixel 10r includes, for example, a first wavelength conversion material 1171r, first single-crystal silicon particles 1172r, and a binder 1173. The green conversion layer 117g provided in the green pixel 10g includes, for example, a second wavelength conversion material 1171g, second single-crystal silicon particles 1172g, and a binder 1173.

[0036] The first wavelength conversion material 1171r and the second wavelength conversion material 1171g are, for example, phosphors or quantum dots. In other words, the first wavelength conversion material 1171r and the second wavelength conversion material 1171g each contain at least one of a phosphor and a quantum dot. The first wavelength conversion material 1171r converts the wavelength of light emitted from the light source 122 to the red wavelength range. The concentration of the first wavelength conversion material 1171r contained in the red conversion layer 117r is, for example, 5 wt% to 50 wt%. The second wavelength conversion material 1171g converts the wavelength of light emitted from the light source 122 to the green wavelength range. The concentration of the second wavelength conversion material 1171g contained in the green conversion layer 117g is, for example, 5 wt% to 70 wt%.

[0037] In the red conversion layer 117r, multiple first single-crystal silicon particles 1172r are dispersed in the binder 1173. The first single-crystal silicon particles 1172r are composed of single-crystal silicon (c-Si). The first single-crystal silicon particles 1172r have, for example, a spherical shape. The particle size D1 corresponding to the peak of the particle size distribution of the multiple first single-crystal silicon particles 1172r is, for example, between 90 nm and 130 nm. The concentration of the first single-crystal silicon particles 1172r contained in the red conversion layer 117r is, for example, 0.5 wt% to 15 wt%.

[0038] In the green conversion layer 117g, multiple second single-crystal silicon particles 1172g are dispersed in the binder 1173. The second single-crystal silicon particles 1172g are composed of single-crystal silicon. The second single-crystal silicon particles 1172g have, for example, a spherical shape. The particle size D2 corresponding to the peak in the particle size distribution of the multiple second single-crystal silicon particles 1172g is different from the particle size D1. As will be described in detail later, this makes it easier to suppress the scattering of light in the red wavelength range in the red conversion layer 117r and light in the green wavelength range in the green conversion layer 117g.

[0039] It is preferable that size D2 is smaller than size D1. Size D2 is, for example, between 80 nm and 110 nm. For example, when size D1 is 100 nm, size D2 is 90 nm. For example, when size D1 is 90 nm, size D2 is 80 nm. For example, when size D1 is 130 nm, size D2 is 110 nm. The concentration of the second single-crystal silicon particles 1172 g contained in the green conversion layer 117 g is, for example, 0.5 wt% to 15 wt%.

[0040] The binder 1173 contained in the red conversion layer 117r and the green conversion layer 117g, respectively, includes, for example, a resin material such as a silicone resin, epoxy resin, or acrylic resin.

[0041] The transparent layer 118 provided on the blue pixel 10b transmits light emitted from the light source 122 to the transparent substrate 111 with high transmittance. The transparent layer 118 transmits light emitted from the light source 122 with a transmittance of, for example, 70% or more. The transparent layer 118 contains, for example, a resin material. The transparent layer 118 does not contain, for example, single-crystal silicon particles.

[0042] (Second structure 120) The second structure 120 includes, for example, a TFT (Thin Film Transistor) substrate 121, a light source 122, and an anisotropic conductive film 123.

[0043] The TFT substrate 121 is positioned opposite the transparent substrate 111 in the Z direction. This TFT substrate 121 is a substrate for driving the light source 122 and includes, for example, a base material, a wiring layer and TFTs provided on the base material. The wiring layer may have other driving elements instead of TFTs. Alternatively, the display device 100 may be passively matrix driven.

[0044] Multiple light sources 122 are provided on the TFT substrate 121. A light source 122 is provided for each of the red pixels 10r, green pixels 10g, and blue pixels 10b. The light source 122 includes, for example, a micro-LED (Light Emitting Diode). This light source 122 has, for example, a rectangular planar (XY plane) shape. The size of one side of this rectangle is, for example, between 1 μm and 100 μm. The light source 122 has a three-dimensional shape, for example, a roughly rectangular parallelepiped or a roughly cube. The light source 122 includes, for example, a gallium nitride (GaN)-based semiconductor material and emits light in the blue wavelength range. An anisotropic conductive film 123 is provided on the TFT substrate 121 together with the multiple light sources 122. Here, a structure including a light source 122 and a red conversion layer 117r, or a structure including a light source 122 and a green conversion layer 117g, corresponds to one specific example of the light-emitting element of the present invention.

[0045] (joint part 130) The joint 130 provided between the first structure 110 and the second structure 120 joins the first structure 110 and the second structure 120. The thickness (size in the Z direction) of the joint 130 is, for example, 5 μm or less. The joint 130 contains an adhesive or glue. Preferably, the joint 130 contains, for example, a transparent epoxy resin and a silicone resin.

[0046] <Method for manufacturing the display device 100> Next, a description of the manufacturing method for the display device 100 will be provided.

[0047] The first structure 110 is manufactured, for example, as follows. First, a light-shielding matrix 112 and a color filter 113 are formed on a transparent substrate 111 in that order. When forming the color filter 113, a red color filter 113r is formed on the red pixel 10r, a green color filter 113g on the green pixel 10g, and a blue color filter 113b on the blue pixel 10b. Subsequently, an overcoat layer 114 is formed on the transparent substrate 111 so as to cover the light-shielding matrix 112 and the color filter 113.

[0048] Next, a partition wall 116 is formed on the overcoat layer 114 using a photolithography process. Then, a color conversion layer 117 and a transparent layer 118 are formed in the region enclosed by the partition wall 116. This forms the first structure 110.

[0049] In the formation of the color conversion layer 117, the red conversion layer 117r contains a first wavelength conversion material 1171r and a plurality of first single-crystal silicon particles 1172r, and the green conversion layer 117g contains a second wavelength conversion material 1171g and a plurality of second single-crystal silicon particles 1172g.

[0050] Multiple first single-crystal silicon particles 1172r having a particle size distribution peak at size D1 and multiple second single-crystal silicon particles 1172g having a particle size distribution peak at size D2 can be formed, for example, as follows.

[0051] First, silicon monoxide (SiO) is subjected to a thermal decomposition reaction to obtain single-crystal silicon particles with a particle size in the nanometer range. Specifically, the solid silicon monoxide is heat-treated in a nitrogen atmosphere at 1450°C to 1550°C, and then the solvent is replaced with hydrofluoric acid etching methanol.

[0052] Next, particles within a predetermined particle size range are extracted from the obtained single-crystal silicon particles. For this extraction, for example, density gradient centrifugation can be used.

[0053] The second structure 120 is manufactured, for example, as follows: First, a TFT substrate 121 is formed. After that, a light source 122 and an anisotropic conductive film 123 are formed on the TFT substrate 121.

[0054] After forming the first structure 110 and the second structure 120, the first structure 110 and the second structure 120 are joined together as follows. First, a joining material that will form the joint 130 is applied to the second structure 120. Next, the first structure 110 is positioned and placed on top of the surface of the second structure 120 coated with the joining material. Subsequently, under reduced pressure, pressure is applied in a direction that brings the first structure 110 and the second structure 120 closer together. After this, energy such as heat or ultraviolet light is applied to the joining material to cure it and form the joint 130. For example, a full-color display device 100 can be manufactured in this way.

[0055] <Effects and Effects of Display Device 100> In this display device 100, light in the blue wavelength range is emitted from light sources 122 provided in each of the red pixel 10r, green pixel 10g, and blue pixel 10b, and passes through the junction 130. In the red pixel 10r, the light that has passed through the junction 130 is incident on the red conversion layer 117r and converted into light in the red wavelength range by the first wavelength conversion material 1171r. This light in the red wavelength range passes through the overcoat layer 114, the red color filter 113r, and the transparent substrate 111 in that order. In the green pixel 10g, the light that has passed through the junction 130 is incident on the green conversion layer 117g and converted into light in the green wavelength range by the second wavelength conversion material 1171g. This light in the green wavelength range passes through the overcoat layer 114, the green color filter 113g, and the transparent substrate 111 in that order. In the blue pixel 10b, light emitted from the light source 122 passes through the junction 130, the transparent layer 118, the overcoat layer 114, the blue color filter 113b, and the transparent substrate 111 in that order.

[0056] In the display device 100 of this embodiment, the red conversion layer 117r contains a plurality of first single-crystal silicon particles 1172r, and the green conversion layer 117g contains a plurality of second single-crystal silicon particles 1172g. These first single-crystal silicon particles 1172r and second single-crystal silicon particles 1172g selectively scatter light in the blue wavelength range. As a result, the red pixel 10r can extract more light in the red wavelength range, and the green pixel 10g can extract more light in the green wavelength range. The effects of this will be explained below using comparative examples.

[0057] Figure 3A shows the configuration of the red conversion layer 117r in this embodiment, and Figure 3B shows the configuration of the red conversion layer 1000r in the comparative example. The red conversion layer 1000r in the comparative example does not contain single-crystal silicon particles. This red conversion layer 1000r contains a first wavelength conversion material 1171r and a plurality of titanium oxide (TiO2) particles 1002r.

[0058] The titanium oxide particles 1002r have, for example, a spherical shape. The particle size of the titanium oxide particles 1002r is, for example, 100 nm to 130 nm. The refractive index of the titanium oxide particles 1002r is, for example, 2.7. The refractive index of the first single-crystal silicon particles 1172r and the second single-crystal silicon particles 1172g is greater than the refractive index of the titanium oxide particles 1002r, for example, 4.

[0059] Figures 4 and 5 show examples of scattering spectra for titanium oxide particles 1002r with a particle size of 130 nm and first single-crystal silicon particles 1172r with a particle size of 100 nm. Figure 4 shows the results of an FDTD (Finite-difference time-domain) simulation, and Figure 5 shows the measured values. As shown in Figures 4 and 5, light in the blue wavelength range is selectively scattered by the first single-crystal silicon particles 1172r compared to the titanium oxide particles 1002r.

[0060] Table 1 below shows the simulation results of the scattering intensity ratio between titanium oxide particles 1002r with a particle size of 100 nm and first single-crystal silicon particles 1172r with a particle size of 100 nm. For titanium oxide particles 1002r, the scattering intensity ratio for light in the blue wavelength range (wavelength approximately 450 nm) and red wavelength range (wavelength approximately 650 nm) was 21%, while for first single-crystal silicon particles 1172r, the scattering intensity ratio was 5%.

[0061] [Table 1]

[0062] Table 2 below shows the simulation results of the scattering intensity ratio between titanium oxide particles 1002r with a particle size of 100 nm and second-generation single-crystal silicon particles 1172g with a particle size of 90 nm. For titanium oxide particles 1002r, the scattering intensity ratio for light in the blue wavelength range (wavelength around 450 nm) and light in the green wavelength range (wavelength around 550 nm) was 43%, while for second-generation single-crystal silicon particles 1172g, the scattering intensity ratio was 10%.

[0063] [Table 2]

[0064] Thus, titanium dioxide particles 1002r emit light in the blue wavelength range L b Along with, light in the red wavelength range L r It also scatters. For this reason, in the red conversion layer 1000r of the comparative example, light in the blue wavelength range L b In addition, light in the red wavelength range L r The optical path length also increases. Therefore, the red wavelength range of light L by the first wavelength conversion material 1171r is also increased. r Self-absorption is more likely to occur. Due to this self-absorption, light in the red wavelength range L r It may become difficult to extract a sufficient amount.

[0065] In contrast, the red conversion layer 117r receives light in the red wavelength range L r Since scattering is suppressed, light in the red wavelength range Lr self-absorption is less likely to occur. Therefore, compared with the red conversion layer 1000r, the light L in the red wavelength range r can be extracted in a larger amount. For example, when calculated from the simulation results shown in FIG. 4, compared with the red conversion layer 1000r, the amount of the light L in the red wavelength range is approximately 1.3 times that of the red conversion layer 1000r r can be extracted. The same applies to the green conversion layer 117g. In the display device 100, more light in the red wavelength range and more light in the green wavelength range can be extracted, so that power consumption can be reduced.

[0066] Further, in the display device 100, a particle size D1 of first single-crystal silicon particles 1172r included in the red conversion layer 117r is different from a particle size D2 of second single-crystal silicon particles 1172g included in the green conversion layer 117g. This makes it possible to use single-crystal silicon particles having particle sizes suitable for each of the red conversion layer 117r and the green conversion layer 117g.

[0067] Specifically, in single-crystal silicon particles, the wavelength selectivity of scattering changes depending on the particle size thereof. In single-crystal silicon particles, when the particle size decreases, the wavelength of the scattering peak tends to shift to a shorter wavelength side. For this reason, by using single-crystal silicon particles having particle sizes suitable for each of the red conversion layer 117r and the green conversion layer 117g, it is possible to extract more of both the light in the red wavelength range and the light in the green wavelength range.

[0068] Hereinafter, modified examples of the display device 100 described in the above embodiment will be described. In the following, in order to avoid duplication of description, detailed descriptions of configurations similar to those of the display device 100 described in the above embodiment are omitted.

[0069] [Modified Example] FIG. 6 shows an example of a configuration of a transparent layer 118 of a display device 100 according to a modified example. The transparent layer 118 includes a plurality of third single-crystal silicon particles 1182. Except for this point, the display device 100 according to the modified example has the same configuration as the display device 100 of the above embodiment.

[0070] Multiple third single-crystal silicon particles 1182 are dispersed in this transparent layer 118. The third single-crystal silicon particles 1182 are composed of single-crystal silicon. The third single-crystal silicon particles 1182 have, for example, a spherical shape. The particle size D3 corresponding to the peak of the particle size distribution of the multiple third single-crystal silicon particles 1182 is different from, for example, sizes D1 and D2. Size D3 may be the same as size D1 or size D2. The concentration of the third single-crystal silicon particles 1182 contained in the transparent layer 118 is, for example, 0.5 wt% to 15 wt%.

[0071] The modified display device 100 also contains, similar to the embodiment described above, a red conversion layer 117r containing a plurality of first single-crystal silicon particles 1172r and a green conversion layer 117g containing a plurality of second single-crystal silicon particles 1172g. This makes it possible to extract more light in the red wavelength range from the red pixel 10r and more light in the green wavelength range from the green pixel 10g.

[0072] The configuration of the display device 100 described above is intended to illustrate the main features of the above-described embodiments and modifications, and is not limited to the above configuration. Various modifications are possible within the scope of the claims. Furthermore, it does not preclude configurations found in general display devices.

[0073] For example, although the case where the light source 122 emits light in the blue wavelength range has been described, the light source 122 may emit light in other wavelength ranges. Alternatively, the red pixel 10r, green pixel 10g, and blue pixel 10b may be provided with light sources 122 that emit light in different wavelength ranges from each other.

[0074] Furthermore, although the above-described embodiments describe an example in which the light source 122 includes a micro-LED, the light source 122 may include other light-emitting elements. For example, the light source 122 may include an LED of normal size, or it may include an organic EL (electroluminescence) or an inorganic EL. The display device 100 may include a liquid crystal display element.

[0075] Furthermore, although the above-described embodiments describe an example in which the display device 100 has a red conversion layer 117r and a green conversion layer 117g, the red conversion layer 117r and the green conversion layer 117g may also be applied to other devices such as lighting devices. In other words, the light-emitting element of the present invention may be applied to devices other than display devices, for example, to lighting devices.

[0076] Furthermore, although the above-described embodiments describe an example in which the blue pixel 10b has a transparent layer 118, the blue pixel 10b may also have a wavelength conversion layer.

[0077] Furthermore, while the above-described embodiments have explained the case in which light in the red wavelength range, light in the green wavelength range, and light in the blue wavelength range are extracted from the display device 100, the wavelength range of the light extracted from the display device 100 is not limited to these. [Explanation of symbols]

[0078] 100 display devices, 10r red pixels, 10g green pixel, 10b blue pixels, 110 first structure, 111 Transparent substrate, 112 light-shielding matrix, 113 Color Filters 113r red color filter, 113g green color filter, 113b Green color filter, 114 Overcoat layer 116 Bulkhead; 117r red conversion layer, 1171r first wavelength conversion material, 1172r First single crystal silicon particles, 117g Green conversion layer, 1171g Second wavelength conversion material, 1172g Second single-crystal silicon particles, 1173 Binder, 118 transparent layer, 120 second structure, 121 TFT substrate, 122 light source, 123 Anisotropic conductive film, 130 Bonding layer.

Claims

1. A light source that emits light in the first wavelength range, A wavelength conversion layer comprising a wavelength conversion material that converts light in the first wavelength range to light in the second wavelength range, and a plurality of single-crystal silicon particles that scatter light in the first wavelength range, A light-emitting element characterized by comprising the above.

2. The two wavelength ranges being checked are in the red wavelength range. The light-emitting element according to claim 1, wherein the size of the single-crystal silicon particles is 90 nm or more and 130 nm or less.

3. The two wavelength ranges found are in the green wavelength range. The light-emitting element according to claim 1, wherein the size of the single-crystal silicon particles is 80 nm or more and 110 nm or less.

4. The light-emitting element according to claim 1, wherein the first wavelength range is the blue wavelength range.

5. The light-emitting element according to claim 1, wherein the wavelength-converting material comprises at least one of a quantum dot and a phosphor.

6. A light source is provided in each of the first and second pixels, which emits light in the first wavelength range, A first wavelength conversion layer provided in the first pixel and comprising a first wavelength conversion material that converts light in the first wavelength range into light in the second wavelength range, and a plurality of first single-crystal silicon particles that scatter light in the first wavelength range, A second wavelength conversion layer provided in the second pixel, comprising a second wavelength conversion material that converts light in the first wavelength range into light in a third wavelength range different from the second wavelength range, and a plurality of second single-crystal silicon particles that scatter light in the first wavelength range. A display device equipped with the following features.

7. The display device according to claim 6, wherein the particle size D1 corresponding to the peak of the particle size distribution of a plurality of first single-crystal silicon particles is different from the particle size D2 corresponding to the peak of the particle size distribution of a plurality of second single-crystal silicon particles.

8. The peak wavelength of the aforementioned third wavelength range is shorter than the peak wavelength of the aforementioned second wavelength range. The display device according to claim 7, wherein size D2 is smaller than size D1.

9. The display device according to claim 8, wherein the first wavelength range is the blue wavelength range, the second wavelength range is the red wavelength range, and the third wavelength range is the green wavelength range.

10. The aforementioned light source is further provided in the third pixel, The display device according to claim 6, further comprising a plurality of third single-crystal silicon particles provided in the third pixel and scattering light in the first wavelength range.

11. The display device according to claim 6, wherein the light source includes a micro-LED (Light Emitting Diode).

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