Light-emitting element and display device

Abstract

Provided are a light-emitting element and a display device which enable extraction of a larger amount of wavelength-converted light. The light-emitting element may include: a light source configured to emit light in a first wavelength region; and a wavelength conversion layer including a wavelength conversion material composed to convert the light in the first wavelength region into light in a second wavelength region, and a plurality of single-crystal silicon particles composed to scatter the light in the first wavelength region.

Description

Light-emitting element and display device

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

[0002] Recently, light-emitting devices equipped with a wavelength conversion layer are being developed. In such light-emitting devices, the wavelength of light emitted from a light source is converted in the wavelength conversion layer and emitted externally. The wavelength conversion layer includes, for example, titanium oxide particles along with quantum dots. The light-emitting device is applied, for example, to a display device or a lighting device.

[0003] In a light-emitting element and a display device having a wavelength conversion layer, it is useful to emit more wavelength-converted light.

[0004] The present invention is made in consideration of the above-described circumstances and aims to provide a light-emitting element and a display device capable of emitting more wavelength-converted light.

[0005] According to one aspect of the present disclosure, a light-emitting device is provided comprising: a light source configured to emit light in a first wavelength region; and a wavelength conversion layer comprising a wavelength conversion material configured to convert the light in the first wavelength region into light in a second wavelength region, and a plurality of single-crystal silicon particles configured to scatter the light in the first wavelength region.

[0006] The second wavelength region above may be a red wavelength region, and the size of one of the plurality of single-crystal silicon particles may be 90 nm or more and 130 nm or less.

[0007] The second wavelength region above may be a green wavelength region, and the size of one of the plurality of single-crystal silicon particles may be 80 nm or more and 110 nm.

[0008] The first wavelength region mentioned above may be a blue wavelength region.

[0009] The wavelength conversion material may include at least one quantum dot and a phosphor.

[0010] According to one aspect of the present disclosure, a display device is provided comprising: a light source provided to each of a first pixel and a second pixel, each light source configured to emit light in a first wavelength region; a first wavelength conversion layer provided to the first pixel and comprising a first wavelength conversion material configured to convert light in the first wavelength region into light in a second wavelength region and a plurality of first single-crystal silicon particles configured to scatter light in the first wavelength region; and a second wavelength conversion layer provided to the second pixel and comprising a second wavelength conversion material configured to convert light in the first wavelength region into light in a third wavelength region different from the second wavelength region and a plurality of second single-crystal silicon particles configured to scatter light in the first wavelength region.

[0011] In the above display device, the particle size D1 corresponding to the peak of the first particle size distribution of the plurality of first single-crystal silicon particles and the particle size D2 corresponding to the peak of the second particle size distribution of the plurality of second single-crystal silicon particles may be different.

[0012] The peak wavelength of the third wavelength region is shorter than the peak wavelength of the second wavelength region, and the size D2 may be smaller than the size D1.

[0013] The first wavelength region may be a blue wavelength region, the second wavelength region may be a red wavelength region, and the third wavelength region may be a green wavelength region.

[0014] The light source may further include a plurality of third single-crystal silicon particles that are provided to the third pixel and scatter light in the first wavelength region.

[0015] The above light source may include a micro LED (Light Emitting Diode).

[0016] According to one aspect of the present disclosure, a lighting device is provided comprising: a first wavelength conversion layer provided in a first pixel and configured to convert light in a first wavelength region into light in a second wavelength region, and a plurality of first single-crystal silicon particles configured to scatter light in the first wavelength region; and a second wavelength conversion layer provided in a second pixel and configured to convert light in the first wavelength region into light in a third wavelength region different from the second wavelength region, and a plurality of second single-crystal silicon particles configured to scatter light in the first wavelength region.

[0017] The lighting device may further include a transparent layer comprising a plurality of third single-crystal silicon particles.

[0018] In the above lighting device, the particle size D1 corresponding to the peak of the first particle size distribution of the plurality of first single-crystal silicon particles and the particle size D2 corresponding to the peak of the second particle size distribution of the plurality of second single-crystal silicon particles may be different.

[0019] The peak wavelength of the third wavelength region is shorter than the peak wavelength of the second wavelength region, and the size D2 may be smaller than the size D1.

[0020] The first wavelength region may be a blue wavelength region, the second wavelength region may be a red wavelength region, and the third wavelength region may be a green wavelength region.

[0021] The lighting device may further include a plurality of third single-crystal silicon particles that scatter light in the first wavelength region.

[0022] The above-described aspects and other aspects, features, and advantages of specific embodiments of the present disclosure can be more clearly understood by referring together with the accompanying drawings and the description below.

[0023] FIG. 1 is a cross-sectional view showing an example of the configuration of a display device according to one embodiment.

[0024] FIG. 2a is a cross-sectional view showing an example of the configuration of the red conversion layer shown in FIG. 1.

[0025] FIG. 2b is a cross-sectional view showing an example of the configuration of the green conversion layer shown in FIG. 1.

[0026] Figure 3a is a figure for explaining the light emitted from the red conversion layer shown in Figure 1.

[0027] Figure 3b is a figure for explaining the light emitted from the red conversion layer according to a comparative example.

[0028] FIG. 4 is a figure showing an example of the scattering spectra of the first single-crystal silicon particle shown in FIG. 3a and the titanium oxide particle shown in FIG. 3b.

[0029] Figure 5 is a figure showing another example of the scattering spectra of the first single-crystal silicon particle shown in Figure 3a and the titanium oxide particle shown in Figure 3b.

[0030] FIG. 6 is a cross-sectional view showing an example of the configuration of a transparent layer in a display device according to a modified example.

[0031] Hereinafter, one or more embodiments of the present invention will be described in detail with reference to the attached drawings. In the drawings below, the same reference numerals indicate the same components, and the size of each component in the drawings may be exaggerated for clarity and convenience of explanation. The embodiments described below are merely illustrative and various modifications are possible from such embodiments.

[0032] In the following, terms designated as "upper" or "above" may include not only those directly above in contact, but also those above without contact. Likewise, terms designated as "lower" or "below" may include not only those directly below in contact, but also those below without contact.

[0033] A singular expression includes a plural expression unless the context clearly indicates that it is singular. Furthermore, where a part 'includes,' 'possesses,' or 'has,' a certain component, this does not exclude other components unless specifically stated otherwise, but means that other components may be further included.

[0034] Regarding the steps constituting the method, there is no explicit description of the order or the opposite thereof, and the steps are executed in an appropriate order. The method is not necessarily limited to the order described above. All examples or the use of exemplary terms are merely for describing the technical concept, and the scope is not limited by such examples or exemplary terms unless limited by the patent claims.

[0035] Furthermore, in the following explanations, when ordinal numbers such as '1' and '2' are used, unless otherwise specifically stated, they are used for convenience and do not prescribe any order.

[0036] [Embodiment]

[0037] FIG. 1 illustrates an example of a cross-sectional configuration of a display device (display device (100)) according to one embodiment. The display device (100) may include, 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, and a joint (130) is provided (or 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 this order and is emitted to the outside of the display device (100). The light source (122) emits light in a blue wavelength range (for example, 430 nm to 495 nm).

[0038] In this display device (100), a plurality of red pixels (10r), a plurality of green pixels (10g), and a plurality of blue pixels (10b) are arranged in a matrix shape. Light in the red wavelength region (e.g., 600nm to 750nm) is emitted from the red pixels (10r), light in the green wavelength region (e.g., 495nm to 570nm) is emitted from the green pixels (10g), and light in the blue wavelength region is emitted from the blue pixels (10b). In the following description, the stacking direction of the second structure (120) and the first structure (110) may be the Z direction, and the arrangement direction of the red pixels (10r), green pixels (10g), and blue pixels (10b) may be the X direction and the Y direction.

[0039] <Configuration of the display device (100)>

[0040] (First structure (110))

[0041] The first structure (110) includes, for example, a transparent substrate (111), a light-blocking 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).

[0042] In the red pixel (10r), a transparent substrate (111), a red color filter (113r), an overcoat layer (114), and a red conversion layer (117r) are arranged in this order along the Z direction. In the green pixel (10g), a transparent substrate (111), a green color filter (113g), an overcoat layer (114), and a green conversion layer (117g) are arranged in this order along the Z direction. In the blue pixel (10b), a transparent substrate (111), a blue color filter (113b), an overcoat layer (114), and a transparent layer (118) are arranged in this order along the Z direction.

[0043] The transparent substrate (111) is, for example, a plate-shaped member having a rectangular planar (XY plane) shape. The transparent substrate (111) has light transmittance. The transparent substrate (111) includes, for example, a glass material or a resin material. The resin material is, for example, polyimide. The transparent substrate (111) may have plasticity.

[0044] The light-blocking matrix (112) is a so-called black matrix. The light-blocking matrix (112) is provided, for example, between the main surface of one side of the transparent substrate (111) and the overcoat layer (114), together with the color filter (113). The light-blocking matrix (112) serves to prevent the mixing of light emitted from each of the red pixel (10r), the green pixel (10g), and the blue pixel (10b). The light-blocking 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 end of the light-blocking matrix (112) may overlap with the end of the color filter (113). The light-blocking matrix (112) is composed of a patternable light-blocking material.

[0045] A color filter (113) selectively transmits light in a predetermined wavelength range. A red color filter (113r) selectively transmits light in a red wavelength range. A green color filter (113g) selectively transmits light in a green wavelength range. A blue color filter (113b) selectively transmits light in a blue wavelength range. By providing such a color filter (113), the color purity of the light emitted from each of the red pixel (10r), the green pixel (10g), and the blue pixel (10b) can be increased. The color filter (113) includes, for example, a resin material.

[0046] 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 also provided between the light-blocking matrix (112) and the partition wall (116). This overcoat layer (114) serves to flatten the main surface of the transparent substrate (111) on which the light-blocking matrix (112) and the color filter (113) are provided, while simultaneously protecting 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.

[0047] The partition wall (116) partitions the red pixel (10r), the green pixel (10g), and the blue pixel (10b). The height (size in the Z direction) of the partition wall (116) is approximately equal to 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. The partition wall (116) may have light reflection properties for light in a wavelength range emitted from the light source (122) and light in a wavelength range converted by the red conversion layer (117r) and the green conversion layer (117g). As a result, light directed toward the partition wall (116) either directly from the light source (122) or through the red conversion layer (117r) and the green conversion layer (117g) from the light source (122) is reflected from the partition wall (116). Therefore, the utilization efficiency of the light emitted from the light source (122) is increased, and it becomes possible to improve the light extraction efficiency. The partition wall (116) includes, for example, a white pigment and a resin material. For the resin material, photosensitive resin materials such as acrylic resin, epoxy resin, silicone resin, and polyimide resin may be used.

[0048] The color conversion layer (117) provided in the red pixel (10r) and the green pixel (10g) converts the wavelength of light incident from the second structure (120) and transmits it to the transparent substrate (111).

[0049] FIG. 2a shows an example of the configuration of a red conversion layer (117r), and FIG. 2b shows an example of the configuration of a green conversion layer (117g). The red conversion layer (117r) provided in the red pixel (10r) includes, for example, a first wavelength conversion material (1171r), a first single-crystal silicon particle (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), a second single-crystal silicon particle (1172g), and a binder (1173).

[0050] 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 include at least one phosphor and a quantum dot. The first wavelength conversion material (1171r) converts the wavelength of light emitted from the light source (122) into a red wavelength region. The concentration of the first wavelength conversion material (1171r) included 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) into a green wavelength region. The concentration of the second wavelength conversion material (1171g) included in the green conversion layer (117g) is, for example, 5wt% to 70wt%.

[0051] In the red conversion layer (117r), a plurality of first single-crystal silicon particles (1172r) are dispersed within 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 a spherical shape, for example. The particle size D1 corresponding to the peak of the particle size distribution of the plurality of first single-crystal silicon particles (1172r) is, for example, 90 nm or more and 130 nm or less. The concentration of the first single-crystal silicon particles (1172r) included in the red conversion layer (117r) is, for example, 0.5 wt% to 15 wt%.

[0052] In the green conversion layer (117g), a plurality of second single-crystal silicon particles (1172g) are dispersed within the binder (1173). The second single-crystal silicon particles (1172g) are composed of single-crystal silicon. The second single-crystal silicon particles (1172g) have a spherical shape, for example. The particle size D2 corresponding to the peak of the particle size distribution of the plurality of second single-crystal silicon particles (1172g) is different from the size D1. As will be described in detail later, this makes it easier to suppress the scattering of light in the red wavelength region in the red conversion layer (117r) and light in the green wavelength region in the green conversion layer (117g).

[0053] Size D2 may be smaller than size D1. Size D2 is, for example, 80 nm or more and 110 nm or less. 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) included in the green conversion layer (117 g) is, for example, 0.5 wt% to 15 wt%.

[0054] The binder (1173) included in each of the red conversion layer (117r) and the green conversion layer (117g) includes, for example, a resin material such as a silicone resin, an epoxy resin, or an acrylic resin.

[0055] The transparent layer (118) provided in the blue pixel (10b) transmits light emitted from the light source (122) to the transparent substrate (111) side with high transmittance. The transparent layer (118) transmits light emitted from the light source (122) with, for example, a transmittance of 70% or more. The transparent layer (118) includes, for example, a resin material. For example, single-crystal silicon particles are not provided in the transparent layer (118).

[0056] (Second structure (120))

[0057] The second structure (120) includes, for example, a Thin Film Transistor (TFT) substrate (121), a light source (122), and an anisotropic conductive film (123).

[0058] The TFT substrate (121) is positioned facing the transparent substrate (111) in the Z direction. This TFT substrate (121) is a substrate for driving a light source (122) and, for example, includes a substrate, a wiring layer provided on the substrate, and a TFT. The wiring layer may have other driving elements instead of a TFT. Alternatively, the display device (100) may be a passive matrix drive.

[0059] A plurality of light sources (122) are provided on the TFT substrate (121). The light sources (122) are provided on each of the red pixel (10r), the green pixel (10g), and the blue pixel (10b). The light sources (122) include, for example, a micro LED (Light Emitting Diode). The light sources (122) have, for example, a rectangular planar (XY plane) shape. The size of one side of this rectangle is, for example, 1 μm or more and 100 μm or less. The light sources (122) have a three-dimensional shape, for example, a roughly rectangular prism or a roughly cube. The light sources (122) include, for example, a gallium nitride (GaN)-based semiconductor material and emit light in the blue wavelength region. An anisotropic conductive film (123) is provided on the TFT substrate (121) together with the plurality of 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 embodiment of the light-emitting element of the present invention.

[0060] (Joining part (130))

[0061] A 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) includes an adhesive or adhesive, etc. The joint (130) may include, for example, a transparent epoxy resin and a silicone resin, etc.

[0062] Method for manufacturing a display device (100)

[0063] Next, a method for manufacturing a display device (100) is described.

[0064] The first structure (110) is manufactured, for example, as follows. First, a light-blocking matrix (112) and a color filter (113) are formed on a transparent substrate (111) in this order. In forming the color filter (113), a red color filter (113r) is formed on a red pixel (10r), a green color filter (113g) is formed on a green pixel (10g), and a blue color filter (113g) is formed on a blue pixel (10g). Subsequently, an overcoat layer (114) is formed on the transparent substrate (111) by covering the light-blocking matrix (112) and the color filter (113).

[0065] Next, a partition wall (116) is formed on the overcoat layer (114) using a photolithography process. Next, a color conversion layer (117) and a transparent layer (118) are formed in the area enclosed by the partition wall (116). As a result, a first structure (110) is formed.

[0066] 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).

[0067] A plurality of first single-crystal silicon particles (1172r) having a peak in the particle size distribution at size D1 and a plurality of second single-crystal silicon particles (1172g) having a peak in the particle size distribution at size D2 can be formed, for example, as follows.

[0068] 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, silicon monoxide in bulk form is heat-treated at 1450°C to 1550°C under a nitrogen atmosphere, and then solvent substitution is performed with hydrofluoric acid etching methanol.

[0069] Next, particles within a predetermined particle size range are extracted from the obtained single-crystal silicon particles. For this extraction, for example, a density gradient centrifugation method may be used.

[0070] The second structure (120) is manufactured, for example, as follows. First, a TFT substrate (121) is formed. Afterward, a light source (122) and an anisotropic conductive film (123) are formed on the TFT substrate (121).

[0071] After forming the first structure (110) and the second structure (120), the first structure (110) and the second structure (120) are joined as follows. First, a bonding material that becomes the bonding portion (130) is coated on the second structure (120). Next, the first structure (110) is positioned and overlapped on the surface of the second structure (120) coated with the bonding material. Subsequently, under reduced pressure, pressure is applied in a direction that brings the first structure (110) and the second structure (120) closer together. Afterward, energy such as heat or ultraviolet rays is added to the bonding material to cure it, thereby forming the bonding portion (130). For example, a full-color display device (100) can be manufactured in this manner.

[0072] <Effect of operation of the display device (100)>

[0073] In this display device (100), light in the blue wavelength region is emitted from a light source (122) provided in each of the red pixel (10r), green pixel (10g), and blue pixel (10b), for example, and passes through the junction (130). In the red pixel (10r), the light passing through the junction (130) is incident on the red conversion layer (117r) and is converted into light in the red wavelength region by the first wavelength conversion material (1171r). This light in the red wavelength region passes through the overcoat layer (114), the red color filter (113r), and the transparent substrate (111) in this order. In the green pixel (10g), the light passing through the junction (130) is incident on the green conversion layer (117g) and is converted into light in the green wavelength region by the second wavelength conversion material (1171g). Light in this green wavelength region passes through the overcoat layer (114), the green color filter (113g), and the transparent substrate (111) in this order. In the blue pixel (10g), 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 this order.

[0074] According to one embodiment, the display device (100) has a red conversion layer (117r) comprising a plurality of first single-crystal silicon particles (1172r) and a green conversion layer (117g) comprising 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 region. As a result, it becomes possible to emit more light in the red wavelength region from the red pixel (10r) and more light in the green wavelength region from the green pixel (10g), respectively. The effect of this operation will be explained below using a comparative example.

[0075] FIG. 3a shows the configuration of a red conversion layer (117r) according to one embodiment, and FIG. 3b shows the configuration of a red conversion layer (1000r) according to a comparative example. The red conversion layer (1000r) according to the comparative example does not contain single-crystal silicon particles. This red conversion layer (1000r) includes a first wavelength conversion material (1171r) and a plurality of titanium oxide (TiO2) particles (1002r).

[0076] Titanium oxide particles (1002r) have a spherical shape, for example. 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.

[0077] FIGS. 4 and 5 show examples of scattering spectra of 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. FIG. 4 shows the results of FDTD (Finite-difference time-domain) simulation, and FIG. 5 shows the measured values. As illustrated in FIGS. 4 and 5, light in the blue wavelength region is selectively scattered in the first single-crystal silicon particles (1172r) compared to the titanium oxide particles (1002r).

[0078] Table 1 below shows the simulation results of the scattering intensity ratio of 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. In the titanium oxide particles (1002r), the scattering intensity ratio of light in the blue wavelength region (wavelength approximately 450 nm) and light in the red wavelength region (wavelength approximately 650 nm) was 21%, whereas in the first single-crystal silicon particles (1172r), the scattering intensity ratio was 5%.

[0079] Table 1 Scattering Intensity Ratio (650nm / 450nm) 1st Single Crystal Silicon Particle 5% Titanium Oxide Particle 21%

[0080] Table 2 below shows the simulation results of the scattering intensity ratio of titanium oxide particles (1002r) with a particle size of 100 nm and second single-crystal silicon particles (1172g) with a particle size of 90 nm. In the titanium oxide particles (1002r), the scattering intensity ratio of light in the blue wavelength region (wavelength approximately 450 nm) and light in the green wavelength region (wavelength approximately 550 nm) was 43%, whereas in the second single-crystal silicon particles (1172g), the scattering intensity ratio was 10%.

[0081] Table 2 Scattering Intensity Ratio (550nm / 450nm) 2nd Single Crystal Silicon Particle 10% Titanium Oxide Particle 43%

[0082] In this way, titanium oxide particles (1002r) are light L in the blue wavelength region b Along with, light L in the red wavelength region r It is also scattered. For this reason, in the red conversion layer (1000r) according to the comparative example, light L in the blue wavelength region b In addition, light L in the red wavelength region r The optical path length of is also increased. Because of this, the light L in the red wavelength region according to the first wavelength conversion material (1171r) r Self-absorption of becomes more likely to occur. Due to this self-absorption, light L in the red wavelength region rThere is a concern that it may become difficult to extract a sufficient amount of. On the other hand, in the red conversion layer (117r), light L in the red wavelength region r Because the scattering of light L in the red wavelength region is suppressed, r It becomes difficult for self-absorption of to occur. Therefore, compared to the red conversion layer (1000r), light L in the red wavelength region r It becomes possible to extract a larger amount of light L in the red wavelength region compared to the red conversion layer (1000r). For example, calculated from the simulation results shown in FIG. 4, about 1.3 times the amount of light L in the red wavelength region compared to the red conversion layer (1000r). r It is possible to extract light in the red wavelength region and light in the green wavelength region. The same applies to the green conversion layer (117g). In the display device (100), since more light in the red wavelength region and light in the green wavelength region can be extracted, it is possible to suppress power consumption.

[0083] In addition, in the display device (100), the particle size D1 of the first single-crystal silicon particle (1172r) included in the red conversion layer (117r) and the particle size D2 of the second single-crystal silicon particle (1172g) included in the green conversion layer (117g) are different. As a result, it becomes possible to use single-crystal silicon particles of a particle size suitable for each of the red conversion layer (117r) and the green conversion layer (117g).

[0084] Specifically, in single-crystal silicon particles, the wavelength selectivity of scattering changes depending on the particle size. In single-crystal silicon particles, as the particle size decreases, the wavelength of the scattering peak tends to shift toward shorter wavelengths. For this reason, by using single-crystal silicon particles of suitable particle sizes for the red conversion layer (117r) and the green conversion layer (117g), it becomes possible to extract more light in both the red wavelength region and the green wavelength region.

[0085] Hereinafter, a modified example of the display device (100) described in the above-described embodiment will be described. In addition, to avoid duplication of description, detailed descriptions of components identical to each component of the display device (100) described in the above-described embodiment will be omitted below.

[0086] [Variation Example]

[0087] FIG. 6 shows an example of the configuration of a transparent layer (118) of a display device (100) according to a modified example. This transparent layer (118) includes a plurality of third single-crystal silicon particles (1182). Except for this, the display device (100) according to the modified example has the same configuration as the display device (100) of one embodiment.

[0088] A plurality of 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 a spherical shape, for example. The particle size D3 corresponding to the peak of the particle size distribution of the plurality of third single-crystal silicon particles (1182) is, for example, different from size D1 and size D2. Size D3 may be the same as size D1 or size D2. The concentration of the third single-crystal silicon particles (1182) included in the transparent layer (118) is, for example, 0.5 wt% to 15 wt%.

[0089] In the display device (100) according to the modified example, as described in the above-described embodiment, the red conversion layer (117r) comprises a plurality of first single-crystal silicon particles (1172r), and the green conversion layer (117g) comprises a plurality of second single-crystal silicon particles (1172g). As a result, it becomes possible to emit more light in the red wavelength region from the red pixel (10r) and more light in the green wavelength region from the green pixel (10g), respectively.

[0090] The configuration of the display device (100) described above describes the main configurations for explaining the features of the embodiments and variations described above, and is not limited to the configurations described above, but can be improved in various ways within the scope of the patent claims. Furthermore, it does not exclude configurations provided by general display devices.

[0091] 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, a light source (122) that emits light in different wavelength ranges may be provided in the red pixel (10r), green pixel (10g), and blue pixel (10b).

[0092] In addition, in the above-described embodiments, an example was described in which the light source (122) includes a micro LED, but the light source (122) may include other light-emitting elements. For example, the light source (122) may include a standard-sized LED, or may include organic EL (electroluminescence) or inorganic EL. The display device (100) may include a liquid crystal display element.

[0093] In addition, in the above-described embodiments, an example was described in which the display device (100) has a red conversion layer (117r) and a green conversion layer (117g), but the red conversion layer (117r) and the green conversion layer (117g) may be applied to other devices such as a lighting device. In other words, the light-emitting element of the present invention may be applied to a device other than a display device, and for example, may be applied to a lighting device.

[0094] In addition, in the above-described embodiments, an example was described in which the blue pixel (10b) has a transparent layer (118), but the blue pixel (10b) may also have a wavelength conversion layer.

[0095] According to one embodiment, a light-emitting device is provided comprising: a light source configured to emit light in a first wavelength region; and a wavelength conversion layer comprising a wavelength conversion material configured to convert the light in the first wavelength region into light in a second wavelength region, and a plurality of single-crystal silicon particles configured to scatter the light in the first wavelength region.

[0096] According to one embodiment, a display device is provided comprising: a light source provided to each of a first pixel and a second pixel, each light source configured to emit light in a first wavelength region; a first wavelength conversion layer provided to the first pixel and comprising a first wavelength conversion material configured to convert light in the first wavelength region into light in a second wavelength region and a plurality of first single-crystal silicon particles configured to scatter light in the first wavelength region; and a second wavelength conversion layer provided to the second pixel and comprising a second wavelength conversion material configured to convert light in the first wavelength region into light in a third wavelength region different from the second wavelength region and a plurality of second single-crystal silicon particles configured to scatter light in the first wavelength region.

[0097] According to one embodiment, and according to one aspect of the present disclosure, a lighting device is provided comprising: a first wavelength conversion layer provided in a first pixel and configured to convert light in a first wavelength region into light in a second wavelength region, and a plurality of first single-crystal silicon particles configured to scatter light in the first wavelength region; and a second wavelength conversion layer provided in a second pixel and configured to convert light in the first wavelength region into light in a third wavelength region different from the second wavelength region, and a plurality of second single-crystal silicon particles configured to scatter light in the first wavelength region.

[0098] In addition, in the above-described embodiments, cases in which light in a red wavelength region, light in a green wavelength region, and light in a blue wavelength region are emitted from the display device (100) have been described, but the wavelength region of light emitted from the display device (100) is not limited thereto.

Claims

1. A light source configured to emit light in a first wavelength region; and A light-emitting device comprising: a wavelength conversion material configured to convert light in a first wavelength region into light in a second wavelength region, and a wavelength conversion layer comprising a plurality of single-crystal silicon particles configured to scatter light in the first wavelength region.

2. In Paragraph 1, The above second wavelength region is a red wavelength region, and A light-emitting device in which the size of one of the plurality of single-crystal silicon particles is 90 nm or more and 130 nm or less.

3. In Paragraph 1, The above second wavelength region is a green wavelength region, and A light-emitting device in which the size of one of the plurality of single-crystal silicon particles is 80 nm or more and 110 nm or less.

4. In Paragraph 1, The above first wavelength region is a light-emitting element in a blue wavelength region.

5. In Paragraph 1, The wavelength conversion material is a light-emitting device comprising at least one quantum dot and a phosphor.

6. A light source provided to each of the first pixel and the second pixel, wherein each light source is configured to emit light in a first wavelength region; A first wavelength conversion layer provided to the first pixel and comprising a first wavelength conversion material configured to convert light in the first wavelength region into light in the second wavelength region, and a plurality of first single-crystal silicon particles configured to scatter light in the first wavelength region; and A display device comprising: a second wavelength conversion layer provided to the second pixel and configured to convert light in the first wavelength region into light in a third wavelength region different from the second wavelength region, and a plurality of second single-crystal silicon particles configured to scatter light in the first wavelength region.

7. In Paragraph 6, The particle size D1 corresponding to the peak of the first particle size distribution of the plurality of first single-crystal silicon particles and the particle size D2 corresponding to the peak of the second particle size distribution of the plurality of second single-crystal silicon particles are different display devices.

8. In Paragraph 7, The peak wavelength of the third wavelength region is shorter than the peak wavelength of the second wavelength region, and The above size D2 is a display device smaller than the above size D1.

9. In Paragraph 8, A display device in which the first wavelength region is a blue wavelength region, the second wavelength region is a red wavelength region, and the third wavelength region is a green wavelength region.

10. In Paragraph 6, A display device comprising a plurality of third single-crystal silicon particles that are provided to a third pixel and scatter light in the first wavelength region, the light source above.

11. In Paragraph 6, The above light source is a display device including a micro LED (Light Emitting Diode).

12. A first wavelength conversion layer provided to a first pixel and comprising a first wavelength conversion material configured to convert light in a first wavelength region into light in a second wavelength region, and a plurality of first single-crystal silicon particles configured to scatter light in the first wavelength region; and A lighting device comprising: a second wavelength conversion layer including a second wavelength conversion material provided to a second pixel and configured to convert light in a first wavelength region into light in a third wavelength region different from the second wavelength region, and a plurality of second single-crystal silicon particles configured to scatter light in the first wavelength region.

13. In Paragraph 12, A lighting device further comprising a transparent layer including a plurality of third single-crystal silicon particles.

14. In Paragraph 12, The particle size D1 corresponding to the peak of the first particle size distribution of the plurality of first single-crystal silicon particles and the particle size D2 corresponding to the peak of the second particle size distribution of the plurality of second single-crystal silicon particles are different lighting devices.

15. In Paragraph 14, The peak wavelength of the third wavelength region is shorter than the peak wavelength of the second wavelength region, and The above size D2 is a lighting device smaller than the above size D1.

Images