Light-emitting device and image display device

Abstract

A light-emitting device according to one embodiment of the present disclosure comprises one or more pixels, wherein each pixel includes a light-emitting element that has a first surface for emitting light in a first wavelength range, a wavelength conversion layer that has a second surface facing the first surface and a third surface on the opposite side of the second surface, the wavelength conversion layer converting light in a first wavelength range into light in a second wavelength range, and one or more fine structures that extend through the wavelength conversion layer in the height direction from the second surface toward the third surface. The refractive index of each of the one or more fine structures is higher than the refractive index of the wavelength conversion layer.

Description

Light-emitting device and image display device

[0001] The present disclosure relates to a light-emitting device and an image display device including the light-emitting device.

[0002] Conventionally, for example, an image display element has been proposed in which a wavelength conversion part and an antenna having a plurality of convex parts made of metal are provided in this order on the light emission surface of a micro light-emitting element (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2021-131527

[0004] By the way, in a light-emitting device using a micro LED (Light Emitting Diode), when performing wavelength conversion of light, high wavelength conversion efficiency and efficient orientation control of scattered light are required.

[0005] A light-emitting device according to an embodiment of the present disclosure includes one or more pixels having a light-emitting element having a first surface that emits light in a first wavelength range, a wavelength conversion layer having a second surface facing the first surface and a third surface on the opposite side of the second surface, and that converts light in the first wavelength range into light in a second wavelength range, and one or more microstructures penetrating the wavelength conversion layer in a height direction from the second surface toward the third surface. The refractive index of each of the one or more microstructures is higher than the refractive index of the wavelength conversion layer.

[0006] An image display device according to an embodiment of the present disclosure includes a light-emitting device, and as the light-emitting device, has the light-emitting device according to the embodiment of the present disclosure.

[0007] In the light-emitting device according to an embodiment of the present disclosure and the image display device according to an embodiment of the present disclosure, the light in the first wavelength range emitted from the first surface of the light-emitting element is orientation-controlled and efficiently wavelength-converted by the wavelength conversion layer and one or more microstructures provided in the same layer above the light-emitting element.

[0008] Figure 1 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device according to one embodiment of the present disclosure. Figure 2 is a schematic cross-sectional view showing an example of the planar configuration of the light-emitting device corresponding to the line I-I shown in Figure 1. Figure 3A is a schematic cross-sectional view illustrating an example of the manufacturing process of the light-emitting device shown in Figure 1. Figure 3B is a schematic cross-sectional view showing the process following Figure 3A. Figure 3C is a schematic cross-sectional view showing the process following Figure 3B. Figure 3D is a schematic cross-sectional view showing the process following Figure 3C. Figure 3E is a schematic cross-sectional view showing the process following Figure 3D. Figure 3F is a schematic cross-sectional view showing the process following Figure 3E. Figure 3G is a schematic cross-sectional view showing the process following Figure 3F. Figure 3H is a schematic cross-sectional view showing the process following Figure 3G. Figure 3I is a schematic cross-sectional view showing the process following Figure 3H. Figure 3J is a schematic cross-sectional view showing the process following Figure 3I. Figure 4 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device according to Modification 1 of the present disclosure. Figure 5A is a schematic cross-sectional view illustrating an example of the manufacturing process of the light-emitting device shown in Figure 4. Figure 5B is a schematic cross-sectional view showing the process following Figure 5A. Figure 6A is a schematic cross-sectional view showing an example of the configuration of a light-emitting device according to Modification 3 of the present disclosure. Figure 6B is a schematic cross-sectional view showing another example of the configuration of a light-emitting device according to Modification 3 of the present disclosure. Figure 7A is a front view showing an example of the appearance of a digital still camera as an application example of the present disclosure. Figure 7B is a rear view showing an example of the appearance of the digital still camera shown in Figure 7A. Figure 8A is a perspective view showing an example of the appearance of a head-mounted display as an application example of the present disclosure. Figure 8B is a perspective view showing another example of the appearance of a head-mounted display as an application example of the present disclosure. Figure 9 is a perspective view showing an example of the appearance of a television device as an application example of the present disclosure.

[0009] Hereinafter, one embodiment of the present disclosure will be described in detail with reference to the drawings. The following description is a 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, dimensional ratios, etc., of each component shown in each figure. The order of description is as follows: 1. Embodiment (Example in which a light-reflecting film is provided on the bottom surface of the light-emitting element and a compound semiconductor layer is provided around the light-emitting element) 1-1. Configuration of the light-emitting device 1-2. Method of manufacturing the light-emitting device 1-3. Operation and effects 2. Modifications 2-1. Modification 1 (Another example of a light-emitting device) 2-2. Modification 2 (Another example of a light-emitting device) 3. Application examples

[0010] <1. Embodiments> Figure 1 schematically shows an example of a cross-sectional configuration of a light-emitting device 1 according to one embodiment of the present disclosure. Figure 2 schematically shows an example of a planar configuration of the light-emitting device 1 corresponding to the line I-I shown in Figure 1. The light-emitting device 1 is suitably applicable to image display devices known as LED displays (for example, the electronic viewfinder 1124 of a digital still camera 1120, see Figure 7B).

[0011] [1-1. Configuration of the Light-Emitting Device] The light-emitting device 1 is equipped with one or more pixels P. In the example shown in Figures 1 and 2, it is equipped with multiple pixels P (in Figures 1 and 2, for example, a case is illustrated in which multiple pixels P include a red pixel Pr that emits red light, a green pixel Pg that emits green light, and a blue pixel Pb that emits blue light). The multiple pixels P are arranged in a two-dimensional array along an XY plane that includes mutually orthogonal X-axis and Y-axis directions (see Figure 2). In this embodiment, the Z-axis direction, which is orthogonal to both the X-axis direction and the Y-axis direction, is called the height direction. That is, the Z-axis direction corresponds to one specific example of the "height direction" as one aspect of this disclosure. The light-emitting device 1 includes, for example, a light-emitting element 11, a wavelength conversion layer 12 (12R, 12G, and 12B are exemplified in Figures 1 and 2), one or more microstructures 13, a protective layer 14, a first light-reflecting film 15, a first light-shielding portion 16, a second light-reflecting film 17, and an insulating layer 18.

[0012] Each of the multiple pixels P (Pr, Pg, Pb) is provided with, for example, a light-emitting element 11, a wavelength conversion layer 12 (12R, 12G, 12B), and one or more microstructures 13. In this embodiment, the case in which each of the multiple pixels P has multiple microstructures 13 will be described as an example.

[0013] The light-emitting element 11 is provided, for example, for each pixel P. In the light-emitting device 1, for example, one light-emitting element 11 is provided for each pixel P. However, in the light-emitting device 1, multiple light-emitting elements 11 may be provided for each pixel P. The light-emitting element 11 is a solid-state light-emitting element that emits light in a predetermined wavelength band from its upper surface, and is, for example, an LED chip. An LED chip refers to an LED that has been cut from a wafer used for crystal growth, and is not a package type covered with molded resin or the like. An LED chip is, for example, 100 μm or less in size, and is what is called a microLED.

[0014] The light-emitting element 11 is formed of, for example, a GaN-based semiconductor material. Light L in the blue band, for example, between 430 nm and 500 nm, is extracted from the light-emitting element 11. Light with wavelengths corresponding to the ultraviolet region (ultraviolet light) may also be extracted from the light-emitting element 11. Light in the green band, for example, between 500 nm and 570 nm, may also be extracted from the light-emitting element 11. Light in the red band, for example, between 600 nm and 670 nm, may also be extracted from the light-emitting element 11. In the light-emitting element 11, the first surface 11S1 facing the wavelength conversion layer is the light-emitting surface of the light-emitting element 11. Here, light L corresponds to one specific example of "light in the first wavelength band" as one aspect of this disclosure.

[0015] The wavelength conversion layer 12 is provided on the first surface 11S1 side of the light-emitting element 11. The wavelength conversion layer 12 has a second surface 12S1 and a third surface 12S2. The second surface 12S1 is the surface facing the first surface 11S1, and the third surface 12S2 is the surface opposite to the second surface 12S1. The position of the second surface 12S1 of the wavelength conversion layer 12 in the Z-axis direction preferably substantially coincides with the position of the bottom surface 13S1 of each of the multiple microstructures 13 in the Z-axis direction.

[0016] The wavelength conversion layer 12 can convert light L emitted from the first surface 11S1 of the light-emitting element 11 into light in a predetermined wavelength range. Specifically, the red pixel Pr is provided with a wavelength conversion layer 12R that converts light L into light in the red band (hereinafter sometimes referred to as red light), the green pixel Pg is provided with a wavelength conversion layer 12G that converts light L into light in the green band (hereinafter sometimes referred to as green light), and the blue pixel Pb is provided with a wavelength conversion layer 12B that converts light L into light in the blue band (hereinafter sometimes referred to as blue light).

[0017] Each of the wavelength conversion layers 12R, 12G, and 12B contains a predetermined color conversion material. Each of the wavelength conversion layers 12R, 12G, and 12B can be formed using quantum dots corresponding to each color, for example. Specifically, when converting light L to red light, the quantum dots can be selected from, for example, InP, GaInP, InAsP, CdSe, CdZnSe, CdTeSe, or CdTe. When converting light L to green light, the quantum dots can be selected from, for example, InP, GaInP, ZnSeTe, ZnTe, CdSe, CdZnSe, CdS, or CdSeS. When converting light L to blue light, the quantum dots can be selected from, for example, ZnSe, ZnTe, ZnSeTe, CdSe, CdZnSe, CdS, CdZnS, and CdSeS.

[0018] Furthermore, when light L in the blue band is emitted from the light-emitting element 11 as described above, the wavelength conversion layer 12B may be formed of a light-transmitting resin. In other words, for blue pixels Pb from which light in approximately the same wavelength range as the light L emitted from the light-emitting element 11 is extracted, a light-transmitting resin layer may be provided as the wavelength conversion layer 12B. For red pixels Pr and green pixels Pg from which light in a different wavelength range than light L is extracted, wavelength conversion layers 12R and 12G containing the quantum dots described above are provided.

[0019] Here, the blue pixel Pb corresponds to one specific example of the "first pixel" as an embodiment of the present disclosure. The red pixel Pr and the green pixel Pg correspond to one specific example of the "second pixel" as an embodiment of the present disclosure. The wavelength conversion layer 12B corresponds to one specific example of the "wavelength conversion layer provided on the first pixel" as an embodiment of the present disclosure. The wavelength conversion layers 12R and 12G correspond to one specific example of the "wavelength conversion layer provided on the second pixel" as an embodiment of the present disclosure, and the quantum dot corresponds to one specific example of the "color conversion material" as an embodiment of the present disclosure. The blue band corresponds to the "first wavelength range" as an embodiment of the present disclosure, and the red band and the green band correspond to the "second wavelength range" as an embodiment of the present disclosure.

[0020] Each of the multiple microstructures 13 has a bottom surface 13S1 and an top surface 13S2. The bottom surface 13S1 is the surface facing the first surface 11S1, and the top surface 13S2 is the surface opposite to the bottom surface 13S1. Each of the one or more microstructures 13 penetrates the wavelength conversion layer 12 in the height direction from the second surface 12S1 to the third surface 12S2. Each of the multiple microstructures 13 includes a photonic crystal formed using at least one of metals, dielectrics, and semiconductors. The multiple microstructures 13 are, for example, made of niobium oxide (Nb ２ O ５ ), are formed using titanium oxide (TiO). The refractive index of each of the multiple microstructures 13 is higher than the refractive index of the wavelength conversion layer 12. The height dimension of each of the multiple microstructures 13, i.e., the Z-axis dimension of the multiple microstructures 13, is greater than the height dimension of the wavelength conversion layer 12, i.e., the Z-axis dimension of the wavelength conversion layer 12.

[0021] The protective layer 14 is provided so as to cover the upper surfaces 13S2 of each of the multiple microstructures 13 and the third surface 12S2 of the wavelength conversion layer 12. The protective layer 14 is intended to fill and flatten the spaces between the wavelength conversion layer 12, the multiple microstructures 13, the first light-reflecting film 15, and the second light-reflecting film 17. The refractive index of the protective layer 14 is lower than the refractive index of each of the multiple microstructures 13. The protective layer 14 is formed using inorganic materials or resins. Examples of inorganic materials constituting the protective layer 14 include silicon oxide (SiO) and silicon nitride (SiN). Examples of resins constituting the protective layer 14 include acrylic resin, epoxy resin, and silicone resin.

[0022] The first light-reflecting film 15 is provided at a position facing the upper surface 13S2 of each of the multiple microstructures 13, and selectively reflects light in a predetermined wavelength range. The first light-reflecting film 15 is provided at a position overlapping with a pixel P that includes a wavelength conversion layer 12 that emits light in a wavelength range different from the predetermined wavelength range in the Z-axis direction. For example, the first light-reflecting film 15 selectively reflects light in the blue band (blue light) and is provided above a red pixel Pr including a wavelength conversion layer 12R and a green pixel Pg including a wavelength conversion layer 12G. This improves the color purity of the red light and green light extracted from the red pixel Pr and green pixel Pg, respectively. The first light-reflecting film 15 is, for example, a DBR (Distributed Bragg Reflector).

[0023] The first light-shielding portion 16 is intended to prevent the mixing of light L passing through adjacent wavelength conversion layers 12. The first light-shielding portion 16 is provided so as to surround at least a part of the periphery of the wavelength conversion layer 12 and to block light entering the wavelength conversion layer 12 from the periphery of the wavelength conversion layer 12 and light transmitted through the wavelength conversion layer 12 from leaking to the surroundings. The first light-shielding portion 16 contains at least one of silicon (Si), nitrogen (N), oxygen (O), and carbon (C). The first light-shielding portion 16 is formed from, for example, silicon oxide (SiO) or silicon nitride (SiN). The position in the Z-axis direction of the upper surface 16S1 of the first light-shielding portion 16 is lower than the position in the Z-axis direction of the upper surfaces 13S2 of each of the multiple microstructures 13.

[0024] The first light-shielding portion 16 may include a substrate 161 and a light-reflective coating 162 covering the substrate 161. The substrate 161 contains at least one of silicon (Si), nitrogen (N), oxygen (O), and carbon (C). The substrate 161 is formed from, for example, silicon oxide (SiO) or silicon nitride (SiN). The coating 162 is formed using a light-reflective metal. Examples of metals used for the coating 162 include silver (Ag), aluminum (Al), copper (Cu), gold (Au), platinum (Pt), rhodium (Rh), and alloys thereof.

[0025] The second light-reflective film 17 fills the space from the upper surface 16S1 of the first light-shielding portion 16 in the height direction to the upper surface 13S2 of each of the multiple microstructures 13 in the height direction. That is, the second light-reflective film 17 occupies the space from the upper surface 16S1 of the first light-shielding portion 16 in the Z-axis direction to the upper surface 13S2 of the multiple microstructures 13, so as to overlap with the first light-shielding portion 16 in the Z-axis direction. The second light-reflective film 17 is formed using a metal that has light-reflecting properties. Examples of metals that can be used for the second light-reflective film 17 include silver (Ag), aluminum (Al), copper (Cu), gold (Au), platinum (Pt), rhodium (Rh), and alloys thereof.

[0026] The insulating layer 18 fills and flattens the first surface 11S1 side of the light-emitting element 11. The insulating layer 18 is formed of, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0027] [1-2. Method for Manufacturing the Light-Emitting Device] The light-emitting device 1 of this embodiment can be manufactured, for example, as follows. Figures 3A to 3I show an example of the manufacturing process for the light-emitting device 1.

[0028] First, as shown in Figure 3A, an insulating layer 18 is formed to cover the light-emitting element 11. This operation seals the light-emitting element 11 with the insulating layer 18.

[0029] Next, as shown in Figure 3B, the insulating layer 18 is processed to selectively excavate, for example, by dry etching, to form a plurality of recesses 18U. A wall-like substrate 161 is formed between adjacent recesses 18U. Subsequently, a coating 162 is formed to cover the surface of the substrate 161. This operation yields a first light-shielding portion 16 including the substrate 161 and the coating 162.

[0030] Next, as shown in Figure 3C, a embedding layer 130 is formed to cover the multiple recesses 18U surrounded by the first light-shielding portion 16 and the upper surface of the first light-shielding portion 16. After that, the upper surface of the embedding layer 130 is flattened, for example, by chemical mechanical polishing (CMP).

[0031] Next, as shown in Figure 3D, the embedded layer 130 is divided and subdivided, for example by reactive ion etching (RIE), to form a plurality of microstructures 13.

[0032] Next, as shown in Figure 3E, wavelength conversion layers 12R, 12G, and 12B are formed to fill the gaps between the multiple microstructures 13, for example, using photolithography or inkjet technology.

[0033] Next, as shown in Figure 3F, a protective layer 141 is formed using silicon oxide or the like so as to cover the wavelength conversion layer 12 and the plurality of microstructures 13. The thickness of the protective layer 141 should be adjusted so that its upper surface is flat. Alternatively, the upper surface of the protective layer 141 may be flattened, for example, by CMP.

[0034] Next, the portions of the embedding layer 130 and the protective layer 141 located directly above the first light-shielding portion 16 are selectively removed, for example, by RIE. After that, as shown in Figure 3G, the embedding layer 130 and the protective layer 141 are selectively removed to form a plurality of grooves 141U. Subsequently, as shown in Figure 3H, the second light-reflective film 17 is embedded and formed in each of the plurality of grooves 141U.

[0035] Next, as shown in Figure 3I, the first light-reflecting film 15 is selectively formed to cover the wavelength conversion layers 12R and 12G, for example, by photolithography.

[0036] Next, as shown in Figure 3J, a protective layer 142 is formed so as to cover the wavelength conversion layer 12B and the first light reflective film 15. The upper surface of the protective layer 142 may be flattened if necessary. This results in a protective layer 14 including protective layers 141 and 142. With the above steps, the light-emitting device 1 shown in Figure 1 is completed.

[0037] [1-3. Operation and Effects] The light-emitting device 1 of this embodiment comprises a light-emitting element 11 having a first surface 11S1 that emits light L in a first wavelength range, a wavelength conversion layer 12 having a second surface 12S1 and a third surface 12S2 that converts light L into light in a second wavelength range, and one or more microstructures 13 that penetrate the wavelength conversion layer 12 in the height direction (Z-axis direction) from the second surface 12S1 to the third surface 12S2. The refractive index of each of the one or more microstructures 13 is higher than the refractive index of the wavelength conversion layer 12. As a result, the light L is oriented and efficiently converted in wavelength by the wavelength conversion layer 12 and the one or more microstructures 13 provided at the same level above the light-emitting element 11. This will be explained below.

[0038] In light-emitting devices using micro-LEDs, a particular challenge with red-emitting LEDs is the decrease in luminous efficiency due to miniaturization.

[0039] To solve the above problem, for example, if a wavelength conversion layer using quantum dots is provided on the light-emitting side of a light-emitting element that emits blue light, red light can be obtained without reducing the luminous efficiency. However, if such a configuration is adopted, the scattering of light that passes through the wavelength conversion layer using quantum dots becomes a further problem.

[0040] In contrast, in the light-emitting device 1 of this embodiment, a wavelength conversion layer 12 containing quantum dots and one or more microstructures 13 containing photonic crystals are provided on the light-emitting surface side of the light-emitting element 11. For example, one or more microstructures 13 provided at the same level as the wavelength conversion layer 12R that converts light L in the blue band on the first surface 11S1 side of the light-emitting element 11 confines the blue light within the microstructure 13 and emits the red light upward. As a result, the light-emitting device 1 can achieve both the maintenance of luminous efficiency and wavelength conversion efficiency and high light distribution control.

[0041] Further, in the light-emitting device 1 of the present embodiment, the dimension of each of the one or more microstructures 13 in the height direction is larger than the dimension of the wavelength conversion layer 12 in the height direction. As a result, since the optical path length of the light L passing through the wavelength conversion layer 12 is extended, further improvement in color conversion efficiency and further improvement in light distribution controllability can be expected.

[0042] <2. Modified Example> Next, modified examples 1 and 2 and application examples of the present disclosure will be described. Note that components corresponding to those of the light-emitting device 1 of the above embodiment are denoted by the same reference numerals and the description thereof will be omitted.

[0043] [2-1. Modified Example 1] FIG. 4 schematically shows an example of a cross-sectional configuration of a light-emitting device (light-emitting device 1A) according to Modified Example 1 of the present disclosure. FIGS. 5A and 5B show an example of a manufacturing process of the light-emitting device 1A.

[0044] In the above embodiment, the case where the height-direction position of the upper surface of each of the one or more microstructures 13 is higher than the height-direction position of the upper surface of the wavelength conversion layer 12 has been exemplified, but the present disclosure is not limited thereto. In the light-emitting device 1A of this modified example, the height-direction position of each of the one or more microstructures 13 is substantially the same as the height-direction position of the upper surface of the wavelength conversion layer 12.

[0045] The manufacturing method of the light-emitting device 1A of this modified example is the same as that of the light-emitting device 1 described above up to the step of forming the one or more microstructures 13. Subsequently, as shown in FIG. 5A, the gaps between the one or more microstructures 13 are filled, and the wavelength conversion layer 12 (12R, 12G, 12B) is formed using, for example, photolithography technology or inkjet technology so as to cover the upper surfaces of the one or more microstructures 13. Next, as shown in FIG. 5B, planarization is performed, for example, by CMP so that the height-direction position of the upper surface of the wavelength conversion layer 12 becomes substantially the same as the height-direction position of the upper surface of each of the one or more microstructures 13. The subsequent manufacturing process of the light-emitting device 1A is the same as that of the light-emitting device 1.

[0046] Except for the above points, the configuration of the light-emitting device 1A is substantially the same as the configuration of the light-emitting device 1 of the above embodiment. Even in such a configuration, the light-emitting device 1A can obtain the same effects as those of the above embodiment.

[0047] [2-2. Modified Example 2] FIG. 6A schematically shows an example of a cross-sectional configuration of a light-emitting device 1B (light-emitting device 1B-1) according to Modified Example 2 of the present disclosure. FIG. 6A schematically shows another example of a cross-sectional configuration of the light-emitting device 1B (light-emitting device 1B-2) according to Modified Example 2 of the present disclosure.

[0048] In the above embodiment, an example in which the light-emitting device 1 includes three types of wavelength conversion layers 12 (12R, 12G, 12B) is shown, but the present disclosure is not limited thereto.

[0049] In the light-emitting device 1B-1 of this modified example, only the wavelength conversion layer 12R that converts to a wavelength in the red band is provided. In the light-emitting device 1B-2 of this modified example, only the wavelength conversion layer 12R that converts to a wavelength in the red band and the wavelength conversion layer 12G that converts to a wavelength in the green band are provided. In the light-emitting devices 1B-1 and 1B-2 of this modified example, the first light reflection film 15 is provided over the entire area occupied by the wavelength conversion layer 12.

[0050] Except for the above points, the configurations of the light-emitting devices 1B-1 and 1B-2 are substantially the same as the configuration of the light-emitting device 1 of the above embodiment. Even in such a configuration, the light-emitting devices 1B-1 and 1B-2 can obtain the same effects as the above embodiment.

[0051] <3. Application Examples> (Application Example 1) FIG. 7A is a front view showing an example of the appearance of a digital still camera (electronic device) 1120. FIG. 7B is a rear view showing an example of the appearance of the digital still camera 1120. The digital still camera 1120 is of a lens-exchangeable single-lens reflex type. The digital still camera 1120 has an interchangeable photographing lens unit (interchangeable lens) 1121 at substantially the center of the front of the camera body portion (camera body) 1122, and has a grip portion 1123 for the photographer to hold on the left side of the front.

[0052] A monitor 1126 is located slightly to the left of the center of the back of the camera body 1122. An electronic viewfinder (eyepiece) 1124 is located above the monitor 1126. The photographer can determine the composition by looking through the electronic viewfinder 1124 and viewing the light image of the subject guided by the photographic lens unit 1121. The electronic viewfinder 1124 is equipped with a light-emitting device 1.

[0053] (Application Example 2) The light-emitting device of this disclosure (for example, light-emitting device 1) is also applicable to a head-mounted display (hereinafter referred to as HMD). The head-mounted display 1130A can be used for VR (Virtual Reality), AR (Augmented Reality), MR (Mixed Reality), or SR (Substantial Reality), etc.

[0054] Figure 8A is a perspective view showing the external appearance of a head-mounted display (electronic device) 1130A. The head-mounted display 1130A has, for example, a glasses-shaped display unit 1132 with ear hooks 1131 on both sides for attachment to the user's head. The display unit 1132 is equipped with a light-emitting device 1.

[0055] Figure 8B is a perspective view showing the appearance of another head-mounted display (electronic device). The head-mounted display is a smart glasses 1130B that displays various information on eyeglasses 1133. The smart glasses 1130B comprises a main body, an arm 1135, and a lens barrel 1136. The main body 1134 is connected to the arm 1135. The main body 1134 is detachable from the eyeglasses 1133. The main body 1134 contains a control board and a display unit for controlling the operation of the smart glasses 1130B. The main body 1134 and the lens barrel 1136 are connected to each other via the arm 1135. The lens barrel 1136 emits image light emitted from the main body 1134 via the arm 1135 towards the lens 1137 of the eyeglasses 1133. This image light enters the human eye through the lens 1137. As shown in Figure 8B, the wearer of the smart glasses 1130B can see not only the surrounding environment but also various information emitted from the lens barrel 1136, just like with regular glasses. The main body 1134 is equipped with a light-emitting device 1.

[0056] (Application Example 3) Figure 9 is a perspective view showing an example of the appearance of a television device (electronic device) 1140. This television device 1140 has, for example, a video display screen section 1141 including a front panel 1142 and a filter glass 1143. The video display screen section 1141 is equipped with a light-emitting device 1.

[0057] The present disclosure has been described above with reference to embodiments, modifications 1 and 2, and application examples. However, the present disclosure is not limited to the above embodiments, and various modifications are possible. For example, the above embodiments show examples in which the light emitted from the light-emitting element is blue light or ultraviolet light, but the present disclosure is not limited to this. For example, the light-emitting device of the present disclosure can also use a light-emitting element that emits two or more types of light, such as blue light and green light, or ultraviolet light and green light.

[0058] Furthermore, although the above embodiments have described each component constituting the light-emitting device 1, etc., it is not necessary to include all components, and other components may also be included. For example, although the above embodiments have shown examples in which there are multiple light-emitting elements 11, the invention is not limited to this. For example, the light-emitting device 1 may have only one light-emitting element 11.

[0059] Furthermore, the effects described herein are merely examples and are not limited to those described; other effects may also occur.

[0060] The present disclosure may also take the following configurations. According to the present disclosure in the following configuration, the orientation of the light-emitting element that emits light in a first wavelength range is controlled and the wavelength is efficiently converted by a wavelength conversion layer and one or more microstructures provided at the same level above the light-emitting element that emits light in a first wavelength range. (1) A light-emitting device comprising: a light-emitting element having a first surface that emits light in a first wavelength range; a wavelength conversion layer having a second surface facing the first surface and a third surface opposite to the second surface, which converts light in the first wavelength range to light in a second wavelength range; and one or more pixels having one or more microstructures that penetrate the wavelength conversion layer in the height direction from the second surface to the third surface, wherein the refractive index of each of the one or more microstructures is higher than the refractive index of the wavelength conversion layer. (2) The light-emitting device according to (1), wherein each of the one or more microstructures is formed using at least one of metal, dielectric, and semiconductor. (3) The light-emitting device according to (1) or (2), wherein the height dimension of each of the one or more microstructures is larger than the height dimension of the wavelength conversion layer. (4) The light-emitting device according to any one of (1) to (3), wherein the wavelength conversion layer comprises a color conversion material. (5) The light-emitting device according to any one of (1) to (4), wherein the position in the height direction of the second surface of the wavelength conversion layer coincides with the position in the height direction of the bottom surface of each of the one or more microstructures. (6) The light-emitting device according to (3), further comprising a protective layer covering the top surface of each of the one or more microstructures and the third surface of the wavelength conversion layer. (7) The light-emitting device according to (6), wherein the refractive index of the protective layer is lower than the refractive index of each of the one or more microstructures. (8) The light-emitting device according to (6) or (7), wherein the protective layer is formed using an inorganic material. (9) The light-emitting device according to any one of (6) to (8), further comprising a first light-reflecting film provided at a position facing the top surface of each of the one or more microstructures, and selectively reflecting light in the first wavelength range. (10) The light-emitting device according to any one of (1) to (9), further comprising a first light-shielding portion provided so as to surround at least a portion of the periphery of the wavelength conversion layer and blocking light from advancing from the periphery of the wavelength conversion layer to the wavelength conversion layer.(11) The light-emitting device according to (10), wherein the first light-shielding portion comprises at least one of silicon, nitrogen, oxygen, and carbon. (12) The light-emitting device according to (10) or (11), wherein the first light-shielding portion comprises a substrate and a light-reflective coating covering the substrate. (13) The light-emitting device according to any one of (10) to (12), further comprising a light-reflective second light-reflective film, wherein the position in the height direction of the upper surface of the first light-shielding portion is lower than the position in the height direction of the upper surface of each of the one or more microstructures, and the second light-reflective film occupies the space from the position in the height direction of the upper surface of the first light-shielding portion to the position in the height direction of the upper surface of each of the one or more microstructures, so as to overlap with the first light-shielding portion in the height direction. (14) The light-emitting device according to any one of (1) to (13), wherein the one or more pixels are a plurality of pixels, and the plurality of pixels comprises a first pixel and a second pixel, and the light-emitting element of the first pixel emits light in the first wavelength range, and the light-emitting element of the second pixel emits light in the second wavelength range. (15) The light-emitting device according to (14), wherein the wavelength conversion layer provided in the first pixel contains a light-transmitting resin, and the wavelength conversion layer provided in the second pixel contains a color conversion substance. (16) The light-emitting device according to (14) or (15), further comprising a first light-reflecting film provided at a position overlapping with the second pixel in the first direction, which selectively reflects light in the first wavelength range. (17) An image display device comprising a light-emitting device, the light-emitting device having a light-emitting element having a first surface that emits light in a first wavelength range, a wavelength conversion layer having a second surface facing the first surface and a third surface opposite to the second surface, and converting light in the first wavelength range to light in a second wavelength range, and one or more pixels having one or more microstructures that penetrate the wavelength conversion layer in the height direction from the second surface to the third surface, wherein the refractive index of each of the one or more microstructures is higher than the refractive index of the wavelength conversion layer.

[0061] This application claims priority based on Japanese Patent Application No. 2025-007121, filed with the Japan Patent Office on 17 January 2025, and all contents of that application are incorporated herein by reference.

[0062] Those skilled in the art will understand that various modifications, combinations, subcombinations, and changes can be conceived depending on design requirements and other factors, and that these fall within the scope of the attached claims and their equivalents.

Claims

1. A light-emitting device comprising: a light-emitting element having a first surface that emits light in a first wavelength range; a wavelength conversion layer having a second surface facing the first surface and a third surface opposite to the second surface, which converts light in the first wavelength range to light in a second wavelength range; and one or more pixels having one or more microstructures that penetrate the wavelength conversion layer in the height direction from the second surface to the third surface, wherein the refractive index of each of the one or more microstructures is higher than the refractive index of the wavelength conversion layer.

2. The light-emitting device according to claim 1, wherein each of the one or more microstructures is formed using at least one of metals, dielectrics, and semiconductors.

3. The light-emitting device according to claim 1, wherein the height dimension of each of the one or more microstructures is greater than the height dimension of the wavelength conversion layer.

4. The light-emitting device according to claim 1, wherein the wavelength conversion layer includes a color conversion material.

5. The light-emitting device according to claim 1, wherein the position in the height direction of the second surface of the wavelength conversion layer coincides with the position in the height direction of the bottom surface of each of the one or more microstructures.

6. The light-emitting device according to claim 3, further comprising a protective layer covering the upper surface of each of the one or more microstructures and the third surface of the wavelength conversion layer.

7. The light-emitting device according to claim 6, wherein the refractive index of the protective layer is lower than the refractive index of each of the one or more microstructures.

8. The light-emitting device according to claim 6, wherein the protective layer is formed using an inorganic material.

9. The light-emitting device according to claim 1, further comprising a first light-reflecting film provided at a position opposite to the upper surface of each of the one or more microstructures, and which selectively reflects light in the first wavelength range.

10. The light-emitting device according to claim 1, further comprising a first light-shielding portion provided so as to surround at least a portion of the periphery of the wavelength conversion layer and blocking light from entering the wavelength conversion layer from the periphery of the wavelength conversion layer.

11. The light-emitting device according to claim 10, wherein the first light-shielding portion comprises at least one of silicon, nitrogen, oxygen, and carbon.

12. The light-emitting device according to claim 10, wherein the first light-shielding portion comprises a substrate and a light-reflective coating covering the substrate.

13. The light-emitting device according to claim 10, further comprising a second light-reflecting film having light reflectivity, wherein the position in the height direction of the upper surface of the first light-shielding portion is lower than the position in the height direction of the upper surface of each of the one or more microstructures, and the second light-reflecting film occupies the space from the position in the height direction of the upper surface of the first light-shielding portion to the position in the height direction of the upper surface of each of the one or more microstructures, so as to overlap with the first light-shielding portion in the height direction.

14. The light-emitting device according to claim 1, wherein the one or more pixels are a plurality of pixels, and the plurality of pixels comprises a first pixel and a second pixel, the light-emitting element of the first pixel emits light in the first wavelength range, and the light-emitting element of the second pixel emits light in the second wavelength range.

15. The light-emitting device according to claim 14, wherein the wavelength conversion layer provided in the first pixel contains a light-transmitting resin, and the wavelength conversion layer provided in the second pixel contains a color conversion substance.

16. The light-emitting device according to claim 14, further comprising a first light-reflecting film that selectively reflects light in the first wavelength range and is provided at a position that overlaps with the second pixel in the height direction.

17. An image display device comprising a light-emitting device, the light-emitting device having a light-emitting element having a first surface that emits light in a first wavelength range, a wavelength conversion layer having a second surface facing the first surface and a third surface opposite to the second surface, and converting light in the first wavelength range to light in a second wavelength range, and one or more pixels having one or more microstructures that penetrate the wavelength conversion layer in the height direction from the second surface to the third surface, wherein the refractive index of each of the one or more microstructures is higher than the refractive index of the wavelength conversion layer.

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