Light-emitting device and image display apparatus

Abstract

A first light-emitting device which is an embodiment of the present disclosure comprises: a substrate; a light-emitting element which is provided on the substrate and includes a light-emitting surface; a first compound semiconductor layer which is provided to at least a portion of the periphery of the light-emitting element in the substrate, is electrically separated from the light-emitting element, and has the same lamination structure as the light-emitting element; and a first light-reflection film which is provided at the side opposite to the light-emitting surface as viewed from the light-emitting element, and which includes a recessed surface having a shape that is recessed toward the light-emitting surface.

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] To date, for example, a micro light-emitting element having a curved side surface and an image display element including the micro light-emitting element have been proposed (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2021-019015

[0004] Incidentally, in light-emitting devices using micro LEDs (Light Emitting Diodes), there is a demand for improved brightness and reduced power consumption.

[0005] A first light-emitting device according to one embodiment of the present disclosure includes a substrate, a light-emitting element provided on the substrate and including a light-emitting surface, a first compound semiconductor layer provided on at least a portion of the substrate around the light-emitting element, electrically isolated from the light-emitting element, and having the same layered structure as the light-emitting element, and a first light-reflecting film provided on the opposite side of the light-emitting element from the light-emitting surface, including a concave surface having a concave shape relative to the light-emitting surface.

[0006] A second light-emitting device according to an embodiment of the present disclosure includes a substrate, one or more light-emitting elements provided on the substrate and including a light-emitting surface, a first compound semiconductor layer provided on the substrate around at least a portion of the light-emitting elements, electrically isolated from the light-emitting elements, and having the same layered structure as the light-emitting elements, and a first light-reflecting film and a second light-reflecting film provided on the opposite side of the light-emitting elements from the light-emitting surfaces. The first compound semiconductor layer includes a first surface facing the light-emitting elements and a second surface located opposite the first surface and inclined at an angle of less than 90° with respect to the substrate, and the second light-reflecting film is provided to cover the second surface.

[0007] In the first and second light-emitting devices according to an embodiment of the present disclosure, a compound semiconductor layer is provided around one or more light-emitting elements, the compound semiconductor layer having a light-reflecting film on the surface opposite to the surface facing the light-emitting element, the light-reflecting film including a concave or inclined surface with respect to the light-emitting surface, thereby improving the front brightness of the light-emitting element.

[0008] FIG. 1 is a cross-sectional view schematically illustrating an example of a configuration of a light-emitting device according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view schematically illustrating an example of a configuration of a light-emitting section according to an embodiment of the present disclosure. FIG. 3 is a plan view schematically illustrating an example of a configuration of a light-emitting element, a compound semiconductor layer, and a buried layer according to an embodiment of the present disclosure. FIG. 4A is a cross-sectional view schematically illustrating an example of a manufacturing process of the light-emitting device shown in FIG. 1. FIG. 4B is a cross-sectional view schematically illustrating a process subsequent to FIG. 4A. FIG. 4C is a cross-sectional view schematically illustrating a process subsequent to FIG. 4B. FIG. 4D is a cross-sectional view schematically illustrating a process subsequent to FIG. 4C. FIG. 4E is a cross-sectional view schematically illustrating a process subsequent to FIG. 4D. FIG. 4F is a cross-sectional view schematically illustrating a process subsequent to FIG. 4E. FIG. 4G is a cross-sectional view schematically illustrating a process subsequent to FIG. 4F. FIG. 4H is a cross-sectional view schematically illustrating a process subsequent to FIG. 4G. FIG. 4I is a cross-sectional view schematically illustrating a process subsequent to FIG. 4H. FIG. 4J is a cross-sectional view schematically illustrating a process subsequent to FIG. 4I. FIG. 4K is a cross-sectional view schematically illustrating a process subsequent to FIG. 4J. FIG. 5 is a schematic cross-sectional view illustrating an example of the configuration of a light-emitting device according to Modification 1 of the present disclosure. FIG. 6 is a schematic cross-sectional view illustrating an example of the configuration of a light-emitting device according to Modification 2 of the present disclosure. FIG. 7A is a schematic cross-sectional view illustrating an example of the configuration of a light-emitting device according to Modification 3 of the present disclosure. FIG. 7B is a schematic cross-sectional view illustrating another example of the configuration of a light-emitting device according to Modification 3 of the present disclosure. FIG. 8 is a schematic cross-sectional view illustrating an example of the configuration of a light-emitting device according to Modification 4 of the present disclosure. FIG. 9 is a schematic cross-sectional view illustrating an example of the configuration of a light-emitting device according to Modification 5 of the present disclosure. FIG. 10 is a schematic cross-sectional view illustrating an example of the configuration of a light-emitting section according to Modification 6 of the present disclosure. FIG. 11A is a schematic cross-sectional view illustrating an example of the configuration of a light-emitting device according to Modification 7 of the present disclosure. FIG. 11B is a circuit diagram illustrating an example of the circuit configuration of a light-emitting device according to Modification 7 of the present disclosure. FIG. 12A is a schematic cross-sectional view illustrating an example of the configuration of a light-emitting section according to Modification 8 of the present disclosure. FIG. 12B is a schematic cross-sectional view illustrating another example of the configuration of a light-emitting section according to Modification 8 of the present disclosure. Fig. 13 is a schematic cross-sectional view showing an example of the configuration of a light-emitting section according to Modification 9 of the present disclosure. Fig. 14 is a schematic cross-sectional view showing an example of the configuration of a light-emitting section according to Modification 10 of the present disclosure. Fig. 15 is a schematic cross-sectional view showing an example of the configuration of a light-emitting section according to Modification 11 of the present disclosure. Fig. 16 is a schematic cross-sectional view showing an example of the configuration of a light-emitting section according to Modification 12 of the present disclosure.Fig. 17 is a cross-sectional schematic diagram illustrating an example of the configuration of a light-emitting section according to Modification 13 of the present disclosure. Fig. 18 is a perspective view illustrating an example of the configuration of an image display device according to an application example of the present disclosure. Fig. 19 is a schematic view illustrating an example of the wiring layout of the image display device shown in Fig. 18. Fig. 20 is a perspective view illustrating an example of the configuration of an image display device according to an application example of the present disclosure. Fig. 21 is a perspective view illustrating the configuration of the mounting board shown in Fig. 20. Fig. 22 is a perspective view illustrating the configuration of the unit board shown in Fig. 21. Fig. 23 is a diagram illustrating an example of an image display device according to an application example of the present disclosure.

[0009] An embodiment of the present disclosure will be described in detail below 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 the components shown in the drawings. The description will be given in the following order: 1. Embodiment (Example in which a light-reflecting film is provided on the bottom surface of a light-emitting element and a compound semiconductor layer is provided around the light-emitting element) 1-1. Configuration of light-emitting device 1-2. Method for manufacturing light-emitting device 1-3. Actions 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) 2-3. Modification 3 (Another example of a light-emitting device) 2-4. Modification 4 (Another example of a light-emitting device) 2-5. Modification 5 (Another example of a light-emitting device) 2-6. Modification 6 (Another example of a light-emitting device) 2-7. Modification 7 (Another example of a light-emitting device) 2-8. Modification 8 (Another example of a light-emitting device) 2-9. Modification 9 (another example of a light emitting device) 2-10. Modification 10 (another example of a light emitting device) 2-11. Modification 11 (another example of a light emitting device) 2-12. Modification 12 (another example of a light emitting device) 2-13. Modification 13 (another example of a light emitting device) 3. Application examples

[0010] 1 is a schematic diagram illustrating an example of a cross-sectional configuration of a light-emitting device 1 according to an embodiment of the present disclosure. The light-emitting device 1 is suitably applicable to an image display device known as an LED display (for example, an image display device 100 shown in FIG. 18 , which will be described later).

[0011] [1-1. Configuration of Light-Emitting Device] The light-emitting device 1 has a layered structure in which, for example, a drive substrate 30, a light-emitting unit 10 including a plurality of light-emitting elements 11, and a wavelength conversion unit 20 are stacked in this order in the Z-axis direction, which is the thickness direction perpendicular to the XY plane.

[0012] 2 is a schematic diagram illustrating an example of a cross-sectional configuration of the light-emitting section 10 according to an embodiment of the present disclosure. The light-emitting section 10 includes a plurality of light-emitting elements 11, one common electrode 12, a plurality of plugs 13, a plurality of pad electrodes 14, one or more insulating layers 15, one or more insulating layers 16, a plurality of pad sections 17, one or more embedded layers 18, and one or more compound semiconductor layers 19. The compound semiconductor layer 19 corresponds to a specific example of a "first compound semiconductor layer" according to one aspect of the present disclosure.

[0013] The light-emitting element 11 is provided for each pixel P, for example. That is, one light-emitting element 11 is provided for one pixel P. However, multiple light-emitting elements 11 may be provided for one pixel P. The light-emitting element 11 is a solid-state light-emitting element that emits light in a predetermined wavelength band from the top surface, for example, an LED (Light Emitting Diode) chip. The LED chip refers to an element cut from a wafer used for crystal growth, and is not a packaged type covered with molded resin or the like. The LED chip is, for example, 100 μm in size or less, and is what is known as a micro LED.

[0014] In the light-emitting element 11, for example, the surface 11S2 opposite the light-emitting surface 11S1 includes a concave surface having a concave shape relative to the light-emitting surface 11S1. In the configuration examples shown in FIGS. 1 and 2 , the entire surface 11S2 is concave, but only a portion of the surface 11S2 may be concave. However, to obtain high directivity and high light extraction efficiency, it is desirable that the entire surface 11S2 be concave. Furthermore, the surface 11S1 may be a concave curved surface. The light-emitting element 11 includes, for example, a first conductivity-type layer 111, an active layer 112, and a second conductivity-type layer 113 stacked in this order from the drive substrate 30 side. The light-emitting element 11 includes, for example, a first light-reflecting film 114 on the side opposite the active layer 112 from the first conductivity-type layer 111. The light-emitting element 11 further includes, for example, a transparent electrode layer 115 on the side of the second conductivity-type layer 113 opposite the active layer 112.

[0015] The first conductivity type layer 111 is formed of, for example, an n-type GaN-based semiconductor material. The active layer 112 has, for example, a multiple quantum well structure in which InGaN and GaN are alternately stacked, and has a light-emitting region within the layer. Light in the blue band of, for example, 430 nm to 500 nm is extracted from the active layer 112. Light with a wavelength corresponding to, for example, the ultraviolet region (ultraviolet light) may also be extracted from the active layer 112. The second conductivity type layer 113 is formed of, for example, a p-type GaN-based semiconductor material. In the light-emitting element 11, the upper surface of the second conductivity type layer 113, i.e., the surface opposite to the active layer 112, serves as a light-emitting surface 11S1 of the light-emitting element 11.

[0016] The first light-reflecting film 114 is provided along the surface 11S2 of the light-emitting element 11 and includes a concave surface that is concave relative to the light-emitting surface 11S1. The first light-reflecting film 114 is electrically connected to the pad electrode 14 via the plug 13. The first light-reflecting film 114 is in ohmic contact with the first conductivity-type layer 111, for example. The first light-reflecting film 114 is formed using a metal material with light reflectivity. The first light-reflecting film 114 is formed using, for example, a light-reflecting metal containing titanium (Ti) and at least one of aluminum (Al) and silver (Ag). The first light-reflecting film 114 is formed using, for example, a transparent electrode material such as ITO, indium zinc oxide (IZO), tin oxide (SnO), or TiO, and a light-reflecting metal containing at least one of aluminum (Al) and silver (Ag).

[0017] The transparent electrode layer 115 is provided on the light-emitting surface 11S1 of the light-emitting element 11. The transparent electrode layer 115 is provided so as to cover the second conductivity type layer 113 of the light-emitting element 11, and is in ohmic contact with the second conductivity type layer 113. The transparent electrode layer 115 is formed of a transparent electrode material such as ITO, indium zinc oxide (IZO), tin oxide (SnO), or TiO.

[0018] The common electrode 12 is provided in common to the plurality of light-emitting elements 11. The common electrode 12 is provided so as to cover the transparent electrode layer 115 of each of the plurality of light-emitting elements 11. The common electrode 12 is electrically connected to the transparent electrode layer 115 of each of the plurality of light-emitting elements 11. The common electrode 12 is formed of a transparent electrode material such as ITO, indium zinc oxide (IZO), tin oxide (SnO), or TiO.

[0019] The plug 13 is provided in contact with the first light reflecting film 114, and electrically connects the light emitting element 11 to the drive substrate 30. The plug 13 is formed using, for example, copper (Cu), aluminum (Al), tungsten (W), silver (Ag), or an alloy thereof.

[0020] A pad electrode 14 and a via 14V are embedded in the insulating layer 15. The pad electrode 14 electrically connects the light emitting element 11 and the drive substrate 30 via the plug 13. The pad electrode 14 and the via 14V are each formed using, for example, copper (Cu), aluminum (Al), tungsten (W), silver (Ag), or an alloy thereof.

[0021] The insulating layer 15 is made of, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0022] Further provided on the drive substrate 30 side of the insulating layer 15 are an insulating layer 16 that forms a bonding surface with the drive substrate 30, and a pad portion 17 that is embedded in the insulating layer 16. The insulating layer 16 is made of, for example, silicon oxide (SiO) or silicon nitride (SiN). The pad portion 17 is made of, for example, copper (Cu).

[0023] The embedded layer 18 is intended to flatten the surfaces of the plurality of light emitting elements 11 that face the drive substrate 30. The embedded layer 18 is formed using, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0024] The compound semiconductor layer 19 has a surface 19S1 facing the light-emitting element 11 and a surface 19S2 opposite to the surface 19S1. The surface 19S2 of the compound semiconductor layer 19 has a concave shape with respect to the surface 19S1. The surface 19S2 of the compound semiconductor layer 19 has a concave curved surface that forms part of a concave curved surface that is continuous with the surface 11S1 of the light-emitting element 11. In other words, the surface 19S2 is provided on an extension of the surface 11S1.

[0025] The compound semiconductor layer 19 is provided around the light-emitting element 11 and is electrically isolated from the light-emitting element 11. The compound semiconductor layer 19 has, for example, the same layered structure as the light-emitting element 11. The compound semiconductor layer 19 has, for example, a first conductivity-type layer 191, an active layer 192, and a second conductivity-type layer 193 stacked in this order from the drive substrate 30 side. The compound semiconductor layer 19 has a second light-reflecting film 194 provided on a surface 19S2. The compound semiconductor layer 19 further has, for example, a transparent electrode layer 195 provided on the surface of the second conductivity-type layer 193 opposite to the active layer 192. The first conductivity-type layer 191 has a configuration corresponding to the first conductivity-type layer 111, the active layer 192 has a configuration corresponding to the active layer 112, the second conductivity-type layer 193 has a configuration corresponding to the second conductivity-type layer 113, the second light-reflecting film 194 has a configuration corresponding to the first light-reflecting film 114, and the transparent electrode layer 195 has a configuration corresponding to the transparent electrode layer 115. The upper surface of the compound semiconductor layer 19 opposite to the drive substrate 30 is at the same height as the light emitting surface 11S1 of the light emitting element 11 with respect to the upper surface of the drive substrate 30.

[0026] The second light-reflecting film 194 is provided at a position facing the surface 19S2 of the compound semiconductor layer 19. The second light-reflecting film 194 is formed using a metal material having light reflectivity. The second light-reflecting film 194 is formed, for example, using a light-reflecting metal containing titanium (Ti) and at least one of aluminum (Al) and silver (Ag). The second light-reflecting film 194 is formed, for example, using a transparent electrode material such as ITO, indium zinc oxide (IZO), tin oxide (SnO), or TiO, and a light-reflecting metal containing at least one of aluminum (Al) and silver (Ag).

[0027] 3, each of the compound semiconductor layers 19 is provided so as to surround each of the plurality of light emitting elements 11 in the XY plane. A distance L1 between the light emitting element 11 and the compound semiconductor layer 19 in the XY plane is, for example, 10 nm or more and 500 nm or less.

[0028] (Configuration of wavelength conversion unit 20) The wavelength conversion unit 20 is provided on the light emission surface 11S1 side of the light emitting unit 10. The wavelength conversion unit 20 is provided with a planarization layer 21 and a protective layer 22 in this order from the light emitting unit 10 side. An on-chip lens layer 23 is further provided on the protective layer 22 for each pixel P.

[0029] The planarization layer 21 is intended to planarize the light emitting surface 11S1 of the light emitting section 10. The planarization layer 21 is formed of, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0030] The protective layer 22 is for protecting the surface of the light emitting device 1, and is formed using, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0031] The on-chip lens layer 23 is provided on the opposite side of the drive substrate 30 as viewed from the light-emitting elements 11. The on-chip lens layer 23 condenses or diverges light emitted from the active layers 112 of one or more light-emitting elements 11. The on-chip lens layer 23 is made of an optically transparent material, and is made of, for example, a single-layer film made of any of silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiCN), etc., or a stacked film made of two or more of these materials. Here, the on-chip lens layer 23 corresponds to a specific example of a "lens" according to one aspect of the present disclosure.

[0032] (Configuration of Drive Substrate 30) The drive substrate 30 is electrically connected to the plurality of light-emitting elements 11 and has a drive circuit 35 that drives the plurality of light-emitting elements 11. The drive substrate 30 has a support substrate 31 made of, for example, silicon (Si), an interlayer insulating layer 32 provided on the support substrate 31 and including a plurality of wiring layers (e.g., wiring layers M1, M2, M3, M4, and M5) and vias that electrically connect the wiring layers, an insulating layer 33 that forms a bonding surface with the light-emitting section 10, and a pad section 34 embedded in the insulating layer 33. The drive circuit 35 is embedded in, for example, the interlayer insulating layer 32. The drive substrate 30 corresponds to a specific example of a "substrate" according to one aspect of the present disclosure.

[0033] The interlayer insulating layer 32 is formed using, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0034] The wiring layers M1, M2, M3, M4, and M5 and the vias electrically connecting the wiring layers are formed using, for example, copper (Cu), aluminum (Al), tungsten (W), silver (Ag), or alloys thereof. The insulating layer 33 is formed using, for example, silicon oxide (SiO), silicon nitride (SiN), or the like. The pad portion is formed using, for example, copper (Cu).

[0035] 1-2. Method for Manufacturing Light-Emitting Device The light-emitting device 1 of this embodiment can be manufactured, for example, as follows: Figures 4A to 4K show an example of a manufacturing process for the light-emitting device 1.

[0036] First, as shown in FIG. 4A , for example, a sapphire substrate is prepared as a growth substrate 40, and then a first conductivity type layer 111, an active layer 112, and a second conductivity type layer 113 are formed in this order on the growth substrate 40 by epitaxial crystal growth using a method such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE).

[0037] Next, the transparent electrode layer 115 is formed so as to be in contact with the second conductivity type layer 113. The transparent electrode layer 115 is obtained by forming a film of indium tin oxide using, for example, a sputtering method or a vapor deposition method.

[0038] 4B , the stacked film 110 including the first conductivity type layer 111, the active layer 112, the second conductivity type layer 113, and the transparent electrode layer 115 was inverted relative to the support substrate 41 so that the transparent electrode layer 115 faced the support substrate 41, and then bonded to the support substrate 41 via an embedded layer 42 made of silicon oxide or the like. Thereafter, the growth substrate 40 was peeled off from the first conductivity type layer 111. This operation sealed the stacked film 110 with the embedded layer 42.

[0039] Next, a resist is applied onto the buried layer 42 and then patterned by photolithography to form a resist pattern R1. Subsequently, the resist pattern R1 is reflowed by heat treatment at, for example, 120 to 140° C., so that the corners of the resist pattern R1 are rounded as shown in FIG. 4C, and the resist pattern R1 is then cooled and hardened.

[0040] Subsequently, using the resist pattern R1 as a mask, dry etching is performed to form a convex shape as shown in FIG. 4D in the laminated film 110.

[0041] Subsequently, as shown in FIG. 4E, a light reflecting film 116 is formed around the periphery of the stacked film 110 and along the upper surface of the buried layer 42.

[0042] 4F, the embedding layer 18 is formed so as to cover the laminated film 110 and the light reflecting film 116. By this operation, the laminated film 110 and the light reflecting film 116 are sealed by the embedding layer 18.

[0043] Subsequently, as shown in FIG. 4G, plugs 13 are formed on the light reflecting film 116 for each convex portion of the laminated film 110 .

[0044] Next, as shown in FIG. 4H , an insulating layer 15 in which a plurality of pad electrodes 14 are embedded and an insulating layer 16 in which a plurality of pad portions 17 are embedded are sequentially formed on the embedded layer 18. At this time, each of the plurality of plugs 13 is bonded to each of the plurality of pad electrodes 14. This results in a light-emitting portion 10 including a laminated film 110, a light-reflecting film 116, insulating layers 15 and 16, and an embedded layer 18. Thereafter, a separately fabricated drive substrate 30 is bonded to the upper surface of the light-emitting portion 10, i.e., the upper surface of the insulating layer 16 and the upper surface of the pad portions 17 (so-called hybrid bonding is performed). In this hybrid bonding, the pad portions 17 and 34 are bonded together, and the insulating layer 16 and 33 are bonded together.

[0045] Next, the bonded light-emitting unit 10 and drive substrate 30 are inverted so that the drive substrate 30 is on the bottom, and then the support substrate 41 and the embedded layer 42 are removed. Next, as shown in FIG. 4I , the stacked film 110 and the light-reflecting film 116 are cleaved into individual pieces by, for example, reactive ion etching (RIE). At this time, each convex portion is cleaved into two parts: a central portion and an annular portion.

[0046] Of the singulated laminated film 110, the annular portions of the convex portions become the compound semiconductor layer 19. Of the cleaved light reflecting film 116, the portion along the center of the convex portions becomes the first light reflecting film 114, and the portion along the compound semiconductor layer 19 becomes the second light reflecting film 194. Of the singulated laminated film 110, the center portions of the convex portions become the light emitting elements 11. The gap between the cleaved light emitting element 11 and the compound semiconductor layer 19 is refilled with the buried layer 18 by, for example, atomic layer deposition (ALD).

[0047] 4J , a common electrode 12 is formed so as to contact the transparent electrode layer 115 of each of the plurality of light-emitting elements 11. Specifically, for example, a planarization layer 21 is formed so as to entirely cover the transparent electrode layer 115, the embedded layer 18, and the compound semiconductor layer 19, and then a portion of the planarization layer 21 corresponding to the transparent electrode layer 115 is selectively removed to expose the transparent electrode layer 115. Thereafter, the common electrode 12 is formed so as to cover the planarization layer 21 and the transparent electrode layer 115.

[0048] 4K, a planarization layer 21 is further formed by, for example, CVD on the surface of the common electrode 12 opposite to the surface facing the light-emitting section 10. This operation flattens the surface that will be in contact with the protective layer 22 to be formed later. Thereafter, the protective layer 22 and the on-chip lens layer 23 are formed in this order on the planarization layer 21. With the above steps, the light-emitting device 1 shown in FIG. 1 is completed.

[0049] [1-3. Actions and Effects] The light emitting device 1 of this embodiment includes a plurality of light emitting elements 11 arranged on a drive substrate 30, and a compound semiconductor layer 19 provided around the plurality of light emitting elements 11. The light emitting element 11 is provided with a first light reflecting film 114 at a position facing a surface 11S2 opposite to the light emitting surface 11S1. As a result, emitted light traveling from the active layer 112 of the light emitting element 11 toward the first light reflecting film 114 is reflected toward the light emitting surface 11S1, improving the directivity of the emitted light. This will be described below.

[0050] Light-emitting devices using micro LEDs are required to have improved brightness and reduced power consumption, especially when used outdoors. To achieve this, the light-emitting elements must have improved light extraction efficiency and high directivity.

[0051] However, in a light emitting device with a narrow pitch, it is difficult to simultaneously improve the light extraction efficiency of the light emitting element and achieve high directivity.

[0052] In contrast to this, in the light emitting device 1 of the present embodiment, as described above, the first light reflecting film 114 having light reflectivity is provided so as to cover the surface 11S2 of the light emitting element 11. As a result, the emitted light traveling from the active layer 112 of the light emitting element 11 toward the surface 11S2 is reflected toward the light emitting surface 11S1, thereby increasing the directivity of the emitted light and enabling an improvement in the light extraction efficiency.

[0053] Furthermore, in the light-emitting device 1 of this embodiment, a compound semiconductor layer 19 is provided around the light-emitting element 11. The compound semiconductor layer 19 has a surface 19S1 facing the light-emitting element 11 and a surface 19S2 opposite to the surface 19S1. The compound semiconductor layer 19 absorbs light emitted from the light-emitting element 11 that enters the compound semiconductor layer 19. The second light-reflecting film 194 is provided along the surface 19S2 of the compound semiconductor layer 19 and has light reflectivity. The second light-reflecting film 194 reflects light emitted from the light-emitting element 11 that travels toward the second light-reflecting film 194. The compound semiconductor layer 19 and the second light-reflecting film 194 surround the light-emitting element 11, thereby absorbing or reflecting light emitted from the light-emitting element 11 that travels in directions other than the upper surface. This prevents light emitted from the light-emitting element 11 from leaking and entering other light-emitting elements 11. Furthermore, since the compound semiconductor layer 19 and the second light reflecting film 194 surround the light emitting element 11 to prevent light leakage, when a plurality of light emitting elements 11 are arranged, the distance between the plurality of light emitting elements 11 can be reduced. In other words, high integration of the light emitting elements 11 is possible.

[0054] Furthermore, in the light-emitting device 1 of the present embodiment, the surface 11S1 of the light-emitting element 11 and the surface 19S2 of the compound semiconductor layer 19 form part of a continuous concave surface. Therefore, the light-emitting element 11 is surrounded by the concave surface formed by the first light-reflecting film 114 and the second light-reflecting film 194. By being surrounded by the concave-shaped light-emitting film, the light-emitting element 11 is expected to have even higher directivity and improved light extraction efficiency.

[0055] In the light emitting device 1 of this embodiment, the compound semiconductor layer 19 provided around the light emitting element 11 is electrically isolated from the light emitting element 11. This puts the compound semiconductor layer 19 in a floating state, allowing for potential control independent of the light emitting element 11.

[0056] 2. Modifications Next, modifications 1 to 13 and application examples of the present disclosure will be described. Note that components corresponding to those in the light emitting device 1 of the above embodiment will be assigned the same reference numerals and descriptions thereof will be omitted.

[0057] [2-1. Modification 1] FIG. 5 is a schematic diagram illustrating an example of a cross-sectional configuration of a light-emitting device (light-emitting device 1A) according to Modification 1 of the present disclosure.

[0058] In the above embodiment, the light-emitting element 11 has a structure in which a first conductivity-type layer 111, an active layer 112, and a second conductivity-type layer 113 are stacked in this order from the drive substrate 30 side. In the above embodiment, the compound semiconductor layer 19 has a structure in which a first conductivity-type layer 191, an active layer 192, and a second conductivity-type layer 193 are stacked in this order from the drive substrate 30 side. In contrast, in the light-emitting device 1A of this modification, the light-emitting element 11a has a structure in which a second conductivity-type layer 113a, an active layer 112a, and a first conductivity-type layer 111a are stacked in this order from the drive substrate 30 side. In the light-emitting device 1A of this modification, the compound semiconductor layer 19a has a structure in which a second conductivity-type layer 193a, an active layer 192a, and a first conductivity-type layer 191a are stacked in this order from the drive substrate 30 side. The compound semiconductor layer 19a has the same configuration as the light emitting element 11a, in which the first conductivity type layer 191a corresponds to the first conductivity type layer 111a, the active layer 192a corresponds to the active layer 112a, and the second conductivity type layer 193a corresponds to the second conductivity type layer 113a.

[0059] 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 with this configuration, the light emitting device 1A can achieve the same effects as the above embodiment.

[0060] [2-2. Modification 2] FIG. 6 is a schematic diagram illustrating an example of a cross-sectional configuration of a light-emitting device (light-emitting device 1B) according to Modification 2 of the present disclosure.

[0061] In the above embodiment, an example has been shown in which the second light-reflecting film 194 is provided along the surface 19S2 of the compound semiconductor layer 19, but the present disclosure is not limited to this. In the light-emitting device 1B of this modified example, for example, as shown in FIG. 6 , the second light-reflecting film 194b may be provided along the surface 19S2 of the compound semiconductor layer 19 and the upper surface of the embedded layer 18. Except for this point, the configuration of the light-emitting device 1B is substantially the same as the configuration of the light-emitting device 1 of the above embodiment. Even with such a configuration, the light-emitting device 1B can achieve the same effects as the above embodiment.

[0062] Light emitting device 1B can be manufactured in the same manner as light emitting device 1 up to the stage of removing support substrate 41 and embedded layer 18. In light emitting device 1B, when light reflective film 116 is cleaved, the light reflective film 116 on the upper surface of embedded layer 18 is left unremoved. This results in a second light reflective film 194b that is along surface 19S2 of compound semiconductor layer 19 and the upper surface of embedded layer 18. After this, light emitting device 1B can be manufactured in the same manner as light emitting device 1.

[0063] 7A is a schematic diagram illustrating an example of a cross-sectional configuration of a light-emitting device (light-emitting device 1C) according to Modification 3 of the present disclosure. FIG. 7B is a schematic diagram illustrating an example of a planar configuration (light-emitting device 1C) of a plurality of light-emitting elements 11 and a compound semiconductor layer 19c according to Modification 3 of the present disclosure.

[0064] In the above embodiment, an example was shown in which adjacent compound semiconductor layers 19 are completely separated, but the present disclosure is not limited to this. In the light emitting device 1C of this modification, the first conductivity type layer 191c and the active layer 192c of the compound semiconductor layer 19c are separated by a second light reflecting film 194c. In the light emitting device 1C, the second conductivity type layer 113c may be continuous in the XY plane, as shown in FIG. 7B, for example. Except for this point, the configuration of the light emitting device 1C is substantially the same as the configuration of the light emitting device 1 of the above embodiment. Even with this configuration, the light emitting device 1C can achieve the same effects as the above embodiment.

[0065] In the above embodiment, as shown in Fig. 3, a plurality of compound semiconductor layers 19 are arranged at regular intervals in a plan view. In contrast, in the light emitting device 1C of this modification, as shown in Fig. 7B, one compound semiconductor layer 19c is provided so as to surround a plurality of light emitting elements 11 in the XY plane. This eliminates the need for an interval between adjacent compound semiconductor layers 19, thereby enabling a narrower pitch in the light emitting device.

[0066] [2-4. Modification 4] FIG. 8 is a schematic diagram illustrating an example of a cross-sectional configuration of a light-emitting device (light-emitting device 1D) according to Modification 4 of the present disclosure.

[0067] In the light emitting device 1D according to the fourth modification, a protective film 51 is provided on the drive substrate 30 side of the light emitting element 11 of the light emitting section 10. The protective film 51 has an opening 51H at a position corresponding to the light emitting element 11. The plug 13 penetrates the opening 51H and connects to the first light reflecting film 114 of the light emitting element 11. The protective film 51 is formed using, for example, titanium (Ti). The protective film 51 may be formed from a material having light absorbing properties. The protective film 51 is made of, for example, silicon (Si).

[0068] Except for the above points, the configuration of the light emitting device 1D is substantially the same as the configuration of the light emitting device 1 of the above embodiment.

[0069] As described above, the light-emitting device 1D of this modified example more effectively prevents light emitted from the light-emitting element 11 from entering the drive substrate 30 by providing a protective film 51 on the drive substrate 30 side of the light-emitting element 11 of the light-emitting section 10.

[0070] [2-5. Modification 5] FIG. 9 is a schematic diagram illustrating an example of a cross-sectional configuration of a light-emitting device (light-emitting device 1E) according to Modification 5 of the present disclosure.

[0071] In the light emitting device 1E according to the fifth modification, a compound semiconductor layer 52 is further provided between adjacent compound semiconductor layers 19. The compound semiconductor layer 52 is electrically isolated from the light emitting element 11 and the compound semiconductor layer 19. The compound semiconductor layer 52 is formed, for example, in the same configuration as the light emitting element 11 and the compound semiconductor layer 19, and has substantially the same thickness as the light emitting element 11. The upper surface of the compound semiconductor layer 52 opposite to the drive substrate 30 is at the same height as the light emitting surface 11S1 of the light emitting element 11, relative to the upper surface of the drive substrate 30.

[0072] Except for the above points, the configuration of the light emitting device 1E is substantially the same as the configuration of the light emitting device 1 of the above embodiment. The compound semiconductor layer 52 corresponds to a specific example of a "second compound semiconductor layer" according to one aspect of the present disclosure.

[0073] In the light-emitting device 1E of this modification, a compound semiconductor layer 52 having substantially the same thickness as the light-emitting element 11 is provided at the same layer as the light-emitting element 11 and the compound semiconductor layer 19. This allows the common electrode 12 to be stably formed on the common plane across the entire light-emitting device 1. This prevents unintended defects, such as breakage of the common electrode 12 or localized reduction in the cross-sectional area of ​​the common electrode 12. As a result, the light-emitting device 1 can be made thinner while avoiding breakage or high resistance of the common electrode 12. Furthermore, the improved flatness of the common plane including the upper surfaces of the light-emitting element 11, the compound semiconductor layer 19, and the compound semiconductor layer 52 facilitates the formation of the wavelength conversion section 20 with high dimensional accuracy during the manufacturing process of the light-emitting device 1E of this modification. As a result, the luminance variation among multiple pixels P can be reduced, resulting in excellent light-emitting performance.

[0074] 2-6. Modification 6 FIG. 10 is a schematic diagram illustrating an example of a cross-sectional configuration of a light-emitting section 10F (light-emitting device 1F) according to Modification 6 of the present disclosure.

[0075] In the light-emitting device 1F according to the sixth modification, a metal film 53 is provided between the light-emitting element 11 and the compound semiconductor layer 19. The metal film 53 is formed using a metal material having optical reflectivity. Examples of metal materials for forming the metal film 53 include metals with high reflectivity in the visible light range. Specific examples of materials for the metal film 53 include aluminum (Al), tungsten (W), silver (Ag), titanium (Ti), cobalt (Co), nickel (Ni), copper (Cu), platinum (Pt), titanium nitride (TiN), and alloys thereof. As shown in FIG. 10 , the distance L2 between the light-emitting element 11 and the compound semiconductor layer 19 in the XY plane is, for example, 200 nm or more and 500 nm or less. Except for this point, the configuration of the light-emitting device 1F is substantially the same as the configuration of the light-emitting device 1 according to the above embodiment.

[0076] The light emitting device 1F can be manufactured using the same method as the light emitting device 1 up to the stage of obtaining the light emitting element 11 and the compound semiconductor layer 19 from the singulated laminated structure. In the light emitting device 1I, for example, a SiN film is formed between the light emitting element 11 and the compound semiconductor layer 19 by, for example, a CVD method or an atomic layer deposition (ALD) method. Next, a metal film 53 is formed by, for example, a CVD method or an atomic layer deposition (ALD) method, and shaped by, for example, dry etching. After this, the light emitting device 1I can be manufactured using the same method as the light emitting device 1.

[0077] In the light emitting device 1F of this modified example, by providing a metal film 53 between the light emitting element 11 and the compound semiconductor layer 19, stray light and leaked light are reflected while maintaining flatness, and therefore, improvement in light extraction efficiency can be expected.

[0078] 11A is a schematic diagram illustrating an example of a cross-sectional configuration of a light-emitting device (light-emitting device 1G) according to Modification 7 of the present disclosure. Fig. 11B is a circuit diagram illustrating a circuit configuration of the light-emitting device (light-emitting device 1G) according to Modification 7 of the present disclosure.

[0079] In the above embodiment, an example has been shown in which the compound semiconductor layer 19 is electrically isolated from the light emitting element 11 and in a floating state, but the present disclosure is not limited to this. In the light emitting device 1G of this modification, the compound semiconductor layer 19 is connected to a readout circuit 50 that is different from the drive circuit 35 that drives the light emitting element 11. Except for this point, the configuration of the light emitting device 1G is substantially the same as the configuration of the light emitting device 1 of the above embodiment.

[0080] In the light emitting device 1G of this modification, the compound semiconductor layer 19 is connected to a readout circuit 50 that is different from the drive circuit 35 that drives the light emitting element 11, and therefore a voltage different from the voltage applied to the light emitting element 11 can be applied to the compound semiconductor layer 19. When a voltage is applied to the compound semiconductor layer 19 arranged around the light emitting element 11, charges move to the periphery of the light emitting element 11, and the path of the current flowing inside the light emitting element 11 is narrowed.

[0081] [2-8. Modification 8] Fig. 12A is a schematic diagram illustrating an example of a cross-sectional configuration of a light-emitting unit 10H-1 (light-emitting device 1H-1) according to Modification 8 of the present disclosure. Fig. 12B is a schematic diagram illustrating another example of a cross-sectional configuration of a light-emitting unit 10H-2 (light-emitting device 1H-2) according to Modification 8 of the present disclosure.

[0082] In the light-emitting device 1H-1 according to the eighth modification, an insulating film 196 is provided between a portion of the first conductivity-type layer 191, the active layer 192, and the second conductivity-type layer 193 of the compound semiconductor layer 19 and the second light-reflecting film 194h. As in the light-emitting device 1H-2 shown in FIG. 12B , the insulating film 196 may be provided between the first conductivity-type layer 191, the active layer 192, and the second conductivity-type layer 193 of the compound semiconductor layer 19 and the second light-reflecting film 194h. As in the light-emitting device 1H-2 of this modification, an insulating film 117 may be further provided between the first conductivity-type layer 111 of the light-emitting element 11 and the first light-reflecting film 114. The insulating film 117 has an opening 117H. The first conductivity-type layer 111 is connected to the first light-reflecting film 114 through the opening 117H. The insulating film 117 and the insulating film 196 are formed of, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0083] Except for the above points, the configuration of the light emitting device 1H is substantially the same as the configuration of the light emitting device 1 of the above embodiment.

[0084] In the light emitting device 1H of this modification, the reflectance of the light reflective film can be improved by providing an insulating film in contact with the light reflective film, thereby improving the light extraction efficiency of the light emitting device 1H.

[0085] [2-9. Ninth Modification] FIG. 13 is a schematic diagram illustrating an example of a cross-sectional configuration of a light-emitting section 10I (light-emitting device 1I) according to a ninth modification of the present disclosure.

[0086] In the light-emitting device 1I according to the ninth modification, a current confinement layer 118a and a current confinement layer 118b are provided on the light-emitting surface 11iS1 side of the light-emitting element 11i. A portion of the first-conductivity-type layer 111i, an active layer 112i, and a second-conductivity-type layer 113i are filled between the current confinement layer 118a and the current confinement layer 118b, in this order from the drive substrate 30 side. The current confinement layer 118a and the current confinement layer 118b are formed by ion implantation. Examples of ion species that form the current confinement layer 118a and the current confinement layer 118b include silicon (Si), boron (B), and gallium (Ga).

[0087] Except for the above points, the configuration of the light emitting device 1I is substantially the same as the configuration of the light emitting device 1 of the above embodiment.

[0088] In the light emitting device 1I of this modification, the current confinement layer 118a and the current confinement layer 118b are provided on the light emitting surface 11iS1 side of the light emitting element 11i as described above, thereby confining the path of the current flowing inside the light emitting element 11i.

[0089] [2-10. Modification 10] FIG. 14 is a schematic diagram illustrating an example of a cross-sectional configuration of a light-emitting section 10J (light-emitting device 1J) according to Modification 10 of the present disclosure.

[0090] The light emitting device 1J according to the tenth modification includes a light emitting element 11j having a third conductivity type layer 119 between the second conductivity type layer 113j and the transparent electrode layer 115j, and a compound semiconductor layer 19j having a third conductivity type layer 197 between the second conductivity type layer 193j and the planarization layer 21. The third conductivity type layer 119 is electrically connected to the second conductivity type layer 113j by a tunnel junction. The third conductivity type layer 197 is electrically connected to the second conductivity type layer 193j by a tunnel junction. The third conductivity type layer 119 and the third conductivity type layer 197 are formed of, for example, an n-type GaN-based semiconductor material.

[0091] Except for the above points, the configuration of the light emitting device 1J is substantially the same as the configuration of the light emitting device 1 of the above embodiment.

[0092] [2-11. Modification 11] FIG. 15 is a schematic diagram illustrating an example of a cross-sectional configuration of a light-emitting section 10K (light-emitting device 1K) according to Modification 11 of the present disclosure.

[0093] In the above embodiment, an example is shown in which the side surface of the light emitting element 11 facing the compound semiconductor layer 19 is in a straight line perpendicular to the drive substrate 30, but the present disclosure is not limited to this.

[0094] In the light emitting device 1K according to the present modification 11, the side surface of the light emitting element 11k facing the compound semiconductor layer 19 may have a tapered angle, as shown in Fig. 15. Except for this point, the configuration of the light emitting device 1K is substantially the same as the configuration of the light emitting device 1 according to the above embodiment. Even with such a configuration, the light emitting device 1B can achieve the same effects as the above embodiment.

[0095] [2-12. Modification 12] FIG. 16 is a schematic diagram illustrating an example of a cross-sectional configuration of a light-emitting section 10L (light-emitting device 1L) according to Modification 12 of the present disclosure.

[0096] In the above embodiment, an example is shown in which the surface 19S2 opposite to the surface 19S1 of the compound semiconductor layer 19 facing the light-emitting element 11 includes a concave shape with respect to the surface 19S1, and the second light-reflecting film 194 is provided along the surface 19S2, but the present disclosure is not limited to this.

[0097] 16 , for example, a surface 19lS2 of the compound semiconductor layer 19l opposite to a surface 19lS1 facing the light emitting element 11 may be inclined at an angle of less than 90° with respect to the drive substrate 30. The second light reflecting film 194l is provided along the inclination of the surface 19lS2 of the compound semiconductor layer 19l.

[0098] Except for the above points, the configuration of the light emitting device 1L is substantially the same as the configuration of the light emitting device 1 of the above embodiment.

[0099] In the light emitting device 1L of this modification, the second light reflecting film 194l is inclined at an angle of less than 90° with respect to the thickness direction, so that light traveling in the direction of the second light reflecting film 194l can be efficiently reflected toward the light emitting surface 11S1, thereby improving the front brightness of the light emitting device 1L.

[0100] [2-13. Modification 13] FIG. 17 is a schematic diagram illustrating an example of a cross-sectional configuration of a light-emitting section 10M (light-emitting device 1M) according to Modification 13 of the present disclosure.

[0101] In the above embodiment, an example has been shown in which the surface 11S2 opposite to the light emitting surface 11S1 of the light emitting element 11 includes a concave surface having a concave shape relative to the light emitting surface 11S1, and the first light reflecting film 114 is provided along the surface 11S2. In the above embodiment, an example has also been shown in which the surface 19S2 opposite to the surface 19S1 of the compound semiconductor layer 19 facing the light emitting element 11 includes a concave shape relative to the surface 19S1, and the second light reflecting film 194 is provided along the surface 19S2. However, the present disclosure is not limited to these.

[0102] 17 , for example, a surface 11mS2 opposite to the light emitting surface 11mS1 of the light emitting element 11m is horizontal to the drive substrate 30. The first light reflecting film 114m is provided along the surface 11mS2 and extends in a horizontal direction relative to the drive substrate 30. Furthermore, in the light emitting device 1M, a surface 19mS2 of the compound semiconductor layer 19m opposite to the surface 19mS1 facing the light emitting element 11m may be inclined at an angle of less than 90° relative to the drive substrate 30. The second light reflecting film 194l is provided along the inclination of the surface 19lS2 of the compound semiconductor layer 19l.

[0103] Except for the above points, the configuration of the light emitting device 1M is substantially the same as the configuration of the light emitting device 1 of the above embodiment.

[0104] In the light emitting device 1M of this modification, the second light reflecting film 194m is inclined at an angle of less than 90° with respect to the thickness direction, so that light traveling in the direction of the second light reflecting film 194m can be efficiently reflected toward the light emitting surface 11S1, thereby improving the front brightness of the light emitting device 1M.

[0105] 18 is a perspective view showing an example of a schematic configuration of an image display device (image display device 100). The image display device 100 is a so-called LED display, and uses a light-emitting device according to the present disclosure (e.g., light-emitting device 1) as a display pixel. As shown in FIG. 18 , the image display device 100 includes a display panel 120 and a control circuit 140 that drives the display panel 120.

[0106] The display panel 120 is formed by stacking a mounting substrate 120A and an opposing substrate 120B. The surface of the opposing substrate 120B serves as an image display surface, with a display area (display section 100A) in the center and a frame section 100B, which is a non-display area, around the display area.

[0107] 19 shows an example of a wiring layout in a region of the surface of the mounting substrate 120A facing the counter substrate 120B, corresponding to the display unit 100A. In the region of the surface of the mounting substrate 120A corresponding to the display unit 100A, a plurality of data wirings 134 are formed extending in a predetermined direction and arranged in parallel at a predetermined pitch, as shown in FIG. 20 . In the region of the surface of the mounting substrate 120A corresponding to the display unit 100A, a plurality of scan wirings 135 are further formed extending in a direction intersecting (e.g., perpendicular to) the data wirings 134 and arranged in parallel at a predetermined pitch. The data wirings 134 and the scan wirings 135 are made of a conductive material, such as Cu.

[0108] The scan lines 135 are formed, for example, in the outermost layer, for example, on an insulating layer (not shown) formed on the surface of the substrate. The substrate of the mounting board 120A is made of, for example, a silicon substrate or a resin substrate, and the insulating layer on the substrate is made of, for example, SiN, SiO, aluminum oxide (AlO), or a resin material. On the other hand, the data lines 134 are formed in a layer different from the outermost layer including the scan lines 135 (for example, a layer below the outermost layer), for example, in an insulating layer on the substrate.

[0109] The display pixels 136 are located near the intersections of the data lines 134 and the scan lines 135, and a plurality of the display pixels 136 are arranged in a matrix within the display unit 100A. Each of the display pixels 136 is equipped with, for example, one of the color pixels Pr, Pg, and Pb of the light-emitting device 1.

[0110] The light-emitting device 1 is provided with a pair of terminal electrodes, for example, one for each of the color pixels Pr, Pg, and Pb, or one common and the other for each of the color pixels Pr, Pg, and Pb. One of the terminal electrodes is electrically connected to a data wiring 134, and the other is electrically connected to a scan wiring 135. For example, one of the terminal electrodes is electrically connected to a pad electrode 134B at the tip of a branch 134A provided on the data wiring 134. Furthermore, for example, the other terminal electrode is electrically connected to a pad electrode 135B at the tip of a branch 135A provided on the scan wiring 135.

[0111] Each of the pad electrodes 134B, 135B is formed, for example, on the outermost layer and is provided at a location where each of the light emitting devices 1 is mounted, as shown in Fig. 24. Here, the pad electrodes 134B, 135B are made of a conductive material such as Au (gold).

[0112] The mounting substrate 120A is further provided with, for example, a plurality of support pillars (not shown) that regulate the distance between the mounting substrate 120A and the counter substrate 120B. The support pillars may be provided in the region facing the display unit 100A, or in the region facing the frame unit 100B.

[0113] The counter substrate 120B is made of, for example, a glass substrate or a resin substrate. The surface of the counter substrate 120B facing the light-emitting device 1 may be flat, but is preferably roughened. The roughened surface may be provided over the entire area facing the display unit 100A, or may be provided only in the area facing the display pixels 136. The roughened surface has fine irregularities that allow light emitted from the color pixels Pr, Pg, and Pb to enter the roughened surface. The irregularities on the roughened surface can be created by, for example, sandblasting or dry etching.

[0114] The control circuit 140 drives each display pixel 136 (each light-emitting device 1) based on a video signal. The control circuit 140 is configured, for example, with a data driver that drives the data wiring 134 connected to the display pixels 136 and a scan driver that drives the scan wiring 135 connected to the display pixels 136. For example, as shown in FIG. 18 , the control circuit 140 may be provided separately from the display panel 120 and connected to the mounting substrate 120A via wiring, or may be mounted on the mounting substrate 120A.

[0115] 20 is a perspective view showing another configuration example (image display device 200) of an image display device using a light-emitting device (e.g., light-emitting device 1) according to the present disclosure. The image display device 200 is a so-called tiling display that uses a plurality of light-emitting devices that use LEDs as light sources. For example, as shown in FIG. 20 , the image display device 200 includes a display panel 220 and a control circuit 240 that drives the display panel 220.

[0116] The display panel 220 is formed by stacking a mounting substrate 220A and a counter substrate 220B on top of each other. The surface of the counter substrate 220B serves as an image display surface, with a display section in the center and a frame section surrounding the display section, which is a non-display area (neither of which is shown). The counter substrate 220B is disposed, for example, in a position opposite the mounting substrate 220A with a predetermined gap therebetween. Note that the counter substrate 220B may also be in contact with the top surface of the mounting substrate 220A.

[0117] Fig. 21 is a schematic diagram showing an example of the configuration of the mounting substrate 220A. For example, as shown in Fig. 21, the mounting substrate 220A is configured from a plurality of unit substrates 250 arranged in a tiled pattern. Note that Fig. 21 shows an example in which the mounting substrate 220A is configured from nine unit substrates 250, but the number of unit substrates 250 may be ten or more, or eight or less.

[0118] 22 shows an example of the configuration of a unit substrate 250. The unit substrate 250 has, for example, a plurality of light-emitting devices 1 arranged in a tiled pattern and a support substrate 260 that supports each of the light-emitting devices 1. Each unit substrate 250 also has a control substrate (not shown). The support substrate 260 is made of, for example, a metal frame (metal plate) or a wiring substrate. If the support substrate 260 is made of a wiring substrate, it can also serve as the control substrate. In this case, at least one of the support substrate 260 and the control substrate is electrically connected to each of the light-emitting devices 1.

[0119] 23 shows the appearance of a transparent display 300. The transparent display 300 has, for example, a display unit 310, an operation unit 311, and a housing 312. The display unit 310 uses a light-emitting device (for example, the light-emitting device 1) of the present disclosure. The transparent display 300 can display images and text information while allowing the background of the display unit 310 to be seen through.

[0120] In the transparent display 300, a light-transmitting substrate is used as the mounting substrate. Each electrode provided in the light-emitting device 1 is formed using a light-transmitting conductive material, similar to the mounting substrate. Alternatively, each electrode is structured to be less visible by increasing the wiring width or reducing the wiring thickness. Furthermore, the transparent display 300 can display black by, for example, overlaying a liquid crystal layer equipped with a drive circuit, and switching between transparent and black display is possible by controlling the light distribution direction of the liquid crystal.

[0121] The present technology has been described above with reference to the embodiments, Modifications 1 to 13, and application examples, but the present technology is not limited to the above embodiments, etc., and various modifications are possible. For example, in the above embodiments, etc., examples have been shown in which the light emitted from the light-emitting element 11 is blue light or ultraviolet light, but the present technology is not limited to this. For example, the light-emitting device 1 may 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.

[0122] Furthermore, in the above embodiments, each component constituting the light emitting device 1 is specifically described, but it is not necessary to include all components, and other components may also be included. For example, in the above embodiments, an example is shown in which there are multiple light emitting elements 11, but this is not limiting. For example, the light emitting device 1 may include only one light emitting element 11.

[0123] In addition, although the above-described embodiments and the like have exemplified the case where light-emitting elements and the like are provided on a drive substrate having a drive circuit, the present disclosure is not limited to this. For example, light-emitting elements and the like may be provided on another substrate that does not have a drive circuit, and the light-emitting elements may be connected to a drive circuit included in a drive substrate separate from the other substrate.

[0124] The effects described in this specification are merely examples and are not limited to those described, and other effects may also be obtained.

[0125] The present technology can also be configured as follows. According to the present technology configured as follows, a compound semiconductor layer having a light-reflecting film including a concave or inclined surface with respect to the light-emitting surface is provided around one or more light-emitting elements, thereby improving the front brightness of the light-emitting elements. This makes it possible to achieve both improved light extraction efficiency and high directivity of the light-emitting elements. (1) A light-emitting device comprising: a substrate; a light-emitting element provided on the substrate and including a light-emitting surface; a first compound semiconductor layer provided on at least a portion of the substrate around the light-emitting element, electrically isolated from the light-emitting element, and having the same layered structure as the light-emitting element; and a first light-reflecting film provided on the opposite side of the light-emitting element from the light-emitting surface, the first light-reflecting film including a concave surface with a concave shape with respect to the light-emitting surface. (2) The light-emitting device according to (1), further comprising a second light-reflecting film, wherein the first compound semiconductor layer includes a first surface facing the light-emitting element and a second surface located opposite the first surface, and the second light-reflecting film is provided to cover the second surface. (3) The light-emitting device according to (2), wherein the second surface of the first compound semiconductor layer includes a concave shape with respect to the first surface. (4) The light-emitting device according to (2) or (3), wherein the second surface of the first compound semiconductor layer is inclined at an angle of less than 90°. (5) The light-emitting device according to any one of (2) to (4), wherein the first light-reflecting film and the second light-reflecting film contain titanium and at least one of aluminum and silver. (6) The light-emitting device according to any one of (2) to (5), wherein the first light-reflecting film and the second light-reflecting film contain a transparent conductive material and at least one of aluminum and silver. (7) The light-emitting device according to any one of (1) to (6), wherein the light-emitting element includes a first conductivity-type layer, an active layer, and a second conductivity-type layer, in this order from the substrate side. (8) The light emitting device according to any one of (1) to (7), wherein the light emitting surface of the light emitting element and an upper surface of the first compound semiconductor layer opposite to the substrate are at the same height position with respect to the upper surface of the substrate.(9) The light-emitting device according to (7), further comprising a plurality of transparent electrode layers and one common electrode, and comprising a plurality of the light-emitting elements, wherein each of the plurality of transparent electrode layers is provided so as to cover the second conductivity type layer of each of the plurality of light-emitting elements, and the common electrode is provided so as to cover each of the plurality of transparent electrode layers. (10) The light-emitting device according to any one of (1) to (9), wherein the substrate has a drive circuit electrically connected to the light-emitting elements and driving the light-emitting elements. (11) The light-emitting device according to (10), wherein the first compound semiconductor layer is connected to a circuit different from the drive circuit. (12) The light-emitting device according to any one of (1) to (11), wherein the distance between the light-emitting elements and the first compound semiconductor layer is 10 nm or more and 500 nm or less. (13) The light emitting device according to any one of (1) to (12), further comprising a second compound semiconductor layer, wherein the second compound semiconductor layer is provided between adjacent first compound semiconductor layers, is electrically isolated from the light emitting element, and has the same layered structure as the light emitting element, and an upper surface of the light emitting element opposite to the substrate and an upper surface of the first compound semiconductor layer opposite to the substrate are at the same height position with respect to an upper surface of the substrate. (14) The light emitting device according to any one of (7) to (9), further comprising a lens, wherein the lens is provided on the light emitting surface side of the light emitting element and focuses or diverges light emitted from the active layer. (15) A light emitting device comprising: a substrate; one or more light emitting elements provided on the substrate and including a light emitting surface; a first compound semiconductor layer provided on the substrate in at least a portion of the periphery of the light emitting element, electrically isolated from the light emitting element, and having the same layered structure as the light emitting element; a first light reflecting film provided on the opposite side of the light emitting element from the light emitting surface and extending in a horizontal direction relative to the substrate; and a second light reflecting film, wherein the first compound semiconductor layer includes a first surface facing the light emitting element and a second surface located on the opposite side of the first surface and inclined at an angle of less than 90° relative to the substrate, and the second light reflecting film is provided so as to cover the second surface.(16) An image display device comprising a light-emitting device, the light-emitting device comprising: a substrate; one or more light-emitting elements provided on the substrate and including a light-emitting surface; a first compound semiconductor layer provided on the substrate in at least a portion of the periphery of the light-emitting element, electrically isolated from the light-emitting element, and having the same layered structure as the light-emitting element; and a first light-reflecting film provided on the opposite side of the light-emitting element from the light-emitting surface, including a concave surface having a concave shape with respect to the light-emitting surface. (17) An image display device comprising: a substrate; one or more light-emitting elements provided on the substrate and including a light-emitting surface; a first compound semiconductor layer provided on the substrate in at least a portion of the periphery of the light-emitting element, electrically isolated from the light-emitting element, and having the same layered structure as the light-emitting element; a first light-reflecting film provided on the opposite side of the light-emitting element from the light-emitting surface and extending in a horizontal direction relative to the substrate; and a second light-reflecting film, wherein the first compound semiconductor layer includes a first surface facing the light-emitting element and a second surface located on the opposite side of the first surface and inclined at an angle of less than 90° relative to the substrate; and the second light-reflecting film provided so as to cover the second surface.

[0126] This application claims priority based on Japanese Patent Application No. 2024-058241, filed on March 29, 2024, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0127] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur depending on design requirements and other factors, and are intended to be within the scope of the appended claims and their equivalents.

Claims

1. A light emitting device comprising: a substrate; a light emitting element provided on the substrate and including a light emitting surface; a first compound semiconductor layer provided on the substrate around at least a portion of the periphery of the light emitting element, electrically isolated from the light emitting element, and having the same layered structure as the light emitting element; and a first light reflecting film provided on the opposite side of the light emitting element from the light emitting surface, including a concave surface that is concave relative to the light emitting surface.

2. The light-emitting device according to claim 1, further comprising a second light-reflecting film, wherein the first compound semiconductor layer includes a first surface facing the light-emitting element and a second surface located opposite the first surface, and the second light-reflecting film is provided so as to cover the second surface.

3. The light emitting device according to claim 2, wherein the second surface of the first compound semiconductor layer includes a concave shape relative to the first surface.

4. The light emitting device according to claim 2, wherein the second surface of the first compound semiconductor layer is inclined at an angle of less than 90° with respect to the substrate.

5. The light emitting device according to claim 2, wherein the first light reflecting film and the second light reflecting film contain titanium and at least one of aluminum and silver.

6. The light emitting device according to claim 2, wherein the first light reflecting film and the second light reflecting film contain a transparent conductive material and at least one of aluminum and silver.

7. The light emitting device according to claim 1, wherein the light emitting element comprises a first conductive type layer, an active layer, and a second conductive type layer in this order from the substrate side.

8. The light emitting device according to claim 1, wherein the light emitting surface of the light emitting element and the upper surface of the first compound semiconductor layer opposite to the substrate are at the same height relative to the upper surface of the substrate.

9. The light-emitting device according to claim 7, further comprising a plurality of transparent electrode layers and one common electrode, a plurality of light-emitting elements, each of the plurality of transparent electrode layers being provided so as to cover the second conductive type layer of each of the plurality of light-emitting elements, and the common electrode being provided so as to cover each of the plurality of transparent electrode layers.

10. The light emitting device according to claim 1, wherein the substrate has a drive circuit electrically connected to the light emitting element for driving the light emitting element.

11. The light emitting device according to claim 10, wherein the first compound semiconductor layer is connected to a circuit different from the drive circuit.

12. The light emitting device according to claim 1, wherein the distance between the light emitting element and the first compound semiconductor layer is 10 nm or more and 500 nm or less.

13. The light-emitting device according to claim 1, further comprising a second compound semiconductor layer, wherein the second compound semiconductor layer is provided between adjacent first compound semiconductor layers, is electrically isolated from the light-emitting element, and has the same layered structure as the light-emitting element, and wherein an upper surface of the light-emitting element opposite to the substrate and an upper surface of the first compound semiconductor layer opposite to the substrate are at the same height relative to the upper surface of the substrate.

14. The light emitting device according to claim 7, further comprising a lens, the lens being provided on the light emitting surface side of the light emitting element and configured to condense or diverge the light emitted from the active layer.

15. A light-emitting device comprising: a substrate; a light-emitting element provided on the substrate and including a light-emitting surface; a first compound semiconductor layer provided on the substrate in at least a portion of the periphery of the light-emitting element, electrically isolated from the light-emitting element, and having the same layered structure as the light-emitting element; a first light-reflecting film provided on the opposite side of the light-emitting element from the light-emitting surface and extending horizontally relative to the substrate; and a second light-reflecting film, wherein the first compound semiconductor layer includes a first surface facing the light-emitting element and a second surface located opposite the first surface and inclined at an angle of less than 90° relative to the substrate, and the second light-reflecting film is provided so as to cover the second surface.

16. An image display device comprising a light emitting device, the light emitting device comprising: a substrate; a light emitting element provided on the substrate and including a light emitting surface; a first compound semiconductor layer provided on the substrate in at least a portion of the periphery of the light emitting element, electrically isolated from the light emitting element, and having the same layered structure as the light emitting element; and a first light reflecting film provided on the opposite side of the light emitting surface from the light emitting element, and including a concave surface having a concave shape relative to the light emitting surface.

17. An image display device comprising a light-emitting device comprising: a substrate; a light-emitting element provided on the substrate and including a light-emitting surface; a first compound semiconductor layer provided on at least a portion of the periphery of the light-emitting element on the substrate, electrically isolated from the light-emitting element, and having the same layered structure as the light-emitting element; a first light-reflecting film provided on the opposite side of the light-emitting element from the light-emitting surface and extending in a horizontal direction relative to the substrate; and a second light-reflecting film, wherein the first compound semiconductor layer includes a first surface facing the light-emitting element and a second surface located opposite the first surface and inclined at an angle of less than 90° relative to the substrate, and the second light-reflecting film is provided so as to cover the second surface.

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