Light-emitting device and image display device

Abstract

A light-emitting device according to an embodiment of the present disclosure comprises: a substrate; a light-emitting unit that is laminated on the substrate in a first direction and includes a first compound semiconductor laminated structure; a light-receiving unit that is laminated on the substrate in the first direction, is provided at a position adjacent to the light-emitting unit, is electrically separated from the light-emitting unit, and includes a second compound semiconductor laminated structure; a first light-reflecting layer provided at a position between the substrate and the light-emitting unit and overlapping the light-emitting unit in the first direction; and a second light-reflecting layer provided at a position opposite to the substrate when viewed from the light-emitting unit and overlapping the light-receiving unit in the first direction.

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 light emitting device in which a photodiode is provided as a light receiving section adjacent to a light emitting section, and an image display element including such a light emitting device have been proposed (see, for example, Patent Document 1).

[0003] JP 2014-194517 A

[0004] Incidentally, in a light-emitting device using a micro LED (Light Emitting Diode), it is required to easily correct variations in brightness while achieving high definition.

[0005] A light emitting device according to one embodiment of the present disclosure includes a substrate, a light emitting portion stacked on the substrate in a first direction and having a first compound semiconductor stack structure, a light receiving portion stacked on the substrate in the first direction, located adjacent to the light emitting portion, electrically isolated from the light emitting portion, and including a second compound semiconductor stack structure, a first light reflecting layer located between the substrate and the light emitting portion at a position overlapping with the light emitting portion in the first direction, and a second light reflecting layer located on the opposite side of the substrate from the light emitting portion at a position overlapping with the light receiving portion in the first direction.

[0006] In a light-emitting device according to an embodiment of the present disclosure, a first light-reflecting layer is provided between the substrate and the light-emitting section at a position overlapping the light-emitting section in a first direction, and a second light-reflecting layer is provided on the opposite side of the substrate from the light-emitting section at a position overlapping the light-receiving section in the first direction, whereby light emitted from the light-emitting section is reflected in a direction traveling toward the light-receiving section or in a first direction as viewed from the substrate.

[0007] FIG. 1 is a cross-sectional schematic diagram illustrating an example of a configuration of a light-emitting device according to an embodiment of the present disclosure. FIG. 2 is a schematic diagram illustrating an example of the overall planar configuration of the light-emitting device shown in FIG. 1. FIG. 3 is a schematic diagram illustrating an enlarged portion of the planar configuration of the light-emitting device shown in FIG. 2. FIG. 4 is a planar schematic diagram illustrating an example of a configuration of an extraction electrode, a light-emitting portion, a plug electrode, and a light-receiving portion according to an embodiment of the present disclosure. FIG. 5 is a cross-sectional schematic diagram illustrating an example of a configuration of a light-emitting device corresponding to line II-II shown in FIG. 4. FIG. 6 is a cross-sectional schematic diagram illustrating an example of a configuration of a light-emitting device corresponding to line III-III shown in FIG. 4. FIG. 7 is a circuit diagram illustrating an example of a circuit configuration of a light-emitting device according to an embodiment of the present disclosure. FIG. 8A is a cross-sectional schematic diagram illustrating an example of a manufacturing process for the light-emitting device shown in FIG. 1. FIG. 8B is a cross-sectional schematic diagram illustrating a process subsequent to FIG. 8A. FIG. 8C is a cross-sectional schematic diagram illustrating a process subsequent to FIG. 8B. FIG. 8D is a cross-sectional schematic diagram illustrating a process subsequent to FIG. 8C. FIG. 8E is a cross-sectional schematic diagram illustrating a process subsequent to FIG. 8D. FIG. 8F is a cross-sectional schematic diagram illustrating a process subsequent to FIG. 8E. FIG. 8G is a schematic cross-sectional view showing a step subsequent to FIG. 8F . FIG. 9 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. FIG. 10 is a schematic plan view showing an example of the configuration of an extraction electrode, a light-emitting portion, a plug electrode, and a light-receiving portion according to Modification 2 of the present disclosure. FIG. 11A is a schematic plan view showing an example of the configuration of an extraction electrode, a light-emitting portion, a plug electrode, and a light-receiving portion according to Modification 3 of the present disclosure. FIG. 11B is a schematic plan view showing another example of the configuration of an extraction electrode, a light-emitting portion, a plug electrode, and a light-receiving portion according to Modification 3 of the present disclosure. FIG. 12 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device according to Modification 4 of the present disclosure. FIG. 13A is a circuit diagram showing an example of the circuit configuration of a light-emitting device according to Modification 5 of the present disclosure. FIG. 13B is a circuit diagram showing another example of the circuit configuration of a light-emitting device according to Modification 5 of the present disclosure. FIG. 14 is a perspective view showing an example of the configuration of an image display device according to an application example of the present disclosure. FIG. 15 is a schematic diagram showing an example of the wiring layout of the image display device shown in FIG. 14 . Fig. 16 is a perspective view illustrating an example of a configuration of an image display device according to an application example of the present disclosure. Fig. 17 is a perspective view illustrating a configuration of a mounting substrate illustrated in Fig. 16. Fig. 18 is a perspective view illustrating a configuration of a unit substrate illustrated in Fig. 17.FIG. 19 is a diagram illustrating an example of an image display device according to an application example of the present disclosure.

[0008] 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) 3. Application examples

[0009] 1. Embodiment Fig. 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. Fig. 2 is a schematic diagram illustrating an example of an overall planar configuration of the light-emitting device 1 illustrated in Fig. 1. 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 illustrated in Fig. 14 described below).

[0010] [1-1. Configuration of the Light-Emitting Device] The light-emitting device 1 includes a display unit 100A extending along an XY plane including, for example, mutually orthogonal X-axis and Y-axis directions, and a frame unit 100B provided around the display unit 100A in the XY plane. The display unit 100A includes a plurality of pixels P (e.g., red pixels Pr emitting red light, green pixels Pg emitting green light, and blue pixels Pb emitting blue light) arranged in a two-dimensional array (see FIG. 2). The light-emitting device 1 also includes a stacked structure in which, for example, a drive substrate 30, a light-emitting region 10 including a plurality of light-emitting units 11, and a wavelength conversion unit 20 are stacked in this order along the Z-axis direction, which is the thickness direction orthogonal to the XY plane. Here, the Z-axis direction corresponds to a specific example of a "first direction" according to one aspect of the present disclosure.

[0011] The plurality of pixels P (Pr, Pg, Pb) each have a substantially regular hexagonal planar shape as shown in FIG. 3, for example, and are arranged in a honeycomb pattern.

[0012] (Configuration of Light-Emitting Region 10) In the light-emitting region 10, for example, in the XY plane, a plurality of extraction electrodes 101 (101A, 101B), a plurality of light-emitting portions 11, a plurality of plug electrodes 13 (13A, 13B, 13C), and a plurality of light-receiving portions 19 are arranged overlapping one another as shown in FIG.

[0013] Fig. 1 is a schematic representation of an example of a cross-sectional configuration of the light-emitting device 1 corresponding to line II shown in Fig. 4. Fig. 5 is a schematic representation of an example of a cross-sectional configuration of the light-emitting device 1 corresponding to line II-II shown in Fig. 4. Fig. 6 is a schematic representation of an example of a cross-sectional configuration of the light-emitting device 1 corresponding to line III-III shown in Fig. 4.

[0014] The light-emitting region 10 includes one or more extraction electrodes 101 (101A, 101B), a plurality of light-emitting sections 11, one or more light-reflecting layers 12, a plurality of plug electrodes 13 (13A, 13B, 13C), one or more light-reflecting layers 14 (14A, 14B), one or more insulating layers 15, one or more insulating layers 16, a plurality of pad sections 17, one or more buried layers 18, and one or more light-receiving sections 19.

[0015] 1, 4, and 5, the extraction electrode 101A is provided so as to cover the plurality of light-emitting sections 11. The extraction electrode 101A is provided in contact with the transparent electrode layer 114 of each of the plurality of light-emitting sections 11, and electrically connects the plurality of light-emitting sections 11 to the drive substrate 30. For example, as shown in FIG. 4, the extraction electrode 101A is provided so as to cover two light-emitting sections 11 provided in each of the X-axis direction and the Y-axis direction. The extraction electrode 101A is formed of a transparent electrode material such as ITO, indium zinc oxide (IZO), tin oxide (SnO), or TiO.

[0016] 1, 4, and 6, the extraction electrode 101B is provided so as to cover the light-receiving section 19. The extraction electrode 101B is provided in contact with the transparent electrode layer 195 of the light-receiving section 19, and electrically connects the light-receiving section 19 and the drive substrate 30. The extraction electrode 101B is formed of a transparent electrode material such as ITO, indium zinc oxide (IZO), tin oxide (SnO), or TiO.

[0017] The light-emitting unit 11 is provided for each pixel P, for example. That is, one light-emitting unit 11 is provided for one pixel P. However, multiple light-emitting units 11 may be provided for one pixel P. The light-emitting unit 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 LED 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 or less in size and is a so-called micro LED.

[0018] The light emitting section 11 has, for example, a mesa-shaped compound semiconductor stacked structure 110. The sidewalls of the light emitting section 11 are inclined at an angle of less than 90° with respect to the drive substrate 30. The light emitting section 11 further includes, for example, a transparent electrode layer 114 on the side opposite the drive substrate 30 as viewed from the compound semiconductor stacked structure 110, in the Z-axis direction. The light emitting section 11 further includes a passivation film 115 on the surface opposite the drive substrate 30 as viewed from the transparent electrode layer 114, and on the sidewalls of the compound semiconductor stacked structure 110. Here, the compound semiconductor stacked structure 110 corresponds to a specific example of a "first compound semiconductor stacked structure" as one aspect of the present disclosure.

[0019] The compound semiconductor stacked structure 110 includes, for example, a first conductivity type layer 111, an active layer 112, and a second conductivity type layer 113 in this order in the Z-axis direction from the drive substrate 30 side.

[0020] 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 inclusive may be extracted from the active layer 112. Light with a wavelength corresponding to, for example, the ultraviolet band (ultraviolet light) may also be extracted from the active layer 112. Light in the green band of, for example, 500 nm to 570 nm inclusive may also be extracted from the active layer 112. Light in the red band of, for example, 600 nm to 670 nm inclusive 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. The first conductivity type layer 111 may be formed of, for example, an n-type AlGaInP-based semiconductor material. The active layer 112 may have a multi-quantum well structure in which, for example, InGaP and AlGaInP are alternately stacked, and has a light-emitting region within the layer. The second conductivity type layer 113 may be formed of, for example, a p-type AlGaInP-based semiconductor material. In the light-emitting section 11, the upper surface of the second conductivity type layer 113, i.e., the surface opposite to the active layer 112, serves as the light-emitting surface of the light-emitting section 11.

[0021] The transparent electrode layer 114 is provided on the light-emitting surface of the light-emitting section 11 and is covered with the extraction electrode 101A. The transparent electrode layer 114 is provided so as to cover the second conductivity-type layer 113 of the light-emitting section 11 and is in ohmic contact with the second conductivity-type layer 113. The transparent electrode layer 114 is formed of a transparent electrode material such as ITO, indium zinc oxide (IZO), tin oxide (SnO), or TiO.

[0022] The passivation film 115 is provided to cover the surface of the light-emitting unit 11 opposite the drive substrate 30 and the sidewalls. The passivation film 115 is formed using a dielectric material, a transparent conductive material, or a multilayer film made by laminating these. Examples of dielectric materials used in the passivation film 115 include silicon oxide (SiO) and silicon nitride (SiN). Examples of transparent conductive materials used in the passivation film 115 include titanium oxide (TiO).

[0023] The light reflecting layer 12 is provided between the drive substrate 30 and the light emitting section 11 at a position overlapping the light emitting section 11 in the Z-axis direction. The light reflecting layer 12 includes, for example, a reflective film 121 and a contact layer 122 in this order in the Z-axis direction from the drive substrate 30 side (see FIGS. 1 and 5 ). Here, the light reflecting layer 12 corresponds to a specific example of a “first light reflecting layer” according to one aspect of the present disclosure.

[0024] The reflective film 121 has an opening 121H. The plug electrode 13A penetrates the opening 121H in the reflective film 121 (see FIGS. 1 and 5 ). The reflective film 121 is formed using a light-reflective metal, a dielectric material, or a multilayer film made by laminating these materials. Examples of metals used in the reflective film 121 include titanium (Ti), aluminum (Al), and silver (Ag).

[0025] The contact layer 122 is electrically connected to the pad portion 17 via the plug electrode 13A (see FIGS. 1 and 5). The contact layer 122 is in ohmic contact with, for example, the first conductivity type layer 111. The contact layer 122 is formed using a transparent conductive material such as a multilayer film (Ni / Au) of nickel (Ni) and gold (Au) or ITO. The contact layer 122 may be formed of a metal such as Ti, TiN, TaN, Al, or Ag, or a multilayer film made by stacking these metals.

[0026] 1 and 4 to 6, plug electrodes 13 (13A, 13B, 13C) are embedded in the insulating layer 15. The plug electrodes 13 (13A, 13B, 13C) are each formed using a metal. Specifically, the plug electrodes 13 (13A, 13B, 13C) are formed using, for example, copper (Cu), aluminum (Al), tungsten (W), silver (Ag), or an alloy thereof.

[0027] The plug electrode 13A is provided in contact with the contact layer 122 and electrically connects the light-emitting unit 11 and the drive substrate 30. The plug electrode 13A is used, for example, as a cathode terminal for applying a cathode voltage to the light-emitting unit 11. The plug electrode 13B is provided in contact with the first electrode 194 of the light-receiving unit 19 and electrically connects the light-receiving unit 19 and the drive substrate 30. The plug electrode 13B connects the light-receiving unit 19 to a power supply VDD, for example. The plug electrode 13C electrically connects the light-emitting unit 11 and the drive substrate 30. The plug electrode 13C is used as an anode terminal for applying an anode voltage to the light-receiving unit 19.

[0028] The light-reflecting layer 14 is provided in a region of the drive substrate 30 between the light-emitting unit 11 and the light-receiving unit 19 and the drive substrate 30, except for the region overlapping with the light-emitting unit 11 and the light-receiving unit 19 in the Z-axis direction. That is, the light-reflecting layer 14 has an opening 14H at a position overlapping with the light-emitting unit 11 and the light-receiving unit 19 in the Z-axis direction. As shown in FIGS. 5 and 6 , the light-reflecting layer 14 includes a light-reflecting layer 14A in ohmic contact with the lead-out electrode 101A and a light-reflecting layer 14B in ohmic contact with the lead-out electrode 101B. The light-reflecting layer 14A and the light-reflecting layer 14B are electrically isolated from each other. The light-reflecting layer 14A is electrically connected to the plug electrode 13B. The light-reflecting layer 14B is electrically connected to the plug electrode 13C. The light-reflecting layer 14 is formed using a light-reflective metal, a dielectric material, or a multilayer film formed by laminating these materials. Examples of metals used in the light-reflecting layer 14 include titanium (Ti), aluminum (Al), and silver (Ag). The light-reflecting layer 14 may have a contact layer similar to the contact layer 122 of the light-reflecting layer 12. Here, the light-reflecting layer 14 corresponds to a specific example of a "third light-reflecting layer" according to one aspect of the present disclosure.

[0029] The insulating layer 15 is made of, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0030] 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).

[0031] The buried layer 18 is provided so as to cover the light-emitting portion 11 and the light-receiving portion 19. The buried layer 18 is intended to flatten the surface of the light-emitting portion 11 opposite to the drive substrate 30. The buried layer 18 is formed using, for example, silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), titanium oxide (TiO), or the like.

[0032] The light-receiving unit 19 is disposed adjacent to the light-emitting unit 11 and is electrically isolated from the light-emitting unit 11. The light-receiving unit 19 has, for example, a mesa-shaped compound semiconductor stacked structure 190. The sidewalls of the light-receiving unit are inclined at an angle of less than 90° with respect to the drive substrate 30. The light-receiving unit 19 further includes a first electrode 194 on the drive substrate 30 side as viewed from the compound semiconductor stacked structure 190 in the Z-axis direction. The light-receiving unit 19 further includes, for example, a transparent electrode layer 195 on the opposite side of the compound semiconductor stacked structure 190 from the drive substrate 30 in the Z-axis direction. The light-receiving unit 19 further includes a passivation film 196 on the surface of the transparent electrode layer 195 opposite the drive substrate 30 as viewed from the drive substrate 30, and on the sidewalls of the compound semiconductor stacked structure 190. Here, the compound semiconductor stacked structure 190 corresponds to a specific example of a "second compound semiconductor stacked structure" as one aspect of the present disclosure.

[0033] The compound semiconductor stacked structure 190 includes, for example, a first conductivity type layer 191, an active layer 192, and a second conductivity type layer 193 in this order in the Z-axis direction from the drive substrate 30 side.

[0034] The first conductivity type layer 191 is made of, for example, an n-type GaN-based semiconductor material. The active layer 192 has, for example, a multiple quantum well structure in which InGaN and GaN are alternately stacked. The second conductivity type layer 193 is made of, for example, a p-type GaN-based semiconductor material.

[0035] The first electrode 194 is electrically connected to the plug electrode 13B. The first electrode 194 is in ohmic contact with, for example, the first conductivity type layer 191. The first electrode 194 is formed using, for example, a multilayer film (Ni / Au) of nickel (Ni) and gold (Au) or a transparent conductive material such as ITO. The first electrode 194 may be made of a metal such as Ti, TiN, TaN, Al, or Ag, or a multilayer film made by stacking these metals.

[0036] The transparent electrode layer 195 is provided so as to cover the second conductivity type layer 193 of the light receiving section 19 and is in ohmic contact with the second conductivity type layer 193. The transparent electrode layer 195 is covered with the extraction electrode 101B. The transparent electrode layer 195 is formed of a transparent electrode material such as ITO, indium zinc oxide (IZO), tin oxide (SnO), or TiO.

[0037] The passivation film 196 is provided to cover the surface of the light-emitting unit 11 opposite the drive substrate 30 and the sidewalls. The passivation film 196 is formed using a dielectric material, a transparent conductive material, or a multilayer film made by laminating these. Examples of dielectric materials used in the passivation film 196 include silicon oxide (SiO) and silicon nitride (SiN). Examples of transparent conductive materials used in the passivation film 115 include titanium oxide (TiO).

[0038] (Configuration of Wavelength Conversion Unit 20) The wavelength conversion unit 20 is provided on the light-emitting surface side of the light-emitting region 10. The wavelength conversion unit 20 includes a planarization layer 21, a partition layer 23, a reflective film 24, a wavelength conversion layer 25, and a protective layer 26, which are stacked in this order from the light-emitting region 10 side in the Z-axis direction. A light-reflecting layer 22 is embedded in the planarization layer 21. The partition layer 23 has a plurality of openings 23H provided for each pixel (e.g., red pixel Pr, green pixel Pg, and blue pixel Pb) (see FIG. 3). The wavelength conversion layer 25 is provided to fill the plurality of openings 23H. The reflective film 24 is provided between the partition layer 23 and the wavelength conversion layer 25. An on-chip lens layer 27 is provided on the opposite side of the protective layer 26 from the light-emitting region 10 in the Z-axis direction.

[0039] The planarization layer 21 is provided between the buried layer 18 and the on-chip lens layer 27. The planarization layer 21 is intended to planarize the surface of the light-emitting region 10 opposite to the drive substrate 30. The planarization layer 21 is formed of a dielectric material having a refractive index lower than both the refractive index of the buried layer 18 and the refractive index of the on-chip lens layer 27. The planarization layer 21 is formed of, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0040] The light-reflecting layer 22 is provided in a region of the driving substrate 30 other than the region overlapping with the light-emitting unit 11 in the Z-axis direction. The light-reflecting layer 22 is provided, for example, on the opposite side of the driving substrate 30 from the light-emitting unit 11, in a position overlapping with the light-receiving unit 19 in the Z-axis direction. The light-reflecting layer 22 is formed using a light-reflective metal, a dielectric material, or a multilayer film formed by laminating these. Examples of metals used in the light-reflecting layer 22 include titanium (Ti), aluminum (Al), and silver (Ag). Here, the light-reflecting layer 22 corresponds to a specific example of a "second light-reflecting layer" as one aspect of the present disclosure.

[0041] The partition wall layer 23 is intended to suppress color mixing due to light leakage between adjacent red, green, and blue pixels Pr, Pg, and Pb. The partition wall layer 23 has, for example, a honeycomb structure, similar to the pixels (e.g., red, green, and blue pixels Pr, Pg, and Pb). Specifically, the partition wall layer 23 has, for example, a substantially regular hexagonal opening 23H for each of the plurality of pixels arranged in an array (see, for example, FIG. 3 ). In cross-sectional view, the opening 23H has, for example, a surface inclined at an angle of less than 90° with respect to the surface of the wavelength conversion unit 20 opposite the light-emitting region 10. In other words, in cross-sectional view, the partition wall layer 23 has a forward tapered shape between adjacent red, green, and blue pixels Pr, Pg, and Pb. The partition wall layer 23 is preferably formed using a material with high thermal conductivity and electrical conductivity, such as a metal such as copper (Cu), aluminum (Al), gold (Au), nickel (Ni), or platinum (Pt).

[0042] The reflective film 24 is provided on the side surface of the opening 23H to efficiently extract the colored light emitted from the active layer 112 of the light-emitting unit 11 and converted in the wavelength conversion layers 25R, 25G, and 25B from the surface 22S1 of the wavelength conversion layer 25. The reflective film 24 is formed using a metal having optical reflectivity. Examples of metals that can form the reflective film 24 include metals with high reflectivity in the visible light range. Specific examples of materials that can be used include silver (Ag), aluminum (Al), copper (Cu), gold (Au), platinum (Pt), rhodium (Rh), and alloys thereof.

[0043] It should be noted that the reflective film 24 does not necessarily have to be formed when the partition wall layer 23 is formed using the above-mentioned light-reflective metal.

[0044] The wavelength conversion layer 25 is provided in the Z-axis direction on the surface of the planarization layer 21 opposite to the light-emitting region 10, and converts light emitted from the active layer 112 of the light-emitting unit 11 into light of a predetermined wavelength band (e.g., red (R) / green (G) / blue (B)). Specifically, the red pixel Pr is provided with a red wavelength conversion layer 25R that converts light emitted from the active layer 112 into light of a red band (red light), the green pixel Pg is provided with a green wavelength conversion layer 25G that converts light emitted from the active layer 112 into light of a green band (green light), and the blue pixel Pb is provided with a blue wavelength conversion layer 25B that converts light emitted from the active layer 112 into light of a blue band (blue light).

[0045] Each wavelength conversion layer 25R, 25G, and 25B can be formed using quantum dots corresponding to each color. Specifically, when red light is obtained, the quantum dots can be selected from, for example, InP, GaInP, InAsP, CdSe, CdZnSe, CdTeSe, or CdTe. When green light is obtained, the quantum dots can be selected from, for example, InP, GaInP, ZnSeTe, ZnTe, CdSe, CdZnSe, CdS, or CdSeS. When blue light is obtained, the quantum dots can be selected from, for example, ZnSe, ZnTe, ZnSeTe, CdSe, CdZnSe, CdS, CdZnS, and CdSeS.

[0046] When blue light is emitted from the active layer 112 as described above, the blue wavelength conversion layer 25B may be formed of a light-transmitting resin layer. That is, a light-transmitting resin layer may be provided as the wavelength conversion layer 25B in the blue pixel Pb from which light in substantially the same wavelength band as the light emitted from the active layer 112 is extracted. The red pixel Pr and the green pixel Pg from which light in a wavelength band different from the light emitted from the active layer 112 is extracted are provided with the wavelength conversion layers 25R and 25G containing the quantum dots described above.

[0047] The protective layer 26 is for protecting the surface of the light emitting device 1, and is formed using, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0048] The on-chip lens layer 27 is provided on the opposite side of the drive substrate 30 as viewed from the light-emitting unit 11, at a position overlapping the light-emitting unit 11 in the Z-axis direction. The on-chip lens layer 27 condenses or diverges light emitted from the active layer 112. The on-chip lens layer 27 is made of an optically transparent material, and is, for example, a single-layer film made of any of silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), and titanium oxide (TiO), or a stacked film made of two or more of these materials. Here, the on-chip lens layer 27 corresponds to a specific example of a "lens" according to one aspect of the present disclosure.

[0049] (Configuration of drive substrate 30) The drive substrate 30 has, for example, a support substrate 31 made of 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 11, and a pad section 34 embedded in the insulating layer 33. In the drive substrate 30, a drive circuit 35 and a readout circuit 36 ​​are embedded in the support substrate 31. The drive substrate 30 corresponds to a specific example of a "substrate" according to one aspect of the present disclosure.

[0050] The interlayer insulating layer 32 is formed using, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0051] 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).

[0052] 7 is a circuit diagram showing the circuit configuration of a light-emitting device 1 according to an embodiment of the present disclosure. The drive circuit 35 is electrically connected to the light-emitting unit 11 and the power supply VDD and drives the light-emitting unit 11. The readout circuit 36 ​​is electrically connected to the light-receiving unit 19 and the power supply VDD and measures the photocurrent generated by photoelectric conversion of the light-receiving unit 19. The drive substrate 30 may have a correction circuit 37 that corrects the signal read out by the readout circuit 36 ​​to match the drive conditions of the light-emitting unit 11. One correction circuit 37 is provided for each drive circuit 35 and readout circuit 36, but the correction circuit 37 does not necessarily have to be provided on the drive substrate 30 and may be provided externally.

[0053] The plurality of drive circuits 35 may operate the respective light-emitting units 11 simultaneously, or may operate the respective light-emitting units 11 at different times.

[0054] 1-2. Method for Manufacturing Light-Emitting Device The light-emitting device 1 of this embodiment can be manufactured, for example, as follows: Figures 8A to 8G show an example of a manufacturing process for the light-emitting device 1.

[0055] First, for example, a sapphire substrate is prepared as growth substrate 401, and then, by epitaxial crystal growth using a method such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE), a first conductivity type layer 111, an active layer 112, and a second conductivity type layer 113 are formed in this order on growth substrate 401, thereby obtaining compound semiconductor stacked structure 110. Similarly, for example, a sapphire substrate is prepared as growth substrate 402, and then, by epitaxial crystal growth using a method such as MOCVD or MBE, a first conductivity type layer 191, an active layer 192, and a second conductivity type layer 193 are formed in this order on growth substrate 402, thereby obtaining compound semiconductor stacked structure 190.

[0056] 8A, transparent electrode layers 114 and 195 are formed so as to be in contact with second conductivity type layers 113 and 193. Transparent electrode layers 114 and 195 are obtained by forming films of indium tin oxide using, for example, a sputtering method or a vapor deposition method.

[0057] Next, after the growth substrates 401 and 402 are peeled off, the compound semiconductor stacked structure 110 and the compound semiconductor stacked structure 190 are inverted and bonded to the support substrate 43 so that the transparent electrode layers 114 and 195 face each other, as shown in FIG. 8B . Next, they are bonded to the support substrate 43 so that the contact layer 122 of the light-reflecting layer 12 faces the upper surface of the first-conductivity-type layer 111. A first electrode 194 is formed on the upper surface of the first-conductivity-type layer 191 by, for example, vapor deposition. Thereafter, a buried layer 44 is formed using silicon oxide or the like so as to cover the support substrate 43, the compound semiconductor stacked structure 110, the compound semiconductor stacked structure 190, the light-reflecting layer 12, and the first electrode 194. This operation seals the compound semiconductor stacked structure 110, the compound semiconductor stacked structure 190, the light-reflecting layer 12, and the first electrode 194 with the buried layer 44.

[0058] Next, the insulating layer 15 in which the light reflecting layer 14 (14A, 14B) having the opening 14H is embedded is formed on the upper surfaces of the embedding layer 44, the light reflecting layer 12, and the first electrode 194. At this time, if the light reflecting layer 14 has a contact layer, the contact layer is made to face the upper surfaces of the light reflecting layer 12 and the first electrode 194. Furthermore, the opening 14H is positioned so that the light reflecting layer 12 and the first electrode 194 are partially exposed when the insulating layer 15 is attached.

[0059] Next, as shown in FIG. 8C , a plug electrode 13A is formed at the exposed position of the light-reflecting layer 12, a plug electrode 13B is formed at the exposed position of the first electrode 194 and on the light-reflecting layer 14A, and a plug electrode 13C is formed on the light-reflecting layer 14B. Furthermore, an insulating layer 16 having a plurality of pad portions 17 embedded therein is formed on the insulating layer 15. At this time, each of the plurality of plug electrodes 13 (13A, 13B, 13C) is bonded to each of the plurality of pad portions. This results in a light-emitting region 10 including the compound semiconductor stack structure 110, the light-reflecting layer 12, the insulating layer 15, the insulating layer 16, the embedded layer 44, and the compound semiconductor stack structure 190. Then, a separately fabricated drive substrate 30 is bonded to the upper surface of the light-emitting region 10, i.e., the upper surface of the insulating layer 16 and the upper surface of the pad portion 17 (so-called hybrid bonding). In this hybrid bonding, the pad portion 17 is bonded to the pad portion 34, and the insulating layer 16 is bonded to the insulating layer 33.

[0060] Next, the bonded light-emitting region 10 and drive substrate 30 are inverted so that the drive substrate 30 is facing downward, and then a portion of the embedded layer 44 and the support substrate 43 are removed to expose the surfaces of the transparent electrode layers 114, 195 and the plug electrodes 13B, 13C. Next, as shown in FIG. 8D , the compound semiconductor stacked structure 110 and the transparent electrode layer 114 are cleaved, for example, by reactive ion etching (RIE), to form a mesa shape. Similarly, the compound semiconductor stacked structure 190 and the transparent electrode layer 195 are cleaved, for example, by reactive ion etching, to form a mesa shape. Thereafter, passivation films 115, 196 are formed along the upper surfaces of the transparent electrode layers 114, 195 and the sidewalls of the compound semiconductor stacked structure 110 and the compound semiconductor stacked structure 190, respectively. This operation results in the light-emitting section 11 and the light-receiving section 19.

[0061] 8E, an extraction electrode 101A is formed in contact with the light-emitting portion 11 and the plug electrode 13B, and an extraction electrode 101B is formed in contact with the light-receiving portion 19 and the plug electrode 13C. A buried layer 18 is formed using silicon oxide or the like so as to cover the light-emitting portion 11 and the light-receiving portion 19.

[0062] 8F, the planarization layer 21 and the partition layer 23 having the light-reflecting layer 22 embedded therein are formed in this order by, for example, CVD, and then openings 23H are formed in the partition layer 23 above each pixel by, for example, photolithography. Subsequently, as shown in FIG. 6R, an Al film is formed on the top surface of the partition layer 23 and the side and bottom surfaces of the openings 23H by, for example, CVD, and then the Al film formed on the top surface of the partition layer 23 and the bottom surface of the openings 23H is removed by etch-back to form reflective films 24 on the side surfaces of the openings 23H.

[0063] 8G, wavelength conversion layers 25 (25R, 25G, 25B) of the respective colors are formed in openings 23H by a coating method such as an inkjet method. After that, on-chip lens layers 27 are bonded onto partition layer 23 and wavelength conversion layers 25. In this manner, light-emitting device 1 shown in FIG. 1 is completed.

[0064] In the above-described method for manufacturing the light-emitting device 1, the compound semiconductor stacked structure 110 is formed from the growth substrate 401, and the compound semiconductor stacked structure 190 is formed from the growth substrate 402, but the present invention is not limited to this. The compound semiconductor stacked structure 110 and the compound semiconductor stacked structure 190 may be formed from, for example, the same growth substrate.

[0065] [1-3. Actions and Effects] The light-emitting device 1 of this embodiment includes a plurality of mesa-shaped light-emitting portions 11 and a plurality of light-receiving portions 19 each having a compound semiconductor stack structure on a drive substrate 30. Furthermore, the light-emitting device 1 includes a light-reflecting layer 12 disposed between the drive substrate 30 and the light-emitting portions 11, overlapping the light-emitting portions 11 in the Z-axis direction, and a light-reflecting layer 22 disposed on the opposite side of the drive substrate 30 from the light-emitting portions 11, overlapping the light-receiving portions 19 in the Z-axis direction. This allows light emitted from the light-emitting portions 11 to be reflected in the direction traveling toward the light-receiving portions 19 or in the Z-axis direction as viewed from the drive substrate 30, thereby improving the detection efficiency of intensity signals and reducing light leakage. This is explained below.

[0066] Light-emitting devices using micro LEDs have issues such as variations in characteristics between pixels and variations in degradation characteristics over time.

[0067] One solution to the above problem is to provide a light receiving unit adjacent to the light emitting element on the substrate or between the substrate and the light emitting element, and intermittently measure the luminance unevenness for each pixel to correct the correction value. However, in a micro LED light emitting device with a light receiving unit located adjacent to the light emitting element on the substrate or between the substrate and the light emitting element, the light receiving sensitivity and front luminance decrease, which is disadvantageous for achieving high definition.

[0068] In contrast, the light-emitting device 1 of the present embodiment includes the light-reflecting layer 12, which is provided between the drive substrate 30 and the light-emitting unit 11 and overlaps with the light-emitting unit 11 in the Z-axis direction, as described above, and the light-reflecting layer 22, which is provided on the opposite side of the drive substrate 30 as viewed from the light-emitting unit 11 and overlaps with the light-receiving unit 19 in the Z-axis direction. Light emitted from the light-emitting unit 11, traveling in a direction other than the Z-axis direction on the opposite side of the drive substrate 30 as viewed from the light-emitting unit 11, is reflected by the light-reflecting layers 12 and 22. This prevents light emitted from the light-emitting unit 11 from leaking and entering other light-emitting units 11, thereby reducing crosstalk. The light emitted from the light-emitting unit 11 passes through the openings 22H in the light-reflecting layer 22 and is focused or diverged by the on-chip lens layer 27. Therefore, the light-emitting device 1 has improved front brightness, enabling improved light extraction efficiency.

[0069] Furthermore, in the light-emitting device 1 of the present embodiment, as described above, the light-reflecting layer 12 is provided between the drive substrate 30 and the light-emitting section 11 at a position overlapping with the light-emitting section 11 in the Z-axis direction, and the light-reflecting layer 22 is provided on the opposite side of the drive substrate 30 as viewed from the light-emitting section 11 at a position overlapping with the light-receiving section 19 in the Z-axis direction. As a result, the light emitted from the light-emitting section 11 is reflected in a direction traveling toward the light-receiving section 19, improving the detection efficiency of the intensity signal of the light-receiving section 19.

[0070] Furthermore, the light emitting device 1 of this embodiment is provided with a plurality of electrically separated light receiving sections 19. As a result, even if one of the plurality of light receiving sections 19 becomes defective, the other light receiving sections 19 are not affected, and therefore redundancy of the light receiving function of the light emitting device 1 is ensured.

[0071] 2. Modifications Next, modifications 1 to 5 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.

[0072] [2-1. Modification 1] FIG. 9 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.

[0073] In the above embodiment, the compound semiconductor stack structure 110 of the light-emitting section 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 the Z-axis direction in this order from the drive substrate 30 side. In the above embodiment, the compound semiconductor stack structure 190 of the light-receiving section 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 the Z-axis direction in this order from the drive substrate 30 side. In contrast, in the light-emitting device 1A of this modified example, the compound semiconductor stack structure 110a of the light-emitting section 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 the Z-axis direction in this order from the drive substrate 30 side. In the light emitting device 1A of this modified example, the compound semiconductor stacked structure 190a of the light receiving section 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 order from the drive substrate 30 side in the Z-axis direction.

[0074] 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.

[0075] The light emitting device 1A of this modification may be a combination of the light emitting unit 11 of the above embodiment and the light receiving unit 19a of the light emitting device 1A. Also, the light emitting device 1A of this modification may be a combination of the light emitting unit 11a of the light emitting device 1A and the light receiving unit 19 of the above embodiment.

[0076] [2-2. Modification 2] FIG. 10 is a schematic diagram illustrating an example of a planar configuration (light-emitting device 1B) of a plurality of extraction electrodes 101 (101A, 101Bb), a plurality of light-emitting portions 11, a plurality of plug electrodes 13 (13A, 13B, 13C), and a plurality of light-receiving portions 19b according to Modification 2 of the present disclosure.

[0077] In the above embodiment, the light receiving portion 19 has a substantially circular shape in a plan view, and the extraction electrode 101B is provided along the side wall of the light receiving portion 19, but the present invention is not limited to this.

[0078] 10, in a plan view, the sidewall of the light-receiving portion 19b has a shape that follows the shape of the surrounding light-emitting portion 11. Furthermore, in the light-emitting device 1B, the shape of the extraction electrode 101Bb includes a shape that follows the shape of the light-receiving portion 19b.

[0079] Except for the above points, 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 this configuration, the light emitting device 1B can achieve the same effects as the above embodiment.

[0080] 11A is a schematic diagram showing an example of a planar configuration (light-emitting device 1C) of a plurality of lead electrodes 101 (101Ac, 101Bc), a plurality of light-emitting units 11, a plurality of plug electrodes 13 (13Ac, 13Bc, 13Cc), and a plurality of light-receiving units 19c according to Modification 3 of the present disclosure. FIG. 11B is a schematic diagram showing an example of a planar configuration (light-emitting device 1C-2) of a plurality of lead electrodes 101 (101Acc, 101Bcc), a plurality of light-emitting units 11, a plurality of plug electrodes 13 (13Ac, 13Bc, 13Cc), and a plurality of light-receiving units 19c according to Modification 3 of the present disclosure.

[0081] In the above embodiment, an example is shown in which multiple light receiving units 19 surround one light emitting unit 11, but this is not limited to this, and one light receiving unit may be provided for one light emitting unit.

[0082] 11A, in plan view, light-emitting device 1C-1 of this modification has extraction electrode 101Bc and light-receiving portion 19c provided so as to surround one light-emitting portion 11. Furthermore, in light-emitting device 1C-1 of this modification, a plurality of plug electrodes 13 (13Ac, 13Bc, 13Cc) are arranged in a square shape.

[0083] 11B, in a plan view, light-emitting device 1C-2 of this modification has extraction electrode 101Bcc and light-receiving portion 19c provided so as to surround one light-emitting portion 11. Furthermore, in light-emitting device 1C-1 of this modification, a plurality of plug electrodes 13 (13Acc, 13Bcc, 13Ccc) are arranged in a square shape in a plan view.

[0084] Except for the above points, 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.

[0085] [2-4. Modification 4] FIG. 12 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.

[0086] In the light emitting device 1D according to the fourth modification, a through electrode 28 is provided in the frame portion 100B and passes through the planarizing layer 21 and the embedded layer 18 in the Z-axis direction. The through electrode 28 applies a voltage to the second conductivity type layer 113 of each of the plurality of light emitting portions 11 via the extraction electrode 101Ad. The through electrode 123 is formed of a transparent electrode material such as ITO, indium zinc oxide (IZO), tin oxide (SnO), or TiO.

[0087] In the light-emitting device 1D according to the fourth modification, the light-reflecting layer 22d has a contact layer 221 in contact with the lead-out electrode 101Ad. The contact layer 221 is formed using a transparent conductive material such as a nickel (Ni) and gold (Au) multilayer film (Ni / Au) or ITO. The lead-out electrode 101Ad is provided to electrically connect the transparent electrode layers 114 of the plurality of light-emitting sections 11, the contact layer 221 of the light-reflecting layer 22d, and the through-electrode 28.

[0088] 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. Even with this configuration, the light emitting device 1D can achieve the same effects as the above embodiment.

[0089] 13A is a circuit diagram illustrating an example of the circuit configuration of a light-emitting device (light-emitting device 1E) according to Modification 5 of the present disclosure. Fig. 13B is a circuit diagram illustrating another example of the circuit configuration of a light-emitting device (light-emitting device 1E) according to Modification 5 of the present disclosure.

[0090] In the above embodiment, an example of a circuit in which one light-receiving unit 19 corresponds to one light-emitting unit 11 has been shown, but the present disclosure is not limited to this. As in the light-emitting device 1E of this modified example, a circuit in which one light-receiving unit 19 is connected to multiple light-emitting units 11 may also be used.

[0091] 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. Even with this configuration, the light emitting device 1E can achieve the same effects as the above embodiment.

[0092] 14 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. The image display device 100 includes a display panel 120 and a control circuit 140 that drives the display panel 120, as shown in FIG. 18, for example.

[0093] 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.

[0094] 15 shows an example of a wiring layout in a region of the surface of the mounting substrate 120A facing the counter substrate 120B, which corresponds 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. 15 . 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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. 15. Here, the pad electrodes 134B, 135B are made of a conductive material such as Au (gold).

[0099] 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.

[0100] 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.

[0101] 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. 14 , 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.

[0102] 16 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. 16 , the image display device 200 includes a display panel 220 and a control circuit 240 that drives the display panel 220.

[0103] 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.

[0104] Fig. 17 is a schematic diagram showing an example of the configuration of the mounting substrate 220A. For example, as shown in Fig. 17, the mounting substrate 220A is configured from a plurality of unit substrates 250 arranged in a tiled pattern. Note that Fig. 17 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.

[0105] 18 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 formed, for example, of a metal frame (metal plate) or a wiring substrate. If the support substrate 260 is formed 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.

[0106] 19 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.

[0107] 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.

[0108] Although the present technology has been described above with reference to the embodiments, variations 1 to 5, and application examples, 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 unit 11 is blue light or ultraviolet light, but the present technology is not limited to this. For example, the light-emitting device 1 may 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.

[0109] Furthermore, in the above-described 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-described embodiments, an example in which there are multiple light-emitting units 11 is shown, but this is not limiting. For example, the light-emitting device 1 may include only one light-emitting unit 11.

[0110] 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.

[0111] The effects described in this specification are merely examples and are not limited to those described, and other effects may also be obtained.

[0112] The present technology can also be configured as follows. According to the present technology configured as follows, a light emitting element includes a plurality of light emitting units and a plurality of light receiving units each having a compound semiconductor stack structure on a substrate, a first light reflecting layer provided between the substrate and the light emitting units and overlapping with the light emitting units in a first direction, and a second light reflecting layer provided on the opposite side of the substrate as viewed from the light emitting units and overlapping with the light receiving units in the first direction. As a result, light emitted from the light emitting units is reflected in a direction traveling toward the light receiving units or in a first direction as viewed from the substrate, which is expected to improve the detection efficiency of intensity signals and reduce leakage light. (1) A light emitting device comprising: a substrate; a light emitting portion stacked on the substrate in a first direction and having a first compound semiconductor stacked structure; a light receiving portion stacked on the substrate in the first direction, disposed adjacent to the light emitting portion, electrically isolated from the light emitting portion, and including a second compound semiconductor stacked structure; a first light reflective layer disposed between the substrate and the light emitting portion in the first direction and overlapping with the light emitting portion; and a second light reflective layer disposed on the opposite side of the substrate from the light emitting portion in the first direction and overlapping with the light receiving portion in the first direction. (2) The light emitting device according to (1), wherein the first compound semiconductor stacked structure and the second compound semiconductor stacked structure each include, in order, a first conductive type layer, an active layer, and a second conductive type layer. (3) The light emitting device according to (2), wherein the first light reflective layer has a contact layer, and the contact layer is in contact with the first conductive type layer of the light emitting portion and is formed using metal. (4) The light emitting device according to any one of (1) to (3), wherein the first light reflective layer contains at least one of a metal and a dielectric material. (5) The light emitting device according to any one of (1) to (4), wherein the second light reflective layer is provided in a region of the substrate other than a region overlapping with the light emitting section in the first direction. (6) The light emitting device according to any one of (1) to (5), wherein the second light reflective layer contains at least one of a metal and a dielectric material. (7) The light emitting device according to any one of (1) to (6), further comprising an embedding layer provided so as to cover the light emitting section and the light receiving section.(8) The light-emitting device according to (7), wherein the embedding layer is formed using at least one of SiO, SiN, SiON, and TiO. (9) The light-emitting device according to (7) or (8), further comprising a lens provided on the opposite side of the substrate as viewed from the light-emitting section, at a position overlapping the light-emitting section in the first direction. (10) The light-emitting device according to (9), wherein the lens is formed using at least one of SiO, SiN, SiON, and TiO. (11) The light-emitting device according to (9) or (10), further comprising a planarization layer, wherein the planarization layer is provided between the embedding layer and the lens, and the second light-reflecting layer is embedded in the planarization layer. (12) The light-emitting device according to (11), wherein the planarization layer is formed of a dielectric material having a refractive index lower than both the refractive index of the embedding layer and the refractive index of the lens. (13) The light emitting device according to any one of (1) to (12), further comprising a third light reflective layer in a region between the light emitting section and the light receiving section and the substrate, in a region occupied by the substrate other than a region overlapping with the light emitting section and the light receiving section in the first direction. (14) The light emitting device according to (13), wherein the third light reflective layer contains at least one of a metal and a dielectric material. (15) The light emitting device according to any one of (1) to (14), wherein the substrate is electrically connected to the light emitting section and has a drive circuit that drives the light emitting section. (16) The light emitting device according to (15), wherein the light receiving section is connected to a circuit different from the drive circuit. (17) An image display device comprising a light-emitting device, the light-emitting device having: a substrate; a light-emitting section stacked on the substrate in a first direction and including a first compound semiconductor stacked structure; a light-receiving section stacked on the substrate in the first direction, provided adjacent to the light-emitting section, electrically separated from the light-emitting section, and including a second compound semiconductor stacked structure; a first light-reflecting layer provided between the substrate and the light-emitting section and at a position overlapping with the light-emitting section in the first direction; and a second light-reflecting layer provided on the opposite side of the substrate as viewed from the light-emitting section and at a position overlapping with the light-receiving section in the first direction.

[0113] This application claims priority based on Japanese Patent Application No. 2024-058228, filed on March 29, 2024, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0114] 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 section stacked on said substrate in a first direction and having a first compound semiconductor stacked structure; a light receiving section stacked on said substrate in said first direction, provided adjacent to said light emitting section, electrically isolated from said light emitting section, and including a second compound semiconductor stacked structure; a first light reflecting layer provided between said substrate and said light emitting section and at a position overlapping with said light emitting section in said first direction; and a second light reflecting layer provided on the opposite side of said substrate as viewed from said light emitting section and at a position overlapping with said light receiving section in said first direction.

2. The light emitting device according to claim 1, wherein each of the first compound semiconductor laminated structure and the second compound semiconductor laminated structure includes a first conductive type layer, an active layer, and a second conductive type layer in that order.

3. The light emitting device according to claim 2, wherein the first light reflecting layer has a contact layer, the contact layer being in contact with the first conductive type layer of the light emitting section and being formed using a metal.

4. The light emitting device according to claim 1, wherein the first light reflecting layer contains at least one of a metal and a dielectric material.

5. The light emitting device according to claim 1, wherein the second light reflecting layer is provided in an area of ​​the substrate other than an area overlapping with the light emitting section in the first direction.

6. The light emitting device according to claim 1, wherein the second light reflective layer contains at least one of a metal and a dielectric material.

7. The light emitting device according to claim 1, further comprising an embedding layer provided so as to cover the light emitting section and the light receiving section.

8. The light emitting device according to claim 7, wherein the buried layer is formed using at least one of SiO, SiN, SiON and TiO.

9. The light emitting device according to claim 7, further comprising a lens provided on the opposite side of the substrate as viewed from the light emitting section, at a position overlapping the light emitting section in the first direction.

10. The light emitting device according to claim 9, wherein the lens is formed using at least one of SiO, SiN, SiON and TiO.

11. The light emitting device according to claim 9, further comprising a planarization layer, the planarization layer being provided between the embedding layer and the lens, and the second light reflecting layer being embedded in the planarization layer.

12. The light emitting device according to claim 11, wherein the planarization layer is formed of a dielectric material having a refractive index lower than both the refractive index of the buried layer and the refractive index of the lens.

13. The light emitting device according to claim 1, further comprising a third light reflecting layer in an area between the light emitting section and the light receiving section and the substrate, in an area occupied by the substrate other than an area overlapping with the light emitting section and the light receiving section in the first direction.

14. The light emitting device according to claim 13, wherein the third light reflective layer includes at least one of a metal and a dielectric material.

15. The light-emitting device according to claim 1, wherein the substrate is electrically connected to the light-emitting section and has a drive circuit for driving the light-emitting section.

16. The light emitting device according to claim 15, wherein the light receiving section is connected to a circuit different from the drive circuit.

17. An image display device comprising a light-emitting device, the light-emitting device having: a substrate; a light-emitting section stacked on the substrate in a first direction and including a first compound semiconductor stacked structure; a light-receiving section stacked on the substrate in the first direction, provided adjacent to the light-emitting section, electrically separated from the light-emitting section, and including a second compound semiconductor stacked structure; a first light-reflecting layer provided between the substrate and the light-emitting section and at a position overlapping with the light-emitting section in the first direction; and a second light-reflecting layer provided on the opposite side of the substrate from the light-emitting section and at a position overlapping with the light-receiving section in the first direction.

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