Light-emitting device and image display device

Abstract

A light-emitting device according to an embodiment of the present disclosure includes: a first layered structure including a first semiconductor layer, a first light-emitting layer which emits first light, and a second semiconductor layer in this order in a first direction; and a second layered structure which is layered on the first layered structure in the first direction and includes a third semiconductor layer, a second light-emitting layer which emits second light and a fourth semiconductor layer in this order in the first direction. At least one of the first semiconductor layer or the second semiconductor layer has, on a first surface orthogonal to the first direction, a first light-emitting region and a first peripheral region provided around the first light-emitting region. At least one of the third semiconductor layer or the fourth semiconductor layer has, on the first surface, a second light-emitting region and a second peripheral region provided around the second light-emitting region.

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] For example, in Patent Document 1, a first compound semiconductor layer having opposing first and second surfaces, an active layer facing the second surface of the first compound semiconductor layer, a third surface facing the active layer, and a fourth surface that serves as a light-emitting surface opposing the third surface, and a second compound semiconductor layer having one or more condensing structures on the fourth surface, and a current constriction structure provided within the layer of the first compound semiconductor layer or the second compound semiconductor layer.

[0003] International Publication No. 2023 / 032300

[0004] Incidentally, in a light-emitting device using a micro LED (Light Emitting Diode), reduction in light emission efficiency due to non-light emission or leakage at the end faces is a problem.

[0005] It is desirable to provide a light-emitting device that achieves both size reduction and maintenance of light emission efficiency, and an image display device including the same.

[0006] A light-emitting device according to an embodiment of the present disclosure includes a first stacked structure including a first semiconductor layer, a first light-emitting layer that emits first light, and a second semiconductor layer in this order in a first direction, and a second stacked structure stacked in the first direction with respect to the first stacked structure, including a third semiconductor layer, a second light-emitting layer that emits second light, and a fourth semiconductor layer in this order in the first direction. At least one of the first semiconductor layer and the second semiconductor layer has, on a first surface orthogonal to the first direction, a first light-emitting region and a first peripheral region provided around the first light-emitting region. At least one of the third semiconductor layer and the fourth semiconductor layer has, on the first surface, a second light-emitting region and a second peripheral region provided around the second light-emitting region.

[0007] An image display device according to an embodiment of the present disclosure includes a light-emitting device, and as the light-emitting device, has the light-emitting device according to the embodiment of the present disclosure described above.

[0008] In a light-emitting device and an image display device according to one embodiment of the present disclosure, two or more stacked structures including semiconductor layers are stacked, and the semiconductor layers have a first light-emitting region and a first peripheral region provided around the first light-emitting region on a first surface perpendicular to a first direction, so that the current concentrates in a certain region.

[0009] Figure 1 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device according to one embodiment of the present disclosure. Figure 2A is a schematic cross-sectional view illustrating an example of the manufacturing process of the light-emitting device shown in Figure 1. Figure 2B is a schematic cross-sectional view showing the process following Figure 2A. Figure 2C is a schematic cross-sectional view showing the process following Figure 2B. Figure 2D is a schematic cross-sectional view showing the process following Figure 2C. Figure 2E is a schematic cross-sectional view showing the process following Figure 2D. Figure 2F is a schematic cross-sectional view showing the process following Figure 2E. Figure 2G is a schematic cross-sectional view showing the process following Figure 2F. Figure 2H is a schematic cross-sectional view showing the process following Figure 2G. Figure 2I is a schematic cross-sectional view showing the process following Figure 2H. Figure 2J is a schematic cross-sectional view showing the process following Figure 2I. Figure 2K is a schematic cross-sectional view showing the process following Figure 2J. Figure 2L is a schematic cross-sectional view showing the process following Figure 2K. Figure 3 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device according to Modification 1 of the present disclosure. Figure 4 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device according to Modification 2 of this disclosure. Figure 5A is a schematic plan view showing an example of the first pad portion according to Modification 3 of this disclosure. Figure 5B is a schematic plan view showing another example of the first pad portion according to Modification 3 of this disclosure. Figure 6 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device according to Modification 4 of this disclosure. Figure 7A is a schematic cross-sectional view showing an example of the configuration of a light-emitting device according to Modification 5 of this disclosure. Figure 7B is a schematic cross-sectional view showing another example of the configuration of a light-emitting device according to Modification 5 of this disclosure. Figure 8 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device according to Modification 6 of this disclosure. Figure 9 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device according to Modification 7 of this disclosure. Figure 10 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device according to Modification 8 of this disclosure. Figure 11 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device according to Modification 9 of this disclosure. Figure 12 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device according to Modification 9 of this disclosure. Figure 13 is a perspective view showing an example of the configuration of an image display device according to an application example of this disclosure. Figure 14 is a schematic diagram showing an example of the wiring layout of the image display device shown in Figure 13. Figure 15 is a perspective view showing an example of the configuration of an image display device according to an application example of this disclosure. Figure 16 is a perspective view showing the configuration of the mounting substrate shown in Figure 15. Figure 17 is a perspective view showing the configuration of the unit substrate shown in Figure 16.Figure 18 is a diagram showing an example of an image display device according to an application example of the present disclosure.

[0010] Hereinafter, one embodiment of the present disclosure will be described in detail with reference to the drawings. The following description is a specific example of the present disclosure, and the present disclosure is not limited to the following embodiment. Furthermore, the present disclosure is not limited to the arrangement, dimensions, dimensional ratios, etc. of each component shown in each figure. The order of description is as follows: 1. Embodiment (Example of a light-emitting device in which two or more compound semiconductor layers including a current-constricting portion are stacked) 1-1. Configuration of the light-emitting device 1-2. Method of manufacturing the light-emitting device 1-3. Operation and effects 2. Modifications 2-1. Modification 1 (Another example of a light-emitting device) 2-2. Modification 2 (Another example of a light-emitting device) 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) 3. Application example (Example of an image display device)

[0011] <1. Embodiment> Figure 1 schematically shows an example of the cross-sectional configuration of a light-emitting device (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 called a so-called LED display (for example, the image display device 100 shown in Figure 13 later).

[0012] [1-1. Configuration of the Light-Emitting Device] The light-emitting device 1 has a laminated structure in which, for example, a drive substrate 30, a first light-emitting unit 10, and a second light-emitting unit 20 are stacked in order in the Z-axis direction, which is the thickness direction perpendicular to the XY plane.

[0013] The first light-emitting section 10 is provided with a first laminated structure 11, a plurality of first current-constricting sections 12, an insulating layer 13, and a plurality of first pad sections 14. The first light-emitting section 10 has a surface 10S1 facing the second light-emitting section 20 and a surface 10S2 opposite to surface 10S1.

[0014] The first stacked structure 11 is a solid-state light-emitting element that emits light in a predetermined wavelength band from its upper surface, and is, for example, an LED (Light Emitting Diode) chip. An LED chip refers to an LED that has been cut from a wafer used for crystal growth, and is not a package type covered with molded resin or the like. The LED chip is, for example, 100 μm or less in size, and is what is known as a microLED.

[0015] The first stacked structure 11 is a stacked structure that sequentially includes a first semiconductor layer 111, a first light-emitting layer 112, and a second semiconductor layer 113 in the Z-axis direction from the drive substrate 30 side. The first stacked structure 11 may have a nanostructure. A nanostructure is, for example, a structure in which a plurality of columnar bodies with the Z-axis direction as their longitudinal direction are discretely arranged in the XY plane. The nanostructure is embedded, for example, in at least one of the first semiconductor layer 111 and the second semiconductor layer 113. The constituent material of the nanostructure has a refractive index different from that of the constituent material of the first semiconductor layer 111 and the constituent material of the second semiconductor layer 113. Examples of constituent materials of the nanostructure include titanium oxide (TiO2). ２ Examples of transparent oxides include )

[0016] The first semiconductor layer 111 is composed of a semiconductor material of a first conductivity type. The first semiconductor layer 111 is composed of, for example, an n-type AsP-based semiconductor material. Alternatively, the first semiconductor layer 111 may be composed of an n-type semiconductor material doped with an element such as Si or Te, such as AlGaInP, GaInP, GaAs, AlInP, AlAs, or AlGaAs. The first light-emitting layer 112 has a multiple quantum well structure in which, for example, AlGaNInP and GaInP are alternately stacked, and has a light-emitting region inside. The first light-emitting layer 112 may have a multiple quantum well structure in which, for example, AlGaNInP and GaAs are alternately stacked. Or, the first light-emitting layer 112 may have a multiple quantum well structure in which, for example, AlGaAs and GaAs are alternately stacked. Or, the first light-emitting layer 112 may have a multiple quantum well structure in which, for example, AlGaInP and GaInP are alternately stacked. From the first light-emitting layer 112, for example, light L1 in the red band is extracted. Note that in Figure 1, only the main ray of light L1 is shown as an example. Light L1 is not limited to traveling in the Z-axis direction as shown in Figure 1, but may also travel at an angle to the Z-axis direction, for example. The second semiconductor layer 113 is composed of a semiconductor material of a second conductivity type different from the first conductivity type. The second semiconductor layer 113 is formed of, for example, a p-type GaN-based semiconductor material. Alternatively, the second semiconductor layer 113 may be composed of a p-type semiconductor material doped with elements such as Zn, Mg, or C, such as GaP, AlGaInP, GaInP, AlInP, AlAs, AlGaAs, etc. Furthermore, as the semiconductor material constituting the first semiconductor layer 111 and the second semiconductor layer 113, for example, an InGaN-based semiconductor material may be used. In that case, for example, light in the blue band or light with wavelengths corresponding to the ultraviolet region (ultraviolet light) is extracted from the first light-emitting layer 112. In the first laminated structure 11, the upper surface of the first light-emitting layer 112, that is, the surface of the first light-emitting layer 112 facing the second semiconductor layer 113, is the light-emitting surface 11S1 of the first laminated structure 11. The light L1 corresponds to one specific example of the "first light" as one aspect of this disclosure.

[0017] At least one of the first semiconductor layer 111 and the second semiconductor layer 113 has a first light-emitting region and a first peripheral region provided around the first light-emitting region in the XY plane. In one embodiment of the present disclosure, a first current-constricting portion 12 is provided, having a first current injection region 121 as the first light-emitting region and a first current-constricting region 122 as the first peripheral region.

[0018] The first current constriction portion 12 imparts a constricting effect to the current flowing through the first light-emitting portion 10. The first current constriction portion 12 is provided in at least a portion of the first semiconductor layer 111 and the second semiconductor layer 113 of the first laminated structure 11. In the example configuration of the light-emitting device 1 shown in Figure 1, the second semiconductor layer 113 has the first current constriction portion 12. It is preferable that at least a portion of the first current constriction portion 12 overlaps with at least a portion of the second current constriction portion 22 in the Z-axis direction.

[0019] Each of the multiple first current constriction regions 12 includes a first current injection region 121 through which current can pass, and a first current constriction region 122 provided around the first current injection region 121. At least a portion of the first current injection region 121 may overlap with at least a portion of the second current injection region 221 in the Z-axis direction. The first current constriction region 122 may be shared by multiple first current constriction regions 12. The first current constriction region 122 is embedded in the second semiconductor layer 113, as shown in Figure 1, for example, and is exposed on the surface 113S of the second semiconductor layer 113 opposite to the surface facing the first light-emitting layer 112. The first current constriction region 122 is a region through which current is less likely to flow than the first current injection region 121, and can be formed, for example, by injecting impurities from the surface 113S of the second semiconductor layer 113. The first light-emitting layer 112 includes a plurality of first light-emitting portions 112R provided in regions corresponding to each of the plurality of first current injection regions 121 in the Z-axis direction. The plurality of first light-emitting portions 112R may be coupled together and integrated, or they may be spaced apart from each other.

[0020] The insulating layer 13 is provided in contact with the surface 113S of the second semiconductor layer 113. The insulating layer 13 is formed of, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0021] Multiple first pad portions 14 are embedded in the insulating layer 13. The first pad portions 14 are exposed from the surface 10S1 of the first light-emitting portion 10. The first pad portions 14 are in ohmic contact with, for example, the first current-constricting portion 12. The first pad portions 14 are formed using, for example, copper (Cu), aluminum (Al), tungsten (W), silver (Ag), or alloys thereof.

[0022] The second light-emitting section 20 is provided with a second laminated structure 21, a plurality of second current-constricting sections 22, an insulating layer 23, a plurality of second pad sections 24, and an electrode layer 25. The second light-emitting section 20 has a surface 20S1 facing the first light-emitting section 10 and a surface 20S2 opposite to surface 20S1.

[0023] The second layered structure 21 is a solid-state light-emitting element that emits light in a predetermined wavelength band from its upper surface, and is, for example, an LED (Light Emitting Diode) chip. An LED chip refers to an LED that has been cut from a wafer used for crystal growth, and is not a package type covered with molded resin or the like. The LED chip is, for example, 100 μm or less in size, and is what is known as a micro-LED.

[0024] The second stacked structure 21 is a stacked structure that sequentially includes a third semiconductor layer 211, a second light-emitting layer 212, and a fourth semiconductor layer 213 in the Z-axis direction from the drive substrate 30 side. The second stacked structure may have the nanostructure described above. The nanostructure is embedded, for example, in at least one of the third semiconductor layer 211 and the fourth semiconductor layer 213. The constituent material of the nanostructure has a refractive index different from that of the constituent material of the third semiconductor layer 211 and the constituent material of the fourth semiconductor layer 213. Examples of constituent materials of the nanostructure include titanium oxide (TiO2). ２ Examples of transparent oxides include )

[0025] The third semiconductor layer 211 is composed of a semiconductor material of the first conductivity type. The third semiconductor layer 211 is formed of, for example, an n-type AsP-based semiconductor material. Alternatively, the third semiconductor layer 211 may be composed of an n-type semiconductor material doped with an element such as Si or Te, such as AlGaInP, GaInP, GaAs, AlInP, AlAs, or AlGaAs. The second light-emitting layer 212 has a multiple quantum well structure in which, for example, AlGaNInP and GaInP are alternately stacked, and has a light-emitting region inside. The second light-emitting layer 212 may have a multiple quantum well structure in which, for example, AlGaNInP and GaAs are alternately stacked. Alternatively, the second light-emitting layer 212 may have a multiple quantum well structure in which, for example, AlGaAs and GaAs are alternately stacked. Alternatively, the second light-emitting layer 212 may have a multiple quantum well structure in which, for example, AlGaInP and GaInP are alternately stacked. From the second light-emitting layer 212, for example, light L2 in the red band is extracted. Note that in Figure 1, only the main ray of light L2 is shown as an example. Light L2 is not limited to traveling in the Z-axis direction as shown in Figure 1, but may also travel at an angle to the Z-axis direction, for example. The fourth semiconductor layer 213 is formed of a semiconductor material of a second conductivity type different from the first conductivity type. The fourth semiconductor layer 213 is formed of, for example, a p-type GaN-based semiconductor material. Alternatively, the fourth semiconductor layer 213 may be composed of a p-type semiconductor material doped with elements such as Zn, Mg, or C, such as GaP, AlGaInP, GaInP, AlInP, AlAs, AlGaAs, etc. Furthermore, as the semiconductor material constituting the third semiconductor layer 211 and the fourth semiconductor layer 213, for example, an InGaN-based semiconductor material may be used. In that case, for example, light in the blue band or light with wavelengths corresponding to the ultraviolet region (ultraviolet light) is extracted from the second light-emitting layer 212. In the second stacked structure 21, the upper surface of the second light-emitting layer 212, that is, the surface of the second light-emitting layer 212 facing the fourth semiconductor layer 213, is the light-emitting surface 21S1 of the second stacked structure 21. Light L2 corresponds to one specific example of the "second light" as one aspect of this disclosure.

[0026] At least one of the first semiconductor layer 111 and the second semiconductor layer 113 has a first light-emitting region and a first peripheral region provided around the first light-emitting region in the XY plane. In one embodiment of the present disclosure, a first current-constricting portion 12 is provided, having a first current injection region 121 as the first light-emitting region and a first current-constricting region 122 as the first peripheral region.

[0027] The second current constriction section 22 imparts a constricting effect to the current flowing through the second light-emitting section 20. The second current constriction section 22 is provided in at least a portion of the third semiconductor layer 211 and the fourth semiconductor layer 213 of the second stacked structure 21. In the example configuration of the light-emitting device 1 shown in Figure 1, the fourth semiconductor layer 213 has the second current constriction section 22. It is preferable that at least a portion of the second current constriction section 22 overlaps with at least a portion of the first current constriction section 12 in the Z-axis direction.

[0028] Each of the multiple second current constriction regions 22 includes a second current injection region 221 through which current can pass, and a second current constriction region 222 provided around the second current injection region 221. The second current constriction region 222 may be shared by multiple second current constriction regions 22. The second current constriction region 222 is embedded in the fourth semiconductor layer 213, as shown in Figure 1, for example, and is exposed on the surface 213S of the fourth semiconductor layer 213 opposite to the surface facing the second light-emitting layer 212. The second current constriction region 222 is a region through which current is less likely to flow than the second current injection region 221, and can be formed, for example, by injecting impurities from the surface 213S of the fourth semiconductor layer 213. The second light-emitting layer 212 includes a plurality of second light-emitting portions 212R provided in regions corresponding to each of the multiple second current injection regions 221 in the Z-axis direction. The multiple second light-emitting portions 212R may be joined together and integrated, or they may be spaced apart from each other.

[0029] The insulating layer 23 is provided in contact with the surface of the third semiconductor layer 211 facing the first light-emitting portion 10. The insulating layer 23 is formed of, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0030] Multiple second pad portions 24 are embedded in the insulating layer 23. The second pad portions 24 are exposed from the surface 20S1 of the second light-emitting portion 20. The second pad portions 24 are in ohmic contact with, for example, the third semiconductor layer 211. The second pad portions 24 are formed using, for example, copper (Cu), aluminum (Al), tungsten (W), silver (Ag), or alloys thereof.

[0031] The electrode layer 25 is provided in contact with the fourth semiconductor layer 214. The electrode layer 25 may transmit light L1 and light L2. The electrode layer 25 is formed using a conductive material that can transmit light L1 and light L2, such as a transparent conductive material such as ITO. However, the electrode layer 25 may be made of a translucent electrode material, or it may be made of a non-transparent material with fine slits.

[0032] The drive substrate 30 is provided on the side of the first laminated structure 11 opposite to the second laminated structure 21 in the Z-axis direction. The drive substrate 30 includes, for example, a support substrate 31 made of silicon (Si), a plurality of wiring layers (for example, wiring layers 321, 322) provided on the support substrate 31, and an insulating layer 33 and a pad portion 34 embedded in the insulating layer 33 that form a bonding surface with the first light-emitting unit 10. On the drive substrate 30, for example, a drive circuit that drives the first light-emitting unit 10 and the second light-emitting unit 20 is embedded in the support substrate 31.

[0033] The wiring layers 321 and 322 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) or silicon nitride (SiN). The pad portion 34 is formed using, for example, copper (Cu). The pad portion 34 may transmit light L1 and light L2. The pad portion 34 is formed using a conductive material that can transmit light L1 and light L2, such as a transparent conductive material such as ITO.

[0034] [1-2. Method for Manufacturing the Light-Emitting Device] The light-emitting device 1 of this embodiment can be manufactured, for example, as follows. Figures 2A to 2L show an example of the manufacturing process for the light-emitting device 1.

[0035] First, as shown in Figure 2A, for example, a GaAs substrate or a Ge substrate is prepared as a growth substrate 411. Then, the first semiconductor layer 111, the first light-emitting layer 112, and the second semiconductor layer 113 are sequentially formed on the growth substrate 41 by epitaxial crystal growth using methods such as metal-organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). Through these operations, the first stacked structure 11 is obtained. Similarly, as shown in Figure 2B, for example, after preparing a GaAs substrate or a Ge substrate as the growth substrate 412, the third semiconductor layer 211, the second light-emitting layer 212, and the fourth semiconductor layer 213 are sequentially formed on the growth substrate 412 by epitaxial crystal growth using methods such as metal-organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). Through these operations, the second stacked structure 21 is obtained.

[0036] Next, as shown in Figure 2C, a resist film 421 having a predetermined pattern shape is selectively formed on the second semiconductor layer 113 of the first stacked structure 11. Similarly, as shown in Figure 2D, a resist film 422 having a predetermined pattern shape is selectively formed on the fourth semiconductor layer 213 of the second stacked structure 21. Subsequently, as shown in Figure 2E, the impurity concentration of the second semiconductor layer 113 in the area exposed and not covered by the resist film 421 is changed by, for example, ion implantation using the resist film 421 as a mask, thereby forming a first current constriction 12. After that, the resist film 421 is removed. Subsequently, as shown in Figure 2F, the impurity concentration of the fourth semiconductor layer 213 in the area exposed and not covered by the resist film 422 is changed by, for example, ion implantation using the resist film 422 as a mask, thereby forming a second current constriction 22. After that, the resist film 422 is removed.

[0037] Next, as shown in Figure 2G, an insulating layer 13 is formed on the second semiconductor layer 113 and the first current constriction portion 12 of the first laminated structure 11, with a plurality of first pad portions 14 embedded in it. After peeling the growth substrate 412 from the third semiconductor layer 211, as shown in Figure 2H, the second laminated structure 21 is inverted and bonded to the support substrate 42 so that the fourth semiconductor layer 213 and the second current constriction portion 22 face the support substrate 42. After that, an insulating layer 23 is formed on the third semiconductor layer 211, with a plurality of second pad portions 24 embedded in it. Through these operations, the first light-emitting portion 10 and the second light-emitting portion 20 are obtained.

[0038] Next, as shown in Figure 2I, the upper surface of the first light-emitting section 10 and the upper surface of the second light-emitting section 20 are bonded together (a so-called hybrid bonding is performed). In this hybrid bonding, the first pad section 14 and the second pad section 24 are bonded together, and the insulating layer 13 and the insulating layer 23 are bonded together.

[0039] Next, after peeling the growth substrate 411 from the first semiconductor layer 111, an insulating layer 33 with multiple wiring layers 322 and multiple pad portions 34 embedded in it is formed on the first semiconductor layer 111, as shown in Figure 2J.

[0040] Next, as shown in Figure 2K, the drive substrate 30 with the wiring layer 321 embedded is bonded to the upper surface of the insulating layer 33 (a so-called hybrid bond is performed). In this hybrid bond, the wiring layer 321 and the wiring layer 322 are joined together.

[0041] Next, as shown in Figure 2L, the support substrate 42 is peeled off from the fourth semiconductor layer 213 and the second current constriction region 222, and then an electrode layer 25 is formed in contact with the fourth semiconductor layer 213 and the second current constriction region 222, for example, using a sputtering method or a vapor deposition method. With these steps completed, the light-emitting device 1 shown in Figure 1 is completed.

[0042] [1-4. Function and Effect] The light-emitting device 1 of this embodiment includes a first stacked structure 11 including a first semiconductor layer 111, a first light-emitting layer 112, and a second semiconductor layer 113 in this order in the Z-axis direction, and a second stacked structure 21 that is stacked on the first stacked structure 11 in the Z-axis direction and includes a third semiconductor layer 211, a second light-emitting layer 212, and a fourth semiconductor layer 213 in this order in the Z-axis direction. In the configuration example of the light-emitting device 1 shown in FIG. 1, the second semiconductor layer 113 has a first current constriction portion 12, and the fourth semiconductor layer 213 has a second current constriction portion 22. As a result, the current flowing through the first light-emitting portion 10 is concentrated in a region corresponding to a first current injection region 121 as a first light-emitting region in the XY plane, and the current flowing through the second light-emitting portion 20 is concentrated in a region corresponding to a second current injection region 221 as a second light-emitting region in the XY plane. Hereinafter, this will be described.

[0043] In a general light-emitting device, by providing a micro LED that is smaller in size than a normal LED, a problem is that the light-emitting efficiency decreases due to non-light-emission or leakage at the end face of the LED.

[0044] As a method for solving the above problem, providing an oxide layer on the end face of the LED or providing a current constriction portion in the light-emitting element can be mentioned.

[0045] In the light-emitting device 1 of this embodiment, a structure in which two or more light-emitting portions having current constriction portions are stacked is provided. Further, the first stacked structure 11 and the second stacked structure 21 are not provided with a pixel isolation structure. With the first current constriction portion 12 and the second current constriction portion 22, the currents flowing through the first light-emitting portion 10 and the second light-emitting portion 20 are each concentrated in a certain region. As a result, it becomes possible to improve the light output and the luminance. That is, even when the light-emitting device 1 is driven at a low current density, it is possible to drive with a high light-emitting efficiency as compared with a general light-emitting device.

[0046] <2. Modified Example> Next, modified examples 1 to 10 and application examples of the present disclosure will be described. Note that the same reference numerals are given to the constituent elements corresponding to the light-emitting device 1 of the above embodiment, and the description thereof will be omitted.

[0047] [2-1. Modification Example 1] FIG. 3 schematically shows an example of the cross-sectional configuration of a light-emitting device (light-emitting device 1A) according to Modification Example 1 of the present disclosure.

[0048] In the light-emitting device 1 of the above embodiment, an example where the first light-emitting unit 10 and the second light-emitting unit 20 are electrically connected via the first pad unit 14 and the second pad unit 24 is shown, but the present disclosure is not limited to this. In the light-emitting device 1A of this modification example, the first light-emitting unit 10 and the second light-emitting unit 20 are electrically connected via the first bonding portion 51. The first bonding portion 51 is formed of a transparent electrode material such as ITO, indium zinc oxide (IZO), tin oxide (SnO), or TiO, for example. The first bonding portion 51 corresponds to a specific example of the "transparent conductive layer" as one aspect of the present disclosure.

[0049] Except for the above points, the configuration of the light-emitting device 1A is substantially the same as the configuration of the light-emitting device 1 of the above embodiment. Even in such a configuration, the light-emitting device 1A can obtain the same effects as the light-emitting device 1 of the above embodiment.

[0050] [2-2. Modification Example 2] FIG. 4 schematically shows an example of the cross-sectional configuration of a light-emitting device (light-emitting device 1B) according to Modification Example 2 of the present disclosure.

[0051] In the light-emitting device 1B of this modification example, a first transparent electrode layer 15 is provided so as to connect adjacent first pad portions 14 to each other. Further, an electrode layer 25b is provided instead of the electrode layer 25. Each of the first transparent electrode layer 15 and the electrode layer 25b is formed of a transparent electrode material such as ITO, indium zinc oxide (IZO), tin oxide (SnO), or TiO. The electrode layer 25b corresponds to a specific example of the "second transparent electrode layer" as one aspect of the present disclosure.

[0052] 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 in such a configuration, the light-emitting device 1B can obtain the same effects as the light-emitting device 1 of the above embodiment.

[0053] [2-3. Modification 3] Figure 5A schematically shows an example of the planar configuration of the first pad portion 14c1 (light-emitting device 1C-1) according to Modification 3 of the present disclosure. Figure 5B schematically shows another example of the planar configuration of the first pad portion 14c2 (light-emitting device 1C-2) according to Modification 3 of the present disclosure.

[0054] In this modified example, the light-emitting device 1C-1 has a first pad portion 14c1 instead of the first pad portion 14. In this modified example, the light-emitting device 1C-2 has a first pad portion 14c2 instead of the first pad portion 14. In this modified example, the first pad portions 14c1 and 14c2 have an opening 14H at a position that does not overlap with the first current constriction portion 12 in the Z-axis direction. The light L1 emitted from the first light-emitting layer 112 passes through the opening 14H. The opening 14H may have a substantially rectangular shape in plan view, as shown in Figure 5A. The opening 14H may have a substantially circular shape in plan view, as shown in Figure 5B.

[0055] Except for the points mentioned above, the configurations of the light-emitting devices 1C-1 and 1C-2 are substantially the same as those of the light-emitting device 1 in the above embodiment. Even with such configurations, the light-emitting devices 1C-1 and 1C-2 can achieve the same effects as the light-emitting device 1 in the above embodiment.

[0056] [2-4. Modification 4] Figure 6 schematically shows an example of the cross-sectional configuration of a light-emitting device (light-emitting device 1D) according to Modification 4 of the present disclosure.

[0057] In the above embodiment of the light-emitting device 1, an example was shown in which the impurity concentration of the first current injection region 121 differs from the impurity concentration of the first current constriction region 122, and the impurity concentration of the second current injection region 221 differs from the impurity concentration of the second current constriction region 222, but the disclosure is not limited thereto. As in the modified light-emitting device 1D, the first current constriction region 122d of the first current constriction portion 12d and the second current constriction region 222d of the second current constriction portion 22d may be voids. The first current constriction region 122d and the second current constriction region 222d are voids formed by selectively removing a part of the second semiconductor layer 113 and a part of the fourth semiconductor layer 213, respectively, by dry etching during the manufacturing process.

[0058] Except for the points mentioned above, the configuration of the light-emitting device 1D is substantially the same as the configuration of the light-emitting device 1 in the above embodiment. Even with such a configuration, the light-emitting device 1D can obtain the same effects as the light-emitting device 1 in the above embodiment.

[0059] [2-5. Modification 5] Figure 7A schematically shows an example of the cross-sectional configuration of a light-emitting device (light-emitting device 1E-1) according to Modification 5 of the present disclosure. Figure 7B schematically shows another example of the cross-sectional configuration of a light-emitting device (light-emitting device 1E-2) according to Modification 5 of the present disclosure.

[0060] In the above embodiment of the light-emitting device 1, an example was shown in which the first current-constricting portion 12 is formed in the second semiconductor layer 113 and the second current-constricting portion 22 is formed in the fourth semiconductor layer 213, but the present disclosure is not limited thereto.

[0061] In the modified light-emitting device 1E-1, as shown in Figure 7A, a first current constriction portion 12e is formed in the first semiconductor layer 111. The first current constriction portion 12e includes a first current injection region 121e through which current can pass, and a first current constriction region 122e provided around the first current injection region 121e.

[0062] Furthermore, in the modified light-emitting device 1E-2, as shown in Figure 7B, in addition to the first current-constricting portion 12 and the second current-constricting portion 22, a first current-constricting portion 12e and a second current-constricting portion 22e are further provided. The second current-constricting portion 22e is formed in the third semiconductor layer 211. The second current-constricting portion 22e includes a second current injection region 221e through which current can pass, and a second current-constricting region 222e provided around the second current injection region 221e.

[0063] Except for the points mentioned above, the configurations of the light-emitting devices 1E-1 and 1E-2 are substantially the same as those of the light-emitting device 1 in the above embodiment. Even with such configurations, the light-emitting devices 1E-1 and 1E-2 can achieve the same effects as the light-emitting device 1 in the above embodiment.

[0064] [2-6. Modification 6] Figure 8 schematically shows an example of the cross-sectional configuration of the light-emitting device (light-emitting device 1F) according to Modification 4 of this disclosure.

[0065] In the above embodiment of the light-emitting device 1, an example was shown in which the first current-constricting portion 12 is formed in the second semiconductor layer 113 and the second current-constricting portion 22 is formed in the fourth semiconductor layer 213, but the disclosure is not limited thereto. In this modified light-emitting device 1F, the first current-constricting portion 12f is provided to separate the first laminated structure 11 in the XY plane direction. Furthermore, the second current-constricting portion 22f is provided to separate the second laminated structure 21 in the XY plane direction.

[0066] Except for the points mentioned above, the configuration of the light-emitting device 1F is substantially the same as the configuration of the light-emitting device 1 in the above embodiment. Even with this configuration, the light-emitting device 1F can obtain the same effects as the light-emitting device 1 in the above embodiment.

[0067] [2-7. Modification 7] Figure 9 schematically shows an example of the cross-sectional configuration of a light-emitting device (light-emitting device 1G) according to Modification 7 of this disclosure.

[0068] In this modified light-emitting device 1G, a through electrode 52 is further provided that electrically connects the electrode layer 25 and the drive substrate 30.

[0069] The through electrode 52 has a contact layer 521 and a reflective film 522. The reflective film 522 is provided so as to cover the side surface of the contact layer 521. The contact layer 521 is in ohmic contact with the electrode layer 25. The contact layer 521 is formed using, for example, a multilayer film of nickel (Ni) and gold (Au) (Ni / Au) or a transparent conductive material such as ITO. The reflective film 522 is formed using a light-reflecting metal, dielectric material, or a multilayer film made by stacking these. Examples of metals used in the reflective film 522 include titanium (Ti), aluminum (Al), and silver (Ag).

[0070] Except for the points mentioned above, the configuration of the light-emitting device 1G is substantially the same as the configuration of the light-emitting device 1 in the above embodiment.

[0071] In this modified example, the light-emitting device 1G is equipped with a through electrode 52 having a reflective film 522 on its side surface, thereby reflecting the light that has traveled from the first light-emitting unit 10 and the second light-emitting unit 20 to the through electrode 52. As a result, the light-emitting device 1G has further improved light output and brightness.

[0072] [2-8. Modification 8] Figure 10 schematically shows an example of the cross-sectional configuration of a light-emitting device (light-emitting device 1H) according to Modification 8 of the present disclosure.

[0073] In the light-emitting device 1H of this modified example, a through electrode 52 is provided to electrically connect the electrode layer 25 and the drive substrate 30, similar to the light-emitting device 1G of modified example 7. Furthermore, in the light-emitting device 1H, a light-reflective pad portion 34h is provided on the side opposite to the second laminated structure 21 when viewed from the first laminated structure 11. The pad portion 34h extends in the XY plane direction to the area occupied by the support substrate 31. The pad portion 34h corresponds to one specific example of the "third pad portion" as one aspect of this disclosure.

[0074] The through electrode 52 has a contact layer 521 and a reflective film 522. The reflective film 522 is provided so as to cover the side surface of the contact layer 521. The contact layer 521 is in ohmic contact with the electrode layer 25. The contact layer 521 is formed using, for example, a multilayer film of nickel (Ni) and gold (Au) (Ni / Au) or a transparent conductive material such as ITO. The reflective film 522 is formed using a light-reflecting metal, dielectric material, or a multilayer film made by stacking these. Examples of metals used in the reflective film 522 include titanium (Ti), aluminum (Al), and silver (Ag).

[0075] Except for the points mentioned above, the configuration of the light-emitting device 1H is substantially the same as the configuration of the light-emitting device 1 in the above embodiment.

[0076] The modified light-emitting device 1H includes a through electrode 52 having a reflective film 522 on its side surface and a pad portion 34h extending in the XY plane. This reflects the light that travels from the first light-emitting unit 10 and the second light-emitting unit 20 to the through electrode 52 or the pad portion 34. As a result, the light-emitting device 1H further improves light output and brightness.

[0077] [2-9. Modification 9] Figure 11 schematically shows an example of the cross-sectional configuration of a light-emitting device (light-emitting device 1I) according to Modification 9 of the present disclosure.

[0078] In the modified light-emitting device 1I, an on-chip lens layer 53 is further provided facing the surface 20S2 of the second light-emitting unit 20. The on-chip lens layer 53 corresponds to one specific example of a "lens" as one aspect of the present disclosure.

[0079] The on-chip lens layer 53 is provided above the second laminated structure 21. The on-chip lens layer 53 focuses or diverges the light emitted from the first light-emitting layer 112 and the second light-emitting layer 212. The lens of the on-chip lens layer 53 includes at least one of silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), and resin.

[0080] Except for the points mentioned above, the configuration of the light-emitting device 1I is substantially the same as the configuration of the light-emitting device 1 in the above embodiment. Even with such a configuration, the light-emitting device 1I can obtain the same effects as the light-emitting device 1 in the above embodiment.

[0081] [2-10. Modification 10] Figure 12 schematically shows an example of the cross-sectional configuration of a light-emitting device (light-emitting device 1J) according to Modification 10 of the present disclosure.

[0082] In the above embodiment, an example was shown in which the light emitted from the first light-emitting layer 112 and the second light-emitting layer 212 is red light, but this disclosure is not limited thereto. The wavelength of the light L1 emitted from the first light-emitting layer 112 may be different from the wavelength of the light L2 emitted from the second light-emitting layer 212.

[0083] In the modified light-emitting device 1J, for example, while the wavelength of light emitted from the first light-emitting layer 112 is 640 nm, the wavelength of light emitted from the second light-emitting layer 212 may be, for example, 620 nm.

[0084] Except for the points mentioned above, the configuration of the light-emitting device 1J is substantially the same as the configuration of the light-emitting device 1 in the above embodiment.

[0085] In this modified light-emitting device 1J, a third light-emitting unit 60 may be provided on the surface 20S2 of the second light-emitting unit 20, for example, as shown in Figure 12. The third light-emitting unit 60 has substantially the same structure as the second light-emitting unit 20 in the above embodiment. The wavelength of light L1 emitted from the first light-emitting layer 112 is, for example, the wavelength of red light (e.g., 630 nm). The wavelength of light L2 emitted from the second light-emitting layer 212 is, for example, the wavelength of green light (e.g., 530 nm). The wavelength of light L3 emitted from the third light-emitting layer 612 of the third light-emitting unit 60 is, for example, the wavelength of blue light (e.g., 450 nm). As a result, the image display device equipped with the light-emitting device 1J can achieve both full-color functionality and high-density mounting.

[0086] <3. Application Examples> (Application Example 1) Figure 13 is a perspective view showing an example of the schematic configuration of an image display device (image display device 100). The image display device 100 is a so-called LED display, and the light-emitting device of this disclosure (for example, light-emitting device 1) is used as the display pixel. The image display device 100 includes, for example, a display panel 120 and a control circuit 140 that drives the display panel 120, as shown in Figure 13.

[0087] The display panel 120 consists of a mounting substrate 120A and an opposing substrate 120B superimposed on each other. The surface of the opposing substrate 120B serves as the image display surface, with a display area (display section 100A) in the center and a non-display area, the frame section 100B, surrounding it.

[0088] Figure 14 shows an example of the wiring layout of the area corresponding to the display unit 100A on the surface of the mounting substrate 120A on the opposing substrate 120B side. On the surface of the mounting substrate 120A, in the area 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 Figure 14. On the surface of the mounting substrate 120A, in the area corresponding to the display unit 100A, a plurality of scan wirings 135 are formed extending in a direction intersecting (for example, orthogonal to) the data wirings 134 and arranged in parallel at a predetermined pitch. The data wirings 134 and scan wirings 135 are made of a conductive material such as Cu.

[0089] The scan wiring 135 is formed, for example, on the outermost layer, and is formed 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 wiring 134 is formed in a layer different from the outermost layer containing the scan wiring 135 (for example, a layer below the outermost layer), and is formed, for example, in an insulating layer on the substrate.

[0090] The vicinity of the intersection of the data wiring 134 and the scan wiring 135 is a display pixel 136, and multiple display pixels 136 are arranged in a matrix within the display unit 100A. Each display pixel 136 is equipped with, for example, the respective color pixels Pr, Pg, and Pb of the light-emitting device 1.

[0091] The light-emitting device 1 is provided with terminal electrodes, for example, one pair for each color pixel Pr, Pg, and Pb, or one common electrode and the other arranged for each color pixel Pr, Pg, and Pb. One terminal electrode is electrically connected to the data wiring 134, and the other terminal electrode is electrically connected to the scan wiring 135. For example, one terminal electrode is electrically connected to the pad electrode 134B at the tip of a branch 134A provided on the data wiring 134. Also, for example, the other terminal electrode is electrically connected to the pad electrode 135B at the tip of a branch 135A provided on the scan wiring 135.

[0092] Each pad electrode 134B, 135B is formed, for example, on the outermost layer and is provided in the area where each light-emitting device 1 is mounted, as shown in Figure 14. Here, the pad electrodes 134B, 135B are made of a conductive material such as Au (gold).

[0093] The mounting substrate 120A is further provided with a plurality of support columns (not shown) that, for example, regulate the distance between the mounting substrate 120A and the opposing substrate 120B. The support columns may be provided in the area facing the display unit 100A, or in the area facing the frame unit 100B.

[0094] The opposing substrate 120B is made of, for example, a glass substrate or a resin substrate. On the opposing substrate 120B, the surface on the side facing the light-emitting device 1 may be flat, but it is preferable that it be rough. The rough surface may be provided over the entire area facing the display unit 100A, or it may be provided only in the area facing the display pixels 136. The rough surface has fine irregularities that allow light emitted from the color pixels Pr, Pg, and Pb to enter the rough surface. The irregularities of the rough surface can be created, for example, by sandblasting or dry etching.

[0095] The control circuit 140 drives each display pixel 136 (each light-emitting device 1) based on the video signal. The control circuit 140 is composed of, for example, a data driver that drives data wiring 134 connected to the display pixel 136 and a scan driver that drives scan wiring 135 connected to the display pixel 136. The control circuit 140 may be provided separately from the display panel 120 and connected to the mounting board 120A via wiring, or it may be mounted on the mounting board 120A, as shown in Figure 14.

[0096] (Application Example 2) Figure 15 is a perspective view showing another configuration example (image display device 200) of an image display device using the light-emitting device of this disclosure (for example, light-emitting device 1). The image display device 200 is a so-called tiling display that uses a plurality of light-emitting devices with LEDs as light sources. The image display device 200 includes, for example, a display panel 220 and a control circuit 240 that drives the display panel 220, as shown in Figure 15.

[0097] The display panel 220 consists of a mounting substrate 220A and an opposing substrate 220B superimposed on each other. The surface of the opposing substrate 220B serves as the image display surface, with a display area in the center and a frame area surrounding it, which is a non-display area (neither of which is shown). The opposing substrate 220B is positioned opposite the mounting substrate 220A, for example, with a predetermined gap between them. The opposing substrate 220B may also be in contact with the upper surface of the mounting substrate 220A.

[0098] Figure 16 schematically shows an example of the configuration of the mounting board 220A. The mounting board 220A is composed of multiple unit boards 250 arranged in a tile-like pattern, as shown in Figure 16. In Figure 16, an example is shown in which the mounting board 220A is composed of nine unit boards 250, but the number of unit boards 250 may be 10 or more, or 8 or less.

[0099] Figure 17 shows an example of the configuration of a unit board 250. The unit board 250 has, for example, a plurality of light-emitting devices 1 arranged in a tile-like pattern, and a support board 260 that supports each light-emitting device 1. Each unit board 250 further has a control board (not shown). The support board 260 is made of, for example, a metal frame (metal plate) or a wiring board. If the support board 260 is made of a wiring board, it can also serve as the control board. In this case, at least one of the support board 260 and the control board is electrically connected to each light-emitting device 1.

[0100] (Application Example 3) Figure 18 shows the appearance of the transparent display 300. The transparent display 300 includes, for example, a display unit 310, an operation unit 311, and a housing 312. The display unit 310 uses the light-emitting device of this disclosure (for example, light-emitting device 1). This transparent display 300 is capable of displaying images and text information while allowing the background of the display unit 310 to pass through.

[0101] In the transparent display 300, the mounting substrate is a light-transmitting substrate. Each electrode provided on the light-emitting device 1 is formed using a conductive material that is light-transmitting, similar to the mounting substrate. Alternatively, each electrode is designed to be difficult to see by reducing the width of the wiring or the thickness of the wiring. Furthermore, the transparent display 300 can display black by, for example, layering a liquid crystal layer equipped with a driving circuit, and switching between transmission and black display is possible by controlling the light distribution direction of the liquid crystal.

[0102] The present technology has been described above with reference to embodiments and modifications 1 to 10 and application examples. However, the present technology is not limited to the above embodiments, and various modifications are possible. For example, in the above embodiments, examples were shown in which the light emitted from the first light-emitting layer 112 and the second light-emitting layer 212 is blue light or ultraviolet light, but the technology is not limited to this. For example, the light-emitting device 1 can also use a light-emitting element that emits two or more types of light, such as blue light and green light, or ultraviolet light and green light.

[0103] Furthermore, although the above embodiments have described the components constituting the light-emitting device 1, etc., it is not necessary to include all components, and other components may also be included.

[0104] Furthermore, while the above embodiments illustrate the case where a light-emitting layer is provided on a drive substrate having a drive circuit, this disclosure is not limited thereto. For example, a light-emitting layer may be provided on another substrate that does not have a drive circuit, and the drive circuit included in a separate drive substrate may be connected to the light-emitting element.

[0105] Furthermore, in the embodiments described above, the first current-constricted region and the second current-constricted region are formed by adjusting the concentration of impurities injected into the semiconductor layer, but this disclosure is not limited thereto. For example, the first light-emitting region and the first peripheral region may be physically separated, or selective light emission may be performed using techniques such as oxidative constriction used in lasers (VCSELs).

[0106] Furthermore, the effects described herein are merely examples and are not limited to those described; other effects may also occur.

[0107] The present disclosure can also take the following configuration. According to the present disclosure with the following configuration, two or more stacked structures including semiconductor layers are stacked, and the semiconductor layers have a first light-emitting region and a first peripheral region provided around the first light-emitting region on a first surface perpendicular to the first direction, so that the current concentrates in a certain region. As a result, the light output and brightness of the light-emitting device are improved. (1) A light-emitting device comprising: a first stacked structure comprising a first semiconductor layer, a first light-emitting layer that emits first light, and a second semiconductor layer in order in a first direction; and a second stacked structure laminated to the first stacked structure in the first direction and comprising a third semiconductor layer, a second light-emitting layer that emits second light, and a fourth semiconductor layer in order in the first direction, wherein at least one of the first semiconductor layer and the second semiconductor layer has a first light-emitting region and a first peripheral region provided around the first light-emitting region on a first surface perpendicular to the first direction; and at least one of the third semiconductor layer and the fourth semiconductor layer has a second light-emitting region and a second peripheral region provided around the second light-emitting region on the first surface. (2) The light-emitting device according to (1), wherein at least one of the first semiconductor layer and the second semiconductor layer has a first current-constricting portion having a first light-emitting region and a first peripheral region, and at least one of the third semiconductor layer and the fourth semiconductor layer has a second current-constricting portion having a second light-emitting region and a second peripheral region. (3) The light-emitting device according to (1) or (2), wherein at least a part of the first current-constricting portion and at least a part of the second current-constricting portion overlap in the first direction. (4) The light-emitting device according to (2) or (3), wherein the first current-constricting portion includes a first current injection region through which current can pass as the first light-emitting region and a first current-constricting region provided around the first current injection region as the first peripheral region, and the second current-constricting portion includes a second current injection region through which current can pass as the second light-emitting region and a second current-constricting region provided around the second current injection region as the second peripheral region. (5) The light-emitting device according to (4), wherein at least a portion of the first current injection region and at least a portion of the second current injection region overlap in the first direction.(6) The light-emitting device according to (4) or (5), wherein the one or more first current-constricting portions have a plurality of first current-constricting portions, and the first light-emitting layer includes a plurality of first light-emitting portions provided in regions corresponding to each of the plurality of first current-injection regions in the first direction. (7) The light-emitting device according to (5) or (6), wherein the one or more second current-constricting portions have a plurality of second current-constricting portions, and the second light-emitting layer includes a plurality of second light-emitting portions provided in regions corresponding to each of the plurality of second current-injection regions in the first direction. (8) The light-emitting device according to any one of (1) to (7), further comprising a first electrode provided on the side opposite to the second laminated structure as viewed from the first laminated structure, and a second electrode provided on the side opposite to the first laminated structure as viewed from the second laminated structure, wherein the second electrode transmits the first light and the second light. (9) The light-emitting device according to (8), further comprising a transparent conductive layer between the first laminated structure and the second laminated structure, wherein the transparent conductive layer transmits at least one of the first light and the second light. (10) The light-emitting device according to any one of (1) to (9), wherein the first semiconductor layer and the third semiconductor layer are composed of a semiconductor material of a first conductivity type, and the second semiconductor layer and the fourth semiconductor layer are composed of a semiconductor material of a second conductivity type different from the first conductivity type. (11) The light-emitting device according to (10), wherein the semiconductor material of the first conductivity type is an n-type AsP-based semiconductor material, and the semiconductor material of the second conductivity type is a p-type AsP-based semiconductor material. (12) The light-emitting device according to any one of (1) to (11), wherein the first laminated structure further has one or more first pad portions exposed on a first surface facing the second laminated structure, and the second laminated structure further has one or more second pad portions exposed on a second surface facing the first surface, and the one or more first pad portions and the one or more second pad portions are joined together. (13) The light-emitting device according to (12), wherein the one or more first pad portions have an opening, and the first light passes through the opening.(14) The light-emitting device according to any one of (1) to (13), wherein the first laminated structure further comprises a first transparent electrode layer provided on the surface of the first laminated structure facing the second laminated structure, and the first transparent electrode layer comprises at least one of ITO, indium zinc oxide (IZO), tin oxide (SnO), and TiO. (15) The light-emitting device according to any one of (1) to (14), wherein the second laminated structure further comprises a second transparent electrode layer laminated in the first direction, and the second transparent electrode layer comprises at least one of ITO, indium zinc oxide (IZO), tin oxide (SnO), and TiO. (16) The light-emitting device according to any one of (1) to (15), further comprising a third pad portion provided on the side opposite to the second laminated structure as viewed from the first laminated structure and having light reflectivity. (17) The light-emitting device according to any one of (1) to (16), further comprising a drive substrate on the side of the first laminated structure opposite to the second laminated structure in the first direction. (18) The light-emitting device according to any one of (1) to (17), wherein at least one of the first laminated structure and the second laminated structure has a nanostructure. (19) The light-emitting device according to any one of (1) to (18), further comprising a lens above the second laminated structure, wherein the lens comprises at least one of silicon oxide, silicon nitride, silicon oxynitride, and resin. (20) The light-emitting device according to any one of (2) to (19), wherein the first current constriction portion separates the first laminated structure in an in-plane direction perpendicular to it. (21) The light-emitting device according to any one of (2) to (20), wherein the second current constriction portion separates the second laminated structure in an in-plane direction perpendicular to it. (22) The light-emitting device according to any one of (1) to (21), wherein the wavelength of the first light is different from the wavelength of the second light.(23) A light-emitting device comprising: a first stacked structure comprising a first semiconductor layer, a first light-emitting layer that emits first light, and a second semiconductor layer in order in a first direction; and a second stacked structure laminated with respect to the first stacked structure in the first direction and comprising a third semiconductor layer, a second light-emitting layer that emits second light, and a fourth semiconductor layer in order in the first direction, wherein at least one of the first semiconductor layer and the second semiconductor layer has a first light-emitting region and a first peripheral region provided around the first light-emitting region on a first surface perpendicular to the first direction; and at least one of the third semiconductor layer and the fourth semiconductor layer has a second light-emitting region and a second peripheral region provided around the second light-emitting region on the first surface.

[0108] This application claims priority based on Japanese Patent Application No. 2025-007362, filed with the Japan Patent Office on January 20, 2025, and all contents of that application are incorporated herein by reference.

[0109] Those skilled in the art will understand that various modifications, combinations, subcombinations, and changes can be conceived depending on design requirements and other factors, and that these fall within the scope of the attached claims and their equivalents.

Claims

1. A light-emitting device comprising: a first stacked structure comprising a first semiconductor layer, a first light-emitting layer that emits first light, and a second semiconductor layer in order in a first direction; and a second stacked structure laminated to the first stacked structure in the first direction and comprising a third semiconductor layer, a second light-emitting layer that emits second light, and a fourth semiconductor layer in order in the first direction, wherein at least one of the first semiconductor layer and the second semiconductor layer has a first light-emitting region and a first peripheral region provided around the first light-emitting region on a first surface perpendicular to the first direction; and at least one of the third semiconductor layer and the fourth semiconductor layer has a second light-emitting region and a second peripheral region provided around the second light-emitting region on the first surface.

2. The light-emitting device according to claim 1, wherein at least one of the first semiconductor layer and the second semiconductor layer has a first current-constricting portion having a first light-emitting region and a first peripheral region, and at least one of the third semiconductor layer and the fourth semiconductor layer has a second current-constricting portion having a second light-emitting region and a second peripheral region.

3. The light-emitting device according to claim 2, wherein at least a portion of the first current constriction and at least a portion of the second current constriction overlap in the first direction.

4. The light-emitting device according to claim 2, wherein the first current-constricting portion includes a first current injection region through which current can pass as the first light-emitting region and a first current-constricting region provided around the first current injection region as the first peripheral region, and the second current-constricting portion includes a second current injection region through which current can pass as the second light-emitting region and a second current-constricting region provided around the second current injection region as the second peripheral region.

5. The light-emitting device according to claim 4, wherein at least a portion of the first current injection region and at least a portion of the second current injection region overlap in the first direction.

6. The light-emitting device according to claim 4, having a plurality of first current constriction portions, wherein the first light-emitting layer includes a plurality of first light-emitting portions provided in regions corresponding to each of the plurality of first current injection regions in the first direction.

7. The light-emitting device according to claim 6, which has a plurality of second current constriction portions, wherein the second light-emitting layer includes a plurality of second light-emitting portions provided in regions corresponding to each of the plurality of second current injection regions in the first direction.

8. The light-emitting device according to claim 1, further comprising a first electrode provided on the side opposite to the second laminated structure when viewed from the first laminated structure, and a second electrode provided on the side opposite to the first laminated structure when viewed from the second laminated structure, wherein the second electrode transmits the first light and the second light.

9. The light-emitting device according to claim 8, further comprising a transparent conductive layer between the first laminated structure and the second laminated structure, wherein the transparent conductive layer transmits at least one of the first light and the second light.

10. The light-emitting device according to claim 1, wherein the first semiconductor layer and the third semiconductor layer are composed of a semiconductor material of a first conductivity type, and the second semiconductor layer and the fourth semiconductor layer are composed of a semiconductor material of a second conductivity type different from the first conductivity type.

11. The light-emitting device according to claim 10, wherein the first conductivity type semiconductor material is an n-type AsP-based semiconductor material, and the second conductivity type semiconductor material is a p-type AsP-based semiconductor material.

12. The light-emitting device according to claim 1, wherein the first laminated structure further has one or more first pad portions exposed on a first surface facing the second laminated structure, the second laminated structure further has one or more second pad portions exposed on a second surface facing the first surface, and the one or more first pad portions and the one or more second pad portions are joined together.

13. The light-emitting device according to claim 12, wherein the one or more first pad portions have an opening, and the first light passes through the opening.

14. The light-emitting device according to claim 1, wherein the first laminated structure further comprises a first transparent electrode layer provided on a surface of the first laminated structure facing the second laminated structure, and the first transparent electrode layer comprises at least one of ITO, indium zinc oxide (IZO), tin oxide (SnO), and TiO.

15. The light-emitting device according to claim 1, wherein the second laminated structure further laminates a second transparent electrode layer in the first direction, and the second transparent electrode layer comprises at least one of ITO, indium zinc oxide (IZO), tin oxide (SnO), and TiO.

16. The light-emitting device according to claim 1, further comprising a third pad portion having light reflectivity, provided on the side opposite to the second laminated structure when viewed from the first laminated structure.

17. The light-emitting device according to claim 1, further comprising a drive substrate on the side of the first laminated structure opposite to the second laminated structure in the first direction.

18. The light-emitting device according to claim 1, wherein at least one of the first laminated structure and the second laminated structure is a nanostructure.

19. The light-emitting device according to claim 1, further comprising a lens above the second laminated structure, wherein the lens comprises at least one of silicon oxide, silicon nitride, silicon oxynitride, and resin.

20. The light-emitting device according to claim 2, wherein the first current constriction portion separates the first laminated structure in an in-plane direction perpendicular to the first direction.

21. The light-emitting device according to claim 2, wherein the second current constriction portion separates the second laminated structure in an in-plane direction perpendicular to the first direction.

22. The light-emitting device according to claim 1, wherein the wavelength of the first light is different from the wavelength of the second light.

23. An image display device comprising a light-emitting device, the light-emitting device having a first stacked structure comprising a first semiconductor layer, a first light-emitting layer that emits first light, and a second semiconductor layer in order in a first direction, and a second stacked structure laminated to the first stacked structure in the first direction and comprising a third semiconductor layer, a second light-emitting layer that emits second light, and a fourth semiconductor layer in order in the first direction, wherein at least one of the first semiconductor layer and the second semiconductor layer has a first light-emitting region and a first peripheral region provided around the first light-emitting region on a first surface perpendicular to the first direction, and at least one of the third semiconductor layer and the fourth semiconductor layer has a second light-emitting region and a second peripheral region provided around the second light-emitting region on the first surface.

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