Photonic crystal surface emitting element and light emitting device

Abstract

The present invention provides a photonic crystal surface emitting element which is capable of easily forming a photonic crystal layer while suppressing a decrease in the luminous efficiency.　A photonic crystal surface emitting element according to the present technology comprises a light emitting element unit that has a layered structure in which a plurality of layers including at least one active layer and a photonic crystal layer are stacked, wherein the active layer has a single quantum well structure. With the photonic crystal surface emitting element according to the present technology, it is possible to provide a photonic crystal surface emitting element that makes it easy to form a photonic crystal layer while suppressing a decrease in the luminous efficiency.

Description

Photonic crystal surface light emitting element and light emitting device

[0001] The technology according to the present disclosure (hereinafter also referred to as "the technology") relates to a photonic crystal surface light-emitting element and a light-emitting device.

[0002] For example, Patent Document 1 discloses a photonic crystal surface emitting laser in which a photonic crystal layer and an active layer are stacked.

[0003] Japanese Patent Application Laid-Open No. 2019-109223

[0004] However, for example, the photonic crystal surface emitting laser disclosed in Patent Document 1 has room for improvement in terms of making it easier to form the photonic crystal layer while suppressing a decrease in light emission efficiency.

[0005] Therefore, a main object of the present technology is to provide a photonic crystal surface light emitting device that can easily form a photonic crystal layer while suppressing a decrease in light emission efficiency.

[0006] The present technology provides a photonic crystal surface light emitting device including a light emitting element portion having a stacked structure in which multiple layers including at least one active layer and a photonic crystal layer are stacked, wherein the active layer has a single quantum well structure. The active layer may include a well layer and a pair of barrier layers sandwiching the well layer. The active layer may have a higher average refractive index than the photonic crystal layer. The stacked structure may not include a layer other than the active layer in the stacked portion including the active layer and the photonic crystal layer, the layer having a higher refractive index than the active layer. The stacked portion may include a semiconductor layer disposed between the active layer and the photonic crystal layer. The stacked portion may further include a cladding layer disposed on one and / or the other side of the light emitting portion including the active layer and the photonic crystal layer, and the cladding layer may have the lowest average refractive index among multiple layers in the stacked portion other than the cladding layer. The laminated structure may further include a semiconductor layer disposed between the active layer and the photonic crystal layer, wherein the refractive index of the semiconductor layer is lower than the refractive index of the barrier layer on the semiconductor layer side of the active layer. The laminated structure may further include a semiconductor layer disposed between the active layer and the photonic crystal layer, wherein the refractive index of the semiconductor layer is higher than the average refractive index of the photonic crystal layer. The laminated structure may further include a cladding layer disposed on one side and / or the other side of a light emitting section including the active layer, the photonic crystal layer, and the semiconductor layer, wherein the refractive index of the cladding layer is lower than the average refractive index of the photonic crystal layer. The laminated structure may not include a layer, other than the active layer, the photonic crystal layer, and the semiconductor layer, between a surface of the cladding layer opposite to the light emitting section side and a surface of the light emitting section opposite to the cladding layer side, the layer having a refractive index higher than that of the cladding layer. The laminated structure may include a layer other than the active layer, the photonic crystal layer, and the semiconductor layer, between the surface of the cladding layer opposite the light emitting section side and the surface of the light emitting section opposite the cladding layer side, the layer having a refractive index higher than that of the cladding layer, and the optical thickness of the layer may be 0.03 or less.The laminated structure may further include a cladding layer disposed on the photonic crystal layer side of a light-emitting section including the active layer, the photonic crystal layer, and the semiconductor layer; and another semiconductor layer disposed between the photonic crystal layer and the cladding layer, wherein the refractive index of the other semiconductor layer is higher than the average refractive index of the photonic crystal layer. The photonic crystal layer may have a plurality of voids disposed in an in-plane direction on the other semiconductor layer side, and the other semiconductor layer may have a plurality of voids on the photonic crystal layer side, each of which communicates with the plurality of voids. The optical thickness of the other semiconductor layer may be 0.2 or less. The laminated structure may further include a semiconductor layer disposed between the active layer and the photonic crystal layer, wherein the average refractive index of the photonic crystal layer is higher than the refractive index of the semiconductor layer. The laminated structure may further include a cladding layer disposed on one and / or the other side of a light-emitting section including the active layer, the photonic crystal layer, and the semiconductor layer, wherein the refractive index of the cladding layer is lower than the refractive index of the semiconductor layer. The laminated structure may not include any layer, other than the active layer, the photonic crystal layer, and the semiconductor layer, having a refractive index higher than that of the clad layer, between the surface of the clad layer opposite the light emitting section side and the surface of the light emitting section opposite the clad layer side. The laminated structure may include any layer, other than the active layer, the photonic crystal layer, and the semiconductor layer, having a refractive index higher than that of the clad layer, between the surface of the clad layer opposite the light emitting section side and the surface of the light emitting section opposite the clad layer side, and the optical thickness of the layer may be 0.03 or less. The photonic crystal layer may have an average refractive index of 3.2 or less. The laminated structure may further include at least one clad layer and a first semiconductor layer disposed between the active layer and at least a portion of the clad layer, the refractive index of the first semiconductor layer being lower than that of the clad layer. The refractive index of the clad layer may be lower than both the average refractive index of the active layer and the average refractive index of the photonic crystal layer. The photonic crystal layer may have a higher average refractive index than the active layer.The photonic crystal layer may be disposed between the active layer and the cladding layer. The cladding layer may be p-type. The stacked structure may further include a second semiconductor layer disposed between the cladding layer and the photonic crystal layer, and the refractive index of the second semiconductor layer may be higher than the refractive index of the cladding layer. The second semiconductor layer may be disposed between the cladding layer and the first semiconductor layer. The optical thickness of the second semiconductor layer may be equal to or greater than the optical thickness of the first semiconductor layer. The first semiconductor layer may be disposed within the cladding layer. The cladding layer may be p-type. The active layer may be disposed between the photonic crystal layer and the cladding layer. The cladding layer may be n-type. The at least one cladding layer may be a pair of cladding layers sandwiching a light emitting section including the active layer and the photonic crystal layer, and the first semiconductor layer may be disposed between at least a portion of at least one of the pair of cladding layers and the light emitting section. The first semiconductor layer may be disposed between at least a portion of each of the pair of cladding layers and the light emitting section. The laminated structure may further include a first semiconductor layer disposed between the cladding layer of the pair of cladding layers on the photonic crystal layer side and the photonic crystal layer, and a second semiconductor layer disposed between the photonic crystal layer. The laminated structure may further include a cladding layer disposed on one or the other side of a light-emitting section including the active layer and the photonic crystal layer, the at least one active layer being a plurality of active layers disposed between the photonic crystal layer and the cladding layer, and the laminated structure may further include a tunnel junction layer disposed between adjacent active layers. The cladding layer may be n-type. The laminated structure may further include a reflector disposed on one or the other side of a light-emitting section including the active layer and the photonic crystal layer. The light-emitting element section may further include a substrate, the laminated structure disposed on the substrate, the surface of the substrate opposite the laminated structure side being an emission surface, and an anti-reflection film may be provided on the emission surface. The material of the photonic crystal layer may be AlGaAs.The active layer may be disposed on the n-side of the photonic crystal layer. The stacked structure may further include a cladding layer disposed on one side and / or the other side of a light-emitting section including the active layer and the photonic crystal layer, the cladding layer containing Al in its composition, and the Al composition of the cladding layer may be 80% or more. When the emission wavelength of the photonic crystal surface light-emitting device is λ and the effective refractive index of the light-emitting device section is neff, the distance n between the photonic crystal layer and the well layer is eff ×d / λ is n eff ×d / λ<0.08 may be satisfied. The optical thickness of the first semiconductor layer may be 0.6745 or less. The photonic crystal surface light emitting element may further include a dummy element portion aligned with the light emitting element portion in an in-plane direction, a first electrode provided on the light emitting element portion, and a second electrode partially provided on the dummy element portion. The present technology also provides a light emitting device comprising: a photonic crystal surface light emitting element including a light emitting element portion having a stacked structure in which a plurality of layers including at least one active layer and a photonic crystal layer are stacked, the active layer having a single quantum well structure; and a mounting substrate on which the photonic crystal surface light emitting element is mounted.

[0007] 4A is a cross-sectional view of a photonic crystal surface light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 4B is a plan view of the photonic crystal surface light-emitting device according to Example 1 of an embodiment of the present technology. FIG. 4A is a cross-sectional view of a stacked structure of the photonic crystal surface light-emitting device according to Example 1. FIG. 4B is a graph showing electric field / refractive index characteristics in the stacked structure of the photonic crystal surface light-emitting device according to Example 1. FIG. 4C is a graph showing effective refractive indexes, lattice constants of photonic crystal layers, and slope efficiency of light-emitting device portions of photonic crystal surface light-emitting devices according to Comparative Example 0 and Example 1. FIG. 6A is a cross-sectional view of a photonic crystal surface light-emitting device according to Comparative Example 0. FIG. 6B is a graph showing electric field / refractive index characteristics in the stacked structure of the photonic crystal surface light-emitting device according to Comparative Example 0. FIG. 6C is a graph showing effective refractive indexes, lattice constants of photonic crystal layers, and slope efficiency of light-emitting device portions of the photonic crystal surface light-emitting device according to Comparative Example 0. 7A is a diagram showing parameters of the main layers of the stacked structure of the photonic crystal surface light-emitting device according to Comparative Example 1. FIG. 7B is a graph showing electric field / refractive index characteristics in the stacked structure of the photonic crystal surface light-emitting device according to Comparative Example 1. FIG. 7C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the light-emitting element portions of the photonic crystal surface light-emitting devices according to Comparative Example 0, Examples 1 to 4, and Comparative Example 1. FIG. 7B is a cross-sectional view of the stacked structure of the photonic crystal surface light-emitting device according to Comparative Example 2. FIG. 9A is a diagram showing parameters of the main layers of the stacked structure of the photonic crystal surface light-emitting device according to Comparative Example 2. FIG. 9B is a graph showing electric field / refractive index characteristics in the stacked structure of the photonic crystal surface light-emitting device according to Comparative Example 2. FIG. 9C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the light-emitting element portions of the photonic crystal surface light-emitting devices according to Comparative Example 0, Example 1, and Comparative Example 2. FIG. 7B is a cross-sectional view of a light-emitting device in which the photonic crystal surface light-emitting device of FIG. 1 is flip-chip mounted on a mounting substrate. FIG. 7C is a flowchart for explaining an example of a method for manufacturing the photonic crystal surface light-emitting device of FIG. 1.FIG. 20A is a diagram showing parameters of main layers in a laminate structure of a photonic crystal surface light emitting device according to Example 2. FIG. 20B is a graph showing electric field and refractive index characteristics in the laminate structure of a photonic crystal surface light emitting device according to Example 2. FIG. 20C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the photonic crystal surface light emitting devices according to Comparative Example 0, Example 1, and Example 2. FIG. 20B is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the photonic crystal surface light emitting devices according to Comparative Example 0, Example 1, and Example 2. FIG. 22A is a diagram showing parameters of major layers in the stacked structure of the photonic crystal surface light-emitting device according to Example 3. FIG. 22B is a graph showing electric field / refractive index characteristics in the stacked structure of the photonic crystal surface light-emitting device according to Example 3. FIG. 22C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the light-emitting device portions of the photonic crystal surface light-emitting devices according to Comparative Example 0 and Examples 1 to 3. FIG. 24A is a diagram showing parameters of major layers in the stacked structure of the photonic crystal surface light-emitting device according to Example 4. FIG. 24B is a graph showing electric field / refractive index characteristics in the stacked structure of the photonic crystal surface light-emitting device according to Example 4. FIG. 24C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the light-emitting device portions of the photonic crystal surface light-emitting devices according to Comparative Example 0 and Examples 1 to 4. FIG. 26A is a diagram showing parameters of major layers in the stacked structure of the photonic crystal surface light-emitting device according to Example 5.FIG. 26B is a graph showing the electric field and refractive index characteristics in the stacked structure of the photonic crystal surface light-emitting device according to Example 5. FIG. 26C is a graph showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the light-emitting device portions of the photonic crystal surface light-emitting devices according to Comparative Example 0 and Examples 1 to 5. FIG. 27A is a graph showing parameters of major layers in the stacked structure of the photonic crystal surface light-emitting device according to Example 6. FIG. 27B is a graph showing the electric field and refractive index characteristics in the stacked structure of the photonic crystal surface light-emitting device according to Example 6. FIG. 27C is a graph showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the light-emitting device portions of the photonic crystal surface light-emitting devices according to Comparative Example 0 and Examples 1 to 6. A cross-sectional view of the stacked structure of the photonic crystal surface light-emitting device according to Example 7. FIG. 29A is a graph showing parameters of major layers in the stacked structure of the photonic crystal surface light-emitting device according to Example 7. FIG. 29B is a graph showing the electric field and refractive index characteristics in the stacked structure of the photonic crystal surface light-emitting device according to Example 7. 29C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the light-emitting element portions of the photonic crystal surface-emitting devices according to Comparative Example 0, Example 1, and Example 7. FIG. 29C is a cross-sectional view of a stacked structure LS8-1 of the photonic crystal surface-emitting device according to Configuration Example 1 of Example 8. FIG. 29D is a cross-sectional view of a stacked structure LS8-2 of the photonic crystal surface-emitting device according to Configuration Example 2 of Example 8. FIG. 32A is a diagram showing parameters of main layers in the stacked structure of the photonic crystal surface-emitting device according to Configuration Example 1 of Example 8. FIG. 32B is a graph showing electric field and refractive index characteristics in the stacked structure of the photonic crystal surface-emitting device according to Configuration Example 1 of Example 8. FIG. 32C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the light-emitting element portions of the photonic crystal surface-emitting devices according to Comparative Example 0 and Configuration Example 1 of Example 8. FIG. 34A is a cross-sectional view of a stacked structure of the photonic crystal surface-emitting device according to Example 9. 34B is a graph showing the electric field and refractive index characteristics in the layered structure of the photonic crystal surface light emitting device according to Example 9. FIG.34C is a graph showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each light-emitting element portion of the photonic crystal surface-emitting devices according to Comparative Example 0 and Example 9. FIG. 35A is a graph showing parameters of main layers in the stacked structure of the photonic crystal surface-emitting device according to Comparative Example 3. FIG. 35B is a graph showing electric field / refractive index characteristics in the stacked structure of the photonic crystal surface-emitting device according to Comparative Example 3. FIG. 35C is a graph showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each light-emitting element portion of the photonic crystal surface-emitting devices according to Comparative Example 0 and Comparative Example 3. A cross-sectional view of the stacked structure of the photonic crystal surface-emitting device according to Comparative Example 4. FIG. 37A is a graph showing parameters of main layers in the stacked structure of the photonic crystal surface-emitting device according to Comparative Example 4. FIG. 37B is a graph showing electric field / refractive index characteristics in the stacked structure of the photonic crystal surface-emitting device according to Comparative Example 4. FIG. 37C is a graph showing the light-inducing layer thickness, light-excluding layer thickness, PC layer optical confinement ratio, and active layer optical confinement ratio of the photonic crystal surface-emitting device according to Comparative Example 4. 39A is a diagram showing parameters of main layers in the stacked structure of a photonic crystal surface light-emitting device according to Comparative Example 5. FIG. 39B is a graph showing electric field and refractive index characteristics in the stacked structure of a photonic crystal surface light-emitting device according to Comparative Example 5. FIG. 39C is a diagram showing the light-inducing layer thickness, light-excluding layer thickness, PC layer optical confinement ratio, and active layer optical confinement ratio of each of the photonic crystal surface light-emitting devices according to Comparative Example 4 and Comparative Example 5. FIG. 39B is a graph showing electric field and refractive index characteristics in the stacked structure of a photonic crystal surface light-emitting device according to Example 10. FIG. 41A is a diagram showing parameters of main layers in the stacked structure of a photonic crystal surface light-emitting device according to Example 10. FIG. 41B is a graph showing electric field and refractive index characteristics in the stacked structure of a photonic crystal surface light-emitting device according to Example 10. FIG. 41C is a diagram showing the light-inducing layer thickness, light-excluding layer thickness, SE improvement ratio, PC layer optical confinement ratio, and active layer optical confinement ratio of each of the photonic crystal surface light-emitting devices according to Comparative Example 4, Comparative Example 5, and Example 10. FIG. 39 ...B is a graph showing electric field and refractive index characteristics in the stacked structure of a photonic crystal surface light-emitting device according to Example 11. FIG. 43A is a diagram showing parameters of main layers in the laminated structure of the photonic crystal surface light emitting device according to Example 11.43B is a graph showing the electric field and refractive index characteristics in the stacked structure of the photonic crystal surface light-emitting device according to Example 11. FIG. 43C is a graph showing the light-inducing layer thickness, light-excluding layer thickness, SE improvement ratio, PC layer light confinement ratio, and active layer light confinement ratio for each of the photonic crystal surface light-emitting devices according to Comparative Example 4, Comparative Example 5, and Example 11. FIG. 45A is a graph showing parameters of the main layers in the stacked structure of the photonic crystal surface light-emitting device according to Example 12. FIG. 45B is a graph showing the electric field and refractive index characteristics in the stacked structure of the photonic crystal surface light-emitting device according to Example 12. FIG. 45C is a graph showing the light-inducing layer thickness, light-excluding layer thickness, SE improvement ratio, PC layer light confinement ratio, and active layer light confinement ratio for each of the photonic crystal surface light-emitting devices according to Comparative Example 4, Comparative Example 5, and Example 12. FIG. 47A is a graph showing parameters of the main layers in the stacked structure of the photonic crystal surface light-emitting device according to Example 13. 47B is a graph showing the electric field and refractive index characteristics in the stacked structure of the photonic crystal surface light emitting device according to Example 13. FIG. 47C is a graph showing the light induction layer thickness, light exclusion layer thickness, SE improvement ratio, PC layer light confinement ratio, and active layer light confinement ratio of each of the photonic crystal surface light emitting devices according to Comparative Example 4, Comparative Example 5, and Example 13. FIG. 49A is a graph showing parameters of the main layers in the stacked structure of the photonic crystal surface light emitting device according to Example 14. FIG. 49B is a graph showing the electric field and refractive index characteristics in the stacked structure of the photonic crystal surface light emitting device according to Example 14. FIG. 49C is a graph showing the light induction layer thickness, light exclusion layer thickness, SE improvement ratio, PC layer light confinement ratio, and active layer light confinement ratio of each of the photonic crystal surface light emitting devices according to Comparative Example 4, Comparative Example 5, and ...C is a graph showing the light induction layer thickness, light exclusion layer thickness, SE improvement ratio, PC layer light confinement ratio, and active layer light confinement ratio of each of the photonic crystal surface light emitting devices according to Comparative Example 4, Comparative Example 5, and Example 14. FIG. 49C is a graph showing the light induction layer thickness, light exclusion layer thickness, SE improvement ratio, PC layer light confinement ratio, and active layer light confinement ratio of each of the photonic crystal surface light emitting devices according to Modification 1. FIG. 49C is a graph showing the light induction layer thickness 10 is a cross-sectional view of a layered structure of a photonic crystal surface light emitting device according to Modification 4. FIG. 11 is a cross-sectional view of a photonic crystal surface light emitting device according to Modification 5. FIG.FIG. 10 is a cross-sectional view of a photonic crystal surface light emitting device according to Modification 6. FIG. 11 is a cross-sectional view of a light emitting device in which a plurality of photonic crystal surface light emitting devices according to Example 1 are mounted on a mounting substrate. FIG. 12 is a cross-sectional view of a photonic crystal surface light emitting device according to Modification 7. FIG. 13 is a cross-sectional view of a photonic crystal surface light emitting device according to Modification 8. FIG. 14 is a diagram showing an example of application of the photonic crystal surface light emitting device according to Example 1 to a distance measurement device. FIG. 15 is a block diagram showing an example of a schematic configuration of a vehicle control system. FIG. 16 is an explanatory diagram showing an example of an installation position of a distance measurement device.

[0008] Preferred embodiments of the present technology will be described in detail below with reference to the accompanying drawings. Note that in this specification and the drawings, components having substantially the same functional configurations will be denoted by the same reference numerals, and redundant description will be omitted. The embodiments described below are representative embodiments of the present technology, and are not intended to narrow the scope of the present technology. Even when this specification describes that the photonic crystal surface light-emitting element and light-emitting device according to the present technology achieve multiple effects, it is sufficient that the photonic crystal surface light-emitting element and light-emitting device according to the present technology achieve at least one effect. The effects described in this specification are merely examples and are not limiting, and other effects may also be achieved.

[0009] The description will be made in the following order: 0. Introduction 1. Photonic crystal surface light-emitting device according to Example 1 of an embodiment of the present technology 2. Photonic crystal surface light-emitting device according to Example 2 of an embodiment of the present technology 3. Photonic crystal surface light-emitting device according to Example 3 of an embodiment of the present technology 4. Photonic crystal surface light-emitting device according to Example 4 of an embodiment of the present technology 5. Photonic crystal surface light-emitting device according to Example 5 of an embodiment of the present technology 6. Photonic crystal surface light-emitting device according to Example 6 of an embodiment of the present technology 7. Photonic crystal surface light-emitting device according to Example 7 of an embodiment of the present technology 8. Photonic crystal surface light-emitting device according to Example 8 of an embodiment of the present technology 9. Photonic crystal surface light-emitting device according to Example 9 of an embodiment of the present technology 10. Photonic crystal surface light-emitting device according to Example 10 of an embodiment of the present technology 11. Photonic crystal surface light-emitting device according to Example 11 of an embodiment of the present technology 12. Photonic crystal surface light-emitting device according to Example 12 of an embodiment of the present technology 13. Photonic crystal surface light-emitting device according to Example 13 of an embodiment of the present technology 14. Photonic crystal surface light emitting device according to Example 14 of an embodiment of the present technology 15. Modification of the present technology 16. Application example to electronic devices 17. Example in which the photonic crystal surface light emitting device is applied to a distance measurement device 18. Example in which the distance measurement device is mounted on a moving body

[0010] <0. Introduction> In recent years, research and development of photonic crystal surface-emitting devices such as photonic crystal surface-emitting lasers has been actively carried out.

[0011] Since the target value of the lattice constant (hole spacing) a of the photonic crystal (PC) layer of a photonic crystal surface light-emitting device is small, at approximately 195 nm, a micro-hole forming device is required to form the PC layer.

[0012] Such micro-hole forming devices include various devices such as electron beam lithography devices, etc. In any device, it is desirable to have as large a lattice constant as possible, as this increases the yield in mass production.

[0013] Therefore, the inventors have determined that the lattice constant a (a ∝ λ / n eff ) is proportional to the oscillation wavelength λ, and the effective refractive index n effBy focusing on the fact that it is inversely proportional to eff We came up with the technical idea of ​​increasing the lattice constant a by lowering

[0014] This technical concept is extremely significant in that it makes it easier to form a PC layer by making the lattice constant a corresponding to the desired oscillation wavelength λ higher than the target value.

[0015] On the other hand, the effective refractive index n eff If the current is reduced unnecessarily, there is a concern that the light emission efficiency, that is, the slope efficiency (SE) which is the amount of beam light per unit current, will decrease.

[0016] Therefore, the inventors have developed a photonic crystal surface light emitting device according to the present technology as a photonic crystal surface light emitting device that embodies the above technical idea. The photonic crystal surface light emitting device according to the present technology can provide a photonic crystal surface light emitting device that can easily form a photonic crystal layer while suppressing a decrease in luminous efficiency.

[0017] Furthermore, the inventors have also developed a light emitting device including the photonic crystal surface light emitting device according to the present technology and a mounting substrate on which the photonic crystal surface light emitting device is mounted.

[0018] Hereinafter, a photonic crystal surface light-emitting device according to an embodiment of the present technology will be described in detail using several examples as examples. In the following description, the upper side in FIG. 1 will be referred to as "upper" and the lower side as "lower" as appropriate.

[0019] 1. Photonic crystal surface light emitting device according to example 1 of an embodiment of the present technology> Fig. 1 is a cross-sectional view of a photonic crystal surface light emitting device 10 according to example 1 of an embodiment of the present technology. Fig. 2 is a plan view of the photonic crystal surface light emitting device 10. Fig. 1 is a cross-sectional view taken along line 1-1 in Fig. 2. Fig. 3 is a cross-sectional view of a stacked structure LS1 of the photonic crystal surface light emitting device 10 according to example 1.

[0020] <Configuration of Photonic Crystal Surface Emitting Device> A photonic crystal surface emitting device 10 according to Example 1 of an embodiment of the present technology is, for example, a photonic crystal-surface emitting laser (PCSEL) as shown in Figures 1 and 2. The photonic crystal surface emitting device 10 is, for example, a rear-surface emitting photonic crystal surface emitting laser. The oscillation wavelength λ of the photonic crystal surface emitting device 10 is, for example, in the NIR (Near Infrared Ray) band, for example, 940 nm.

[0021] As an example, the photonic crystal surface light emitting device 10 includes a light emitting element section LE having a stacked structure LS1 in which a plurality of layers including at least one active layer 104 and a photonic crystal layer 106 are stacked. Hereinafter, the direction (vertical direction) in which the plurality of layers including the active layer 104 and the photonic crystal layer 106 are stacked in the stacked structure LS1 will also be referred to as the "stacking direction."

[0022] As an example, the photonic crystal surface light emitting device 10 further includes a dummy element portion DE aligned in the in-plane direction with the light emitting element portion LE, an anode electrode 111 (first electrode) provided on the light emitting element portion LE, and a cathode wiring 113 (second electrode) provided on the dummy element portion DE. The dummy element portion DE is also called a "non-light emitting element portion."

[0023] The light-emitting element unit LE and the dummy element unit DE share a substrate 101. The stacked structure LS and the dummy element unit DE are arranged on the substrate 101. The surface of the substrate 101 opposite to the stacked structure LS1 side is the light-emitting surface. An AR film 114 (anti-reflection film) is provided on the light-emitting surface. Note that the AR film 114 is not essential.

[0024] As an example, the photonic crystal surface light emitting device 10 is a photonic crystal surface light emitting device that is flip-chip mounted (junction-down mounted) on a mounting substrate 5 (see FIG. 10 ). The mounting substrate 5 is, for example, a substrate (drive substrate) having a driver (drive circuit) or a wiring substrate electrically connected to the driver. In this example, the mounting substrate 5 is the drive substrate. The driver includes a switching element made of, for example, an nMOS, pMOS, or other transistor.

[0025] In the stacked structure LS1, as an example, the light emitting section is configured to include an active layer 104 and a photonic crystal layer 106 stacked on each other (for example, arranged adjacent to each other in the stacking direction). Here, the active layer 104 is arranged on the substrate 101 side (lower side, for example, n-side) of the photonic crystal layer 106, but the active layer 104 may also be arranged on the opposite side of the photonic crystal layer 106 from the substrate 101 side (upper side, for example, p-side). Note that when the active layer 104 is arranged on the n-side of the photonic crystal layer 106, the electrical characteristics are improved compared to when it is arranged on the p-side.

[0026] A carrier block layer 105 (CB layer), which is a semiconductor layer, is provided between the active layer 104 and the photonic crystal layer 106. Note that the carrier block layer 105 is not essential.

[0027] The stacked structure LS1 has first and second cladding layers 103 and 107 that sandwich a light-emitting section including an active layer 104, a photonic crystal layer 106, and a carrier blocking layer 105. The first cladding layer 103 is disposed on the substrate 101 side (lower side) of the light-emitting section, and the second cladding layer 107 is disposed on the opposite side of the light-emitting section from the substrate 101 side (upper side).

[0028] In the laminated structure LS1, the active layer 104, the photonic crystal layer 106, the carrier block layer 105, and the first and second clad layers 103 and 107 form a resonator (laminated portion).

[0029] The laminated structure LS further includes a first contact layer 102 arranged on the substrate 101 side (lower side) of the resonator, a reflector 108 arranged on the opposite side (upper side) of the resonator from the substrate 101 side, and a second contact layer 109 arranged on the opposite side (upper side) of the reflector 108 from the resonator side.

[0030] That is, in the stacked structure LS, a first contact layer 102, a first cladding layer 103, an active layer 104, a carrier blocking layer 105, a photonic crystal layer 106, a second cladding layer 107, a reflecting mirror 108, and a second contact layer 109 are arranged in this order on a substrate 101.

[0031] The light-emitting element portion LE has a light-emitting mesa LM including at least a part (for example, a part) of the laminated structure LS. Here, the light-emitting mesa LM is provided to protrude from the first contact layer 102 and includes a first cladding layer 103, an active layer 104, a carrier blocking layer 105, a photonic crystal layer 106, a second cladding layer 107, a reflecting mirror 108, and a second contact layer 109.

[0032] The dummy element portion DE has a dummy mesa DM having a layer structure generally similar to that of the light-emitting mesa LM. The dummy mesa DM is also called a "non-light-emitting mesa." Here, the dummy mesa DM protrudes from the first contact layer 102 and includes a first cladding layer 103, an active layer 104, a carrier blocking layer 105, a base material for the photonic crystal layer 106, a second cladding layer 107, a reflecting mirror 108, and a second contact layer 109.

[0033] The light emitting mesa LM and the dummy mesa DM are covered with an insulating film 110. For example, the insulating film 110 does not cover the center of the top (second contact layer 109) of the light emitting mesa LM, and an anode electrode 111 (p-side electrode, first electrode) is provided on this center. For example, the insulating film 110 does not cover a portion of the first contact layer 102 between the light emitting element portion LE and the dummy element portion DE, and a cathode electrode 112 (n-side intermediate electrode, part of the second electrode) is provided on this portion. A cathode wiring 113 (another part of the second electrode) for pulling up the cathode is provided along the dummy mesa DM covered with the insulating film 110. One end of the cathode wiring 113 contacts the cathode electrode 112, an intermediate portion is provided on the side surface of the dummy mesa DM via the insulating film 110, and the other end is provided on the top of the dummy mesa DM via the insulating film 110.

[0034] That is, photonic crystal surface light emitting device 10 has an intra-cavity structure in which anode electrode 111 , cathode electrode 112 and cathode wiring 113 are provided on the same surface (upper surface) of substrate 101 .

[0035] (Substrate) The substrate 101 is, for example, a semiconductor substrate containing impurities, a semi-insulating substrate (e.g., a semiconductor substrate containing no impurities), or the like. Here, the substrate 101 is made of GaAs. In order to reduce light absorption, the substrate 101 is preferably made of, for example, lightly doped GaAs (n-GaAs or p-GaAs), SI (Semi-Insulating)-GaAs, or the like. Furthermore, the substrate 101 is preferably transparent to the emission wavelength of the active layer 104. The thickness of the substrate 101 is, for example, 150,000 nm. The refractive index of the substrate 101 is, for example, 3.5.

[0036] (AR Film) The AR film 114 has, for example, a laminated structure in which a plurality of dielectric films (for example, SiO2 film, SiN film, SiON film, etc.) are laminated.

[0037] (First Contact Layer) The first contact layer 102 is, for example, an Al layer of a first conductivity type (for example, n-type). x0 Ga 1-x0 The first contact layer 102 is made of, for example, n-GaAs (0≦x0<1). The first contact layer 102 contains n-type impurities such as silicon (Si). In addition to providing ohmic contact between the first cladding layer 103 and the cathode electrode 112, the first contact layer 102 also functions as a current diffusion layer that allows current to reach the center of the stacked structure LS. The thickness of the first contact layer 102 is, for example, 300 nm. The refractive index of the first contact layer 102 is, for example, 3.5.

[0038] (First Cladding Layer) The first cladding layer 103 is, for example, an Al layer of a first conductivity type (for example, n-type). x1 Ga 1-x1 The first cladding layer 103 is made of As (0≦x1<1). The cladding layer is also called a “spacer layer.” The first cladding layer 103 contains an n-type impurity such as silicon (Si).

[0039] (Active Layer) The active layer 104 has, for example, a single quantum well structure (1QW structure). The active layer 104 has a well layer 104a and a pair of barrier layers 104b and 104c sandwiching the well layer 104a. The refractive index of the well layer 104a is higher than the refractive index of each of the barrier layers. The band gap of the well layer 104a is smaller than the band gap of each of the barrier layers. The thickness of the well layer 104a is thinner than the thickness of each of the barrier layers. For example, the thickness of each of the barrier layers is the same. For example, the refractive index of each of the barrier layers is the same. The well layer is also called a "quantum well layer." The barrier layer is also called a "barrier layer."

[0040] The well layer 104a and the pair of barrier layers 104b and 104c are made of, for example, GaAs-based compound semiconductors. x2 Ga 1-x2 The pair of barrier layers 104b and 104c are made of undoped Al. x3 Ga 1-x3 The active layer 104 is made of As (0<x3<1). The emission wavelength of the active layer 104 is, for example, 935 nm. The active layer is also called a "light-emitting layer."

[0041] Here, the average refractive index n of the active layer 104 av (average refractive index in the thickness direction) is the refractive index n QW , thickness t QW , the refractive index of each barrier layer n ba (same), thickness t ba Using n av = (n QW ×t QW +n ba x 2t ba ) / (t QW +2t ba ) is defined as

[0042] (Carrier Block Layer) The carrier block layer 105 is, for example, Al x4 Ga 1-x4 As (0≦x4<1).

[0043] (Photonic Crystal Layer) The photonic crystal layer 106 provides a photonic crystal resonance and diffraction effect to the light emitted from the active layer 104 adjacent in the stacking direction.

[0044] The photonic crystal layer 106 includes, for example, a base portion 106b (a portion without holes) which is a part of a plate-shaped base material 106BM (see FIG. 12 ), and a modified refractive index periodic structure 106a (photonic crystal) arranged on the base portion 106b. In the modified refractive index periodic structure 106a, as can be seen, for example, from a surface SEM (Scanning Electron Microscope) image of the photonic crystal layer 106, modified refractive index regions (e.g., holes (air or vacuum)) are arranged periodically (e.g., in a two-dimensional lattice pattern) along the in-plane direction of the base portion 106b. The modified refractive index periodic structure 106a generates a periodic refractive index distribution in the photonic crystal layer 106. In the photonic crystal layer 106, the period (e.g., hole spacing, lattice spacing, lattice constant) of the modified refractive index regions is, for example, the same as or close to the emission wavelength of the active layer 104. The base material 106BM is, for example, Al. x5 Ga 1-x5 The modified refractive index periodic structure 106 a is made of, but not limited to, GaAs, AlGaAs, AlAs, etc. Here, the modified refractive index periodic structure 106 a is provided at a position corresponding to at least the center in the plane of the active layer 104, but may be provided at a position corresponding to the entire area in the plane of the active layer 104.

[0045] Due to the presence of the periodic refractive index distribution described above, light of a specific wavelength (e.g., oscillation wavelength λ) forms a two-dimensional standing wave state in a specific direction within the photonic crystal plane within the photonic crystal layer 106. In the photonic crystal layer 106, diffraction occurs not only in directions parallel to the photonic crystal plane but also in directions perpendicular thereto, allowing a beam with a narrow exit angle to be emitted in a direction intersecting the in-plane direction (e.g., perpendicular to the plane), thereby providing a surface emission output.

[0046] The photonic crystal layer 106 can control the intensity and emission direction of the beam by adjusting the positions and areas of the holes (air holes) and the modulation amounts thereof.

[0047] Here, the dielectric constant ε (square of the refractive index) is used to calculate the average refractive index ε of the photonic crystal layer (specifically, the photonic crystal). av (average refractive index in the in-plane direction) is ε av = fε a +(1-f)ε b where f is the area ratio of holes, ε a is the dielectric constant of the hole, ε b is the refractive index of the material.

[0048] (Second Cladding Layer) The second cladding layer 107 is, for example, an AlN layer of a second conductivity type (for example, p-type). x6 Ga 1-x6 The second cladding layer 107 is made of As (0≦x6<1). The cladding layer is also called a “spacer layer.” The second cladding layer 107 contains p-type impurities such as carbon (C).

[0049] (Reflector) Reflector 108 is provided to reflect light emitted from the light emitting section including active layer 104 and photonic crystal layer 106 to the opposite side (upper side) from substrate 101 toward substrate 101 (lower side) and use it as emitted light (to improve light utilization efficiency). In this way, reflector 108 is provided to improve efficiency and is not essential.

[0050] The reflecting mirror 108 is, for example, a semiconductor multilayer reflecting mirror. A multilayer reflecting mirror is also called a distributed Bragg reflector. More specifically, the reflecting mirror 108 is, for example, a second conductivity type (for example, p-type) semiconductor multilayer reflecting mirror, and has a structure in which a plurality of types (for example, two types) of semiconductor layers having different refractive indices are alternately stacked with an optical thickness of ¼ wavelength of the emission wavelength. Each refractive index layer of the reflecting mirror 108 is made of an AlGaAs-based compound semiconductor of the second conductivity type (for example, p-type). Specifically, the reflecting mirror 108 has a low refractive index layer made of, for example, p-Al x7 Ga 1-x7 As (0<x7<1), and the high refractive index layer is, for example, p-Al x8 Ga 1-X8 As (0≦x8<x7).

[0051] (Second Contact Layer) The second contact layer 109 is, for example, an Al layer of a second conductivity type (for example, p-type). x9 Ga 1-x9 The second contact layer 109 is made of, for example, p-GaAs (0≦x9<1). The second contact layer 109 contains a p-type impurity such as carbon (C). The second contact layer 109 is a layer for making ohmic contact between the reflecting mirror 108 and the anode electrode 111. The thickness of the second contact layer 109 is, for example, 300 nm. The refractive index of the second contact layer 109 is, for example, 3.5.

[0052] (Insulating Film) The insulating film 110 is made of a dielectric material such as SiN, SiO2, SiON, etc. In particular, when the insulating film 110 is made of SiN, it contributes to suppressing the penetration of moisture from the outside.

[0053] (Anode Electrode) The anode electrode 111 is, for example, configured to include a non-alloy metal film. Specifically, the anode electrode 111 has a laminated structure in which, for example, a Ti layer and an Au layer are laminated in this order from the second contact layer 109 side. Note that the anode electrode 111 may further have a Pt layer laminated on the Au layer to improve solderability. The anode electrode 111 is electrically connected to the anode terminal 5a of the mounting substrate 5 via a bump B1 (see FIG. 10 ).

[0054] The cathode electrode 112 serving as an n-side intermediate electrode is, for example, made of an alloy. Specifically, the cathode electrode 112 has a layered structure in which, for example, an AuGe layer, a Ni layer, and an Au layer are layered in this order from the first contact layer 102 side.

[0055] (Cathode Wiring) The cathode wiring 113 is made of, for example, Au plating, Ag plating, Al plating, etc. The thickness of the cathode wiring 113 is preferably a thickness that can sufficiently suppress voltage drop. The cathode wiring 113 is electrically connected to the cathode terminal 5b of the mounting substrate 5 via a bump B2 (see FIG. 10 ).

[0056] (Details of stacked structure) Fig. 4A is a diagram showing parameters (material, film thickness, hereinafter the same) of the main layers (each constituent layer of the resonator) of the stacked structure LS1 of the photonic crystal surface light emitting device 10 according to Example 1. The vertical arrangement of the multiple layers in Fig. 4A corresponds to the vertical arrangement of the corresponding multiple layers in Fig. 3. Fig. 4B is a graph showing the electric field and refractive index characteristics in the stacked structure LS1 of the photonic crystal surface light emitting device 10 according to Example 1. Fig. 4C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each light emitting element portion of the photonic crystal surface light emitting devices according to Comparative Example 0 and Example 1. Here, the effective refractive index n eff means the electric field weighted average refractive index of all layers of the stack structure LS other than the first and second contact layers 102, 109. That is, n eff = ∫(E(t)×n(t))dt, where t is the thickness of each layer in the stacking direction. The photonic crystal surface light emitting device 10 according to Example 1 oscillates by mainly utilizing the M point in a square lattice arrangement of holes in the photonic crystal layer (this is also true for the other Examples). Note that similar effects can be obtained by oscillating by utilizing the Γ point or the like other than the M point. The photonic crystal surface light emitting device 10 has an oscillation wavelength of, for example, 940 nm.

[0057] In the stacked structure LS1, as described above, the active layer 104 has a single quantum well structure (1QW structure) having a single well layer 104a (see FIG. 4A). effIt is possible to lower the lattice constant a (for example, about 3.0), and increase the lattice constant a (for example, 217 nm) (relative to the desired oscillation wavelength λ) without changing the oscillation wavelength λ (see FIG. 4C). Furthermore, the proximity of the quantum well structure of the active layer 104 to the photonic crystal layer 106 increases the electric field confined within the photonic crystal surface light-emitting device 106, achieving high slope efficiency. While oscillation is possible with a quantum well count of one or more, the greater the number of quantum wells, the greater the excess gain. As a result, the threshold current Ith increases, making oscillation more difficult, and at the same time, the amount of unwanted light generated by the LED increases, degrading sensing performance such as ToF. Therefore, from the perspective of suppressing excess gain, it is important to set the number of quantum wells to one, the minimum number at which oscillation is possible.

[0058] The stacked structure LS preferably does not include any layer other than the active layer 104 that has a refractive index higher than the average refractive index of the active layer 104 in the resonator (stacked portion) including the active layer 104 and the photonic crystal layer 106 (see FIG. 4A ; in FIG. 4A , the lower the Al composition, the higher the refractive index, and the lower the In composition of the well layer, the higher the refractive index; the same applies below). This allows the electric field distribution in the resonator to approximate a Gaussian distribution with its peak at the position of the active layer 104 (see FIG. 4B ), thereby enabling the lattice constant a to be increased while suppressing a decrease in the luminous efficiency (slope efficiency SE) (see FIG. 4C ). However, if the electric field distribution is steep (if the electric field peak is narrow), it becomes difficult to increase the electric fields in both the active layer 104 and the photonic crystal layer 106, i.e., to increase the luminous efficiency (slope efficiency SE). Therefore, it is preferable to adjust the refractive index of each layer so that the electric field distribution does not become steep.

[0059] By disposing the carrier blocking layer 105 between the active layer 104 and the photonic crystal layer 106, it is possible to improve carrier confinement in the active layer 104.

[0060] It is preferable that the photonic crystal layer 106 has the lowest average refractive index among the layers other than the first and second clad layers 103 and 107 in the stacked structure including the active layer 104, the carrier block 105, the photonic crystal layer 106, and the first and second clad layers 103 and 107 (see FIG. 4A). eff can be reduced to reduce the lattice constant a.

[0061] The refractive index of each of the first and second cladding layers 103 and 107 is preferably lower (for example, 3.0) than the average refractive index of the photonic crystal layer 106 (see FIG. 4A ), thereby improving optical confinement in the light-emitting portion including the active layer 104, the photonic crystal layer 106, and the carrier block layer 105.

[0062] In the stacked structure LS1, it is preferable that the average refractive index of the active layer 104 is higher than the average refractive index of the photonic crystal layer 106 (see FIG. 4A). As a result, as shown in FIGS. 4B and 4C, the effective refractive index n eff can be reduced to reduce the lattice constant a.

[0063] It is preferable that the refractive index of the carrier block layer 105 (CB layer) disposed between the active layer 104 and the photonic crystal layer 106 (PC layer) be lower (e.g., 3.24) than the refractive index (e.g., 3.4) of the barrier layer 104c of the active layer 104 on the carrier block layer 105 side (see FIG. 4A). This makes it possible to suppress a decrease in the optical confinement factor Γact in the active layer 104.

[0064] The refractive index of the carrier blocking layer 105 is preferably higher (e.g., 3.2) than the average refractive index of the photonic crystal layer 106 (see FIG. 4A ). This ensures the carrier blocking effect. The average refractive index of the photonic crystal layer 106 is preferably less than 3.2.

[0065] The refractive index of each of the first and second cladding layers 103, 107 sandwiching the light emitting section including the active layer 104, photonic crystal layer 106, and carrier block layer 105 is preferably lower (e.g., 3.0) than the average refractive index of the photonic crystal layer 106 (see FIG. 4A ). This makes it possible to suppress a decrease in the optical confinement factor Γact in the active layer 104 and a decrease in the optical confinement factor Γpc in the photonic crystal layer 106.

[0066] It is preferable that the laminated structure LS1 does not include any layer, other than the active layer 104, the photonic crystal layer 106, and the carrier block layer 105, whose refractive index is higher than the refractive index of the clad layer (for example, 3.0) between the surface of each clad layer opposite to the laminated portion side and the surface of the laminated portion opposite to the clad layer side. By not including such a layer, the effective refractive index n eff This can prevent the lattice constant a from becoming too large, and thus prevent the lattice constant a from becoming too small.

[0067] The base material 106BM of the photonic crystal layer 106 is preferably made of AlGaAs. This reduces the effective refractive index n eff It is possible to reduce the

[0068] The Al composition of the first and second cladding layers 103 and 107 is preferably 80% or more, more preferably 90% or more. This improves the optical confinement in the active layer 104 and the photonic crystal layer 106 while reducing the effective refractive index n eff can be lowered.

[0069] The distance n between the photonic crystal layer 106 and the well layer 104a eff ×d / λ is n eff ×d / λ<0.08, and n eff × d / λ<0.05 is more preferable, and n eff It is more preferable that ×d / λ<0.02 be satisfied, which can suppress the spread of the electric field.

[0070] In the photonic crystal surface light emitting device 10, as an example, when the arrangement of holes in the photonic crystal layer 106 oscillates using point M of a square lattice (for the purpose of emitting light in any direction) and the oscillation wavelength λ is 940 nm, the lattice constant a is preferably 200 nm or more, more preferably 210 nm or more, more preferably 215 nm or more, and even more preferably 220 nm or more.

[0071] The effective refractive index n of the light-emitting element portion LE eff is preferably 3.2 or less, more preferably 3.17 or less, more preferably less than 3.14, more preferably less than 3.11, and more preferably less than 3.08.

[0072] (Comparative Example 0) Fig. 5 is a cross-sectional view of the stacked structure LS-C0 of the photonic crystal surface light emitting device according to Comparative Example 0. Fig. 6A is a diagram showing parameters of the main layers (each constituent layer of the resonator) of the stacked structure of the photonic crystal surface light emitting device according to Comparative Example 0. The vertical arrangement of the multiple layers in Fig. 6A corresponds to the vertical arrangement of the corresponding multiple layers in Fig. 5. Fig. 6B is a graph showing the electric field and refractive index characteristics in the stacked structure of the photonic crystal surface light emitting device according to Comparative Example 0. Fig. 6C is a diagram showing the effective refractive index of the light emitting device portion, the lattice constant of the photonic crystal layer, and the slope efficiency of the photonic crystal surface light emitting device according to Comparative Example 0.

[0073] 5 and 6A , the photonic crystal surface light emitting device according to Comparative Example 0 has a configuration generally similar to that of photonic crystal surface light emitting device 10 according to Example 1, except that active layer 104C has a multiple quantum well structure (5QW structure) and has a high refractive index layer (GaAs layer) between photonic crystal layer 106C (PC layer) and second cladding layer 107C (p-cladding layer). That is, reference numerals 102C, 103C, 104C, 105C, 106C, 117C, 107C, 108C, and 109C denote the first contact layer, first cladding layer, active layer, carrier block layer, photonic crystal layer, high refractive index layer, second cladding layer, reflector, and second contact layer, respectively (the same applies to the other comparative examples). In the photonic crystal surface light emitting device according to Comparative Example 0, the effective refractive index (average refractive index) of the light emitting device portion cannot be made low (e.g., 3.40), and the electric field distribution is a broad-based distribution (see FIG. 6B) that deviates from the desirable Gaussian distribution (see FIG. 4B). That is, while the photonic crystal surface light emitting device according to Comparative Example 0 has a relatively high luminous efficiency (slope efficiency SE) (e.g., 0.4 W / A), it is not possible to increase the lattice constant a for a given oscillation wavelength λ (e.g., to 200 nm or more) (see FIGS. 6B and 6C).

[0074] (Comparative Example 1) Fig. 7A is a diagram showing parameters of main layers in the layered structure of the photonic crystal surface light emitting device according to Comparative Example 1. Fig. 7B is a graph showing electric field and refractive index characteristics in the layered structure of the photonic crystal surface light emitting device according to Comparative Example 1. Fig. 7C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the light emitting device components of the photonic crystal surface light emitting devices according to Comparative Example 0, Examples 1 to 4, and Comparative Example 1.

[0075] The photonic crystal surface light emitting device according to Comparative Example 1 has a configuration generally similar to that of the photonic crystal surface light emitting device 10 according to Example 1, except that the refractive index of the carrier block layer (CB layer) is higher than the refractive index of the barrier layer on the carrier block layer side of the active layer (specifically, adjacent to the carrier block layer) (see FIG. 7A ). The photonic crystal surface light emitting device according to Comparative Example 1 can achieve a relatively large lattice constant a for a given oscillation wavelength λ (e.g., 214 nm), but its luminous efficiency (slope efficiency SE) is reduced (see FIGS. 7B and 7C ). This is due to a reduction in the optical confinement factor Γact in the active layer 104.

[0076] (Comparative Example 2) Fig. 8 is a cross-sectional view of the stacked structure LS-C2 of the photonic crystal surface light-emitting device according to Comparative Example 2. Fig. 9A is a diagram showing parameters of the main layers (each constituent layer of the resonator) of the stacked structure LS-C2 of the photonic crystal surface light-emitting device according to Comparative Example 2. The vertical arrangement of the multiple layers in Fig. 9A corresponds to the vertical arrangement of the corresponding multiple layers in Fig. 8. Fig. 9B is a graph showing the electric field and refractive index characteristics of the stacked structure LS-C2 of the photonic crystal surface light-emitting device according to Comparative Example 2. Fig. 9C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the light-emitting device components of the photonic crystal surface light-emitting devices according to Comparative Example 0, Comparative Example 2, and Example 1.

[0077] 8 and 9A, the photonic crystal surface light emitting device according to Comparative Example 2 has a configuration generally similar to that of photonic crystal surface light emitting device 10 according to Example 1, except that active layer 104C has a multiple quantum well structure (3QW structure). In the photonic crystal surface light emitting device according to Comparative Example 2, active layer 104C, which has the highest refractive index (specifically, average refractive index), is thick (e.g., 110 nm), and therefore the luminous efficiency (slope efficiency SE) is significantly reduced (see FIGS. 9B and 9C). This is due to the fact that Γpc is reduced by the 3QW structure.

[0078] <Operation of Photonic Crystal Surface Light Emitting Device> The operation of photonic crystal surface light emitting device 10 will be described below with reference to Figures 1 and 10. Current flows from anode terminal 5a of mounting substrate 5, which serves as a drive substrate, to light emitting element LE via bump B1 anode electrode 111. The current passes through second contact layer 109, reflector 108, second cladding layer 107, photonic crystal layer 106, and carrier block layer 105, in this order, and is then injected into active layer 104. At this time, active layer 104 emits light, and the light forms a standing wave in the in-plane direction within photonic crystal layer 106. When the resonance condition is satisfied, light is emitted from photonic crystal layer 106 toward substrate 101 and the side opposite substrate 101. The light emitted toward substrate 101 is then emitted as laser light from the back surface of substrate 101. The light emitted in the direction opposite to the substrate 101 side is reflected by the reflecting mirror 108 toward the substrate 101 side and is emitted as laser light from the rear surface of the substrate 101. The current that passes through the active layer 104 flows through the first cladding layer 103, the first contact layer 102 (a lateral current path is formed in the first contact layer 102), the cathode electrode 112, the cathode wiring 113, and the bump B2 in this order, and then flows out to the cathode terminal 5b of the mounting substrate 5.

[0079] <<Method for Manufacturing Photonic Crystal Surface Light Emitting Device>> A method for manufacturing photonic crystal surface light emitting device 10 will be described below with reference to the flowchart in Fig. 11, etc. The overall flow is as follows: first, a semiconductor manufacturing method using semiconductor manufacturing equipment is used to simultaneously produce multiple photonic crystal surface light emitting devices 10 on a single wafer (hereinafter referred to as "substrate 101" for convenience) which is the base material of substrate 101. Next, the multiple photonic crystal surface light emitting devices 10, which are connected together, are separated from each other by dicing (e.g., stealth dicing) to obtain chip-shaped photonic crystal surface light emitting devices 10.

[0080] In the first step S1, a stack is produced (see FIG. 12 ). Specifically, the stack is formed by stacking first contact layer 102, first cladding layer 103, active layer 104, carrier block layer 105, and base material 106BM of photonic crystal layer 106 in this order on substrate 101 (e.g., an n-GaAs substrate, an SI-GaAs substrate, or the like) by an epitaxial crystal growth method such as MOCVD (Metal Organic Chemical Vapor Deposition). As raw materials for the compound semiconductor, for example, methyl-based organometallic gases such as trimethylaluminum (TMAl), trimethylgallium (TMGa), and trimethylindium (TMIn), and arsine (AsH) gas are used, as raw materials for the donor impurities, for example, disilane (SiH), and as raw materials for the acceptor impurities, for example, carbon tetrabromide (CBr).

[0081] In the next step S2, the photonic crystal layer 106 is formed (see FIG. 13). Specifically, the modified refractive index periodic structure 106a is formed by finely patterning the base material 106BM (see FIG. 12) of the photonic crystal layer 106. Specific examples of fine patterning include lithography such as EBL (electron beam lithography) and NIL (nanoimprint lithography).

[0082] When fine patterning is performed, for example, by EBL, a resist pattern for forming the modified refractive index periodic structure 106a of the photonic crystal layer 106 is formed on the upper surface of the base material 106BM of the photonic crystal layer 106 by photolithography. Since the lattice constant a of the photonic crystal layer 106 is large (200 nm or more), the resist pattern can be formed with high precision. Next, the base material 106BM is etched using the resist pattern as a mask. For this, it is preferable to use RIE (Reactive Ion Etching) using, for example, a Cl-based gas. The resist pattern is then removed.

[0083] When performing NIL (Nuclear Ink Jet Printing) as a fine patterning technique, a UV-curable resin is applied to the base material 106BM by inkjet printing, and a mold (also called a plate, metal mold, stamper, or template) having a modified refractive index periodic structure is stamped (pressed) onto the UV-curable resin. The UV-curable resin is then cured by irradiating it with ultraviolet light, transferring the modified refractive index periodic structure, and the mold is then released to form a resin pattern. Since the lattice constant a of the photonic crystal layer 106 is large (200 nm or greater), the resin pattern can be formed with high precision. The base material 106BM is then etched using the resin pattern as a mask, resulting in a photonic crystal layer 106 having a modified refractive index periodic structure 106a formed in the base material 106BM.

[0084] In the next step S3, second cladding layer 107, reflecting mirror 108, and second contact layer 109 are laminated (see FIG. 14). Specifically, second cladding layer 107, reflecting mirror 108, and second contact layer 109 are laminated in this order by another epitaxial growth on the laminate on which photonic crystal layer 106 has been formed.

[0085] In the next step S4, the light emitting mesa LM and the dummy mesa DM are formed (see FIG. 15). Specifically, a resist pattern for forming the light emitting mesa LM and the dummy mesa DM is formed on the stacked body (see FIG. 14) by photolithography, and the stacked body is etched by dry etching or wet etching using the resist pattern as a mask. The etching depth here is set to, for example, until the first contact layer 102 is exposed. Thereafter, the resist pattern is removed.

[0086] In the next step S5, the anode electrode 111 and the cathode electrode 112 are formed (see FIG. 16 ). Specifically, the anode electrode 111 is formed on the center of the top of the light-emitting mesa LM (more specifically, the second contact layer 109) by, for example, a lift-off method. The cathode electrode 112 is formed on the region of the first contact layer 102 between the region where the light-emitting mesa LM protrudes and the region where the dummy mesa DM protrudes by, for example, a lift-off method. The electrode materials for the anode electrode 111 and the cathode electrode 112 are formed by, for example, evaporation, sputtering, or the like.

[0087] In the next step S6, an insulating film 110 is formed (see FIG. 17 ). Specifically, first, the insulating film 110 is formed over the entire surface of the stack (see FIG. 16 ) on which the anode electrode 111 and the cathode electrode 112 are formed, for example, by CVD (Chemical Vapor Deposition), sputtering, evaporation, or the like. Next, the insulating film 110 covering the anode electrode 111 and the cathode electrode 112 is removed by photolithography and etching to expose the anode electrode 111 and the cathode electrode 112.

[0088] Alternatively, instead of steps S5 and S6, an insulating film 110 may be formed before the anode electrode 111 and the cathode electrode 112 are formed on the laminate, and contact holes for forming the anode electrode 111 and the cathode electrode 112 may be formed in the insulating film 110, and electrodes corresponding to each contact hole may be formed by, for example, lift-off.

[0089] In the next step S7, the cathode wiring 113 is formed (see FIG. 18 ). Specifically, the cathode wiring 113 is formed by, for example, plating so that one end contacts the cathode electrode 112, the other end covers the top of the dummy mesa DM via the insulating film 110, and the middle part covers the side of the dummy mesa DM via the insulating film 110. Note that, prior to plating, it is preferable to form a seed layer in the area to be plated.

[0090] In the final step S8, the substrate 101 is thinned to form an AR film 114 (see FIG. 19 ). Specifically, first, the back surface of the substrate 101 is thinned by grinding using, for example, a grinder or a CMP (Chemical Mechanical Polisher) device. Next, the AR film 114 (anti-reflection film) is formed on the back surface of the thinned substrate 101 by, for example, sputtering or vapor deposition. Thereafter, the substrate 101 is diced to obtain a plurality of chip-shaped photonic crystal surface light-emitting devices 10. Note that, before dicing, it is preferable to remove the portion of the insulating film 110 to be diced.

[0091] <Effects of Photonic Crystal Surface Light Emitting Device> Hereinafter, effects of the photonic crystal surface light emitting device 10 according to Example 1 of an embodiment of the present technology will be described.

[0092] The photonic crystal surface light emitting device 10 comprises a light emitting element portion LE having a stacked structure LS1 in which a plurality of layers including at least one active layer 104 and a photonic crystal layer 106 are stacked, and the active layer 104 has a single quantum well structure.

[0093] In photonic crystal surface light emitting device 10, active layer 104 has a single quantum well structure, so the effective refractive index of the light emitting element portion can be reduced while suppressing a decrease in light emission efficiency. That is, in photonic crystal surface light emitting device 10, the lattice constant a of photonic crystal layer 106 can be made small for the desired oscillation wavelength λ while suppressing a decrease in light emission efficiency.

[0094] As a result, photonic crystal surface light emitting device 10 can provide a photonic crystal surface light emitting device that can easily form a photonic crystal layer while suppressing a decrease in light emission efficiency.

[0095] <2. Photonic crystal surface light emitting device according to example 2 of an embodiment of the present technology> Fig. 20A is a diagram showing parameters of main layers (each constituent layer of the resonator) in the laminate structure of the photonic crystal surface light emitting device according to example 2. Fig. 20B is a graph showing electric field and refractive index characteristics in the laminate structure of the photonic crystal surface light emitting device according to example 2. Fig. 20C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the light emitting device components of the photonic crystal surface light emitting devices according to comparative example 0, example 1, and example 2.

[0096] The photonic crystal surface light-emitting device of Example 2 has the same configuration as the photonic crystal surface light-emitting device 10 of Example 1, except that the average refractive index of the photonic crystal layer 106 is higher than the refractive index of the carrier block layer 105 (see Figure 20A).

[0097] Here, the refractive index can be lowered by increasing the Al composition of AlGaAs, which is the base material of the photonic crystal layer 106 (PC layer). However, it becomes more difficult to form holes in the PC layer with an Al composition that is too high. Therefore, in Example 2, the average refractive index of the photonic crystal layer 106 is set slightly higher than that of Example 1 (specifically, higher than the refractive index of the carrier block layer 105 (e.g., 3.24) and lower than the average refractive index of the active layer 104 (e.g., 3.3). This makes it possible to achieve a slightly higher light emission efficiency than that of Example 1 (similar to that of Comparative Example 0) and to set the lattice constant a to a slightly smaller value than that of Example 1 (see FIGS. 20B and 20C ). Note that the average refractive index of the photonic crystal layer 106 may be the same as the refractive index of the first cladding layer 103 and / or the refractive index of the second cladding layer 107.

[0098] 3. Photonic crystal surface light emitting device according to Example 3 of an embodiment of the present technology> Fig. 21 is a cross-sectional view of a stacked structure LS3 of a photonic crystal surface light emitting device according to Example 3. Fig. 22A is a diagram showing parameters of main layers of the stacked structure LS3 of the photonic crystal surface light emitting device according to Example 3. Fig. 22B is a graph showing electric field and refractive index characteristics in the stacked structure LS3 of the photonic crystal surface light emitting device according to Example 3. Fig. 22C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the light emitting device components of the photonic crystal surface light emitting devices according to Comparative Example 0 and Examples 1 to 3.

[0099] As shown in Figures 21 and 22A, the photonic crystal surface emitting device of Example 3 has a configuration similar to that of the photonic crystal surface emitting device 10 of Example 1, except that in the stack structure LS3, a base portion 106c, which is part of the base material (for example, refractive index: 3.1) of the photonic crystal layer 106, is also present on the second clad layer 107 (p-clad layer) side of the modified refractive index periodic structure 106a of the photonic crystal layer 106.

[0100] The thickness of the base portion 106c is, for example, much thinner (for example, 10 nm) than the thickness of the base portion 106b (for example, 78 nm).

[0101] Base portion 106c can be formed by thinly regrowing the base material of photonic crystal layer 106 during the second epitaxial process after forming modified refractive index periodic structure 106a. Note that the base material of photonic crystal layer 106 may be GaAs instead of AlGaAs.

[0102] The photonic crystal surface light emitting device according to Example 3 provides substantially the same effects as the photonic crystal surface light emitting device 10 according to Example 1 (see FIGS. 22B and 22C).

[0103] <4. Photonic crystal surface light emitting device according to example 4 of an embodiment of the present technology> Fig. 23 is a cross-sectional view of a stacked structure LS4 of a photonic crystal surface light emitting device according to example 4. Fig. 24A is a diagram showing parameters of main layers of the stacked structure LS4 of the photonic crystal surface light emitting device according to example 4. Fig. 24B is a graph showing electric field and refractive index characteristics in the stacked structure LS4 of the photonic crystal surface light emitting device according to example 4. Fig. 24C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the light emitting device portions of the photonic crystal surface light emitting devices according to comparative example 0 and examples 1 to 4.

[0104] The photonic crystal surface light emitting device of Example 4 has a configuration similar to that of the photonic crystal surface light emitting device 10 of Example 1, except that the stacked structure LS4 has a 2J (two junction) structure in which two active layers 104 stacked on top of each other are connected by a tunnel layer 115, as shown in Figures 23 and 24A.

[0105] For example, the tunnel layer 115 has a three-layer structure in which an InGaAs layer is sandwiched between two AlGaAs layers.

[0106] The photonic crystal surface light emitting device of Example 4 has a 2J structure, so that even with the same amount of current as a 1J (one junction) structure having one active layer 104, approximately twice as many photons are generated, improving the light emission efficiency (slope efficiency SE) (approximately twice that of the 1J structure) (see Figure 24C).

[0107] However, since the tunnel layer absorbs light, it is desirable that the electric field in the tunnel layer be small. In the case of the 1J structure as in each of the above-mentioned embodiments, the electric field distribution is set to the zeroth mode (single peak), but in the case of the 2J structure as in Example 4, it is preferable to design the electric field to be of the first mode (two peaks) in order to align the antinodes (peaks) of the electric field with the positions of the two active layers 104 and the node (valley) of the electric field with the position of the tunnel layer 115 (see Figure 24B). If the electric field of the zeroth mode is also mixed, the oscillation wavelength will be about 990 nm (n eff changes in mode), the amount of photons generated in the active layer 104 decreases, and the peak of the electric field coincides with the position of the tunnel layer 115, causing a lot of light to be absorbed in the tunnel layer 115, making it difficult for light to be emitted to the outside.

[0108] 5. Photonic crystal surface light emitting device according to example 5 of an embodiment of the present technology> Fig. 25 is a cross-sectional view of a stacked structure LS5 of a photonic crystal surface light emitting device according to example 5. Fig. 26A is a diagram showing parameters of main layers of the stacked structure LS5 of the photonic crystal surface light emitting device according to example 5. Fig. 26B is a graph showing electric field and refractive index characteristics in the stacked structure LS5 of the photonic crystal surface light emitting device according to example 5. Fig. 26C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the light emitting device components of the photonic crystal surface light emitting devices according to comparative example 0 and examples 1 to 5.

[0109] The photonic crystal surface emitting device of Example 5 has a configuration similar to that of the photonic crystal surface emitting device 10 of Example 1, except that the stacked structure LS5 has a 3J (three junction) structure in which adjacent active layers 104 of the three active layers 104 stacked on top of each other are connected by a tunnel layer 115, as shown in Figures 25 and 26A.

[0110] Each tunnel layer 115 has, for example, a three-layer structure in which an InGaAs layer is sandwiched between two AlGaAs layers.

[0111] The photonic crystal surface light emitting device of Example 5 has a 3J structure, and therefore generates approximately three times as many photons as a 1J (one junction) structure having one active layer 104 with the same amount of current, thereby improving the light emitting efficiency (slope efficiency SE) (approximately 2.5 times that of the 1J structure).

[0112] However, since the tunnel layer absorbs light, it is desirable that the electric field in the tunnel layer be small. In the case of the 1J structure as in each of the above embodiments, the electric field distribution is zero-order mode (single peak). However, in the case of the 3J structure as in Example 5, it is preferable to design the electric field in second-order mode (three peaks) so that the antinodes (peaks) of the electric field coincide with the positions of the two active layers 104 and the nodes (valleys) of the electric field coincide with the positions of the two tunnel layers 115 (see FIG. 26B). If the electric fields of the zeroth-order mode and the first-order mode are mixed, the oscillation wavelengths of the zeroth-order mode and the first-order mode are 1090 nm and 974 nm, respectively, which are regions where the sensitivity of the active layer is zero. Furthermore, the electric field of the tunnel layer 115 becomes non-zero and photons are absorbed, making it difficult for light to be emitted to the outside.

[0113] 6. Photonic crystal surface light-emitting device according to Example 6 of an embodiment of the present technology> Fig. 27A is a diagram showing parameters of main layers in the stacked structure of the photonic crystal surface light-emitting device according to Example 6. Fig. 27B is a graph showing electric field and refractive index characteristics in the stacked structure of the photonic crystal surface light-emitting device according to Example 6. Fig. 27C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each light-emitting device portion of the photonic crystal surface light-emitting devices according to Comparative Example 0 and Examples 1 to 6.

[0114] The photonic crystal surface light-emitting device of Example 6 has a configuration similar to that of the photonic crystal surface light-emitting device 10 of Example 1, except that the layer structure has a layer configuration in which the oscillation wavelength λ is in the SWIR (Short-Wavelength InfraRed) band (e.g., 1350 nm), as shown in Figure 27A.

[0115] The photonic crystal surface light emitting device according to Example 6 is made of an InP-based compound semiconductor (a compound semiconductor lattice-matched to InP).

[0116] In the photonic crystal surface light emitting device of Example 6, as an example, the well layer and each barrier layer of the active layer are made of AlGaInAs, the base material of the PC layer is made of GaInAsP, the CB layer is made of InP, and each clad layer is made of GaP or InP.

[0117] According to the photonic crystal surface light emitting device of Example 6, since the oscillation wavelength λ is long, the lattice constant a can be made sufficiently large while suppressing a decrease in the luminous efficiency (slope efficiency SE) (see Figures 27B and 27C).

[0118] 7. Photonic crystal surface light emitting device according to Example 7 of an embodiment of the present technology> Fig. 28 is a cross-sectional view of a layered structure LS7 of a photonic crystal surface light emitting device according to Example 7. Fig. 29A is a diagram showing parameters of main layers of the layered structure LS7 of the photonic crystal surface light emitting device according to Example 7. Fig. 29B is a graph showing electric field and refractive index characteristics in the layered structure LS7 of the photonic crystal surface light emitting device according to Example 7. Fig. 29C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each of the light emitting device components of the photonic crystal surface light emitting devices according to Comparative Example 0, Example 1, and Example 7.

[0119] The photonic crystal surface-emitting device of Example 7 has a configuration similar to that of the photonic crystal surface-emitting device 10 of Example 1, except that the stacked structure LS7 includes, between the surface of the first cladding layer 103 (n-cladding layer) opposite the light-emitting section side and the surface of the light-emitting section opposite the first cladding layer 103 side, as shown in Figures 28 and 29A.

[0120] The optical thickness n of the high refractive index layer 116 _eff ×d / λ(n _eff is the effective refractive index, d is the thickness, and λ is the oscillation wavelength) is preferably, for example, 0.03 or less. _eff When is 3.17, d is 10 nm, and λ is 940 nm, n _eff×d / λ is 0.03. Here, the high refractive index layer 116 is disposed in the n-clad layer away from the PC layer, and because the film thickness is relatively thin, the luminous efficiency (slope efficiency SE) decreases, but the lattice constant a can be made comparable to that of Example 1 (see FIGS. 29B and 29C ).

[0121] 8. Photonic crystal surface light emitting device according to Example 8 of an embodiment of the present technology

[0122] Fig. 30 is a cross-sectional view of a stacked structure LS8-1 of a photonic crystal surface light-emitting device according to Structural Example 1 of Example 8. Fig. 31 is a cross-sectional view of a stacked structure LS8-2 of a photonic crystal surface light-emitting device according to Structural Example 2 of Example 8. Fig. 32A is a diagram showing parameters of main layers of stacked structure LS8-1 of a photonic crystal surface light-emitting device according to Structural Example 1 of Example 8. Fig. 32B is a graph showing electric field and refractive index characteristics in stacked structure LS8-1 of a photonic crystal surface light-emitting device according to Structural Example 1 of Example 8. Fig. 32C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each light-emitting device component of photonic crystal surface light-emitting devices according to Comparative Example 0 and Structural Example 1 of Example 8.

[0123] The photonic crystal surface light-emitting device of configuration example 1 of Example 8 has a configuration similar to that of the photonic crystal surface light-emitting device 10 of Example 1, except that, as shown in Figures 30 and 32A, in the stacked structure LS8-1, a light-inducing layer 117 is provided between the photonic crystal layer 106 and the second cladding layer 107.

[0124] The light-inducing layer 117 is a high-refractive index layer (e.g., a refractive index of 3.53) made of a semiconductor (compound semiconductor) such as GaAs, and has the function of attracting light to the photonic crystal layer 106. The refractive index of the light-inducing layer 117 is preferably higher than the average refractive index of the photonic crystal layer 106. The optical thickness n _eff ×d / λ(n _eff is the effective refractive index, d is the thickness, and λ is the oscillation wavelength), is preferably, for example, 0.2 or less. Here, the optical thickness of the light-inducing layer 117 is, for example, 0.0674. The light-inducing layer 117 has, for example, n _effWhen is 3.17, d is 20 nm, and λ is 940 nm, n _eff ×d / λ is 0.0674.

[0125] According to the photonic crystal surface light emitting device of configuration example 1 of Example 8, the lattice constant a is comparable to that of Example 1, and the light emitting efficiency (slope efficiency SE) can be slightly improved (see Figures 32B and 32C).

[0126] The photonic crystal surface light-emitting device according to configuration example 2 of Example 8 has a configuration similar to that of the photonic crystal surface light-emitting device according to configuration example 1 of Example 8, except that, as shown in Figure 31, in LS8-2, the light-inducing layer 117 has, on the photonic crystal layer 106 side, a plurality of holes that are each connected to a plurality of holes (modified refractive index areas) arranged in the in-plane direction of the photonic crystal layer 106.

[0127] According to the photonic crystal surface emitting device of configuration example 2 of Example 8, the thickness of the modified refractive index periodic structure 106a of the photonic crystal layer 106 is substantially thicker than that of the photonic crystal surface emitting device of configuration example 1 of Example 8, so that the effect of the photonic crystal layer can be strengthened, and thus a further improvement in the light emission efficiency (slope efficiency SE) can be expected.

[0128] 9. Photonic crystal surface light emitting device according to Example 9 of an embodiment of the present technology

[0129] Fig. 33 is a cross-sectional view of the layered structure LS9 of the photonic crystal surface light emitting device according to Example 9. Fig. 34A is a diagram showing parameters of the main layers of the layered structure LS9 of the photonic crystal surface light emitting device according to Example 9. Fig. 34B is a graph showing the electric field and refractive index characteristics in the layered structure LS9 of the photonic crystal surface light emitting device according to Example 9. Fig. 34C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each light emitting device portion of the photonic crystal surface light emitting devices according to Comparative Example 0 and Example 9.

[0130] As shown in Figures 33 and 34A, the photonic crystal surface light-emitting device of Example 9 has a configuration similar to that of the photonic crystal surface light-emitting device of Configuration Example 1 of Example 8, except that the optical thickness of the light-inducing layer 117 of the stacked structure LS9 is thicker.

[0131] In the photonic crystal surface light emitting device according to Example 9, the optical thickness (n _eff ×d / λ) is, for example, 0.2. _eff When is 3.17, d is 60 nm, and λ is 940 nm, n _eff ×d / λ is 0.2.

[0132] In the photonic crystal surface light emitting device according to Example 9, the light emitting efficiency (slope efficiency SE) is higher than that of Example 1 due to the large optical thickness of the light inducing layer 117, which is a high refractive index layer. eff is slightly larger, so the lattice constant a is slightly smaller than that in Example 1 (see FIGS. 34B and 34C).

[0133] (Comparative Example 3) Fig. 35A is a diagram showing parameters of main layers in the stacked structure of a photonic crystal surface light emitting device according to Comparative Example 3. Fig. 35B is a graph showing electric field and refractive index characteristics in the stacked structure of a photonic crystal surface light emitting device according to Comparative Example 3. Fig. 35C is a diagram showing the effective refractive index, lattice constant of the photonic crystal layer, and slope efficiency of each light emitting device portion of the photonic crystal surface light emitting devices according to Comparative Examples 0 and 3.

[0134] As shown in FIG. 35A, the photonic crystal surface light emitting device of Comparative Example 3 has the same configuration as the photonic crystal surface light emitting device of Example 9, except that the optical thickness of the light induction layer is greater.

[0135] In the photonic crystal surface light emitting device according to Comparative Example 3, the optical thickness (n _eff ×d / λ) is, for example, 0.3372. _eff When is 3.17, d is 100 nm, and λ is 940 nm, n _eff ×d / λ is 0.3372.

[0136] In the photonic crystal surface light emitting device according to Comparative Example 3, the optical thickness of the light induction layer is increased, so the luminous efficiency (slope efficiency SE) is high, but the effective refractive index n eff becomes higher (e.g., 3.14), resulting in a smaller lattice constant a (e.g., 211 nm). Furthermore, since the peak of the optical field (electric field) does not coincide with the position of the active layer, Γact is small and oscillation is difficult. In other words, the photonic crystal surface-emitting device according to Comparative Example 3 cannot function as a photonic crystal surface-emitting laser.

[0137] In PCSELs, the aforementioned light emission efficiency (slope efficiency SE) is important, and it is desirable to increase this efficiency. To improve SE, not only the hole pattern of the PC layer but also the refractive index and thickness of each layer in the laminate structure are important.

[0138] (Improvement of Slope Efficiency SE) One effective measure for improving SE is to confine photons in both the photonic crystal layer and the active layer.

[0139] Here, the greater the refractive index and film thickness of each layer, the easier it is to confine photons, and conversely, the lower the refractive index of each layer and the thicker the film thickness, the easier it is to leak. The optical confinement ratio Γi is the proportion of light distributed in the i-th layer (i: active layer / photonic crystal layer) of the light distribution in the cross-sectional direction (thickness direction) of the device, and is defined by the following equation (1):

[0140] where θ(z) is the electric field, and z represents the position in the thickness direction.

[0141] (Regarding the optical confinement rate Γpc of the PC layer) The radiation coefficient a that determines the beam intensity v [cm -1 ] is roughly proportional to Γpc when the pores in the PC layer are perfect cylinders (a v ∝ Γpc), the higher the better.

[0142] Beam slope efficiency η SE [W / A] is defined by the following equation (2), v The larger (∝Γpc), the higher the value (the higher the better).

[0143] where λ is the oscillation wavelength, A is the absorption coefficient of the substrate, and α || represents the in-plane loss, and α0 represents the internal loss. ... (2)

[0144] (Regarding the optical confinement ratio Γact of the active layer) The net gain g is proportional to Γact (g ∝ g max The larger Γact and Γact are, the more desirable they are. Also, if Γact is large, the number of QWs can be reduced, which also leads to a reduction in unwanted light. max is the bulk gain.

[0145] The larger the net gain g, the smaller the SE (≒ a v ) can also be improved. However, if the difference between gain and loss is large, unwanted light like that of an LED will be generated. The beam oscillation condition is defined by the following equation (3).

[0146] ...(3)

[0147] (Comparative Example 4) Fig. 36 is a cross-sectional view of the stacked structure LS-C4 of the photonic crystal surface light-emitting device according to Comparative Example 4. Fig. 37A is a diagram showing parameters of the main layers of the stacked structure LS-C4 of the photonic crystal surface light-emitting device according to Comparative Example 4. Fig. 37B is a graph showing the electric field and refractive index characteristics of the stacked structure LS-C4 of the photonic crystal surface light-emitting device according to Comparative Example 4. Fig. 37C is a diagram showing the light-inducing layer thickness, light-excluding layer thickness, PC layer optical confinement ratio, and active layer optical confinement ratio of the photonic crystal surface light-emitting device according to Comparative Example 4.

[0148] In Comparative Example 4, the optical confinement ratio Γpc of the PC layer is, for example, 15.3%, and the optical confinement ratio Γact of the active layer is, for example, 9.0% (see FIG. 37C).

[0149] The photonic crystal surface light emitting device according to Comparative Example 4 has a layer structure similar to that of photonic crystal surface light emitting device 10 (see FIG. 1) according to Example 1. However, the layer structure LS-C4 of the photonic crystal surface light emitting device according to Comparative Example 4 differs in refractive index and thickness of each layer from that of layer structure LS1 of photonic crystal surface light emitting device 10 according to Example 1, and therefore the same effect cannot be obtained.

[0150] (Comparative Example 5) Fig. 38 is a cross-sectional view of the layered structure LS-C5 of the photonic crystal surface light emitting device according to Comparative Example 5. Fig. 39A is a diagram showing parameters of the main layers of the layered structure LS-C5 of the photonic crystal surface light emitting device according to Comparative Example 5. Fig. 39B is a graph showing the electric field and refractive index characteristics of the layered structure LS-C5 of the photonic crystal surface light emitting device according to Comparative Example 5. Fig. 39C is a diagram showing the light attraction layer thickness, light exclusion layer thickness, PC layer optical confinement ratio, and active layer optical confinement ratio of each of the photonic crystal surface light emitting devices according to Comparative Examples 4 and 5.

[0151] The stacked structure LS-C5 of the photonic crystal surface light-emitting device according to Comparative Example 5 has a similar configuration to Comparative Example 4, except that the photonic crystal layer 106C (PC layer) and the carrier blocking layer 105C are sandwiched between the high-refractive-index layer 117C and the active layer 104C. In Comparative Example 5, the high refractive index of the light-inducing layer 117C attracts light from the active layer 104C. This allows light to flow into the photonic crystal layer 106C located between the active layer 104C and the light-inducing layer 117C, improving the optical confinement ratio of the PC layer (e.g., 22.5%) and increasing the beam intensity. Meanwhile, in Comparative Example 5, the side effect of the light-inducing layer 117C is a decrease in the optical confinement ratio Γact of the active layer 104C (e.g., 6.6%), resulting in a decrease in SE, a decrease in gain, and an increase in threshold current (Ith). Therefore, further improvement of SE and single-mode oscillation become issues. Therefore, in Comparative Example 5, it is necessary to suppress the decrease in Γact caused by providing the light-inducing layer 117C.

[0152] <10. Photonic crystal surface light emitting device according to Example 10 of an embodiment of the present technology>

[0153] Fig. 40 is a cross-sectional view of the layered structure LS10 of the photonic crystal surface light emitting device according to Example 10. Fig. 41A is a diagram showing parameters of the main layers of the layered structure LS10 of the photonic crystal surface light emitting device according to Example 10. Fig. 41B is a graph showing the electric field and refractive index characteristics of the layered structure LS10 of the photonic crystal surface light emitting device according to Example 10. Fig. 41C is a diagram showing the light attraction layer thickness, light exclusion layer thickness, SE improvement ratio, PC layer optical confinement ratio, and active layer optical confinement ratio of each of the photonic crystal surface light emitting devices according to Comparative Example 4, Comparative Example 5, and Example 10.

[0154] As shown in FIGS. 40 and 41A , the photonic crystal surface light-emitting device of Example 10 has a configuration generally similar to that of the photonic crystal surface light-emitting device 10 of Example 1 (see FIG. 1 ), except that the stacked structure LS10 includes a light-excluding layer 118 (first semiconductor layer) disposed between the active layer 104 and the first cladding layer 103, and a light-excluding layer 118 (first semiconductor layer) disposed between the active layer 104 and the second cladding layer 107. The refractive index of each light-excluding layer 118 is preferably lower than the refractive index of the cladding layer on the light-excluding layer 118 side. The refractive index of each cladding layer is preferably lower than the average refractive index of the active layer 104 and the average refractive index of the photonic crystal layer 106. The average refractive index of the photonic crystal layer 106 is preferably higher than the average refractive index of the active layer 104. The photonic crystal layer 106 is disposed between the active layer 104 and the second cladding layer 107. In this case, the second cladding layer 107 is preferably p-type. The stacked structure LS10 further includes a light-inducing layer 117 (second semiconductor layer) disposed between the second cladding layer 107 and the photonic crystal layer 106. The refractive index of the light-inducing layer 117 is preferably higher than the refractive index of the second cladding layer 107. The light-inducing layer 117 is preferably disposed between the second cladding layer 107 and the light-excluding layer 118. The light-excluding layer 118 may be disposed within the cladding layer. In this case, the cladding layer may be p-type or n-type. The active layer 104 is disposed between the photonic crystal layer 106 and the first cladding layer 103. In this case, the first cladding layer 103 is preferably n-type. The photonic crystal surface light-emitting device according to Example 10 may include a spacer layer (e.g., an AlGaAs layer with a film thickness of 60 nm and a refractive index of 3.43) between the light-excluding layer 118 on the first cladding layer 103 side and the active layer 104.

[0155] The refractive index of each light exclusion layer 118 (eg, 3.0) is lower than the refractive index of the corresponding cladding layer (eg, 3.29, 3.21) (see FIG. 41A).

[0156] The optical thickness of the light-inducing layer 117, which is a high refractive index layer, is preferably equal to or greater than the optical thickness of the light-excluding layer 118, which is a low refractive index layer. _eff ×d / λ) is the same (for example, 0.3372(n _eff is 3.17, d is 100 nm, and λ is 940 nm) (see FIG. 41A).

[0157] The optical thickness (n _eff ×d / λ) is 0.6745 (for example, n _eff Here, it is preferable that the optical thickness of each light-exclusion layer 118 is equal to or less than 0.3372 (for example, n _eff is 3.17, d is 100 nm, and λ is 940 nm) (see Figure 41A).

[0158] The refractive index of first cladding layer 103 is preferably lower than the average refractive index of active layer 104 and the average refractive index of photonic crystal layer 106 .

[0159] The average refractive index of the photonic crystal layer 106 is preferably higher than the average refractive index of the active layer 104, and is preferably higher (for example, 3.53) than the refractive index of each barrier layer (for example, 3.43).

[0160] The photonic crystal layer 106 is disposed between the active layer 104 and the first cladding layer 103. In this case, the first cladding layer 103 is preferably p-type.

[0161] It is preferable that the stacked structure LS10 further includes a light-inducing layer 117 (second semiconductor layer) disposed between the first cladding layer 103 and the photonic crystal layer 106. In this case, it is preferable that the refractive index of the light-inducing layer 117 (e.g., 3.53) is higher than the refractive index of the first cladding layer 103 (e.g., 3.21). This makes it possible to efficiently attract light to the photonic crystal layer 106 and efficiently confine the light in the photonic crystal layer 106.

[0162] It is preferable that the light-inducing layer 117 is disposed between the first cladding layer 103 and the light-excluding layer 118. This makes it possible to suppress a decrease in Γact due to a side effect of the light-inducing layer 117.

[0163] The active layer 104 is disposed between the photonic crystal layer 106 and the first cladding layer 103. In this case, the first cladding layer 103 is preferably n-type.

[0164] Here, a light-excluding layer 118 is disposed between each of the first and second cladding layers 103 and 107 and the light-emitting portion including the active layer 104 and the photonic crystal layer 106 .

[0165] The stacked structure LS10 further includes a light-exclusion layer 118 arranged between the photonic crystal layer 106 and the second cladding layer 107, which is the cladding layer on the photonic crystal layer 106 side of the first and second cladding layers 103, 107, and a light-attracting layer 117 arranged between the photonic crystal layer 106.

[0166] The stacked structure LS10 may include a plurality of active layers 104 disposed between the photonic crystal layer 106 and the first cladding layer 103, and a tunnel layer 115 (tunnel junction layer) disposed between adjacent active layers 104. In this case, the first cladding layer 103 is preferably n-type.

[0167] The photonic crystal surface light emitting device according to the tenth embodiment can be manufactured by a method generally similar to the method for manufacturing the photonic crystal surface light emitting device 10 according to the first embodiment.

[0168] According to the photonic crystal surface light-emitting device of Example 10, a multilayer structure in which a light-inducing layer 117 is provided on the photonic crystal layer 106 side of the light-emitting section including the active layer 104 and the photonic crystal layer 106 is sandwiched between two light-excluding layers 118 (low refractive index layers) (see Figures 40, 41A and 41B), so that both Γpc and Γact can be improved compared to Comparative Examples 4 and 5 (see Figure 41C).

[0169] Supplementally, in Example 10, the light attracting layer 117 (high refractive index layer) collects light into the photonic crystal layer 106, while the two light excluding layers 118 (low refractive index layers) sandwiching the light emitting section can suppress light leakage to both sides of the light emitting section. This improves Γpc and increases the beam intensity, and also improves Γact, thereby improving the gain and reducing the threshold current (Ith), thereby achieving an improvement in SE.

[0170] In particular, when the photonic crystal surface light-emitting device of Example 10 has a multi-junction structure in which multiple active layers 104 are stacked, the multi-junction structure is thick and it is difficult to obtain sufficient Γact and Γpc. However, in Example 10, by adjusting both, it is possible to reduce the number of wells in the active layer 104 while improving SE, lowering Ith, reducing unwanted light (LED light (spontaneous emission light)), and improving beam intensity.

[0171] In Example 10, the light-rejecting layer 118, which is a low-refractive-index layer, is provided in addition to the light-inducing layer 117, which is a high-refractive-index layer. Therefore, the effective refractive index n eff Therefore, the increase in the lattice constant a can be suppressed, and the decrease in the lattice constant a can be suppressed.

[0172] <11. Photonic crystal surface light emitting device according to Example 11 of an embodiment of the present technology>

[0173] Fig. 42 is a cross-sectional view of the stacked structure LS11 of the photonic crystal surface light emitting device according to Example 11. Fig. 43A is a diagram showing parameters of main layers of the stacked structure LS11 of the photonic crystal surface light emitting device according to Example 11. Fig. 43B is a graph showing electric field and refractive index characteristics in the stacked structure LS11 of the photonic crystal surface light emitting device according to Example 11. Fig. 43C is a diagram showing the light attraction layer thickness, light exclusion layer thickness, SE improvement ratio, PC layer optical confinement ratio, and active layer optical confinement ratio of each of the photonic crystal surface light emitting devices according to Comparative Example 4, Comparative Example 5, and Example 11.

[0174] The photonic crystal surface light-emitting device of Example 11 has a configuration similar to that of the photonic crystal surface light-emitting device of Example 10 (see Figure 40), except that, as shown in Figures 42 and 43A, no light-excluding layer 118 is provided between the first cladding layer 103 and the active layer 104.

[0175] In the photonic crystal surface light-emitting device of Example 11, a light-exclusion layer 118 and a light-attraction layer 117 are provided in this order from the second cladding layer 107 side between the light-emitting section including the active layer 104 and the photonic crystal layer 106 and the second cladding layer 107.

[0176] In Example 11, the optical thickness of the light-attracting layer 117 and the optical thickness of the light-excluding layer 118 are the same (for example, 0.6745 (for example, n _eff is 3.17, d is 200 nm, and λ is 940 nm) (see FIG. 43A).

[0177] According to the photonic crystal surface light emitting device of Example 11, the light attracting layer 117 can attract sufficient light to the photonic crystal layer 106, and the light excluding layer 118 can reduce the leakage of light from the light emitting portion toward the second cladding layer 107. As a result, although it is slightly inferior to the photonic crystal surface light emitting device of Example 10, it is possible to improve both Γact (gain·Ith) and Γpc, and ultimately to achieve an improvement in SE.

[0178] <12. Photonic crystal surface light emitting device according to Example 12 of an embodiment of the present technology>

[0179] Fig. 44 is a cross-sectional view of the stacked structure LS12 of the photonic crystal surface light emitting device according to Example 12. Fig. 45A is a diagram showing parameters of the main layers of the stacked structure LS12 of the photonic crystal surface light emitting device according to Example 12. Fig. 45B is a graph showing the electric field and refractive index characteristics of the stacked structure LS12 of the photonic crystal surface light emitting device according to Example 12. Fig. 45C is a diagram showing the light attraction layer thickness, light exclusion layer thickness, SE improvement ratio, PC layer optical confinement ratio, and active layer optical confinement ratio of each of the photonic crystal surface light emitting devices according to Comparative Example 4, Comparative Example 5, and Example 12.

[0180] The photonic crystal surface light-emitting device of Example 12 has a configuration similar to that of the photonic crystal surface light-emitting device of Example 10 (see Figure 40), except that no light-excluding layer 118 is provided between the second cladding layer 107 (p-cladding layer) and the light-inducing layer 117, as shown in Figures 44 and 45A.

[0181] In the photonic crystal surface light emitting device according to Example 12, a light inducing layer 117 is provided between the light emitting section including the active layer 104 and the photonic crystal layer 106 and the second cladding layer 107 .

[0182] In Example 12, the optical thickness of the light-inducing layer 117 (for example, 0.5059 (for example, n _eff is 3.17, d is 150 nm, and λ is 940 nm)) is set to the optical thickness (e.g., 0.3372 (e.g., n _eff The thickness is greater than that of the conventional SiO 2 thin film (see FIG. 45A).

[0183] According to the photonic crystal surface light emitting device of Example 12, the light is collected into the photonic crystal layer 106 by the light attracting layer 117 (high refractive index layer), while the light excluding layer (low refractive index layer) is disposed only on the n-side of the light emitting section, thereby minimizing light leakage from the active layer 104 side, where light leakage is particularly strong.

[0184] <13. Photonic crystal surface light emitting device according to Example 13 of an embodiment of the present technology>

[0185] Fig. 46 is a cross-sectional view of the stacked structure LS13 of the photonic crystal surface light emitting device according to Example 13. Fig. 47A is a diagram showing parameters of the main layers of the stacked structure LS13 of the photonic crystal surface light emitting device according to Example 13. Fig. 47B is a graph showing the electric field and refractive index characteristics in the stacked structure LS13 of the photonic crystal surface light emitting device according to Example 13. Fig. 47C is a diagram showing the light attraction layer thickness, light exclusion layer thickness, SE improvement ratio, PC layer optical confinement ratio, and active layer optical confinement ratio of each of the photonic crystal surface light emitting devices according to Comparative Example 4, Comparative Example 5, and Example 13.

[0186] As shown in Figures 46 and 47A, the photonic crystal surface light-emitting device of Example 13 has a configuration similar to that of the photonic crystal surface light-emitting device of Example 10 (see Figure 40), except that the optical thickness of the light-inducing layer 117 and each light-excluding layer 118 is thicker.

[0187] In Example 13, the optical thickness of the light-attracting layer 117 and the optical thickness of each light-excluding layer 118 are both, for example, 0.6745 (for example, n _eff is 3.17, d is 200 nm, and λ is 940 nm (see Figure 47A).

[0188] In the photonic crystal surface light emitting device of Example 13, Γpc can be improved compared to Comparative Examples 4 and 5, but Γact is reduced (see Figures 47B and 47C). When the active layer region is thick and there is ample gain, such as in a multi-junction structure (e.g., 2J structure) or a multiple quantum well structure (e.g., 4QW structure), oscillation is possible even with a low Γact, so increasing Γpc can be the main focus. This can reduce the modulation amount of the holes in the PC layer, and can alleviate dimensional constraints on the drawing device (micro-hole forming device).

[0189] <14. Photonic crystal surface light emitting device according to example 14 of an embodiment of the present technology> Fig. 48 is a cross-sectional view of a stacked structure LS14 of a photonic crystal surface light emitting device according to example 14. Fig. 49A is a diagram showing parameters of main layers of the stacked structure LS14 of the photonic crystal surface light emitting device according to example 14. Fig. 49B is a graph showing electric field and refractive index characteristics in the stacked structure LS14 of the photonic crystal surface light emitting device according to example 14. Fig. 49C is a diagram showing the light attraction layer thickness, light exclusion layer thickness, SE improvement ratio, PC layer optical confinement ratio, and active layer optical confinement ratio of each of the photonic crystal surface light emitting devices according to comparative example 4, comparative example 5, and example 14.

[0190] The photonic crystal surface light-emitting device of Example 14 has a configuration similar to that of the photonic crystal surface light-emitting device of Example 10 (see Figure 40), except that it does not have a light-inducing layer 117, as shown in Figures 48 and 49A.

[0191] In Example 14, the thickness of the light-inducing layer 117 and the thickness of each light-excluding layer 118 are both, for example, 0.1686 (for example, n _eff is 3.17, d is 50 nm, and λ is 940 nm (see Figure 49A).

[0192] In the photonic crystal surface light emitting device according to Example 14, Γact can be improved compared to Comparative Examples 4 and 5, but there is a problem in improving Γpc (see Figures 49B and 49C). In Example 14, even though Γpc is low, Γact is sufficiently high, so it is possible to achieve an SE improvement ratio equivalent to that of Comparative Example 5. In addition, because Γact is high, the amount of unwanted light (such as LED light) generated is suppressed.

[0193] In Example 14, the light-excluding layer 118 on the photonic crystal layer 106 side is provided between the photonic crystal layer 106 and the second cladding layer 107, but it may also be provided, for example, within the second cladding layer 107. This is expected to have a certain degree of light-attracting effect on the photonic crystal layer 106.

[0194] 15. Modifications of the present technology

[0195] The present technology is not limited to the examples of the above-described embodiment, and various modifications are possible.

[0196] For example, like the photonic crystal surface light emitting device of variant example 1, whose stacked structure is shown in Figure 50, it may have a stacked structure LS-M1 in which the 1J structure of the photonic crystal surface light emitting device of example 10 (see Figure 40) is replaced with a multi-junction structure (e.g., a 2J structure).

[0197] For example, like the photonic crystal surface emitting device of variant example 2, whose stacked structure is shown in Figure 51, it may have a stacked structure LS-M2 in which the 1J structure of the photonic crystal surface emitting device of example 10 (see Figure 40) is replaced with a 3J structure.

[0198] For example, like the photonic crystal surface emitting device of Modification Example 3, whose stacked structure is shown in Figure 52, it may have a stacked structure LS-M3 in which the light attracting layer 117 and the light excluding layer 118 between the photonic crystal layer 106 and the second cladding layer 107 are omitted from the photonic crystal surface emitting device of Example 10 (see Figure 40).

[0199] For example, like the photonic crystal surface emitting device of Modification Example 4, whose stacked structure is shown in Figure 53, the photonic crystal surface emitting device of Example 10 (see Figure 40) may have a stacked structure LS-M4 in which the light exclusion layer 118 and light attraction layer 117 between the light emitting section and the first cladding layer 103 are omitted, and the light exclusion layer 118 on the photonic crystal layer 106 side is arranged within the second cladding layer 107.

[0200] For example, like the photonic crystal surface light emitting device of Modification Example 5, whose stacked structure is shown in Figure 54, the photonic crystal surface light emitting device of Example 10 (see Figure 40) may have a stacked structure LS-M5 in which the light attracting layer 117 and the light excluding layer 118 between the photonic crystal layer 106 and the second cladding layer 107 are omitted, and the light excluding layer 118 on the active layer 104 side is provided within the first cladding layer 103.

[0201] For example, as in the photonic crystal surface light emitting device of Modification Example 6, whose stacked structure is shown in Figure 55, a stacked structure LS-M5 may be used in which the light attracting layer 117 is omitted from the photonic crystal surface light emitting device of Example 10 (see Figure 40), and a light exclusion layer 118 may be arranged inside each of the first and second clad layers 103 and 107.

[0202] For example, a light emitting device 2 according to a modified example shown in Fig. 56 includes a photonic crystal surface light emitting device array in which a plurality of photonic crystal surface light emitting devices 10 (see Fig. 1) according to Example 1 are arranged in the in-plane direction, and a mounting substrate 5 on which the photonic crystal surface light emitting device array is flip-chip mounted. In the light emitting device 2, as an example, a plurality of photonic crystal surface light emitting devices 10 share a substrate 101 and a first contact layer 102. That is, the photonic crystal surface light emitting device array of the light emitting device 2 has an electrode layout with a common cathode and an independent anode, and each light emitting element unit LE can be driven independently.

[0203] For example, the photonic crystal surface light emitting element 10 according to Example 1 (see FIG. 1 ) can be modified to a surface-emitting type, as in the photonic crystal surface light emitting element 10-M7 according to Modification 7 shown in FIG. 57 (more specifically, a modification of the photonic crystal surface light emitting element 10 according to Example 1). In the stacked structure LS-M7 of the photonic crystal surface light emitting element 10-M7, a reflector 108 made of an n-type semiconductor multilayer film reflector is disposed between the first contact layer 102 and the first cladding layer 103, a second contact layer 109 is disposed on the second cladding layer 107, and a circumferential (e.g., ring-shaped) anode electrode 111 is disposed on the second contact layer 109. The photonic crystal surface light emitting element 10-M7 can be junction-up mounted on a mounting substrate. A light emitting device can also be provided in which the photonic crystal surface light emitting element 10-M7 is junction-up mounted on a mounting substrate.

[0204] For example, the photonic crystal surface light emitting element of Example 10 (see FIG. 40 ) can be modified to a surface-emitting type, as in the photonic crystal surface light emitting element 100-M8 of Modification 8 shown in FIG. 58 (more specifically, a modified example of the photonic crystal surface light emitting element of Example 10). In the stacked structure LS-M8 of the photonic crystal surface light emitting element 100-M8, a reflector 108 made of an n-type semiconductor multilayer film reflector is disposed between the first contact layer 102 and the first cladding layer 103, a second contact layer 109 is disposed on the second cladding layer 107, and a circumferential (e.g., ring-shaped) anode electrode 111 is disposed on the second contact layer 109. The photonic crystal surface light emitting element 100-M8 can be junction-up mounted on a mounting substrate. A light emitting device can also be provided in which the photonic crystal surface light emitting element 100-M8 is junction-up mounted on a mounting substrate.

[0205] For example, the photonic crystal surface light emitting device according to the present technology may have a multi-junction structure in which four or more active layers 104 are stacked. In this case, too, it is preferable that a tunnel layer 115 is disposed between the active layers 104 adjacent to each other in the stacking direction.

[0206] For example, in each of the above-mentioned embodiments and variant examples, a photonic crystal surface-emitting laser has been used as an example of a photonic crystal surface-emitting device according to the present technology, but the present technology can also be applied to, for example, a photonic crystal surface-emitting diode (resonant or non-resonant type).

[0207] For example, in each of the above-described embodiments and modified examples, a semiconductor multilayer film reflector is used as the reflector, but this is not limited thereto. For example, a dielectric multilayer film reflector or a hybrid mirror including at least two of a semiconductor multilayer film reflector, a dielectric multilayer film reflector, and a metal reflector may also be used.

[0208] For example, in each of the above embodiments and variants, the photonic crystal surface light emitting element is made of a material that is lattice-matched to GaAs or a material that is lattice-matched to InP, but this is not limited to this, and a material that is lattice-matched to GaN, for example, may also be used.

[0209] At least one of the first and second contact layers 102 and 109 may not be provided.

[0210] One of the first and second cladding layers 103 and 107 may not be provided. In this case, the semiconductor multilayer film reflecting mirror serving as the reflecting mirror 108 may also serve as the one of the cladding layers.

[0211] The reflecting mirror 108 may not be provided.

[0212] The dummy element portion DE does not necessarily have to be provided.

[0213] For example, in the above-described embodiments and modifications, the light emitting element portion and the dummy element portion of the photonic crystal surface light emitting element have a mesa structure, but they may have a mesares structure.

[0214] For example, in each of the above embodiments and modifications, a MOSFET (nMOS or pMOS) is used as the switching element of the laser driver, but other field effect transistors such as a junction FET or a bipolar transistor may also be used.

[0215] Parts of the configurations of the photonic crystal surface light emitting device or light emitting device of each of the above-described embodiments and modifications may be combined within a range that does not contradict each other.

[0216] In each of the above embodiments and modifications, the material, conductivity type, thickness, width, value, shape, size, etc. of each layer constituting the photonic crystal surface light emitting device can be changed as appropriate within the range in which the device functions as a photonic crystal surface light emitting device.

[0217] 16. Application Examples to Electronic Devices The technology according to the present disclosure (the present technology) can be applied to various products (electronic devices). For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, personal mobility, an airplane, a drone, a ship, or a robot, a low-power device (e.g., a smartphone, a smartwatch, a tablet, a mouse, a laptop computer, etc.), or a communication device.

[0218] The photonic crystal surface light emitting device according to the present technology can also be used as a light source for devices that form or display images using laser light (for example, laser printers, laser copiers, projectors, head-mounted displays, head-up displays, etc.).

[0219] 17. Example of Application of Photonic Crystal Surface Light Emitting Device to Distance Measuring Device An application example of the photonic crystal surface light emitting device 10 according to the first embodiment will be described below.

[0220] 59 shows an example of a schematic configuration of a distance measurement device 1000 (distance measuring device) including a photonic crystal surface light emitting element 10, as an example of an electronic device according to the present technology. The distance measurement device 1000 measures the distance to a subject S by a TOF (Time Of Flight) method. The distance measurement device 1000 includes the photonic crystal surface light emitting element 10. The distance measurement device 1000 includes, for example, the photonic crystal surface light emitting element 10, a light receiving device 125, lenses 128 and 130, a signal processing unit 145, a control unit 155, a display unit 165, and a storage unit 170.

[0221] The light receiving device 125 receives light emitted from the photonic crystal surface light emitting device 10 and reflected by the specimen S (object). That is, the light receiving device 125 detects the light reflected by the specimen S. The lens elements constituting the lens 128 are lenses for collimating the light emitted from the photonic crystal surface light emitting device 10, such as collimating lenses. Because the light emitted from the photonic crystal surface light emitting device 10 is collimated from the start due to its characteristics, the minimum number of lenses 128 is sufficient to obtain the desired beam quality, and the number of lenses can be fewer than that of conventional surface emitting lasers (e.g., VCSELs). Another feature of the photonic crystal surface light emitting device 10 is its ability to emit multiple beams of light in desired directions, roughly equivalent to a diffraction grating. In normal use, this function is included in the external lens 128. The lens 130 is a lens for collecting the light reflected by the specimen S and guiding it to the light receiving device 125, such as a collecting lens.

[0222] The signal processing unit 145 is a circuit for generating a signal corresponding to the difference between the signal input from the light receiving device 125 and the reference signal input from the control unit 155. The control unit 155 is configured to include, for example, a time-to-digital converter (TDC). The reference signal may be a signal input from the control unit 155, or may be an output signal from a detection unit that directly detects the output of the photonic crystal surface light emitting device 10. The control unit 155 is, for example, a processor that controls the photonic crystal surface light emitting device 10, the light receiving device 125, the signal processing unit 145, the display unit 165, and the storage unit 170. The control unit 155 is a circuit that measures the distance to the subject S based on the signal generated by the signal processing unit 145. The control unit 155 generates a video signal for displaying information about the distance to the subject S and outputs it to the display unit 165. The display unit 165 displays the information about the distance to the subject S based on the video signal input from the control unit 155. The control unit 155 stores the information about the distance to the subject S in the storage unit 170.

[0223] In this application example, instead of the photonic crystal surface light-emitting element 10, any of the photonic crystal surface light-emitting elements according to Examples 1 to 14, the photonic crystal surface light-emitting elements according to Modifications 1 to 8, the light-emitting device 1, and the light-emitting device 2 can also be applied to the distance measurement device 1000.

[0224] 18. Example in which distance measuring device is mounted on a moving body> FIG. 60 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a moving body control system to which the technology according to the present disclosure can be applied.

[0225] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in Fig. 60, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside-vehicle information detection unit 12030, an inside-vehicle information detection unit 12040, and an integrated control unit 12050. Also shown as functional components of the integrated control unit 12050 are a microcomputer 12051, an audio / video output unit 12052, and an in-vehicle network I / F (interface) 12053.

[0226] The drivetrain control unit 12010 controls the operation of devices related to the drivetrain of the vehicle in accordance with various programs. For example, the drivetrain control unit 12010 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle.

[0227] The body system control unit 12020 controls the operation of various devices equipped in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, backup lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves transmitted from a portable device that serves as a key or signals from various switches can be input to the body system control unit 12020. The body system control unit 12020 receives these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

[0228] The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, a distance measurement device 12031 is connected to the outside-vehicle information detection unit 12030. The distance measurement device 12031 includes the above-described distance measurement device 1000. The outside-vehicle information detection unit 12030 causes the distance measurement device 12031 to measure the distance to an object outside the vehicle (subject S) and acquires the distance data obtained thereby. The outside-vehicle information detection unit 12030 may perform object detection processing for people, cars, obstacles, signs, etc. based on the acquired distance data.

[0229] The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing off.

[0230] The microcomputer 12051 can calculate control target values ​​for the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside-vehicle information detection unit 12030 or the inside-vehicle information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc.

[0231] In addition, the microcomputer 12051 can perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on driver operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle obtained by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

[0232] Furthermore, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the outside information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside information detection unit 12030, and perform cooperative control aimed at preventing glare, such as switching from high beams to low beams.

[0233] The audio / video output unit 12052 transmits at least one output signal of audio and / or video to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle of information. In the example of Fig. 60, the output devices are exemplified by an audio speaker 12061, a display unit 12062, and an instrument panel 12063. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

[0234] FIG. 61 is a diagram showing an example of the installation position of the distance measurement device 12031.

[0235] In FIG. 61, a vehicle 12100 has distance measurement devices 12101, 12102, 12103, 12104, and 12105 as a distance measurement device 12031.

[0236] Distance measuring devices 12101, 12102, 12103, 12104, and 12105 are provided, for example, at positions such as the front nose, side mirrors, rear bumper, back door, and the top of the windshield inside the vehicle cabin of vehicle 12100. Distance measuring device 12101 provided on the front nose and distance measuring device 12105 provided on the top of the windshield inside the vehicle cabin mainly acquire data ahead of vehicle 12100. Distance measuring devices 12102 and 12103 provided on the side mirrors mainly acquire data on the sides of vehicle 12100. Distance measuring device 12104 provided on the rear bumper or back door mainly acquires data behind vehicle 12100. The forward data acquired by distance measuring devices 12101 and 12105 is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, etc.

[0237] 61 shows an example of the detection ranges of the distance measuring devices 12101 to 12104. Detection range 12111 indicates the detection range of the distance measuring device 12101 provided on the front nose, detection ranges 12112 and 12113 indicate the detection ranges of the distance measuring devices 12102 and 12103 provided on the side mirrors, respectively, and detection range 12114 indicates the detection range of the distance measuring device 12104 provided on the rear bumper or back door.

[0238] For example, based on the distance data obtained from the distance measuring devices 12101 to 12104, the microcomputer 12051 can calculate the distance to each three-dimensional object within the detection ranges 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100), thereby extracting as a preceding vehicle, in particular, the three-dimensional object that is the closest three-dimensional object on the path of the vehicle 12100 and traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km / h or higher). Furthermore, the microcomputer 12051 can set a vehicle-to-vehicle distance to be maintained in advance in front of the preceding vehicle, and perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), etc. In this way, cooperative control can be performed for the purpose of autonomous driving, which runs autonomously without relying on driver operation.

[0239] For example, based on the distance data obtained from the distance measuring devices 12101 to 12104, the microcomputer 12051 classifies and extracts three-dimensional object data regarding three-dimensional objects into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects, and can use the data for automatic obstacle avoidance. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. The microcomputer 12051 then determines the collision risk, which indicates the risk of collision with each obstacle, and when the collision risk is equal to or greater than a set value and a collision is possible, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

[0240] The above describes an example of a mobile object control system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to the distance measurement device 12031 of the above-described configuration.

[0241] The present technology can also be configured as follows: (1) A photonic crystal surface light emitting device comprising a light emitting device portion having a stacked structure in which a plurality of layers including at least one active layer and a photonic crystal layer are stacked, the active layer having a single quantum well structure. (2) The photonic crystal surface light emitting device according to (1), in which the active layer includes: a well layer; and a pair of barrier layers sandwiching the well layer. (3) The photonic crystal surface light emitting device according to (1) or (2), in which the average refractive index of the active layer is higher than the average refractive index of the photonic crystal layer. (4) The photonic crystal surface light emitting device according to any one of (1) to (3), in which the stacked structure does not include a layer other than the active layer in a stacked portion including the active layer and the photonic crystal layer, the layer having a refractive index higher than the average refractive index of the active layer. (5) The photonic crystal surface light emitting device according to (4), in which the stacked portion includes a semiconductor layer disposed between the active layer and the photonic crystal layer. (6) The photonic crystal surface light emitting device according to (4) or (5), wherein the stacked section further includes a cladding layer disposed on one and / or the other side of a light emitting section including the active layer and the photonic crystal layer, and the photonic crystal layer has the lowest average refractive index among multiple layers of the stacked section other than the cladding layer. (7) The photonic crystal surface light emitting device according to any one of (2) to (6), wherein the stacked structure further includes a semiconductor layer disposed between the active layer and the photonic crystal layer, and the refractive index of the semiconductor layer is lower than the refractive index of the barrier layer of the active layer on the semiconductor layer side. (8) The photonic crystal surface light emitting device according to any one of (1) to (7), wherein the stacked structure further includes a semiconductor layer disposed between the active layer and the photonic crystal layer, and the refractive index of the semiconductor layer is higher than the average refractive index of the photonic crystal layer. (9) The photonic crystal surface light emitting device according to (8), wherein the laminated structure further includes a cladding layer disposed on one side and / or the other side of a light emitting section including the active layer, the photonic crystal layer, and the semiconductor layer, and the refractive index of the cladding layer is lower than the average refractive index of the photonic crystal layer.(10) The photonic crystal surface light-emitting device according to (9), wherein the laminated structure does not include a layer, other than the active layer, the photonic crystal layer, and the semiconductor layer, having a refractive index higher than that of the clad layer, between a surface of the clad layer opposite to the light-emitting section side and a surface of the light-emitting section opposite to the clad layer side. (11) The photonic crystal surface light-emitting device according to (9) or (10), wherein the laminated structure includes a layer, other than the active layer, the photonic crystal layer, and the semiconductor layer, having a refractive index higher than that of the clad layer, between a surface of the clad layer opposite to the light-emitting section side and a surface of the light-emitting section opposite to the clad layer side, and wherein the optical thickness of the layer is 0.03 or less. (12) The photonic crystal surface emitter according to any one of (9) to (11), wherein the stacked structure further includes a cladding layer disposed on the photonic crystal layer side of a light emitting section including the active layer, the photonic crystal layer, and the semiconductor layer, and another semiconductor layer disposed between the photonic crystal layer and the cladding layer, wherein the refractive index of the another semiconductor layer is higher than the average refractive index of the photonic crystal layer. (13) The photonic crystal surface emitter according to (12), wherein the photonic crystal layer has a plurality of voids disposed in an in-plane direction on the another semiconductor layer side, and the another semiconductor layer has a plurality of voids on the photonic crystal layer side, the voids respectively communicating with the plurality of voids. (14) The photonic crystal surface emitter according to (12) or (13), wherein the optical thickness of the another semiconductor layer is 0.2 or less. (15) The photonic crystal surface light-emitting device according to any one of (1) to (14), wherein the laminated structure further includes a semiconductor layer disposed between the active layer and the photonic crystal layer, and the average refractive index of the photonic crystal layer is higher than the refractive index of the semiconductor layer. (16) The photonic crystal surface light-emitting device according to (15), wherein the laminated structure further includes a cladding layer disposed on one side and / or the other side of a light-emitting section including the active layer, the photonic crystal layer, and the semiconductor layer, and the refractive index of the cladding layer is lower than the refractive index of the semiconductor layer.(17) The photonic crystal surface light-emitting device according to (16), wherein the laminated structure does not include a layer, other than the active layer, the photonic crystal layer, and the semiconductor layer, having a refractive index higher than that of the clad layer, between the surface of the clad layer opposite to the light-emitting section side and the surface of the light-emitting section opposite to the clad layer side. (18) The photonic crystal surface light-emitting device according to (16), wherein the laminated structure includes a layer, other than the active layer, the photonic crystal layer, and the semiconductor layer, having a refractive index higher than that of the clad layer, between the surface of the clad layer opposite to the light-emitting section side and the surface of the light-emitting section opposite to the clad layer side, and the optical thickness of the layer is 0.03 or less. (19) The photonic crystal surface light-emitting device according to any one of (1) to (18), wherein the lattice constant of the photonic crystal layer is 200 nm or more. (20) The photonic crystal surface light-emitting device according to any one of (1) to (19), wherein the lattice constant of the photonic crystal layer is 210 nm or more. (21) The photonic crystal surface emitter according to any one of (1) to (20), wherein the photonic crystal layer has an average refractive index of 3.2 or less. (22) The photonic crystal surface emitter according to any one of (1) to (21), wherein the stacked structure further has at least one cladding layer, and further includes a first semiconductor layer disposed between the active layer and at least a portion of the cladding layer, and wherein the refractive index of the first semiconductor layer is lower than the refractive index of the cladding layer. (23) The photonic crystal surface emitter according to (22), wherein the refractive index of the cladding layer is lower than the average refractive index of the active layer and the average refractive index of the photonic crystal layer. (24) The photonic crystal surface emitter according to (22) or (23), wherein the average refractive index of the photonic crystal layer is higher than the average refractive index of the active layer. (25) The photonic crystal surface emitter according to any one of (22) to (24), wherein the photonic crystal layer is disposed between the active layer and the cladding layer. (26) The photonic crystal surface light emitting device according to (25), wherein the cladding layer is p-type.(27) The photonic crystal surface emitter according to (22), wherein the stacked structure further includes a second semiconductor layer disposed between the cladding layer and the photonic crystal layer, and wherein the refractive index of the second semiconductor layer is higher than the refractive index of the cladding layer. (28) The photonic crystal surface emitter according to (27), wherein the second semiconductor layer is disposed between the cladding layer and the first semiconductor layer. (29) The photonic crystal surface emitter according to (27) or (28), wherein the optical thickness of the second semiconductor layer is equal to or greater than the optical thickness of the first semiconductor layer. (30) The photonic crystal surface emitter according to any one of (22) to (29), wherein the first semiconductor layer is disposed within the cladding layer. (31) The photonic crystal surface emitter according to (30), wherein the cladding layer is p-type. (32) The photonic crystal surface emitter according to any one of (22) to (31), wherein the active layer is disposed between the photonic crystal layer and the cladding layer. (33) The photonic crystal surface light-emitting device according to (32), wherein the cladding layer is n-type. (34) The at least one cladding layer is a pair of cladding layers sandwiching a light-emitting section including the active layer and the photonic crystal layer, and the first semiconductor layer is disposed between at least a portion of at least one of the pair of cladding layers and the light-emitting section. (35) The photonic crystal surface light-emitting device according to (34), wherein the semiconductor layer is disposed between at least a portion of each of the pair of cladding layers and the light-emitting section. (36) The photonic crystal surface light-emitting device according to (34) or (35), wherein the stacked structure further includes the first semiconductor layer disposed between the cladding layer of the pair of cladding layers on the photonic crystal layer side and the photonic crystal layer, and a second semiconductor layer disposed between the photonic crystal layer.(37) The photonic crystal surface light-emitting device according to any one of (1) to (36), wherein the laminated structure further includes a cladding layer disposed on one or the other side of a light-emitting section including the active layer and the photonic crystal layer, the at least one active layer being a plurality of active layers disposed between the photonic crystal layer and the cladding layer, and the laminated structure further includes a tunnel junction layer disposed between adjacent active layers. (38) The photonic crystal surface light-emitting device according to (37), wherein the cladding layer is n-type. (39) The photonic crystal surface light-emitting device according to any one of (1) to (38), wherein the laminated structure further includes a reflecting mirror disposed on one or the other side of a light-emitting section including the active layer and the photonic crystal layer. (40) The photonic crystal surface light emitting device according to any one of (1) to (39), wherein the light emitting element portion further includes a substrate, the laminated structure is disposed on the substrate, the surface of the substrate opposite to the laminated structure is an emission surface, and an antireflection film is provided on the emission surface. (41) The photonic crystal surface light emitting device according to any one of (1) to (40), wherein the material of the photonic crystal layer is AlGaAs. (42) The photonic crystal surface light emitting device according to any one of (1) to (41), wherein the active layer is disposed on the n-side of the photonic crystal layer. (43) The photonic crystal surface light emitting device according to any one of (1) to (42), wherein the laminated structure further includes a cladding layer disposed on one and / or the other side of the light emitting element portion including the active layer and the photonic crystal layer, the cladding layer containing Al in its composition, and the Al composition of the cladding layer is 80% or more. (44) The emission wavelength of the photonic crystal surface light-emitting element is λ, and the effective refractive index of the light-emitting element portion is n. eff Then, the distance λ / n between the photonic crystal layer and the well layer is eff is λ / n eff<0.5. (45) The photonic crystal surface light emitting device according to any one of (1) to (43), wherein the optical thickness of the first semiconductor layer is 0.6745 or less. (46) The photonic crystal surface light emitting device according to any one of (1) to (45), further comprising: a dummy element portion aligned with the light emitting element portion in an in-plane direction; a first electrode provided on the light emitting element portion; and a second electrode partially provided on the dummy element portion. (47) A light emitting device comprising: a photonic crystal surface light emitting device including a light emitting element portion having a stacked structure in which a plurality of layers including at least one active layer and a photonic crystal layer are stacked, the active layer having a single quantum well structure; and a mounting substrate on which the photonic crystal surface light emitting device is mounted. (48) Electronic equipment comprising: a light emitting element portion having a stacked structure in which a plurality of layers including at least one active layer and a photonic crystal layer are stacked, the active layer having a single quantum well structure.

[0242] 1, 2: Light emitting device 10, 10-M7, 10-M8 101: Substrate 103: First cladding layer (cladding layer) 104: Active layer 105: Carrier blocking layer (semiconductor layer) 106: Photonic crystal layer 107: Second cladding layer (cladding layer) 108: Reflector 111: Anode electrode (first electrode) 112: Cathode electrode (part of second electrode) 113: Cathode wiring (other part of second electrode) 114: AR film (anti-reflection film) 115: Tunnel layer (tunnel junction layer) 116: High refractive index layer (layer) 117: Light attracting layer (second semiconductor layer) 118: Light excluding layer (first semiconductor layer) LE: Light emitting element section LS1, LS3, LS4, LS5, LS7, LS8-1, LS8-2, LS9, LS10, LS11, LS12, LS13, LS14, LS-M1, LS-M2, LS-M3, LS-M4, LS-M5, LS-M6: laminated structure

Claims

1. A photonic crystal surface light emitting device comprising a light emitting element section having a laminated structure in which multiple layers including at least one active layer and a photonic crystal layer are stacked, wherein the active layer has a single quantum well structure.

2. The photonic crystal surface light emitting device according to claim 1, wherein the active layer comprises: a well layer; and a pair of barrier layers sandwiching the well layer.

3. The photonic crystal surface light emitting device according to claim 1, wherein the average refractive index of said active layer is higher than the average refractive index of said photonic crystal layer.

4. The photonic crystal surface light emitting device according to claim 1, wherein the stacked structure does not include any layer other than the active layer within the stacked portion including the active layer and the photonic crystal layer, the layer having a refractive index higher than the average refractive index of the active layer.

5. The photonic crystal surface light emitting device according to claim 4, wherein the stacked layer includes a semiconductor layer disposed between the active layer and the photonic crystal layer.

6. The photonic crystal surface light emitting device according to claim 4, wherein the laminated section further includes a cladding layer disposed on one side and / or the other side of a light emitting section including the active layer and the photonic crystal layer, and the photonic crystal layer has the lowest average refractive index among the plurality of layers of the laminated section other than the cladding layer.

7. The photonic crystal surface light-emitting device according to claim 2, wherein the laminated structure further includes a semiconductor layer disposed between the active layer and the photonic crystal layer, and the refractive index of the semiconductor layer is lower than the refractive index of the barrier layer on the semiconductor layer side of the active layer.

8. The photonic crystal surface light-emitting device according to claim 1, wherein the laminated structure further includes a semiconductor layer disposed between the active layer and the photonic crystal layer, and the refractive index of the semiconductor layer is higher than the average refractive index of the photonic crystal layer.

9. The photonic crystal surface light emitting device according to claim 8, wherein the laminated structure further includes a cladding layer disposed on one side and / or the other side of a light emitting section including the active layer, the photonic crystal layer, and the semiconductor layer, and the refractive index of the cladding layer is lower than the average refractive index of the photonic crystal layer.

10. A photonic crystal surface light-emitting device according to claim 9, wherein the laminated structure does not include any layer other than the active layer, the photonic crystal layer, and the semiconductor layer, whose refractive index is higher than that of the cladding layer, between the surface of the cladding layer opposite the light-emitting section side and the surface of the light-emitting section opposite the cladding layer side.

11. The photonic crystal surface light-emitting device according to claim 9, wherein the laminated structure includes a layer other than the active layer, the photonic crystal layer, and the semiconductor layer, the layer having a refractive index higher than that of the clad layer, between the surface of the clad layer opposite the light-emitting section side and the surface of the light-emitting section opposite the clad layer side, and the optical thickness of the layer is 0.03 or less.

12. The photonic crystal surface light emitting device according to claim 8, wherein the laminated structure further includes: a clad layer disposed on the photonic crystal layer side of the light emitting section including the active layer, the photonic crystal layer, and the semiconductor layer; and another semiconductor layer disposed between the photonic crystal layer and the clad layer, and the refractive index of the another semiconductor layer is higher than the average refractive index of the photonic crystal layer.

13. A photonic crystal surface light-emitting device according to claim 12, wherein the photonic crystal layer has a plurality of voids arranged in an in-plane direction on the side of the other semiconductor layer, and the other semiconductor layer has a plurality of voids on the side of the photonic crystal layer that are each connected to the plurality of voids.

14. The photonic crystal surface light-emitting device according to claim 12, wherein the optical thickness of the other semiconductor layer is 0.2 or less.

15. The photonic crystal surface light emitting device according to claim 1, wherein the laminated structure further includes a semiconductor layer disposed between the active layer and the photonic crystal layer, and the average refractive index of the photonic crystal layer is higher than the refractive index of the semiconductor layer.

16. The photonic crystal surface light-emitting device according to claim 15, wherein the laminated structure further includes a clad layer disposed on one side and / or the other side of a light-emitting section including the active layer, the photonic crystal layer, and the semiconductor layer, and the refractive index of the clad layer is lower than the refractive index of the semiconductor layer.

17. A photonic crystal surface light-emitting device as described in claim 16, wherein the laminated structure does not include any layer other than the active layer, the photonic crystal layer, and the semiconductor layer, whose refractive index is higher than that of the cladding layer, between the surface of the cladding layer opposite the light-emitting section side and the surface of the light-emitting section opposite the cladding layer side.

18. The photonic crystal surface light-emitting device according to claim 16, wherein the laminated structure includes a layer other than the active layer, the photonic crystal layer, and the semiconductor layer, the layer having a refractive index higher than that of the clad layer, between the surface of the clad layer opposite the light-emitting section side and the surface of the light-emitting section opposite the clad layer side, and the optical thickness of the layer is 0.03 or less.

19. The photonic crystal surface light emitting device according to claim 1, wherein the average refractive index of the photonic crystal layer is 3.2 or less.

20. The photonic crystal surface light-emitting device according to claim 1, wherein the laminated structure further has at least one clad layer, and further includes a first semiconductor layer disposed between the active layer and at least a portion of the clad layer, and the refractive index of the first semiconductor layer is lower than the refractive index of the clad layer.

21. The photonic crystal surface light emitting device according to claim 20, wherein the refractive index of the cladding layer is lower than the average refractive index of the active layer and the average refractive index of the photonic crystal layer.

22. The photonic crystal surface light emitting device according to claim 20, wherein the average refractive index of the photonic crystal layer is higher than the average refractive index of the active layer.

23. The photonic crystal surface light emitting device according to claim 20, wherein the photonic crystal layer is disposed between the active layer and the cladding layer.

24. The photonic crystal surface light-emitting device according to claim 23, wherein the cladding layer is p-type.

25. The photonic crystal surface light-emitting device according to claim 20, wherein the laminated structure further comprises a second semiconductor layer disposed between the cladding layer and the photonic crystal layer, and the refractive index of the second semiconductor layer is higher than the refractive index of the cladding layer.

26. The photonic crystal surface light-emitting device according to claim 25, wherein the second semiconductor layer is disposed between the cladding layer and the first semiconductor layer.

27. The photonic crystal surface light-emitting device according to claim 25, wherein the optical thickness of the second semiconductor layer is equal to or greater than the optical thickness of the first semiconductor layer.

28. The photonic crystal surface light-emitting device according to claim 20, wherein the first semiconductor layer is disposed within the cladding layer.

29. The photonic crystal surface light-emitting device according to claim 28, wherein the cladding layer is p-type.

30. The photonic crystal surface light emitting device according to claim 20, wherein the active layer is disposed between the photonic crystal layer and the cladding layer.

31. The photonic crystal surface light-emitting device according to claim 30, wherein the cladding layer is n-type.

32. The photonic crystal surface light-emitting device according to claim 20, wherein the at least one clad layer is a pair of clad layers sandwiching a light-emitting section including the active layer and the photonic crystal layer, and the first semiconductor layer is disposed between at least a portion of at least one of the pair of clad layers and the light-emitting section.

33. The photonic crystal surface light-emitting device according to claim 32, wherein the first semiconductor layer is disposed between at least a portion of each of the pair of cladding layers and the light-emitting portion.

34. A photonic crystal surface light-emitting device as described in claim 32, wherein the laminated structure further comprises the first semiconductor layer disposed between the photonic crystal layer and the cladding layer of the pair of cladding layers on the photonic crystal layer side, and a second semiconductor layer disposed between the photonic crystal layer.

35. The photonic crystal surface light-emitting device according to claim 1, wherein the laminated structure further includes a clad layer disposed on one or the other side of the light-emitting portion including the active layer and the photonic crystal layer, the at least one active layer being a plurality of active layers disposed between the photonic crystal layer and the clad layer, and the laminated structure further includes a tunnel junction layer disposed between adjacent active layers.

36. The photonic crystal surface light-emitting device according to claim 35, wherein the cladding layer is n-type.

37. The photonic crystal surface light emitting device according to claim 1, wherein the laminated structure further includes a reflector disposed on one side or the other side of the light emitting portion including the active layer and the photonic crystal layer.

38. The photonic crystal surface light-emitting device according to claim 1, wherein the light-emitting element portion further comprises a substrate, the laminated structure is disposed on the substrate, the surface of the substrate opposite to the laminated structure is an emission surface, and an anti-reflection film is provided on the emission surface.

39. The photonic crystal surface light emitting device according to claim 1, wherein the material of the photonic crystal layer is AlGaAs.

40. The photonic crystal surface light emitting device according to claim 1, wherein the active layer is disposed on the n-side of the photonic crystal layer.

41. The photonic crystal surface light-emitting device according to claim 1, wherein the laminated structure further includes a cladding layer disposed on one side and / or the other side of a light-emitting section including the active layer and the photonic crystal layer, the cladding layer including Al in its composition, and the Al composition of the cladding layer is 80% or more.

42. The emission wavelength of the photonic crystal surface light emitting device is λ, and the effective refractive index of the light emitting device portion is n eff Then, the distance n between the photonic crystal layer and the well layer is eff ×d / λ is n eff The photonic crystal surface light emitting device according to claim 1 , which satisfies ×d / λ<0.

08.

43. The photonic crystal surface light-emitting device according to claim 20, wherein the optical thickness of the first semiconductor layer is 0.6745 or less.

44. The photonic crystal surface light-emitting device according to claim 1, further comprising: a dummy element portion aligned in an in-plane direction with the light-emitting element portion; a first electrode provided on the light-emitting element portion; and a second electrode partially provided on the dummy element portion.

45. A light-emitting device comprising: a photonic crystal surface light-emitting element including a light-emitting element section having a stacked structure in which multiple layers including at least one active layer and a photonic crystal layer are stacked, the active layer having a single quantum well structure; and a mounting substrate on which the photonic crystal surface light-emitting element is mounted.

Images