# US 11,908,972 B2 · Semiconductor light-emitting device and optical coupling device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,908,972 B2 - Document ID: US11908972B2 - Status: Granted - Kind: B2 - Application number: 17/466,995 - Filed: 2021-09-03 - Published: 2022-09-15 - Granted: 2024-02-20 - Earliest claimed: 2021-03-15 - Assignees: Kabushiki Kaisha Toshiba; Toshiba Electronic Devices & Storage Corporation - Applicants: Kabushiki Kaisha Toshiba; Toshiba Electronic Devices & Storage Corporation - Inventors: Akira Tanaka; Hideto Sugawara; Katsufumi Kondo; Masanobu Iwamoto; Kenji Isomoto; Hiroaki Ootsuka - Web page: https://patentgrep.com/patent/US11908972B2 ## CPC - H10H 20/812: within the light-emitting regions, e.g. having quantum confinement structures - H10F 55/25: wherein the radiation-sensitive devices and the electric light source are all semiconductor devices - H10F 55/255: formed in, or on, a common substrate - H10F 77/306: {for devices having potential barriers} - H10H 20/824: comprising only Group III-V materials, e.g. GaP - H10W 90/00: Package configurations - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract A semiconductor light-emitting device includes a substrate having a first energy bandgap, a first semiconductor layers on the substrate, an active layer on the first semiconductor layer, and a second semiconductor layer on the active layer. The active layer includes a quantum well layer, and a first barrier layer between the first semiconductor layer and the quantum well layer. The first semiconductor layer has a second energy bandgap wider than the first energy bandgap. The quantum well layer has a third energy bandgap narrower than the first and second energy bandgaps. The second semiconductor layer has a fourth energy bandgap wider than the third energy bandgap. The substrate has a refractive index greater than a refractive index of the first semiconductor layer. The refractive index of the first semiconductor layer is not less than a refractive index of the first barrier layer. ## Claims ### Claim 1 An optical coupling device, comprising: a semiconductor light-emitting device comprising: a substrate having a first energy bandgap; a first semiconductor layer of a first conductivity type provided on the substrate, the first semiconductor layer having a second energy bandgap, the second energy bandgap being wider than the first energy bandgap; an active layer provided on the first semiconductor layer, the active layer including at least one quantum well layer and a first barrier layer, the quantum well layer having a third energy bandgap narrower than the first and second energy bandgaps, the first barrier layer being provided between the first semiconductor layer and the quantum well layer; and a second semiconductor layer of a second conductivity type provided on the active layer, the second semiconductor layer having a fourth energy bandgap wider than the third energy bandgap, the substrate having a refractive index greater than a refractive index of the first semiconductor layer at a wavelength of light radiated from the active layer, the refractive index of the first semiconductor layer being not less than a refractive index of the first barrier layer at the wavelength of the light radiated from the active layer; and a light-receiving element configured to receive the light radiated from the active layer of the semiconductor light-emitting device, the substrate of the semiconductor light-emitting device being provided between the active layer and the light-receiving element, the light-receiving element being bonded to the substrate via a resin layer, and the resin layer transmitting the light radiated from the active layer. ### Claim 2 (depends on 1) The device according to claim 1, wherein the second semiconductor layer having a refractive index less than the refractive index of the first semiconductor layer at the wavelength of the light radiated from the active layer. ### Claim 3 (depends on 1) The device according to claim 1, further comprising: an intermediate layer of the first conductivity type provided between the substrate and the first semiconductor layer, the intermediate layer having a fifth energy bandgap wider than the third energy bandgap, the intermediate layer having a refractive index higher than the refractive index of the first semiconductor layer at the wavelength of the light radiated from the active layer. ### Claim 4 (depends on 3) The device according to claim 3, wherein the refractive index of the intermediate layer is less than the refractive index of the substrate. ### Claim 5 (depends on 1) The device according to claim 1, wherein the active layer further includes a second bather layer provided between the quantum well layer and the second semiconductor layer, the second barrier layer including a material having a same composition as a material of the first barrier layer. ### Claim 6 (depends on 1) The device according to claim 1, wherein the active layer further includes a second bather layer provided between the quantum well layer and the second semiconductor layer, the second bather layer including a material having a different composition from a material of the first barrier layer. ### Claim 7 (depends on 1) The device according to claim 1, wherein the active layer includes first and second quantum well layers, the first barrier layer, a second bather layer and a third bather layers, the first quantum well layer being provided between the first semiconductor layer and the second quantum well layer, the second quantum well layer being provided between the second semiconductor layer and the first quantum well layer, the first barrier layer is provided between the first semiconductor layer and the first quantum well layer, the second barrier layer is provided between the second quantum well layer and the second semiconductor layer, and the third barrier layer is provided between the first quantum well layer and the second quantum well layer. ### Claim 8 (depends on 1) The device according to claim 1, wherein the active layer includes a plurality of quantum layers and a plurality of bather layers, the plurality of quantum layers including first and second quantum well layers, the plurality of barrier layers including the first barrier layer, a second barrier layer and a third barrier layers, the first quantum well layer being provided between the first semiconductor layer and the second quantum well layer, the second quantum well layer being provided between the second semiconductor layer and the first quantum well layer, the first barrier layer is provided between the first semiconductor layer and the first quantum well layer, the second barrier layer is provided between the second quantum well layer and the second semiconductor layer, and the third barrier layer is provided between the first quantum well layer and the second quantum well layer. ### Claim 9 (depends on 7) The device according to claim 7, wherein the first to third barrier layers include a material of a same composition. ### Claim 10 (depends on 7) The device according to claim 7, wherein at least one of the first and third barrier layers includes a material having a different composition from a material of the second bather layer. ### Claim 11 (depends on 1) The device according to claim 1, wherein the substrate includes gallium arsenide, the first semiconductor layer includes a first aluminum gallium arsenide mixed crystal, and the first barrier layer includes a second aluminum gallium arsenide mixed crystal, the first aluminum gallium arsenide mixed crystal having an aluminum composition ratio not more than an aluminum composition ratio of the second aluminum gallium arsenide mixed crystal. ### Claim 12 (depends on 11) The device according to claim 11, wherein the second semiconductor layer includes a third aluminum gallium arsenide mixed crystal, the third aluminum gallium arsenide mixed crystal having an aluminum composition ratio greater than the aluminum composition ratio of the first aluminum gallium arsenide mixed crystal and the aluminum composition ratio of the second aluminum gallium arsenide mixed crystal. ### Claim 13 (depends on 1) The device according to claim 1, wherein the active layer further includes a second barrier layer provided between the quantum well layer and the second semiconductor layer, the quantum well layer including an indium gallium arsenide mixed crystal, the first barrier layer including an aluminum gallium arsenide mixed crystal, the second barrier layer including an aluminum gallium arsenide phosphide mixed crystal. ### Claim 14 (depends on 1) The device according to claim 1, wherein the active layer further includes a second barrier layer provided between the quantum well layer and the second semiconductor layer, the quantum well layer including an indium gallium arsenide mixed crystal, the first barrier layer and the second barrier layer including aluminum gallium arsenide phosphide mixed crystals.