# US 12,615,855 B1 · Near-omnidirectional InP nanowire-HBT photodetectors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,615,855 B1 - Document ID: US12615855B1 - Status: Granted - Kind: B1 - Application number: 18/162,123 - Filed: 2023-01-31 - Granted: 2026-04-28 - Earliest claimed: 2023-01-31 - Assignees: Northrop Grumman Systems Corporation - Applicants: Northrop Grumman Systems Corporation - Inventors: Katherine T. Fountaine; Philip W. C. Hon; Augusto L. Gutierrez-Aitken - Web page: https://patentgrep.com/patent/US12615855B1 ## CPC - H10F 30/245: {Bipolar phototransistors} - H10F 77/1437: {Quantum wires or nanorods} - H10D 10/021: {of heterojunction BJTs [HBT]} - H10D 62/119: {Nanowire, nanosheet or nanotube semiconductor bodies} - H10D 62/133: {Emitter regions of BJTs} - H10D 62/177: {Base regions of bipolar transistors, e.g. BJTs or IGBTs} - H10D 62/85: being Group III-V materials, e.g. GaAs - H10D 84/01: Manufacture or treatment - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES ## Abstract A photodetector including a high electron mobility transistor (HEMT) device or an indium phosphide (InP)-based heterojunction bipolar transistor (HBT) device including a collector layer, a base layer formed on the collector layer and an emitter layer formed on the base layer. The photodetector also includes a nanowire array electrically coupled to the HEMT device or the base layer of the HBT device, and may include a first sub-array positioned on one side of the emitter layer and second sub-array positioned on an opposite side of the emitter layer. The nanowire array includes a plurality of spaced apart and conical-shaped InP nanowires encased in a transparent medium, and are operable to absorb light over a wavelength band of 400-925 nm and convert the light to an electrical signal that is received by the HEMT or HBT device. ## Claims ### Claim 1 A detector comprising: a semiconductor device; and a nanowire array electrically coupled to the semiconductor device, said nanowire array including a plurality of spaced apart nanowires, said plurality of nanowires being operable to absorb radiation over a predetermined wavelength band and convert the radiation to an electrical signal that is received and amplified by the semiconductor device, wherein the semiconductor device is a heterojunction bipolar transistor (HBT) device including a collector layer, a base layer and an emitter layer, and wherein the nanowire array is separate from and formed directly on and in electrical contact with the base layer and laterally adjacent to the emitter layer. ### Claim 2 (depends on 1) The detector according to claim 1 wherein the nanowire array includes a first nanowire sub-array position on one side of the emitter layer and a second nanowire sub-array positioned on an opposite side of the emitter layer. ### Claim 3 (depends on 1) The detector according to claim 1 wherein the HBT device is an indium phosphide (InP) HBT device and the plurality of nanowires are InP nanowires. ### Claim 4 (depends on 1) The detector according to claim 1 wherein the nanowire array covers an entire exposed portion of the base layer. ### Claim 5 (depends on 1) The detector according to claim 1 wherein the detector is a photodetector and the nanowire array absorbs light. ### Claim 6 (depends on 5) The detector according to claim 5 wherein the nanowire array absorbs light in 400-925 nm wavelength band. ### Claim 7 (depends on 1) The detector according to claim 1 wherein each nanowire is conical-shaped. ### Claim 8 (depends on 1) The detector according to claim 1 wherein the nanowire array includes a contact that is transparent to the radiation and in electrical contact with the plurality of nanowires. ### Claim 9 (depends on 1) The detector according to claim 1 wherein a length and diameter of the plurality of nanowires is selected based on the wavelength band. ### Claim 10 (depends on 1) The detector according to claim 1 wherein a length of the plurality of nanowires is in a range of 1-3 μm and a diameter of the nanowires is in a range of 50 nm to 200 nm. ### Claim 11 (depends on 1) The detector according to claim 1 has a field-of-view of +/−60° with near unity absorption. ### Claim 12 A photodetector comprising: an indium phosphide (InP)-based heterojunction bipolar transistor (HBT) device including a collector layer, a base layer formed on the collector layer and an emitter layer formed on the base layer; and a nanowire array electrically coupled to the base layer, said nanowire array including a first sub-array positioned on one side of the emitter layer and second sub-array positioned on an opposite side of the emitter layer, each sub-array including a plurality of spaced apart and conical-shaped InP nanowires encased in a transparent medium, said plurality of nanowires being operable to absorb light over a wavelength band of 400-925 nm and convert the light to an electrical signal that is received by the base layer, wherein the nanowire array is separate from and formed directly on and in electrical contact with the base layer and laterally adjacent to the emitter layer. ### Claim 13 (depends on 12) The photodetector according to claim 12 wherein the first and second sub-arrays each include a contact that is transparent to light opposite to the base layer and in electrical contact with the plurality of nanowires. ### Claim 14 (depends on 12) The photodetector according to claim 12 wherein the nanowire array covers an entire exposed portion of the base layer. ### Claim 15 (depends on 12) The photodetector according to claim 12 wherein a length of the plurality of nanowires is in a range of 1-3 μm and a diameter of the nanowires is in a range of 50 nm to 200 nm. ### Claim 16 (depends on 12) The photodetector according to claim 12 has a field-of-view of +/−60° with near unity absorption. ### Claim 17 (depends on 12) The photodetector according to claim 12 wherein the photodetector is part of a receiver for optical communications. ### Claim 18 (depends on 12) The photodetector according to claim 12 wherein the photodetector is part of an imager. ### Claim 19 A detector comprising: a semiconductor device; and a nanowire array electrically coupled to the semiconductor device, said nanowire array including a plurality of spaced apart nanowires and an InP layer electrically coupled to the plurality of nanowires, said plurality of nanowires being operable to absorb radiation over a predetermined wavelength band and convert the radiation to an electrical signal that is received and amplified by the semiconductor device, wherein the semiconductor device is a high electron mobility transistor (HEMT) device including a channel layer, and wherein the nanowire array and the HEMT device are spaced apart on a common substrate and the InP layer is electrically coupled to the channel layer by a conductive bridge. ### Claim 20 (depends on 19) The detector according to claim 19 wherein the substrate is an InP:Fe substrate and the channel layer is an InGaAs channel layer.