# US 12,218,265 B2 · Methods and systems for photovoltaic devices using silicon particles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,218,265 B2 - Document ID: US12218265B2 - Status: Granted - Kind: B2 - Application number: 17/931,462 - Filed: 2022-09-12 - Published: 2023-03-16 - Granted: 2025-02-04 - Earliest claimed: 2021-09-10 - Assignees: Leap Photovoltaics Inc. - Applicants: Leap Photovoltaics Inc. - Inventors: David Berney Needleman; Matthew Robinson; Nathanael Fehrenbach; Jimmy Mei; Arnaud Lepert - Web page: https://patentgrep.com/patent/US12218265B2 ## CPC - H10F 10/166: the Group IV-IV heterojunctions being heterojunctions of crystalline and amorphous materials, e.g. silicon heterojunction [SHJ] photovoltaic cells - H10F 77/147: {Shapes of bodies} - H10F 10/14: Photovoltaic cells having only PN homojunction potential barriers - H10F 10/164: comprising heterojunctions with Group IV materials, e.g. ITO/Si or GaAs/SiGe photovoltaic cells - H10F 71/103: {including only Group IV materials} - H10F 71/121: {The active layers comprising only Group IV materials} - H10F 71/138: {Manufacture of transparent electrodes, e.g. transparent conductive oxides [TCO] or indium tin oxide [ITO] electrodes} - H10F 77/162: Non-monocrystalline materials, e.g. semiconductor particles embedded in insulating materials (H10F77/169 takes precedence) - H10F 77/244: {made of transparent conductive layers, e.g. transparent conductive oxide [TCO] layers} - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION ## Abstract Photovoltaic devices and methods for fabricating a photovoltaic devices. The method includes applying a coating layer that surrounds each of a plurality of silicon particles. The method also includes implanting the plurality of silicon particles into a substrate layer such that an exposed portion of each of the plurality of silicon particles extends away from a surface of the substrate layer. The method further includes removing a portion of the coating layer that is positioned around the exposed portion of each of the plurality of silicon particles. The method also includes placing an insulator layer on the surface of the substrate layer. The method further includes placing a selective carrier transport layer on the exposed portion of each of the plurality of silicon particles. ## Claims ### Claim 1 A method for fabricating a photovoltaic device, comprising: applying a coating layer that surrounds each of a plurality of silicon particles, wherein the coating layer is applied to the plurality of silicon particles by deposition; implanting the plurality of silicon particles into a substrate layer such that an exposed portion of each of the plurality of silicon particles extends away from a surface of the substrate layer; removing a portion of the coating layer that is positioned around the exposed portion of each of the plurality of silicon particles; placing an insulator layer on the surface of the substrate layer; and placing a selective carrier transport layer on the exposed portion of each of the plurality of silicon particles, wherein the coating layer includes an oxide layer and a polysilicon layer, and wherein the oxide layer is positioned between each of the plurality of silicon particles and the polysilicon layer. ### Claim 2 (depends on 1) The method of claim 1, wherein the coating layer is highly-conductive for negative charge carriers and highly-resistive for positive charge carriers, and wherein the selective carrier transport layer is highly-conductive for the positive charge carriers and highly-resistive for the negative charge carriers. ### Claim 3 (depends on 1) The method of claim 1, further comprising: placing a transparent conductor layer on the selective carrier transport layer for lateral charge transport. ### Claim 4 (depends on 1) The method of claim 1, wherein the portion of the coating layer that is positioned around the exposed portion of each of the plurality of silicon particles is removed by etching. ### Claim 5 A photovoltaic device, comprising: a substrate layer including a surface; a plurality of silicon particles implanted in the substrate layer such that an exposed portion of each of the plurality of silicon particles extends away from the surface of the substrate layer; a coating layer positioned between each of the plurality of silicon particles and the substrate layer, wherein the coating layer is applied to the plurality of silicon particles by deposition; an insulator layer positioned on the surface of the substrate layer; and a selective carrier transport layer positioned on the exposed portion of each of the plurality of the silicon particles, wherein the coating layer includes an oxide layer and a polysilicon layer, and wherein the oxide layer is positioned between each of the plurality of silicon particles and the polysilicon layer. ### Claim 6 (depends on 5) The photovoltaic device of claim 5, wherein the coating layer is highly-conductive for negative charge carriers and highly-resistive for positive charge carriers, and wherein the selective carrier transport layer is highly-conductive for the positive charge carriers and highly-resistive for the negative charge carriers. ### Claim 7 (depends on 5) The photovoltaic device of claim 5, further comprising: a transparent conductor layer positioned on the selective carrier transport layer for lateral charge transport. ### Claim 8 (depends on 5) The photovoltaic device of claim 5, wherein the portion of the coating layer that is positioned around the exposed portion of each of the plurality of silicon particles is removed by etching. ### Claim 9 (depends on 5) The photovoltaic device of claim 5, wherein the coating layer is doped with an n-type dopant, wherein the coating layer surrounds each of the plurality of silicon particles, and wherein the portion of the coating layer that is positioned around the exposed portion of each of the plurality of silicon particles is doped with an p-type dopant. ### Claim 10 A method for fabricating a photovoltaic device, comprising: applying a coating layer that surrounds each of a plurality of silicon particles; implanting the plurality of silicon particles into a substrate layer such that an exposed portion of each of the plurality of silicon particles extends away from a surface of the substrate layer; placing an insulator layer on the surface of the substrate layer and on the exposed portion of each of the plurality of the silicon particles; removing a portion of the insulator layer that is positioned around a portion of the coating layer that is positioned around the exposed portion of each of the plurality of silicon particles; and generating a selective carrier transport layer by counter-doping a first portion of the coating layer to be an opposite polarity from a second portion of the coating layer, wherein the first portion of the coating layer is positioned around the exposed portion of each of the plurality of silicon particles, and wherein the second portion of the coating layer is implanted in the substrate layer. ### Claim 11 (depends on 10) The method of claim 10, wherein the first portion of the coating layer is highly-conductive for negative charge carriers and highly-resistive for positive charge carriers, and wherein the second portion of the coating layer is highly-conductive for the positive charge carriers and highly-resistive for the negative charge carriers. ### Claim 12 (depends on 10) The method of claim 10, wherein the coating layer includes amorphous silicon. ### Claim 13 (depends on 10) The method of claim 10, wherein the coating layer includes an oxide layer and a polysilicon layer. ### Claim 14 (depends on 10) The method of claim 10, wherein a major axis of each of the plurality of silicon particles is less than 100 micrometers. ### Claim 15 (depends on 1) The method of claim 1, wherein the coating layer is applied to the plurality of silicon particles before the plurality of silicon particles are implanted into the substrate layer. ### Claim 16 (depends on 5) The photovoltaic device of claim 5, further comprising an interlayer layer positioned between the coating layer and the substrate layer, wherein the interlayer layer forms an ohmic contact between each of the plurality of silicon particles and the substrate layer.