# US 12,009,445 B2 · Method of patterning a thin-film photovoltaic layer stack > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,009,445 B2 - Document ID: US12009445B2 - Status: Granted - Kind: B2 - Application number: 17/800,617 - Filed: 2021-02-17 - Published: 2023-03-16 - Granted: 2024-06-11 - Earliest claimed: 2020-02-20 - Applicants: Nice Solar Energy GmbH - Inventors: Shuping Lin; Raffael Reineker; Hongqing Shan; Joachim Leopold Ludwig Müller; Bernd Sprecher; Kay Ogassa - Web page: https://patentgrep.com/patent/US12009445B2 ## CPC - H10F 19/33: Patterning processes to connect the photovoltaic cells, e.g. laser cutting of conductive or active layers - H10F 71/00: Manufacture or treatment of devices covered by this subclass (patterning processes to connect thin photovoltaic cells in integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/33; manufacture or treatment of encapsulations or containers for integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/80; manufacture or treatment of integrated devices, or assemblies of multiple devices, comprising at least one element in which radiation controls the flow of current H10F39/00) - H10F 77/126: {comprising only Group I-III-VI chalcopyrite materials, e.g. CuInSe2, CuGaSe2 or CuInGaSe2 [CIGS]} - H10F 77/211: {for photovoltaic cells} - Y02E 10/50: Photovoltaic [PV] energy - Y02E 10/541: CuInSe2 material PV cells - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A method of patterning a thin-film photovoltaic layer stack includes the steps of providing a continuous layer stack comprising a planar substrate, a first electrode layer on the substrate and a photovoltaic layer on the first electrode layer, immersing the layer stack into an electrically conductive solution, applying a bias voltage between the electrolyte solution and the first electrode layer and converting a first material or a first material composition provided in at least a first portion of the layer stack into a first reaction product by an electrochemical reaction, wherein the first reaction product has an electrical conductivity that is lower than an electrical conductivity of the first material or first material composition, or removing a first material or a first material composition provided in at least a first portion of the layer stack by an electrochemical reaction. ## Claims ### Claim 1 A method of patterning a thin-film photovoltaic layer stack comprising: providing a continuous layer stack, the layer stack comprising a substrate, a first electrode layer on the substrate and a photovoltaic layer on the first electrode layer; immersing the layer stack into an electrically conductive solution; applying a bias voltage between the electrically conductive solution and the first electrode layer; selectively removing the photovoltaic layer along a first line and forming a first trench in the photovoltaic layer before or after immersing the layer stack into the electrically conductive solution; and converting a first material or a first material composition provided in at least a first portion of the layer stack into a first reaction product by an electrochemical reaction, wherein the first reaction product has an electrical conductivity that is lower than an electrical conductivity of the first material or the first material composition, wherein the first material or the first material composition of the first portion of the layer stack comprises Molybdenum (Mo), and wherein the first reaction product comprises MoOx, with 2.52z; and wherein the first reaction product comprises a CIGS semiconductor material with a composition of Cux(In,Ga)ySez,Ow, with x+3y≤2(w+z) and w>0. ### Claim 19 (depends on 18) The method according to claim 18, wherein selectively removing the photovoltaic layer and forming the first trench comprises: applying a laser beam onto the layer stack and moving the laser beam along the first line; or moving a mechanical scribing tool along the first line. ### Claim 20 (depends on 18) The method according to claim 18, wherein the first portion of the layer stack is a side edge of the photovoltaic layer extending along the first trench. ### Claim 21 (depends on 18) The method according to claim 18, wherein immersing the layer stack in the electrically conductive solution includes immersing the layer stack in a basic solution and thereafter immersing the layer stack in a neutral pH or acidic conductive solution. ### Claim 22 (depends on 18) The method according to claim 18, wherein a window layer is deposited onto the layer stack, and wherein the photovoltaic layer is selectively removed along a second line to form a second trench parallel to the first trench and adjacent to the first trench. ### Claim 23 (depends on 22) The method according to claim 22, wherein a second electrode layer is deposited onto the layer stack, and wherein the photovoltaic layer is selectively removed along a third line to form a third trench parallel to the second trench and adjacent to the second trench.