# US 8,569,099 B2 · Enhanced methods for fabricating solar cells with textured surfaces > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,569,099 B2 - Document ID: US8569099B2 - Status: Granted - Kind: B2 - Application number: 13/595,404 - Filed: 2012-08-27 - Published: 2013-02-21 - Granted: 2013-10-29 - Earliest claimed: 2007-02-15 - Assignees: Massachusetts Institute of Technology - Applicants: Emanuel M. Sachs; James F. Bredt - Inventors: Emanuel M. Sachs; James F. Bredt - Web page: https://patentgrep.com/patent/US8569099B2 ## CPC - H10F 77/703: {of the semiconductor bodies, e.g. textured active layers} - C23C 18/1607: {by direct patterning} - C23C 18/1608: {from pretreatment step, i.e. selective pre-treatment} - C23C 18/161: {from plating step, e.g. inkjet} - C23C 18/1635: {Composition of the substrate} - C23C 18/1653: {Two or more layers with at least one layer obtained by electroless plating and one layer obtained by electroplating} - C23C 18/1692: {Heat-treatment} - C23C 18/1893: {with use of organic or inorganic compounds other than metals, first} - C25D 5/011: {Electroplating using electromagnetic wave irradiation (using locally applied electromagnetic radiation C25D5/024)} - C25D 5/02: Electroplating of selected surface areas - C25D 5/022: {using masking means} - C25D 7/126: {for solar cells} - H10F 77/211: {for photovoltaic cells} - H10F 77/315: {the coatings being antireflective or having enhancing optical properties} - Y02E 10/50: Photovoltaic [PV] energy - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - C25D: PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract Semiconductor photovoltaic cells have surfaces that are textured for processing and photovoltaic reasons. The absorbing regions may have grooves that reduce loss of solar energy that would otherwise be lost by reflection. One form of texturing has grooves and ridges. The cell also includes metallizations for collecting generated electrical carriers and conducting them away, which may be channels. The topography is considered during production, using a process that takes advantage of the topography to govern what locations will receive a specific processing, and which locations will not. Liquids are treated directly into zones. They migrate throughout a zone and act upon the locations contacted. They do not migrate to other zones, due to impediments to flow, such as edges, walls and ridges. Liquid may also be deposited and migrate within a zone, to block or mask a subsequent activity, such as etching. ## Claims ### Claim 1 A method for fabricating a photovoltaic device, comprising: a. forming a topographically textured semiconductor surface of a semiconductor body; b. forming a junction involving the semiconductor body; c. applying a liquid to a first zone of the surface which application is guided at least in part by the surface texture, and which liquid remains excluded from a second zone of the surface that is contiguous with the first zone, the exclusion arising due, at least in part, to the surface texture; d. allowing a reaction to occur in one of the first zone and the second zone of the surface but not both simultaneously; and e. applying a metal coating to the semiconductor surface capable of collecting electric power from the semiconductor and further distribution to an electronic system. ### Claim 2 A method for fabricating a photovoltaic device, comprising: a. forming a topographically textured semiconductor surface of a semiconductor body; b. forming a junction involving the semiconductor body; c. applying a reactive liquid to a first zone of the surface which application is guided at least in part by the surface texture, and which liquid remains excluded from a second zone of the surface that is contiguous with the first zone, the exclusion arising due, at least in part, to the surface texture; and d. allowing a chemical reaction to occur in one of the first zone and the second zone of the surface but not both simultaneously. ### Claim 3 (depends on 2) The method of claim 2, further comprising the step of creating a chemically modified volume of material comprising an electronic contact with the semiconductor, within the first zone due to the chemical reaction. ### Claim 4 (depends on 2) The method of claim 2, further wherein the first zone comprises a metallization region of the photovoltaic device. ### Claim 5 (depends on 4) The method of claim 4, further wherein the first zone comprises a busbar region of a photovoltaic device and a gridline region of a photovoltaic device. ### Claim 6 (depends on 4) The method of claim 4, further wherein the first zone comprises a gridline region of a photovoltaic device. ### Claim 7 (depends on 2) The method of claim 2, further wherein the chemical reaction forms a metallic coating within the first zone. ### Claim 8 (depends on 2) The method of claim 2, further wherein the chemical reaction is a catalyzing reaction with a catalyst that specifically enables the formation of a metallic film by electroless plating within the first zones. ### Claim 9 (depends on 2) The method of claim 2, further wherein the chemical reaction forms a metallic coating by electroless plating within the first zone. ### Claim 10 (depends on 2) The method of claim 2, further wherein the chemical reaction forms a metallic coating within the first zone using an organometallic material. ### Claim 11 A method for fabricating a photovoltaic device, comprising: a. forming a topographically textured semiconductor surface of a semiconductor body; the semiconductor being selected from the group consisting of: silicon, germanium and gallium arsenide; b. forming a junction involving the semiconductor body; c. applying a liquid to a first zone of the surface which application is guided at least in part by the surface texture, and which liquid remains excluded from a second zone of the surface that is contiguous with the first zone, the exclusion arising due, at least in part, to the surface texture; and d. allowing a reaction to occur in one of the first zone and the second zone of the surface but not both simultaneously. ### Claim 12 A method for fabricating a photovoltaic device, comprising: a. forming a topographically textured semiconductor surface of a semiconductor body; b. forming a junction involving the semiconductor body; c. applying a liquid to a first zone of the surface, the first zone of the textured surface comprising at least one channel having a first and a second portion, which application is guided at least in part by the surface texture, and which liquid remains excluded from a second zone of the surface that is contiguous with the first zone, the exclusion arising due, at least in part, to the surface texture; and d. allowing a reaction to occur in one of the first zone and the second zone of the surface but not both simultaneously. ### Claim 13 A method for fabricating a photovoltaic device, comprising: a. forming a topographically textured semiconductor surface of a semiconductor body; the textured semiconductor surface comprising a thin semiconductor film supported by a textured substrate body; b. forming a junction involving the semiconductor body; c. applying a liquid to a first zone of the surface which application is guided at least in part by the surface texture, and which liquid remains excluded from a second zone of the surface that is contiguous with the first zone, the exclusion arising due, at least in part, to the surface texture; and d. allowing a reaction to occur in one of the first zone and the second zone of the surface but not both simultaneously. ### Claim 14 A method for fabricating a photovoltaic device, comprising: a. forming a topographically textured semiconductor surface of a semiconductor body; the textured semiconductor surface comprising a thin semiconductor film supported by a textured superstrate body; b. forming a junction involving the semiconductor body; c. applying a liquid to a first zone of the surface which application is guided at least in part by the surface texture, and which liquid remains excluded from a second zone of the surface that is contiguous with the first zone, the exclusion arising due, at least in part, to the surface texture; and d. allowing a reaction to occur in one of the first zone and the second zone of the surface but not both simultaneously. ### Claim 15 (depends on 14) The method of claim 14, the superstrate comprising a glass. ### Claim 16 (depends on 13) The method of claim 13, the substrate comprising a glass. ### Claim 17 A method for fabricating a photovoltaic device, comprising: a. forming a topographically textured semiconductor surface of a semiconductor body; b. forming a junction involving the semiconductor body; c. applying a blocking material liquid to a first zone of the surface which application is guided at least in part by the surface texture, and which liquid remains excluded from a second zone of the surface that is contiguous with the first zone, the exclusion arising due, at least in part, to the surface texture; and d. allowing a chemical reaction to occur in the second zone. ### Claim 18 (depends on 17) The method of claim 17, further wherein the blocking material hardens after it is applied. ### Claim 19 (depends on 17) The method of claim 17, further comprising before the step of applying a liquid, the step of coating the first and second zones with an antireflection material, wherein the step of applying a blocking material comprises the step of applying a material that protects the antireflection coating against a chemical etchant.