# US 10,153,387 B2 · Fabricating thin-film optoelectronic devices with added potassium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,153,387 B2 - Document ID: US10153387B2 - Status: Granted - Kind: B2 - Application number: 15/810,535 - Filed: 2017-11-13 - Published: 2018-03-08 - Granted: 2018-12-11 - Earliest claimed: 2012-12-21 - Assignees: Flisom AG; Empa - Applicants: Flisom AG; Empa - Inventors: Adrian Chirila; Stephan Buecheler; Fabian Pianezzi; Patrick Reinhard; Ayodhya Nath Tiwari - Web page: https://patentgrep.com/patent/US10153387B2 ## CPC - H10F 77/1265: {characterised by the dopants} - C23C 14/14: Metallic material, boron or silicon - C23C 14/24: Vacuum evaporation - 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) - H10P 14/22: using physical deposition, e.g. vacuum deposition or sputtering - H10P 14/2922: {being non-crystalline insulating materials, e.g. glass or polymers} - H10P 14/3436: {being chalcogenide semiconductor materials not being oxides, e.g. ternary compounds} - H10P 14/3444: {P-type} - Y02E 10/541: CuInSe2 material PV cells - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - 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) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A method (200) and deposition zone apparatus (300) for fabricating thin-film optoelectronic devices (100), the method comprising: providing a potassium-nondiffusing substrate (110), forming a back-contact layer (120); forming at least one absorber layer (130) made of an ABC chalcogenide material, adding at least two different alkali metals, and forming at least one front-contact layer (150) wherein one of said at least two different alkali metals is potassium and where, following forming said front-contact layer, in the interval of layers (470) from back-contact layer (120), exclusive, to front-contact layer (150), inclusive, the comprised amounts resulting from adding at least two different alkali metals are, for potassium, in the range of 500 to 10000 ppm and, for the other of said at least two different alkali metals, in the range of 5 to 2000 ppm and at most ½ and at least 1/2000 of the comprised amount of potassium. The method (200) and apparatus (300) are advantageous for more environmentally-friendly production of photovoltaic devices (100) on flexible substrates with high photovoltaic conversion efficiency and faster production rate. ## Claims ### Claim 1 A thin-film optoelectronic device, comprising: a substrate; a back-contact layer disposed over the substrate; an absorber layer disposed over the back-contact layer, wherein the absorber layer comprises a chalcogenide material; a buffer layer comprising an alkali metal disposed over the absorber layer; and a front-contact layer disposed over the buffer layer. ### Claim 2 (depends on 1) The thin-film optoelectronic device of claim 1, wherein the alkali metal of the buffer layer comprises potassium (K). ### Claim 3 (depends on 1) The thin-film optoelectronic device of claim 1, wherein the alkali metal of the buffer layer comprises sodium (Na). ### Claim 4 (depends on 1) The thin-film optoelectronic device of claim 1, wherein the buffer layer comprises cadmium (Cd). ### Claim 5 (depends on 4) The thin-film optoelectronic device of claim 4, wherein the alkali metal of the buffer layer comprises potassium (K). ### Claim 6 (depends on 4) The thin-film optoelectronic device of claim 4, wherein the alkali metal of the buffer layer comprises sodium (Na). ### Claim 7 (depends on 1) The thin-film optoelectronic device of claim 1, wherein the buffer layer has a thickness between about 20 nm and about 30 nm. ### Claim 8 (depends on 1) The thin-film optoelectronic device of claim 1, wherein the absorber layer comprises at least two alkali metals. ### Claim 9 (depends on 8) The thin-film optoelectronic device of claim 8, wherein the at least two alkali metals of the absorber layer comprise potassium (K) and sodium (Na). ### Claim 10 (depends on 8) The thin-film optoelectronic device of claim 8, wherein the at least two alkali metals of the absorber layer comprise potassium (K) and sodium (Na), a concentration of potassium (K) in the absorber layer is in a range of 1000 to 2000 ppm, and a concentration of sodium (Na) in the absorber layer is in a range of 5 to 500 ppm. ### Claim 11 (depends on 1) The thin-film optoelectronic device of claim 1, wherein the buffer layer has a thickness between about 20 nm and about 30 nm. ### Claim 12 A thin-film optoelectronic device, comprising: a substrate; a back-contact layer disposed over the substrate; an absorber layer disposed over the back-contact layer, wherein the absorber layer comprises a chalcogenide material; a buffer layer comprising at least two alkali metals disposed over the absorber layer; and a front-contact layer disposed over the buffer layer. ### Claim 13 (depends on 12) The thin-film optoelectronic device of claim 12, wherein the at least two alkali metals of the buffer layer comprise potassium (K) and sodium (Na). ### Claim 14 (depends on 12) The thin-film optoelectronic device of claim 12, wherein the buffer layer comprises cadmium sulfide (CdS). ### Claim 15 (depends on 12) The thin-film optoelectronic device of claim 12, wherein the absorber layer comprises at least two alkali metals. ### Claim 16 (depends on 15) The thin-film optoelectronic device of claim 15, wherein the at least two alkali metals of the absorber layer comprise potassium (K) and sodium (Na), a concentration of potassium (K) in the absorber layer is in a range of 1000 to 2000 ppm, and a concentration of sodium (Na) in the absorber layer is in a range of 5 to 500 ppm. ### Claim 17 (depends on 16) The thin-film optoelectronic device of claim 16, wherein the buffer layer has a thickness between about 20 nm and about 30 nm. ### Claim 18 A thin-film optoelectronic device, comprising: a substrate; a back-contact layer disposed over the substrate; an absorber layer disposed over the back-contact layer, the absorber layer formed of a chalcogenide material and comprising least two alkali metals including potassium (K) and sodium (Na), wherein the chalcogenide material comprises Cu(In,Ga)Se2, a concentration of potassium (K) in the absorber layer is in a range of 1000 to 2000 ppm, and a concentration of sodium (Na) in the absorber layer is in a range of 5 to 500 ppm; a buffer layer comprising potassium (K) disposed over the absorber layer wherein the buffer layer has a thickness between about 20 nm and about 30 nm; and a front-contact layer disposed over the buffer layer. ### Claim 19 (depends on 18) The thin-film optoelectronic device of claim 18, wherein the buffer layer comprises cadmium sulfide (CdS). ### Claim 20 (depends on 18) The thin-film optoelectronic device of claim 18, wherein thin-film optoelectronic device has a photovoltaic efficiency of at least 20%.