# US 10,396,218 B2 · Self-assembly pattering for fabricating thin-film devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,396,218 B2 - Document ID: US10396218B2 - Status: Granted - Kind: B2 - Application number: 15/510,473 - Filed: 2015-09-02 - Published: 2017-08-24 - Granted: 2019-08-27 - Earliest claimed: 2014-09-18 - Assignees: Flisom AG; Empa - Applicants: Flisom AG; Empa - Inventors: Patrick Reinhard; Benjamin Bissig; Stephan Buecheler; Ayodhya Nath Tiwari; Fabian Pianezzi - Web page: https://patentgrep.com/patent/US10396218B2 ## CPC - H10F 77/311: {for photovoltaic cells} - B81C 1/00031: {Regular or irregular arrays of nanoscale structures, e.g. etch mask layer (photomechanical, e.g. photolithographic, production of textured or patterned surfaces G03F7/00; lithographic processes for making patterned surfaces using printing and stamping G03F7/0002)} - H10F 10/00: Individual photovoltaic cells, e.g. solar cells (electrolytic light-sensitive devices, e.g. dye-sensitised solar cells, H01G9/20) - H10F 19/50: Integrated devices comprising at least one photovoltaic cell and other types of semiconductor or solid-state components (H10F19/75 takes precedence) - H10F 77/126: {comprising only Group I-III-VI chalcopyrite materials, e.g. CuInSe2, CuGaSe2 or CuInGaSe2 [CIGS]} - H10F 77/30: Coatings (arrangements for preventing damage to photovoltaic cells caused by corpuscular radiation H10F77/80) - H10F 77/315: {the coatings being antireflective or having enhancing optical properties} - H10F 77/413: {directly associated or integrated with the devices, e.g. back reflectors (directly associated or integrated with photovoltaic cells H10F77/42)} - H10P 14/00: Formation of materials, e.g. in the shape of layers or pillars - H10P 14/20: of semiconductor materials - B81C 2201/0149: Forming nanoscale microstructures using auto-arranging or self-assembling material - H10P 14/2922: {being non-crystalline insulating materials, e.g. glass or polymers} - H10P 14/3241: {being conductive materials} - H10P 14/3436: {being chalcogenide semiconductor materials not being oxides, e.g. ternary compounds} - H10P 14/38: {characterised by treatments done after the formation of the materials} - 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 - B81C: PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS (making microcapsules or microballoons B01J13/02; processes or apparatus specially adapted for the manufacture or treatment of piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/01) - 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) for fabricating patterns on the surface of a layer of a device (100), the method comprising: providing at least one layer (130, 230); adding at least one alkali metal (235); controlling the temperature (2300) of the at least one layer, thereby forming a plurality of self-assembled, regularly spaced, parallel lines of alkali compound embossings (1300, 1305) at the surface of the layer. The method further comprises forming cavities (236, 1300) by dissolving the alkali compound embossings. The method (200) is advantageous for nanopatterning of devices (100) without using templates and for the production of high efficiency optoelectronic thin-film devices (100). ## Claims ### Claim 1 A method for fabricating patterns on a surface of a layer of a solar cell, an optoelectronic, or a photovoltaic device formed on a substrate, comprising: adding at least one alkali metal to at least one layer that is disposed on the substrate; and processing the at least one layer to form a plurality of embossings at the surface of the at least one layer by a method comprising: forming a plurality of alkali crystals on the surface of the at least one layer, wherein the plurality of alkali crystals comprise at least one alkali metal; and forming the alkali crystals so that the formed alkali crystals are disposed within a portion of the at least one layer, and thereby forming at least a first line of regularly spaced embossings that are adjacent to at least a second line of regularly spaced embossings within at least one region of the at least one layer. ### Claim 2 (depends on 1) The method according to claim 1, wherein the at least one alkali metal comprises potassium. ### Claim 3 (depends on 1) The method according to claim 1, wherein the step of adding at least one alkali metal further comprises adding sulfur (S), selenium (Se), or tellurium (Te). ### Claim 4 (depends on 1) The method according to claim 1, wherein the at least one layer comprises a chalcogenide material, wherein the chalcogenide material comprises at least one first element that includes copper (Cu) or silver (Ag), at least one second element that includes indium (In), gallium (Ga), or aluminum (Al), and at least one third element that includes sulfur (S), selenium (Se), or tellurium (Te). ### Claim 5 (depends on 1) The method according to claim 1, wherein the at least one layer comprises Cu(In,Ga)Se2. ### Claim 6 (depends on 1) The method according to claim 1, wherein the step of processing the at least one layer comprises controlling the temperature of the at least one layer between a range from about 310° C. to about 380° C. ### Claim 7 (depends on 1) The method according to claim 1, further comprising coating at least a portion of the surface of the at least one layer with a functional layer, wherein the functional layer comprises a passivation layer, a buffer layer or a conductive layer. ### Claim 8 (depends on 1) The method according to claim 1, further comprising forming at least one cavity by dissolving at least a portion of at least one of the alkali crystals into the at least one layer, wherein the process of forming the at least one cavity comprises: forming at least one buffer layer; adding an element that has an oxidation state +1 or +2 element to a layer surface of the at least one layer; wetting the surface of the at least one layer with a solution comprising water; and wetting the surface of the at least one layer with a diluted aqueous ammonia solution, wherein the molarity of the diluted aqueous ammonia solution is in a range from about 1 M to about 20 M. ### Claim 9 (depends on 8) The method according to claim 8, further comprising a step of filling at least a portion of the at least one cavity by forming a filler layer onto at least one cavity. ### Claim 10 (depends on 1) The method according to claim 1, wherein the substrate is delivered between a delivery roll and a take-up roll of a roll-to-roll manufacturing apparatus during the process of fabricating patterns on the surface of the at least one layer of a device. ### Claim 11 A photovoltaic device, comprising: at least one layer that is disposed on a substrate; and a plurality of embossings at a surface of the at least one layer, and at least a portion of the plurality of embossings resulting from a process comprising: forming a plurality of alkali crystals that comprise at least one alkali metal on the surface of the at least one layer; and self-assembling the alkali crystals so that the formed plurality of alkali crystals are disposed within the surface of the at least one layer, and thereby forming at least a first line of regularly spaced embossings that is adjacent to at least a second line of regularly spaced embossings within at least one region of the at least one layer. ### Claim 12 (depends on 11) A device according to claim 11, wherein the at least one alkali metal comprises potassium. ### Claim 13 (depends on 11) A device according to claim 11, wherein the long axis of at least one embossing in at least one line of regularly spaced embossings is collinear or approximately collinear with the at least one line. ### Claim 14 (depends on 11) A device according to claim 11, wherein at least one line of regularly spaced embossings is embossed along at least one crystal striation of at least one region of the surface of the at least one layer. ### Claim 15 (depends on 11) A device according to claim 11, wherein at least one region is positioned on a surface of a crystal at the surface of the at least one layer. ### Claim 16 (depends on 11) A device according to claim 11, wherein at least one embossing is comprised in the at least one layer and at least one functional layer, wherein the functional layer comprises a passivation layer, a buffer layer or a conductive layer. ### Claim 17 (depends on 11) A device according to claim 11, wherein at least one embossing has a shape of a cavity in the at least one layer comprising at least one cavity at a location corresponding to an at least partly dissolved embossing. ### Claim 18 (depends on 11) A device according to claim 11, wherein at least one embossing comprises an electrical point contact between the substrate and at least one filler layer, at least some material of which is positioned within the at least one embossing. ### Claim 19 (depends on 11) A device according to claim 11, wherein the at least one layer comprises a reacted layer. ### Claim 20 (depends on 11) A device according to claim 11, wherein the at least one layer comprises a chalcogenide material, wherein the chalcogenide material comprises at least one first element that includes copper (Cu) or silver (Ag), at least one second element that includes indium (In), gallium (Ga), or aluminum (Al), and at least one third element that includes sulfur (S), selenium (Se), or tellurium (Te). ### Claim 21 (depends on 11) A device according to claim 11, wherein the at least one layer comprises Cu(In,Ga)Se2. ### Claim 22 (depends on 11) A device according to claim 11, wherein the device is a thin-film optoelectronic device. ### Claim 23 (depends on 11) A device according to claim 11, wherein the device comprises a flexible substrate. ### Claim 24 A method for fabricating patterns of alkali metal containing material on a layer disposed on a substrate, which is useful for forming a solar cell, an optoelectronic, or a photovoltaic device, comprising: depositing an alkali metal on the layer disposed on the substrate; and forming a plurality of convex embedded alkali crystals on a surface of the layer, wherein the plurality of convex embedded alkali crystals form a regularly spaced first line that are adjacent to a regularly spaced second line, and the forming the plurality of convex embedded alkali crystals comprises self-assembly of the plurality of convex embedded alkali crystals.