Producing photovoltaic modules useful for converting sunlight into electrical energy, comprises string-ribbon-method, post treatment of the string-ribbon-wafers, and producing the photovoltaic modules by assembling and electrical connection

摘要

Producing photovoltaic modules having multiple solar cells made of silicon, comprises (a) producing multi-crystalline string-ribbon-wafer by silicon crystallization of a liquid silicon melt according to the string-ribbon-method (1), (b) post treatment of the solidified string-ribbon-wafers, where the string-ribbon-wafers during the post treatment are subjected to several post treatment processes, preferably e.g. an etching process (4) and/or a diffusion process (5), and (c) producing the photovoltaic modules (3) by assembling and electrically connecting the solar cells in a housing. Producing photovoltaic modules having multiple solar cells made of silicon, comprises (a) producing multi-crystalline string-ribbon-wafer by silicon crystallization of a liquid silicon melt according to the string-ribbon-method (1), (b) post treatment of the solidified string-ribbon-wafers for producing solar cells, where the string-ribbon-wafers during the post treatment are subjected to several post treatment processes, preferably an etching process (4), a diffusion process (5), a coating process and/or a metallization process, and (c) producing the photovoltaic modules (3) by assembling and electrically connecting the solar cells in a housing, where: the string-ribbon-wafers are subjected to a temperature annealing process at least once during the post treatment; the string-ribbon-wafers are heated to a predetermined annealing temperature during the temperature annealing process, within a heating period, then subsequently annealed during a retention time according to the annealing temperature, and then cooled during a cooling period; the annealing temperature is 750-1050[deg] C; and the sum of heating time and retention time is 30-240 minutes. Independent claims are also included for: (1) a string-ribbon-wafer for producing solar cells for photovoltaic modules comprising subjecting the string-ribbon-wafer at least once to a temperature annealing process, then subsequently annealed during a retention time according to the annealing temperature, and then cooled during a cooling period; and (2) a photovoltaic module having multiple solar cells made of silicon, which are produced from the string-ribbon-wafers.