A method for producing photovoltaic thin-film solar modules, comprising, in this order, the steps: - providing an, in particular, flat substrate , - applying a back electrode layer onto the substrate , - applying a conductive barrier layer , - applying an, in particular ohmic, contact layer , - applying a, in particular kesterite or chalcopyrite, semiconductor absorber layer , - if necessary applying a first buffer layer , - if necessary applying a second buffer layer , characterised in that the production further comprises the following steps: - a first structuring step, comprising removing the applied layers along mutually spaced lines by means of laser treatment (first laser treatment) during formation of the first channels , which separate adjacent solar cells, - filling the first channels with at least one insulating material , - a second structuring step, comprising -- removing the layers which extend from the barrier layer in the direction of the semiconductor absorber layer or buffer layer(s) , along mutually spaced lines, during formation of the second channels which are adjacent to corresponding first channels or adjoin these, in particular run parallel to these, - applying a transparent front electrode layer during filling and contacting the second channels , so that adjacent solar cells are connected in series, and - a third structuring step comprising removing the layers which extend from the barrier layer in the direction of the front electrode layer along mutually spaced lines during formation of the third channels , which are adjacent to corresponding second channels or adjoin these, in particular run parallel to these, wherein the conductive barrier layer is a bidirectional barrier layer for components migrating from and/or through the back electrode layer and for components migrating from and/or through the contact layer . - providing an, in particular, flat substrate , - applying a back electrode layer onto the substrate , - applying a conductive barrier layer , - applying an, in particular ohmic, contact layer , - applying a, in particular kesterite or chalcopyrite, semiconductor absorber layer , - if necessary applying a first buffer layer , - if necessary applying a second buffer layer , - a first structuring step, comprising removing the applied layers along mutually spaced lines by means of laser treatment (first laser treatment) during formation of the first channels , which separate adjacent solar cells, - filling the first channels with at least one insulating material , - a second structuring step, comprising -- removing the layers which extend from the barrier layer in the direction of the semiconductor absorber layer or buffer layer(s) , along mutually spaced lines, during formation of the second channels which are adjacent to corresponding first channels or adjoin these, in particular run parallel to these, -- removing the layers which extend from the barrier layer in the direction of the semiconductor absorber layer or buffer layer(s) , along mutually spaced lines, during formation of the second channels which are adjacent to corresponding first channels or adjoin these, in particular run parallel to these, - applying a transparent front electrode layer during filling and contacting the second channels , so that adjacent solar cells are connected in series, and - a third structuring step comprising removing the layers which extend from the barrier layer in the direction of the front electrode layer along mutually spaced lines during formation of the third channels , which are adjacent to corresponding second channels or adjoin these, in particular run parallel to these, wherein the conductive barrier layer is a bidirectional barrier layer for components migrating from and/or through the back electrode layer and for components migrating from and/or through the contact layer . <EOS>