Development of a reproducible laser structuring process of stacked thin films on ultra-barrier films for organic solar devices

Aim of the work presented in this paper is the development of reproducible and scalable laser processes for selective ablation of stacked thin films on top of an integrated ultra-barrier foil. Industrial manufacturing of functional modules with defined opto-electrical properties requires various coating and structuring processes. Therefore, transparent front contact layer (P1), the absorber layer stack (P2) and the back contact (P3) have to be structured without damage to the ultra-barrier underneath. Focus of the paper is the P1 process as most critical laser process. The laser parameter investigation was performed on sheet-to-sheet samples prepared with a process suitable for upscaling to roll to roll production on 1200 mm web width. A test process was developed in order to find the optimal laser ablation settings for each scribe which include an electrical isolation test and a barrier damage test (optical Ca-test). With this test routine it was possible to identify the process windows for two TCO types without barrier damage and promising solar device performances.