This paper addresses the development of silicon thin film solar cells by plasma-enhanced chemical vapour deposition (PECVD) at 13.56 MHz excitation frequency. For an efficient light trapping we focus on textured ZnO:Al films prepared by sputtering and post deposition wet chemical etching. These films were optimised with respect to conductivity, transparency and film structure, the latter one controlling the surface texture obtained after etching. A-Si:H/μc-Si:H tandem cells yielded stable efficiencies up to 11.2% for a cell area of 1 cm 2, Initial module efficiencies of 10.8% and 10.1% were achieved for aperture areas of 64 cm 2 and 676 cm 2, respectively.