"Recent photovoltaic market trends point to an increased market share of thin film technologies in addition to an increased volume of module production. In particular for amorphous silicon (a-Si) and microcrystalline silicon (uc-Si) this is driven by the recently increased availability of large area deposition systems from different equipment suppliers. The present project identifies optical light confinement as a key point to increase module efficiency. The optimization of the properties of Transparent Conductive Oxide (TCO) layers at the front contact and the back reflector have to be achieved for large area deposition. Additionally, methods for the reduction of reflection losses at the front glass shall be developed. This optimization has to be done, on the one hand, for single a-Si cell modules and, on the other hand, for modules with a-Si/u-Si tandem structures, where, in the latter case, also an intermediate reflector has to be considered. Objective of the project is to push the implementation of optical layers as part of adapted thin film silicon solar cells into large scale production facilities."