This project contributed significantly to further developments in the field of Cu(In,Ga)Se2 thin film solar cells on flexible substrates such as plastic and metal foils. Process optimization at low temperature deposition conditions resulted in a new world record of the highest achieved solar conversion efficiency for any solar cell on plastic substrate. 14.1% efficient cells were obtained with a prospect for efficiencies beyond 15% by reduction of reflection losses. Preliminary tests of larger area solar cells connected with metal grids resulted in flexible solar cells of 8% efficiency on 16 cm2. Further, Improvements in efficiency of cells on alternative back contact materials such as transparent conducting oxides were made and 6.7% efficient solar cells on aluminium foils, an alternative low-cost substrate material, were shown. For up scaling the laboratory scale processes to industrial manufacturing an inline deposition system was designed and installed. This equipment was used to investigate the coevaporation of absorber layer deposition on substrate sizes of up to 30x30 cm2. Improvement of the evaporation system is necessary to fulfil the requirements of homogeneous large area deposition.
