Dynamically deposited thin-film silicon solar cells on imprinted foil using linear PECVD sources

ECN is developing nip silicon solar cells based on amorphous and microcrystalline thin films on foil. To optimise light trapping we create nanoscale texturisation of the back reflector of the cells by imprinting a UV curable coating layer on the foil. This contribution focuses on i) the suitability of imprinted UV curable coating layers on foil as substrate for thin film Si solar cells; ii) inline PECVD of silicon layers, using linear plasma sources. We show that amorphous silicon solar cells deposited on foil with random texture can achieve the same good light trapping as cells on Asahi U-type glass (J_sc~15-16 mA/cm²). Furthermore, we show that a-Si nip cells on foil, processed in dynamic mode in an industrial pilot roll-to-roll system for 30 cm wide foils, can achieve efficiencies (of over 7%) which are only slightly less than for cells made in a UHV lab-scale cluster tool. Future work will focus on developing and implementing optimised periodic nanotextures for μc-Si and micromorph tandem cells and the further development of cells in order to achieve efficiencies of more than 10% at high deposition rates.