Development of Optimal SnO2 Contacts for CdTe Photovoltaic Applications

41349 November 20, 1996 Green Development Thin film cadmium telluride technology manifests potential advantages over competing photovoltaic (PV) technologies, such as economy of manufacturing over large areas and high stabilized efficiency. Yet, present day, large area cadmium telluride (CdTe) module efficiencies (7-8%) lag far behind laboratory scale device efficiencies (l2-15%). This project seeks to increase the efficiency of manufacturing CdTe PV modules by developing a front transparent conductor which is specifically optimized for this PV technology. The technology to be used for the development of this transparent conductor will be atmospheric pressure chemical vapor deposition (APCVD). In Phase I, fluorine doped tin oxide will be demonstrated and grown by APCVD using well established precursor chemistry. In Phase II, alternate precursor chemistry for the growth of optimized tin and indium-tin oxide materials will be demonstrated. In both phases, high efficiency CdTe devices will be fabricated and grown. In Phase II, improved sodium anti-diffusion barriers and alternate processing methods for the back contact will be established. Commercial Applications and Other Benefits as described by the awardee: This project should lead to improved transparent electrical conductor material and contacts for higher conversion efficiency of CdTe solar cells. The same technology should also lead to improved material for low emissivity glass for architectural applications. In both applications there is a positive impact on energy production and/or conservation.