Optimization of CuGaSe/sub 2/ for wide-bandgap solar cells

We report on enhancements to CuGaSe/sub 2/ film quality and their application to photovoltaic devices with high-voltage and low-current outputs. Using co-evaporation from elemental sources for film growth, we study deposition parameters such as substrate temperature and selenium overpressure to investigate their effect on film quality and device performance. Similar to CuInSe/sub 2/ materials, high Se overpressures change structural aspects of the CuGaSe/sub 2/ films, particularly those related to preferred orientation. Additionally, the use of higher substrate temperatures (>600/spl deg/C), also leads to significant changes on film morphology, optoelectronic properties, and device performance.