Research on Polycrystalline Thin-Film Submodules Based on CuInSe2 Materials: Final Technical Report, 14 December 1995 - 31 December 1996

This report describes the progress made at Solarex for both device and module efficiencies from the inception of the CIS research program to the present. A rapid improvement in efficiency is apparent, culminating in the fabrication of a 15.5%-efficient device (total area) and a 13%-efficient submodule (aperture area). The device represents the highest efficiency device measured by NREL for anyindustrial source at that time. The module represented a new world record for any thin-film module at the time of its measurement. The factors leading to these results included improvements in absorber layer quality, transparent contacts, scribing and module formation processes. Other elements critical to the commercialization of CIS-based photovoltaics were also successfully attacked, includingreduction of absorber deposition times into the range of 10 to 20 minutes and the successful scale-up of the absorber deposition process to greater than 500 cm2. Other requisite processes saw continued development, such as a rapid, low-cost method for transparent window deposition. Subsequent to the demonstration of 13% module efficiency, scribing techniques were further improved that resultedin a reduction in shunt losses and higher module fill factor. This improvement, and the concomitant gain in fill factor, would yield efficiencies approaching 14% on modules having a short-circuit and open-circuit voltage comparable to the record module.