Chemical vapor deposition for ultralightweight thin-film solar arrays

The development of thin-film solar cells on flexible, lightweight, space-qualified substrates provides an attractive cost solution to fabricating solar arrays with high specific power, (W/kg). The use of a polycrystalline chalcopyrite absorber layer for thin film solar cells is considered as the next generation photovoltaic devices. A key technical issues outlined in the 2001 US Photovoltaic Roadmap, is the need to develop low cost, high throughput manufacturing for high-efficiency thin film solar cells. At NASA GRC we have focused on the development of new single-source-precursors (SSP's) and their utility to deposit the chalcopyrite semiconducting layer (CIS) onto flexible substrates for solar cell fabrication. The syntheses and thermal modulation of SSP's via molecular engineering is described. Thin-film fabrication studies demonstrate the SSP's can be used in a spray CVD process, for depositing CIS at reduced temperatures, which display good electrical properties, suitable for PV devices.