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.