Flexible PV technology development program at IIT Bombay

This paper describes the ongoing flexible PV technology program at the Indian Institute of Technology Bombay. Flexible solar cells are fabricated by depositing amorphous silicon (a-Si) on stainless steel substrate. We have relied on hot-wire CVD technology to deposit films at 110 C, since conventional PECVD processes have proven to be inadequate at that temperature. The primary requirement was a high doping concentration of the p-type and n-type a-Si layers. The efficiency of the single-junction PV cells under simulated AM1.5 global radiation initially was 2.8%, which improved to 4.8% following optimization. Further improvements in efficiency will require development of a technique for low temperature texturing of the transparent conducting oxide film.