Searching for a fabrication route of efficient Cu2ZnSnS4 solar cells by post-sulfuration of co-sputtered Sn-enriched precursors†
Abstract
We have systematically investigated the Sn loss in the Cu2ZnSnS4 (CZTS) thin film formation process using a sputtering/sulfuration approach with highly Sn-enriched precursors. It was found that the remaining Sn content in the CZTS absorber is strongly dependent on the peak sulfuration temperature, H2S concentration in the sulfuration atmosphere, the temperature ramping rate, and the Zn content in the precursors. Since the Sn content could be controlled by the Sn loss during the thermal treatment process, the final composition of the CZTS thin films could be manipulated simply by tailoring the Cu/Zn ratio in the precursors. With such a route, highly efficient solar cells could be achieved from Sn-rich precursors.