Comparison of Cu2ZnSnS4 thin films and solar cell performance using Zn target with ZnS target

Cu2ZnSnS4 (CZTS) thin films are considered as ideal absorption materials for next generation thin film solar cells due to their excellent optical and electrical properties as well as low cost. Two types of CZTS thin films were prepared via sputtering with Zn or ZnS targets (Cu/SnS/Zn and Cu/SnS/ZnS). After sulfurization, the microstructure and distribution of the elements and the electrical properties of the thin films obtained using the Zn and ZnS targets were compared. The CZTS thin films obtained from the Zn target exhibit a large grain, smooth surface and less ZnS accumulation between the CZTS and Mo, resulting in improved junction characteristics and electrical properties. The CZTS solar cells that were fabricated with the Zn target exhibit an improved conversion efficiency of 5.06% relative to that of CZTS solar cells using the ZnS target. (C) 2015 Elsevier B.V. All rights reserved.