Fabrication of Cu2SnS3 solar cells by screen-printing and high-pressure sintering process

Abstract

Cu-poor Cu_{2− x} SnS₃ (CTS) powders with x = 0.0–0.3 prepared by mixing the elemental powders and post-heating at 600 °C in N₂ gas were analyzed by X-ray diffraction and ultraviolet–visible–near-infrared (UV–vis–NIR) spectroscopy. The area of the solid solution region in the Cu-poor side of CTS was quite small in the Cu₂S–SnS₂ pseudo-binary system. We deposited CTS films by a screen printing and high-pressure sintering (PHS) process and post-annealing at 575 °C for 10 min under a 1% H₂S/N₂ gas atmosphere. The solar cells were fabricated with a device structure of Ag/indium tin oxide (ITO)/i-ZnO/CdS/Cu₂SnS₃ (CTS)/Mo/soda-lime glass. The CTS solar cell with x = 0.1 showed maximum efficiency of 1.03%. Then, we prepared Cu_1.9SnS₃ powders by mixing the elemental powders and post-heating at various temperatures. The CTS solar cell with Cu_1.9SnS₃ powder prepared by post-heating at 300 °C showed an efficiency of 1.38% with V _oc of 182 mV, J _sc of 21.7 mA/cm², and FF of 0.350.