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

Cu-poor Cu2-xSnS3 (CTS) powders with x = 0.0-0.3 prepared by mixing the elemental powders and post-heating at 600 degrees C in N-2 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 degrees C for 10 min under a 1% H2S/N-2 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 Cu1.9SnS3 powders by mixing the elemental powders and post-heating at various temperatures. The CTS solar cell with Cu1.9SnS3 powder prepared by post-heating at 300 degrees C showed an efficiency of 1.38% with V-oc of 182mV, J(sc) of 21.7mA/cm(2), and FF of 0.350. (C) 2014 The Japan Society of Applied Physics