A simple one-step chemical bath process was developed to fabricate Cu2ZnSnS4 (CZTS) thin films. Effects of pH value and ZnCl2 precursor content on the formation of CZTS were investigated. The best process parameters were a pH value of 3.5-4 and a ZnCl2 content of 1.75 mmoL for deposition of high quality of CZTS films. The films consist of kesterite phase CZTS nanocrystals and exhibit a band-gap of similar to 1.48 eV. A conversion efficiency of 0.30% was achieved in one of the CZTS thin film solar cells. The route developed here may provide an alternative approach to produce low-cost and large area solar cells. (C) 2013 Elsevier B.V. All rights reserved.