Annealing Temperature Dependence of Properties of Cu2ZnSnS4 Thin Films Prepared by Sol-Gel Sulfurization Method

Cu2ZnSnS4 (CZTS) thin films were fabricated by a sol-gel sulfurization method with a rapid thermal process. The films preheated at 250 degrees C for 1h and sulfurized from 350 to 600 degrees C for 1 h were investigated. The chemical composition of sulfur was 40% for the preheated film and 50% for the films sulfurized at temperatures higher than 400 degrees C. The grain size of the films markedly increased with increasing sulfurization temperature from 400 to 450 degrees C and that of the films sulfurized at temperatures higher than 450 degrees C was similar to 2 mu m. The preheated film and the films sulfurized at temperatures lower than 400 degrees C were composed of CuxS and CZTS. The CuxS phase was eliminated from the CZTS films by sulfurization at temperatures higher than 500 degrees C. (C) 2011 The Japan Society of Applied Physics