Abstract
Cu2ZnSnS4 (CZTS) thin films were fabricated by a sol–gel sulfurization method with a rapid thermal process. The films preheated at 250 °C for 1 h and sulfurized from 350 to 600 °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 °C. The grain size of the films markedly increased with increasing sulfurization temperature from 400 to 450 °C and that of the films sulfurized at temperatures higher than 450 °C was ∼2 µm. The preheated film and the films sulfurized at temperatures lower than 400 °C were composed of CuxS and CZTS. The CuxS phase was eliminated from the CZTS films by sulfurization at temperatures higher than 500 °C.