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

Cu2ZnSnS4 (CZTS) thin films were fabricated using a rapid thermal process in 5% H2S+ N2 atmosphere from precursors prepared by the sol–gel method. The precursors were preheated at 250 °C for 10 min and then sulfurized at different temperatures from 300 to 600 °C for 10 min. XRD studies showed that the samples sulfurized at 500–600 °C had a CZTS structure. With increasing sulfurization temperature, the chemical composition ratio of sulfur/metal and the grains size of CZTS increased. From the (αh ν)2–hν plot, the CZTS films had a band gap of ~1.5 eV.