Preparation of Cu2ZnSnSe4 thin films by selenization of precursor evaporated from Cu2ZnSnSe4 compound

Cu2ZnSnSe4 ingot was synthesized and then used as a precursor for selenization process in order to fabricate Cu2ZnSnSe4 thin films. The thin films were prepared at each point A-F in our selenization process and their properties were investigated. Cu2ZnSnSe4 ingot and thin films had a kesterite Cu2ZnSnSe4 structure. From EPMA analysis and XRD studies, the mechanism of Cu2ZnSnSe4 formation was discussed. Cu-Se phases were related to Cu2ZnSnSe4 formation. Cu2ZnSnSe4 may decompose to Sn-Se compound during the annealing process at 550 oC. Cu2ZnSnSe4 thin film solar cells demonstrated Voc=300 mV, Isc=7.25 mA/cm2. The band gap energy of Cu2ZnSnSe4 thin film determined from the QE spectra estimated to be approximately 1.04 eV. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)