Deposition of Cu2ZnSnS4 thin films by vacuum thermal evaporation from single quaternary compound source

Cu2ZnSnS4 (CZTS) thin films were successfully deposited using vacuum thermal evaporation from single quaternary CZTS semiconducting material powder source, followed by annealing at 300 degrees C for 40 min under high purity N-2 atmosphere. X-ray diffraction (XRD) patterns indicated that as-deposited CZTS thin films transformed from amorphous state into crystalline state with kesterite structure after annealing. Energy dispersive X-ray spectroscopy (EDS) determined the compositions of the CZTS thin films were Zn-poor, Sn-rich and S-rich. Scanning electron microscope (SEM) images, ultraviolet-visible-near infrared (UV-Vis-NIR) spectra and the Hall measurements showed the annealed CZTS thin film exhibited a smooth, densely packed and homogeneous surface, a direct band gap of 1.55 eV and a p-type conductivity. The fabricated photovoltaic device obtained a conversion efficiency of 0.36%, open-circuit voltage of 493 mV, short-circuit current density of 1.76 mA.cm(-2), and fill factor of 0.42. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.