Synthesis of Cu2ZnSnS4 thin film solar cells by sulfurization of sputtered Sn/Zn/Cu precursors is studied. The sulfurization temperatures were varied, and the morphology, cross section, and composition of the CZTS were investigated by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and Raman scattering. To further explore the CZTS layer, the following additional layers were deposited to complete the solar cells: CdS with chemical bath deposition; ZnO and AZO with RF magnetron deposition; and, finally, silver fingers as the front contact. The efficiency and characteristics of the thin film solar cells were measured and a detailed comparison is reported. Sulfurization at 550 degrees C yields a maximum efficiency of 5.75% without any anti-reflective layers. (C) 2013 Elsevier Ltd. All rights reserved.