Tin diselenide thin films were prepared by spray pyrolysis technique using SnCl2 center dot H2O and 1,1-dimethyl-2-selenourea as precursor compounds with a Se:Sn atomic ratio of 1:1 in the starting solution. The deposition process was carried out in the substrate temperature range of 275 degrees C to 400 degrees C using two solution flow rates of 5 ml/min and 8 ml/min. The phases of SnSe2 were obtained when the deposition was carried ou at a flow rate of 5 ml/min, while for the films deposited at 8 ml/min mixed phases of SnSe2/SnSe were observed. Heat treatment of the deposited SnSe2/SnSe thin films in an atmosphere of 95% N-2 and 5% H-2 led to crystallization of the SnSe compound. The as deposited SnSe2 thin films have an optical band gap of 1.59 eV with n-type electrical conductivity in the range of 10(-1) (Omega cm)(-1) to 101 (Omega cm)(-1). The annealed thin films have an optical band gap of 0.81 eV and show p-type electrical conductivity of 2x10(-1) (Omega cm)(-1). (C) 2013 Elsevier B.V. All rights reserved.