CuIn3Se5 thin films were grown by stepwise flash evaporation from the polycrystalline powder source. Bulk CuIn3Se5 was synthesized by melt-quench technique, starting from the stoichiometric mixture of constituent elements. Phase purity of the synthesized material was confirmed by powder X-ray diffraction. Structural investigations by transmission electron microscopy (TEM) show that the films grown at 370K and above were polycrystalline in nature. Compositional analysis by Rutherford backscattering spectrometry (RBS) revealed that the films have near stoichiometric composition. Analysis of optical transmittance data yielded a band gap value of similar to 1.26+0.02eV. (C) 2004 Elsevier B.V. All rights reserved.