Characterization of Electrochemically Grown Crystalline CuInSe2 Thin Films

Abstract

To obtain thin films of crystalline copper indium diselenide (CuInSe2) onto the conducting substrates, the electrochemical experiments were conducted in an aqueous acidic solution of mixture of the corresponding salts. The influence of potential and substrate onto the orientation and surface morphology of CuInSe2 encountered by an electrodeposition technique is reported. The thin films have been characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy, and UV-visible spectroscopy. The Cu:In:Se ratio of electrodeposited CuInSe2 thin films was determined to be near 1:1:2 by electron dispersive spectroscopy. The XRD results revealed that the electrosynthesized thin film, deposited at cathodic potential of 700 mV (vs Ag/AgCl) have a preferential orientation along the (112) directions for tetragonal CuInSe2. The structural and morphological effects were observed with different substrates and potentials. The UV-visible absorption measurements indicated that the bandgap of the CuInSe2 film is 1.15 eV.