Transport properties of copper indium aluminum selenide thin films deposited by successive Ionic layer adsorption and reaction

Cu(InAl)Se2 (CIAS) thin films have been prepared by successive ionic layer adsorption and reaction (SILAR) technique on well-cleaned glass substrates. The structure, composition, morphology, optical, electrical, and Hall effect studies of prepared thin films have been studied. X-ray diffraction studies confirmed the polycrystalline nature of the thin films with a chalcopyrite structure. Scanning electron microscopy studies revealed that the morphology of the prepared films was smooth, dense, uniform, and granular. Composition of various constituents such as Cu, In, Al, and Se in the CIAS films has been determined from energy dispersive x-ray analysis. Optical properties have been studied in detail from the transmittance spectra in the visible and near infrared region and the optical transition has been found to be direct and allowed with the band gap of around 1.16–1.50 eV. Electrical analysis helps to identify that in high temperature region the conductivity is attributed due to thermal excitation of the charge carriers from grain boundaries to the neutral region of the grains. Transport properties of CIAS thin films have been studied in the temperature range 298–398 K and the transport parameters are evaluated and reported in this paper in detail.