Preparation and characterization of CuIn0.75Al0.25Se2 thin films by co-evaporation

摘要

Single-phase Culn(0.75)Al(0.25)Se(2) thin films were deposited by four-source co-evaporation method on soda lime glass substrates held at 673 K. Post-deposition annealing of the films in selenium atmosphere was carried out for an hour at 723 K. X-ray diffraction (XRD) studies of the films revealed the structure to be chalcopyrite with a = 0.577 and c = 1.141 run. Optical absorption studies of the films indicated three-fold band structure. Crystal field (Delta(CF)) and spin-orbit (Delta(SO)) splitting parameters were deduced from the optical band gap values obtained. The deformation potential was estimated by using quasi-cubic model and the percentage of hybridization of the orbitals was determined using linear hybridization model. The films are found to be p-type conducting and the temperature dependence of conductivity studies are carried out to determine the activation energies of the films. (c) 2006 Elsevier B.V. All rights reserved.