The aim of the present research is to determine the optimal deposition conditions of copper indium diselenide (CuInSe2 or CIS) thin films for photovoltaic cells. The films were produced by vacuum free Close-Spaced Vapour Transport (CSVT) process. They were deposited on glass substrate from a source heated at temperatures of 400, 450, 500, 550 and 600°C. The deposition time was about 3 h. Characterizations were carried out by means of compositional, structural and morphological analysis. The composition of the CIS films was determined by Energy Dispersive Spectrometry (EDS) coupled to a scanning electron microscope. The results showed a quasi-stoichiometric composition in the range of source temperatures starting from 400 to 600°C. The best stoichiometry was obtained at a source temperature of 500°C. Structural characterization of the CIS films was made by X-ray diffraction (XRD). The spectra revealed that all the films were polycrystalline in nature with chalcopyrite structure. The preferred orientation along (112) direction suitable for photovoltaic device was obtained at a source temperature of 500°C with a maximum intensity. When the source temperature was higher than 500°C, secondary phases appeared and the intensity of the peak (112) decreased. Scanning Electron Microscope (SEM) micrographs showed that the films deposited at source temperature of 500°C had the best morphology to be used as solar cells. As a result of the characteristics of CIS films obtained by EDS, XRD and SEM studies, the source temperature 500°C is the most apt to produce photovoltaic cells with high efficiency.
K. Konan , J.K. Saraka , J.T. Zoueu and P. Gbaha , 2007. Structural and Morphological Analysis of CuInSe2 Thin Films Prepared by Vacuum Free CSVT for Photovoltaic Cells
. Journal of Applied Sciences, 7: 478-483.