Structural properties of CuInSe2 thin films for solar cell applications

Structural properties for CuInSe2 films formed by two methods, (a) three-source co-evaporation and (b) selenization of Cu/In/Se-stacked layer, were studied using X-ray diffraction, Raman scattering and SEM imaging. It is found that films by co-evaporation show stronger (112) orientation than the selenization films and A1 mode peak in Raman spectra is seen for selenized films even with a ratio of Cu/In < 0.6 in which composition the peak relating to A1 mode disappeas in co-evaporated films. A conversion efficiency of 10.5% was obtained for a CuInSe2 solar cell using the co-evaporated film.