Growth of highly (1 1 1) oriented CuIn0.75Al0.25Se2 thin films

CuIn0.75Al0.25Se2 thin films prepared onto glass substrates at TS=573 K were single phase, nearly stoichiometric and polycrystalline with a strong (1 1 1) preferred orientation showing sphalerite structure. The results of X-ray diffraction and electron diffraction studies are compared, interpreted and correlated with micro-Raman spectra. The optical absorption studies indicated a direct band gap of 1.16 eV with high absorption coefficient (>104 cm−1) near the fundamental absorption edge.