Preparation of CuInxGa1-xSe2 thin films on Si substrates

For fabricating efficient tandem solar cells, CuIn_xGa _1-xSe₂ thin films have been prepared on Si(100), Si(110) and Si(111) substrates in the temperature range (R.T.~400°C) by RF sputtering. From EPMA analysis, these sputtered thin films are found to be nearly stoichiometric over the whole substrate temperature range, irrespective of the azimuth plane of the Si substrate. XPS studies showed that the compositional depth profile in these thin films is uniform. X-ray diffraction analysis indicated that all the thin films had a chalcopyrite structure. CuIn_xGa_1-xSe₂ thin films were strongly oriented along the (112) plane with increasing the substrate temperature, independent of the azimuth plane of the Si substrate, suggesting the larger grain growth