Characterization by Photoluminescence of ICB-Grown CuInSe2 Thin Films

Abstract

CuInSe2 thin films were prepared by the ICB (ionized cluster beam) technique on glass substrates. It is found that the apparent grain size increased more than 1 µm when Cu cluster is ionized, even in In-excess CuInSe2 films which usually shows a specular surface with a small grain size of less than 0.2 µm. These films were characterized by photoluminescence (PL) spectra employing Ar and YAG lasers as excitation sources. In those films with a slightly In-excess composition, the 0.85 eV-peak was observed, which has been correlated with the good solar cells performance. The PL peak gained intensity with the increase of acceleration voltage of In-cluster up to 2 kV. It is concluded that ICB is a promising technique for preparation of good quality CuInSe2 thin films for solar cells.