Effect of annealing for CuInS2 thin films prepared from Cu-rich ternary compound

Evaporated CuInS2 films using a single-source were annealed in H2S atmosphere from 250 to 500 C for 60 min. after the evaporation. Polycrystalline CuInS2 powder grown by a hot-press method was employed as a source material. Cu/In ratios of the source were 1.0, 1.2 and 1.5. All the films annealed above 350 C were of CuInS2 single phase regardless of the Cu/In ratio of the source material. The films prepared from the source material of the Cu/In ratio of 1.5 became Cu-rich films, which had the Cu/In ratio of 1.37. Carrier concentrations, resistivities and mobilities of the films annealed above 350 C prepared from the source material of the Cu/In ratio of 1.5 were approximately 1 x 1021 cm-3, 0.1 Ωcm and 0.1 cm2/Vs, respectively, at room temperature. The activation energy of the film annealed at 400 C was evaluated to be 6.5 meV. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)