Chalcopyrite CuGaxIn(1-x)Se2 semiconducting thin films produced by radio frequency sputtering

CuGaxIn1-xSe2 thin films have been deposited by rf sputtering from three targets with different (Ga,In) content (x = 0.25, x = 0.5, and x = 0.75). A structural, compositional, optical, and electrical study has been carried out for films grown at substrates temperatures higher than 350-degrees-C. We have successfully obtained chalcopyrite single phase stoichiometric films. Very sharp absorption edges are obtained, with band gaps of 1.12, 1.35, and 1.51 eV for x = 0, x = 0.5, and x = 0.75, respectively