The preparation of CuInSe2 films by direct selenization of the CuIn oxides precursors

A low-cost non-vacuum process for the deposition of CuInSe2 (CIS) films is reported in this work. First, Cu-In oxides precursors are prepared by the traditional grinding method. Second, the precursor layers are deposited via spin-coating from oxides slurry. Finally, CIS films are achieved after direct selenization reaction without the complicated hydrogen reduction process. The desired near stoichiometric CIS films with up to micron-scaled grain size show the dominant chalcopyrite structure with preferred (112) orientation by XRD, Raman spectra, SEM and XRF. A band gap about 1.0 eV and an absorption coefficient exceeding 10(5) cm(-1) are also obtained by absorption spectroscopy measurement in our study.