The preparation of CuInSe2 films by solvothermal route and non-vacuum spin-coating process

A low-cost non-vacuum process for fabrication of CuInSe2 (CIS) films by a solvothermal route and spin-coating method is described. First, the CIS precursor powders are synthesized by solvothermal technology. Second, the CIS films are deposited via spin-coating from precursor slurry consisting of CIS particles and selenization process. Through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and absorption spectroscopy measurement, the CIS nanoparticle precursors consisted mainly of plate-like particles showing the chalcopyrite structure with preferred (1 1 2) orientation. Typical near stoichiometric single phase CIS films with a micron-sized dense grains are prepared after selenization process. An energy band gap about 1.02 eV and an absorption coefficient exceeding 105 cm−1 are also obtained in our work.