The preparation of CuInSe2 films by combustion method and non-vacuum spin-coating process

A low-cost non-vacuum process for fabrication of CuInSe2 (CIS) films by combustion method and spin-coating process is described. First, the Cu, In oxides precursors are synthesized by combustion method, which is simpler and cheaper than the other preparation methods and is also the first applied in the CIS solar cells. Second, the CIS films are deposited via spin-coating from precursor slurry consisting of Cu, In oxides components and selenization process. Through X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive x-ray spectroscopy (EDS) and absorption spectroscopy measurement, it is found that Cu, In oxides precursors show the dominant CuO, In2O3 and Cu2In2O5 phases and have a uniform distribution of the particle size. The CIS films show the dominant chalcopyrite structure, In2O3 and Cu2Se phases and have a micron-sized dense gain. A typical near stoichiometric little Cu-rich CIS films is obtained. An energy band gap about 0.9 eV and an absorption coefficient exceeding 105 cm−1 are also obtained in our work.