CuInSe2 (CIS) chalcopyrite thin films were prepared using a low-cost non-vacuum doctor-blade coating and the thermal annealing method An acetone-based precursor solution containing copper chloride indium chloride selenium chloride and an organic binder was deposited onto a Mo-sputtered soda lime glass substrate using a doctor-blade coating method After coating the precursor films were annealed in a quartz tube furnace under low vacuum without the use of a Se atmosphere or reduction conditions Evolution of the morphology crystal structure and thermal decomposition behavior of the films was analyzed by X-ray diffraction scanning electron microscopy and thermogravimetric analysis and the film formation mechanism was suggested The as-deposited precursor film gradually decomposed with increase in temperature and formed Cu2-xSe and In2Se3 nuclei on the surface of the film Incorporation of Cu2-xSe with In2Se3 yielded a chalcopyrite CIS phase which crystallized on annealing above 400 degrees C The obtained CIS film showed low-resistive ohmic behavior with a Mo electrode and a high absorption efficiency for visible-infrared (IR) light making It suitable for use in photovoltaic applications (C) 2010 Elsevier BV All rights reserved