To investigate the effect of alternating Cu poor/Cu rich/Cu poor/Cu rich/ layers in Cu-In precursors on the properties of the absorber, CuInSe(2) polycrystalline thin films were prepared on glass substrates using the spin coating technique by thermal decomposition in N(2)+H(2) (10%) gas of Cu-In naphthenates and subsequent selenization in vacuum scaled ampoules of the obtained precursors with Se shots. Structure, crystal orientation and morphology of the obtained samples were studied by X-ray diffraction and scanning electron microscopy for different selenization temperatures. For the optical and electrical characterizations, photo luminescence and electrical conductivity measurements were also carried out. The deposited films were polycrystalline and showed a single phase with an intense (112) orientation for selenization temperature of 500 degrees C and time of 60 min. Alternating Cu poor/Cu rich/Cu poor/Cu rich/ layers of metal naphthenates in the precursors improved the optical and electrical properties of the CuInSe(2) polycrystalline absorber layers. The principles of this procedure and the obtained results are detailed in this paper. (c) 2008 Elsevier B.V. All rights reserved.