Effect of the substrate temperature on the properties of spray deposited Sb-Se thin films from non-aqueous medium

Semiconducting Sb-Se thin films are prepared on glass substrates from a non-aqueous medium using a spray pyrolysis technique. The films are deposited at a fixed solution concentration of 0.1 M and at various substrate temperatures. The film thickness is of the order of 0.5 mu m and is found to be relatively higher for the film deposited at 175 degrees C substrate temperature, X-ray diffraction studies reveal that the as deposited films are amorphous in nature, while after annealing in the N-2 atmosphere at 325 degrees C for 2 h, the films deposited at 200 degrees C turn into polycrystalline ones. The analysis of the absorption coefficient data reveals that as the substrate temperature increases, the optical bandgap value of the material increases. It has also been found, for the film deposited at 200 degrees C and annealed in N-2 atmosphere, that the polycrystalline material follows the direct optical transition with energy gap Eg(opt) equal to 2.14 eV. The electrical resistivity at room temperature (300 K) is of the order of 10(6)-10(7) Ohm cm, which changes slightly after annealing. (C) 1997 Elsevier Science S.A.