X-ray photoelectron spectroscopy, scanning electron microscopy and optical transmittance studies of indium tin oxide and cadmium sulphide thin films for solar cells

Thin indium tin oxide (ITO) films were deposited onto borosilicate glass by d.c. sputtering from an oxide target (91 mass% In2O3 and 9 mass% SnO2). CdS thin films suitable for solar cells were obtained by chemical bath deposition (CBD) from aqueous solutions of CdSO4 and thiourea followed by thermal annealing of the layers deposited onto the electroconductive glass. The chemical changes occurring on the surface of ITO and CdS layers, as evidenced by X-ray photoelectron spectroscopy during their preparation, are discussed. The surface topography and optical properties of ITO/glass and CdS/ITO/glass films were characterized by scanning electron microscopy and optical transmittance. (C) 1997 Elsevier Science S.A.