In situ growth of metal-sulfide film with solvent-free element-direct reaction: the case of PbS on ITO

In order to prevent the metal-sulfide film from falling off a substrate during in situ preparation, a solvent-free element-direct reaction was developed. To exploit this new strategy, lead sulfide (PbS) film was selected to grow on Indium-Tin-Oxide-coated glass (ITO/glass) at 150 degrees C. The prepared PbS film exhibited outstanding adhesion on the substrate according to the tape test results. The analyses of X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) indicated the PbS film possessed good crystallinity and nearly balanced stoichiometry. In addition, the prepared PbS film exhibited intensive blue-shifted interband absorption. Moreover, photoelectrochemical (PEC) measurements illustrated that it possessed great photosensitivity and n-type conductivity. Other important properties such as crystal structure, film thickness, current-voltage (I-V) characteristics, surface roughness and topography were studied in detail.