Wide Bandgap InS-based Thin Film: Deposition, Characterization, and Application for SnS Solar Cells

A wide band gap InS-based thin film was deposited onto F-doped SnO2-coated glass by electrochemical deposition from an aqueous solution using a two-step periodic-pulse voltage. The film was characterized optically by a double beam spectrometer, morphologically by a scanning electron microscope. In addition, the composition ratios of the film were measured by Auger electron spectroscopy. Furthermore, the photosensitivity of the film was observed by means of photoelectrochemical measurements, which confirmed that the film showed n-type conduction. Finally, a detailed X-ray photoelectron spectroscopy (XPS) study was performed in order to understand the chemical states of the elements involved in the film composition. The XPS results revealed that the deposited film can be written in the form of InSxOy(OH)(z). The film was used along with tin sulfide thin film to fabricate a novel heterojunction. (C) 2009 The Japan Society of Applied Physics