LAUSR

Abstract In this study, indium sulfide (β-In 2 S 3 ) thin films were synthesized on fluorine doped tin oxide (FTO) coated glass substrates by hydrothermal reactions. The hydrothermal reaction time (HRT) was varied from 4 to 16 h and the synthesis temperature was maintained at 160 °C. The morphological, physical and electrochemical properties of the processed In 2 S 3 films show a clear HRT dependency. XRD analysis indicates that both crystallinity and crystal size increase as HRT increases. UV–Vis absorbance spectra analysis reveals that the HRT influence greatly the In 2 S 3 optical properties with an estimated band gap varying from 3.6 to 2.1 eV. We present as well, the influence of the HRT on the photo-electrochemical performances of In 2 S 3 based photo-anodes investigated with electrochemical impedance spectroscopy (EIS). In 2 S 3 photo-anodes with a photocurrent as high as 1 mA cm −2 at 0.5 V were prepared for a HRT equal to 12 h. These experimental findings promote the hydrothermal method as a simple, low cost and low temperature route allowing the preparation of β-In 2 S 3 thin films on FTO glass suitable for photo-electrochemical applications.