Facile synthesis of NiSe2:-Fe2O3 thin film: Physical, optical and photoelectronic properties

In this study, a highly scalable approach to fabricating NiSe2:alpha-Fe2O3 heterojunction thin film in the absence of a dehydration step or lattice parameter matching was established. The attachment of NiSe2 to alpha-Fe2O3 leads to an 82% and 97% decrease in charge transfer resistance (with and without illumination respectively) compared to pristine alpha-Fe2O3. The magnitude of the open circuit potential increased from approximately-0.30 V to-0.42 V vs Ag/AgCl, providing a stronger electric field for charge carrier separation. Charge transfer efficiency was calcu-lated by using a ratio of charge carriers removed and those produced in the bulk. Scanning electron microscopy coupled with the electrodeposition current-time transients study proved that the attachment process involved the progressive nucleation of NiSe2 and the simultaneous cathodic reduction of alpha-Fe2O3.