Direct growth of SnS₂ nanowall photoanode for high responsivity self-powered photodetectors

Tin sulfide (SnS₂) has attracted growing attention due to its environmental friendliness, tunable band gap and potential applications for high-sensitivity photodetectors. However, the low responsivity and slow response speed severely hinder its further applications. In this work, SnS₂ nanowalls have been successfully fabricated on FTO substrates by a facile hydrothermal approach. The prepared SnS₂ nanowalls were used as a photoanode material for photoelectrochemical (PEC)-type photodetectors. The SnS₂ based PEC-type photodetectors exhibit excellent photocurrent density (39.06 μA cm^-2), responsivity (1460 μA W^-1), long-term cycling stability and self-powered behavior. The responsivity of the detector is higher than that of most reported SnS₂ based PEC-type photodetectors and even some SnS₂ based photoconductive photodetectors. The high responsivity and self-powered behavior enable the extended potential applications of SnS₂ in PEC-type photodetectors.