Two-Dimensional Hybrid Composites of SnS2 Nanosheets Array Film with Graphene for Enhanced Photoelectric Performance

Two-dimensional (2D) metal dichalcogenides have attracted considerable attention for use in photoelectric devices due to their unique layer structure and strong light-matter interaction. In this paper, vertically grown SnS₂ nanosheets array film was synthesized by a facile chemical bath deposition (CBD). The effects of deposition time and annealing temperature on the quality of SnS₂ films was investigated in detail. By optimizing the preparation conditions, the SnS₂ array film exhibited efficient photoelectric detection performance under sunlight. Furthermore, in order to improve the performance of the photodetector based on SnS₂ nanosheets film, a transparent graphene film was introduced as the hole-transport layer by wet-chemical method directly transferring techniques. Graphene/SnS₂ nanosheets array film heterojunction photodetectors exhibit enhanced photoresponsivity. The light on/off ratio of the photodetector based on graphene/SnS₂ was 1.53, about 1.4 times higher than that of the pristine SnS₂ array films. The improved photoresponse performance suggested that the effective heterojunction between vertical SnS₂ nanosheets array film and graphene suppresses the recombination of photogenerated carriers. The results indicate that the graphene/SnS₂ heterojunction photodetectors have great potential in photodetection devices.