High responsivity and broadband photodetector based on SnS2/Ag2S heterojunction

Photodetectors made of single Selenium sulfide (SnS2) or Silver sulfide (Ag2S) are difficult to achieve superiority in performance. Therefore, it is a good idea to prepare SnS2/Ag2S heterojunctions on hexagonal boron nitride (hBN). The responsivity (R) of SnS2/Ag2S photodetector under 405 nm laser is 4.52 A/W, the specific detectivity (D*) is 3.53 × 1011 Jones and the response speed reaches 37/50 ms. Ag2S quantum dots (QDs) overcome the problem of easy recombination of photogenerated carriers in SnS2. This makes the R of SnS2/Ag2S photodetectors about three orders of magnitude higher than that of Ag2S or SnS2 devices.