Au/SnS₂/Al Schottky Structure for High Detectivity and Low Dark Current Visible Light Detector

Due to their high optical absorption and atomic thickness, light detectors based on tin disulfide (SnS ₂ ) have been investigated extensively. In this letter, a light detector based on a SnS ₂ monolayer with an Al/SnS ₂ /Au structure for visible light detection is demonstrated. Benefiting from the Au/SnS ₂ Schottky structure, photoexcited electron-hole pairs are separated, and a remarkable photoresponse is achieved. At $11 ~\mu \text{W}/$ mm ² , the peak responsivity and detectivity are 586.18 $\text{A}/\text{W}$ and $1.22\,\,\times10$ ¹⁴ Jones, which indicate that these detectors are superior both to most detectors based on two dimensional materials and to commercial Si detectors. The light detector also exhibits a fast response speed with the response time at the microsecond level. Moreover, a low dark current of 2.18 nA is achieved in this structure.