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 (SnS2) have been investigated extensively. In this letter, a light detector based on a SnS2 monolayer with an Al/SnS2/Au structure for visible light detection is demonstrated. Benefiting from the Au/SnS2 Schottky structure, photoexcited electron-hole pairs are separated, and a remarkable photoresponse is achieved. At 11 mu W/mm(2), the peak responsivity and detectivity are 586.18 A/W and 1.22 x 10(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.