WSe 2 /Au vertical Schottky junction photodetector with low dark current and fast photoresponse.

Atomically thin two-dimensional materials including graphene, transition metal dichalcogenides, black phosphorus and so forth have been considered as promising channel medias for electronic and optoelectronic devices in the past few years. However, the poor photoresponse time and the large dark current are the two major issues which greatly block their applications. Here, we report a vertical Au-WSe2 -ITO (indium tin oxide) Schottky junction photodetector with a broadband photoresponse from 550-950 nm and a stable photovoltaic responsivity of ∼0.1 A W-1 . The fast photoresponse of ∼50 μs and low dark current of ∼1 pA are achieved at the vertical Au-WSe2 -ITO photodetector. These results indicate that metal contact to a 2D material-based vertical Schottky junction can achieve an excellent photoelectric response.