Vertical MoTe2/Ge Heterojunction Photodiode for 1550-nm Near-Infrared Photodetection

We demonstrate a vertical MoTe2/Ge heterojunction near-infrared photodiode that exhibits a low dark current density, an improved capacity of weak optical signal detection with a peak detectivity of 1.15 x 10(11) Jones under a light density of 1 mW cm(-2), and a response speed with a rise/ fall time of 8/6 mu s operating at a 1550-nm light illumination. The device performance characteristics indicate that MoTe2/Ge heterojunction photodiode is promising for the potential practical applicationof photodetectionat 1550nm.