High performance Ge/MoS2 heterojunction photodetector with a short active region

Abstract

We present a Ge/MoS2 van der Waals heterojunction photodetector with a short active region constructed using a transfer process. The device exhibits broadband, self-powered, superior device performance within the visible to infrared wavelength (500–1700 nm) operated in a photovoltaic mode. Intriguingly, a sharp increased gain of 10 556 (93) with a varied breakdown voltage of −8.02 V (−6.25 V) under the 700 nm (1550 nm) laser illumination was observed, which was interpreted as the synergistic effect of both soft and avalanche breakdown behavior. These results imply disposable high-sensitivity broadband light-detection potentials with a simple Ge/MoS2 heterojunction, exempting it from the complex and strict construction requirement of conventional avalanche photodetectors.