Abstract
Two-dimensional (2D) molybdenum selenide (MoSe2) is promising for use in the development of photodetectors for the harvesting of light from the ultraviolet to the near-infrared band, while high responsivity and fast response speed are difficult to simultaneously realize. Herein, we present a dual-mode MoSe2 photodetector with asymmetric electrodes, in which graphene and Cr metal are utilized as ohmic and Schottky contacts, respectively. The photodiode possesses fabulous Schottky characteristics, with a rectification ratio of ∼250 and a low dark current of ∼40 pA at −1 V. Under forward bias voltage of 1 V, the photodetector works in photoconductive mode with a slow response speed (decay time: ∼5 min) but high responsivity (632 mA W−1). However, at reverse bias voltage, the photodetector acts as a photovoltaic-type device due to the Schottky barrier between Cr and MoSe2. Because of the reinforced built-in electric field, the photodetector driven at −5 V shows much faster response speeds (rise time: 1.96 ms; decay time: 755 µs). This study provides a deep understanding of asymmetric structure MoSe2 photodetectors operated in two modes, which promotes a forward step toward 2D material optoelectronics.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.