2D MoS2 photovoltaic detectors with a switchable mode

Abstract

Photodetectors based on two-dimensional (2D) materials have demonstrated their advantages of low-cost, high-performance, small-size, flexibility and large-scale manufacture. In this work, 2D MoS₂-based photovoltaic detectors with a switchable mode have been achieved through a Schottky and lateral PN homojunction. By applying different bias voltages, the photodetection mode can be switched between the photodiode and photoconductor, combining the advantageous features of both modes in one device. In the photodiode mode, a significant rectifying and photovoltaic behavior can be achieved and tuned by the gate voltages, achieving a fast photo-response speed of ∼10 ms. In the photoconductor mode, the photoconductive effect can lead to a photo-gain mechanism, a high responsivity up to 10³ A W⁻¹ and a high detectivity of 4.1 × 10¹² Jones in the Schottky device. This work develops a MoS₂ photodetector based on a Schottky and PN homojunction using a facile method, and the switchable operation mode endows our device with the capability of customized photodetection applications for different needs.