Adaptive photocurrent generation of ReS2-2D Te heterostructure

Abstract

In this study, we analyzed the photocurrent generation mechanism (PGM) of a heterostructure comprising n-type ReS2 and p-type two-dimensional (2D) Te. The PGM of the integrated structure was not solely driven by the photovoltaic effect, which is attributed to the built-in potential invoked by the bandgap mismatch and Fermi level difference. The PGM was manipulated and dramatically varied as the source-drain bias (Vds) and backgate bias (Vgs) were modulated. Under the control of Vds and Vgs, the dominant photocurrent generation in our heterostructure was attributed to photovoltaic (PV), photothermoelectric (PTE) effects, and their combinations PV+PTE. In addition, the photocurrent hotspot varied depending on the bias conditions. Our results provide new insights into the possibility to adapt the PGM of a conventional photovoltaic system, which can contribute to the development of multimodal detection of the incident light, extend the spectral detection range, and facilitate the design of photodetectors and energy-harvesting devices with enhanced performance.