ReS₂-Based Field-Effect Transistors and Photodetectors

Atomically thin 2D layered transition metal dichalcogenides (TMDs) have been extensively studied in recent years because of their appealing electrical and optical properties. Here, the fabrication of ReS₂ field-effect transistors is reported via the encapsulation of ReS₂ nanosheets in a high-κ Al₂O₃ dielectric environment. Low-temperature transport measurements allow to observe a direct metal-to-insulator transition originating from strong electron-electron interactions. Remarkably, the photodetectors based on ReS₂ exhibit gate-tunable photoresponsivity up to 16.14 A W^-1 and external quantum efficiency reaching 3168%, showing a competitive device performance to those reported in graphene, MoSe₂, GaS, and GaSe-based photodetectors. This study unambiguously distinguishes ReS₂ as a new candidate for future applications in electronics and optoelectronics. Few-layer ReS₂ is successfully synthesized via chemical vapor deposition. Top-gated FET devices, back-gated four-terminal devices, and photodetectors are built based on the as-grown high-quality materials. All of them show great device performance, which distinguishes ReS₂ a great platform for future applications in electronic and optoelectronic devices.