Probing Distinctive Electron Conduction in Multilayer Rhenium Disulfide

Abstract

Charge carrier transport in multilayer van der Waals (vdW) materials, which comprise multiple conducting layers, is well described using Thomas-Fermi charge screening (λ_TF ) and interlayer resistance (R_int ). When both effects occur in carrier transport, a channel centroid migrates along the c-axis according to a vertical electrostatic force, causing redistribution of the conduction centroid in a multilayer system, unlike a conventional bulk material. Thus far, numerous unique properties of vdW materials are discovered, but direct evidence for distinctive charge transport behavior in 2D layered materials is not demonstrated. Herein, the distinctive electron conduction features are reported in a multilayer rhenium disulfide (ReS₂ ), which provides decoupled vdW interaction between adjacent layers and much high interlayer resistivity in comparison with other transition-metal dichalcogenides materials. The existence of two plateaus in its transconductance curve clearly reveals the relocation of conduction paths with respect to the top and bottom surfaces, which is rationalized by a theoretical resistor network model by accounting of λ_TF and R_int coupling. The effective tunneling distance probed via low-frequency noise spectroscopy further supports the shift of electron conduction channel along the thickness of ReS₂ .