Layer-dependent electrical transport property of two-dimensional ReS2 thin films

Abstract

In this study, the controlled-layer and large-area two-dimensional (2D) rhenium disulfide (ReS2) thin films were grown on mica substrates by chemical vapor deposition method using S powder and Re-Te powder as starting materials. The morphology, thickness and crystallographic structure of 2D ReS2 thin films were investigated using optical microscope (OM), field emission scanning electronic microscope (SEM), atomic force microscopy (AFM) and Raman spectroscopy, respectively. In order to study the layer-dependent electrical transport property of 2D ReS2 thin films, the back-gated field effect transistors (FETs) based on 2D ReS2 thin films with different layer number and different channel lengths were prepared. The dependence relationship between carrier mobility and layer number of 2D ReS2 thin films were studied and discussed. Results show that the controlled-layer and substrate-scale ReS2 thin films can be grown on mica substrate at temperature of 650 °C. The layer number of 2D ReS2 thin films can be adjusted from 1 to 10 layers by changing the location of the substrate. The carrier mobility of 2D ReS2 thin films increases with an increasing number of layers (from 1 to 5 layers) and to be saturated when further increase the number of layers.