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

In this study, the controlled-layer and large-area two-dimensional (2D) rhenium disulfide (ReS 2 ) 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 ReS 2 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 ReS 2 thin films, the back-gated field effect transistors (FETs) based on 2D ReS 2 thin films with different layer number and different channel lengths were prepared. The dependence relationship between carrier mobility and layer number of 2D ReS 2 thin films were studied and discussed. Results show that the controlled-layer and substrate-scale ReS 2 thin films can be grown on mica substrate at temperature of 650 °C. The layer number of 2D ReS 2 thin films can be adjusted from 1 to 10 layers by changing the location of the substrate. The carrier mobility of 2D ReS 2 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.