Controlling the electronic bands of a 2D semiconductor by force microscopy

Abstract In this work, we investigate the transverse transport properties of few-layers MoS ₂ using a Conductive Atomic Force Microscopy based technique. We find that the system changes between a low-force regime, characterized by a nearly-ideal contact between the MoS ₂ flake and the substrate, and a high-force regime, for which this contact starts to become highly non-ideal. We propose a 3-diode model that effectively describes the current-voltage characteristics of few-layers MoS ₂ . From this model, we estimate how fast the energy gaps of two-dimensional MoS ₂ materials change as a function of the applied force. From our analysis, we estimate that MoS ₂ -Au Schottky barrier heights change at the rate of 0.21, 0.23, and 0.78 meV nN ⁻¹ for the few-layers, three-layers, and two-layers MoS ₂ , respectively. Our work opens up new possibilities of investigating and controlling the electronic properties of 2D semiconducting materials.