Electron transport through the multiple sulfur vacancies in MoS2

Abstract

We conducted a thorough investigation of the impact of sulfur vacancies on electronic structures and electron transport in MoS2, with a particular focus on neighboring sulfur vacancies by employing density functional theory (DFT) and non-equilibrium Green's function (NEGF) methods. Although pristine MoS2 exhibits a Schottky-like behavior, an intriguing behavior emerged in the presence of aligned vacancies. The current flows through interconnected in-gap states even at low bias region (0.0–0.2 V), but it does through tunneling from defect states to the conduction bands (CBs) at higher voltages. Negative differential resistance (NDR) appears in the middle range of voltage. Through systematic examination of the inter-vacancy distance at which current could flow, we found that MoS2 ribbons could exhibit a random network of vacancies capable of mediating current at feasible vacancy concentration, which means percolation emerges. This research offers valuable insights into the potential of defect-engineered MoS2 for novel electronic applications.