Quantitative, experimentally-validated, model of MoS2 nanoribbon Schottky field-effect transistors from subthreshold to saturation

Abstract

We investigate the channel length dependence of the electrical characteristics of chemical vapor transport (CVT)-grown MoS 2 nanoribbon (NR) Schottky barrier field-effect transistors to provide insights into the transport properties of such nanostructures. The MoS 2 NRs form spontaneously during the CVT growth, without the application of etching. Back gated transmission line measurement FETs were fabricated on a 45 μ m-long NR with channel lengths ranging between 200 nm and 3 μ m. Contact and sheet resistances were extracted from the electrical measurements and their back-gate bias dependence was analyzed. Numerical modeling based on a virtual probe approach combined with the Landauer formalism shows excellent agreement with the measurements. The model enables a quantitative extraction of the intrinsic FET properties, e.g., mean-free-path and electron mobility, and their dependence on carrier density and investigation of plausible trap distributions. A record electron mobility for a MoS 2 NR channel of ∼ 81 cm 2 / V s was achieved.