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

We investigate the channel length dependence of the electrical characteristics of chemical vapor transport (CVT)-grown MoS2 nanoribbon (NR) Schottky barrier field-effect transistors to provide insights into the transport properties of such nanostructures. The MoS2 NRs form spontaneously during the CVT growth, without the application of etching. Back gated transmission line measurement FETs were fabricated on a 45μm-long NR with channel lengths ranging between 200 nm and 3μm. 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 MoS2 NR channel of ∼81cm2/Vs was achieved.