  In this article, a novel two-path model is proposed to quantitatively explain
sub-threshold characteristics of back-gated Schottky barrier FETs (SB-FETs)
from 2D channel materials. The model integrates the 'conventional' model for
SB-FETs with the phenomenon of contact gating - an effect that significantly
affects the carrier injection from the source electrode in back-gated field
effect transistors. The two-path model is validated by a careful comparison
with experimental characteristics obtained from a large number of back-gated
WSe2 devices with various channel thicknesses. Our findings are believed to be
of critical importance for the quantitative analysis of many three-terminal
devices with ultrathin body channels.
