Nonequilibrium Green’s function method: Transport and band tail predictions in transition metal dichalcogenides

Transition metal dichalcogenides (TMDCs) based 2D materials appear to very promising materials for tunnel field-effect transistors (TFETs). [1], [2]. The intrinsic subthreshold slope (SS) of these devices is determined by exponentially decaying band tail states/Urbach tails below conduction and valence band edges which places a lower bound on SS. Though there have been few recent studies on calculating and extracting band tails using simple models and qualitative analysis [3], [4], a rigorous study based on atomistic approach is still lacking.