Quantum Transport Simulation of III-V TFETs with Reduced-Order $$ \varvec{k} \cdot \varvec{p} $$ k · p Method

III-V tunnel field-effect transistors (TFETs) offer great potentials in future low-power electronics application due to their steep subthreshold slope and large “on” current. Their 3D quantum transport study using non-equilibrium Green’s function method is computationally very intensive, in particular when combined with multiband approaches such as the eight-band \( \varvec{k} \cdot \varvec{p} \) method. To reduce the numerical cost, an efficient reduced-order method is developed in this chapter and applied to study homojunction InAs and heterojunction GaSb–InAs nanowire TFETs. Device performances are obtained for various channel widths, channel lengths, crystal orientations, doping densities, source–pocket lengths, and strain conditions.