Transport calculation of semiconductor nanowires coupled to quantum well reservoirs

摘要

Semiconductor nanowires are possible candidates to replace the metal-oxide-semiconductor field-effect transistors (MOSFET) since they can act both as active devices or as device connectors. In this article, the transmission coefficients of Si and GaAs nanowires with arbitrary transport directions and cross sections are simulated in the nearest-neighbor sp~3d~5s~* semi-empirical tight-binding method. The open boundary conditions (OBC) are calculated with a new scattering boundary method where a normal eigenvalue problem of reduced size is solved. Two different types of contacts are studied. In the ideal case, semi-infinite reservoirs (the source and the drain) that are the prolongation of the device are assumed. In a more realistic configuration, the active nanowire is embedded between two quantum well (QW) reservoirs. The electrical properties of the device are obtained by a non-equilibrium Green's function (NEGF) calculation.