Multiscale modeling of nanowire-based Schottky-barrier field-effect transistors for sensorapplications

Abstract

We present a theoretical framework for the calculation of charge transport throughnanowire-based Schottky-barrier field-effect transistors that is conceptually simple but stillcaptures the relevant physical mechanisms of the transport process. Our approach combinestwo approaches on different length scales: (1) the finite element method is used to modelrealistic device geometries and to calculate the electrostatic potential across the Schottkybarrier by solving the Poisson equation, and (2) the Landauer–Büttiker approach combinedwith the method of non-equilibrium Green’s functions is employed to calculate thecharge transport through the device. Our model correctly reproduces typicalI–V characteristics of field-effect transistors, and the dependence of the saturated drain currenton the gate field and the device geometry are in good agreement with experiments. Ourapproach is suitable for one-dimensional Schottky-barrier field-effect transistors of arbitrarydevice geometry and it is intended to be a simulation platform for the development ofnanowire-based sensors.