An Open-Source Multiscale Framework for the Simulation of Nanoscale Devices

We present a general simulation framework for assessing the performance of nanoscale devices that combines several powerful and widely used open-source codes, and based on minimal but chemically accurate tight-binding Hamiltonians obtained from density-functional theory calculations and using maximally localized Wannier functions to represent the electronic state. Transport properties are then computed within the nonequilibrium Green´s function formalism. We illustrate the capabilities of this framework applying it to a transistor with generic gate geometries, i.e., a double-gate nanoscale field-effect transistor where the channel is formed by graphene nanoribbons terminated with hydrogen, fluorine, and OH groups.