(Invited) First Principles Electron Transport Calculations: From Molecular Contacts to Large 2D Devices

摘要

The combination of Density Functional Theory (DFT) with non-equilibrium Greens functions (NEGF) allows for first principles calculations of electronic devices under working conditions, i.e. under the non-equilibrium conditions in the presence of finite electronic current. I will show examples of how the DFT-NEGF method is used to gain insights into the non-equilibrium conduction and current-induced atomic forces in molecular contacts. I will describe how we apply DFT-NEGF including electrostatic gating to study devices based on 2D materials. Finally, I will present a recently developed multi-scale approach, combining spatial regions described by DFT with larger regions described by DFT-derived tight-binding. We have employed the multi-scale approach to study transport in molecular-based 2D graphene nanomesh structures going towards the (100 nm)-by-(100 nm) scale.