Multiscale modelling of charged impurities in two-dimensional materials

Abstract

Charged impurities influence functional properties of two-dimensional materials and a detailed theoretical understanding of charged defects is required to enable a rational design of defect-engineered nanomaterials for applications in ultrathin devices. To achieve this goal, we have developed multiscale approaches that combine atomistic first-principles theories, such as density-functional theory, with coarse-grained continuum models, such as effective mass models. This allows us to model large supercells which are required to accurately describe the slow decay of the screened defect potential and the defect-induced changes in the electronic properties of the two-dimensional host material. I will describe the results of our multiscale calculations for charged defects in doped graphene and in transition-metal dichalcogenide monolayers which have revealed novel mechanisms for controlling and tuning the electronic structure of two-dimensional materials.