Charged Impurity Scattering in Graphene Nanostructures

TL;DR

This paper investigates how charged impurities and static screening affect carrier mobility in top-gated graphene nanostructures, revealing that the top gate and dielectric thickness significantly influence electronic transport properties.

Contribution

It introduces a model incorporating boundary conditions into impurity scattering analysis and predicts mobility enhancements with ultrathin top dielectrics.

Findings

Carrier mobility decreases with thicker top dielectric layers.

Mobility increases by up to 60% in ultrathin top-gated graphene.

The dielectric response and boundary conditions critically affect scattering behavior.

Abstract

We study charged impurity scattering and static screening in a top-gated substrate-supported graphene nanostructure. Our model describes how boundary conditions can be incorporated into scattering, sheds light on the dielectric response of these nanostructures, provides insights into the effect of the top gate on impurity scattering, and predicts that the carrier mobility in such graphene heterostructures decreases with increasing top dielectric thickness and higher carrier density. An increase of up to almost 60 percent in carrier mobility in ultrathin top-gated graphene is predicted.