Electron Transport Properties of Bilayer Graphene

TL;DR

This study analyzes electron transport in bilayer graphene using first principles and Monte Carlo simulations, revealing intrinsic limitations but highlighting the impact of extrinsic factors and bias-induced bandgap effects on mobility and velocity.

Contribution

It provides a comprehensive first-principles and simulation analysis of bilayer graphene's transport properties, emphasizing extrinsic influences and bias effects not thoroughly explored before.

Findings

Intrinsic mobility and saturation velocity are lower in bilayer than monolayer graphene.

Extrinsic factors like substrate and impurities significantly affect transport properties.

Bias-induced bandgap reduces mobility but has little effect on saturation velocity.

Abstract

Electron transport in bilayer graphene is studied by using a first principles analysis and theMonte Carlo simulation under conditions relevant to potential applications. While the intrinsic properties are found to be much less desirable in bilayer than in monolayer graphene, with significantly reduced mobilities and saturation velocities, the calculation also reveals the dominant influence of extrinsic factors such as the substrate and impurities. Accordingly, the difference between two graphene forms are more muted in realistic settings although the velocity-field characteristics remain substantially lower in the bilayer. When bilayer graphene is subject to an interlayer bias, the resulting changes in the energy dispersion lead to stronger electron scattering at the bottom of the conduction band. The mobility decreases significantly with the size of the generated bandgap, whereas the saturation velocity remains largely unaffected.