Anomalous Doping Effects on Charge Transport in Graphene Nanoribbons

TL;DR

This study uses first-principles calculations to explore how chemical doping with boron and nitrogen affects charge transport in graphene nanoribbons, revealing symmetry-dependent backscattering and potential for novel switching devices.

Contribution

It provides detailed insights into doping-induced transport phenomena in graphene nanoribbons, highlighting symmetry effects and unique acceptor-donor transitions.

Findings

Resonant backscattering depends on ribbon symmetry and dopant position.

Full suppression of backscattering occurs when doping preserves mirror symmetry.

Unconventional acceptor-donor transition observed in zig-zag ribbons.

Abstract

We present first-principles calculations of quantum transport in chemically doped graphene nanoribbons with a width of up to 4 nm. The presence of boron and nitrogen impurities is shown to yield resonant backscattering, whose features are strongly dependent on the symmetry and the width of the ribbon, as well as the position of the dopants. Full suppression of backscattering is obtained on the pi-pi* plateau when the impurity preserves the mirror symmetry of armchair ribbons. Further, an unusual acceptor-donor transition is observed in zig-zag ribbons. These unconventional doping effects could be used to design novel types of switching devices.