An Ab Initio Study on Energy Gap of Bilayer Graphene Nanoribbons with Armchair Edges

TL;DR

This study uses ab initio calculations to analyze how the energy bandgap of bilayer armchair graphene nanoribbons depends on width, interlayer distance, and edge doping, revealing tunable electronic properties.

Contribution

It provides new insights into the effects of interlayer distance and edge doping on the energy gap of bilayer graphene nanoribbons, which was not extensively studied before.

Findings

AGNRB has smaller Eg than AGNRM but shows metallic and semiconducting groups.

Eg of AGNRB is highly sensitive to interlayer distance D.

Edge doping reduces Eg by 11-17% in AGNRM and 4-10% in AGNRB.

Abstract

Dependency of energy bandgap (Eg) of bilayer armchair graphene nanoribbons (AGNRB) on their widths, interlayer distance (D) and edge doping concentration of boron/nitrogen is investigated using local density approximation and compare to the results of monolayer graphene nanoribbons (AGNRM). Although Eg of AGNRB, in general, is smaller than that of AGNRM, AGNRB exhibits two distinct groups, metal and semiconductor, while AGNRM displays purely semiconducting behavior. Eg of AGNRB, moreover, is highly sensitive to D, indicating a possible application in tuning Eg by varying D. Finally, edge doping of both AGNR systems reduces Eg by 11-17%/4-10% for AGNRM/AGNRB, respectively.