Atomic structure and electronic properties of folded graphene nanoribbons: a first-principles study

TL;DR

This study uses first-principles calculations to explore the atomic and electronic structures of folded graphene nanoribbons, revealing new stacking configurations, stability conditions, and a method to open the band gap.

Contribution

It introduces novel stacking styles and stability criteria for folded graphene nanoribbons, expanding understanding of their atomic and electronic properties.

Findings

Folded graphene nanoribbons have racket-like structures.

New stacking styles are observed beyond traditional AB-stacking.

Band gap in zigzag nanoribbons can be tuned to about 0.17 eV.

Abstract

The atomic structure, stacking sequences and electronic structure of folded graphene nanoribbons (FGNRs) are investigated by first-principles calculations. It reveals that the common configurations of all FGNRs are racket-like structures including a nanotube-like edge and two flat nanoribbons. Interestingly, the two flat nanoribbons can form new stacking styles instead of the most stable AB-stacking sequences for bilayer nanoribbons. The stability of the FGNRs are associated with several factors of initial structures, such as interlayer distance of two nanoribbons, stacking sequences, edge styles, and width of nanoribbons. These folded nanoribbons can only be thermodynamically stable when the width reaches about 61 {\AA} and 95 {\AA} for the zigzag and armchair nanoribbons, respectively. In addition, the band gap of the folded zigzag graphene nanoribbons becomes about 0.17 eV, which provides a new way to open the band gap.