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

Folded graphene nanoribbons (FGNRs) have attracted great attentions because of extraordinary properties and potential applications. The atomic structure, stacking sequences, and electronic structure of FGNRs are investigated by first-principle 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 form new stacking styles instead of the most stable AB-stacking sequences for flat zone. The final configurations of FGNRs are greatly affected by the initial interlayer distance, stacking sequences, and edge styles. The stability of folded graphene nanoribbon depends on the length, and it can only be thermodynamically stable when it reaches the critical length. The band gap of the folded zigzag graphene nanoribbons becomes about 0.17 eV, which provides a new way to open the band gap.