Spiral graphone and one sided fluorographene nano-ribbons

TL;DR

This study investigates the instability and transformation of one-sided fluorinated graphene nano-ribbons into stable spiral structures using various simulation methods, revealing new stable configurations with unique electronic properties.

Contribution

It demonstrates that one-sided fluorinated graphene nano-ribbons spontaneously form stable spiral structures, a behavior not observed in double-sided counterparts.

Findings

Spiral structures are more stable than flat nano-ribbons.

Spiral B-GO and B-GF are energetically favored over AC counterparts.

Localized HOMO-LUMO states appear at edges with increasing energy gap.

Abstract

The instability of a free-standing one sided hydrogenated/fluorinated graphene nano-ribbon, i.e. graphone/fluorographene, is studied using ab-initio, semiempirical and large scale molecular dynamics simulations. Free standing semi-infinite arm-chair like hydrogenated/fluorinated graphene (AC-GO/AC-GF) and boat like hydrogenated/fluorinated graphene (B-GO/B-GF) (nano-ribbons which are periodic along the zig-zag direction) are unstable and spontaneously transform into spiral structures. We find that rolled, spiral B-GO and B-GF are energetically more favorable than spiral AC-GO and AC-GF which is opposite to the double sided flat hydrogenated/fluorinated graphene, i.e. graphane/fluorographene. We found that the packed, spiral structures exhibit unexpected localized HOMO-LUMO at the edges with increasing energy gap during rolling. These rolled hydrocarbon structures are stable beyond room temperature up to at least $T$=1000\,K.