Theoretical investigation on armchair graphene nanoribbons with oxygen-terminated edges

TL;DR

This study uses density functional theory to explore how edge oxygen atoms affect the electronic properties of armchair graphene nanoribbons, revealing edge state-induced semiconductor-metal transitions and mobility variations.

Contribution

It provides a theoretical analysis of how oxygen termination influences electronic structure and mobility in graphene nanoribbons, highlighting the effects of edge oxygen atom arrangements.

Findings

Edge oxygen atoms induce semiconductor-metal transition via edge states.

Carrier mobility varies with edge oxygen content, reaching up to 103 cm²V⁻¹s⁻¹.

Mobility can be 18%-65% of hydrogen-terminated nanoribbons.

Abstract

Armchair graphene nanoribbons with different proportions of edge oxygen atoms are investigated by using crystal orbital method based on density functional theory. All the nanoribbons are energetically favorable, although buckled edges are present. Isolated edge oxygen atoms cause semiconductor-metal transition via introducing edge states, while adjacent edge oxygen atoms not. For the graphene nanoribbons with all oxygen atoms on the edges, both band gap and carrier mobility alternate with respect to the ribbon width. The carrier mobilities are as 18%-65% large as those of the graphene nanoribbons with hydrogen-terminated edges. These values are as large as 103 cm2V-1s-1, which are still quite high for electronic devices. Crystal orbital analysis gives pictorial explanations to the phenomenon.