Tuning the electronic structures of armchair graphene nanoribbons through chemical edge modification: A theoretical study

TL;DR

This study uses theoretical calculations to explore how chemical modifications at the edges of armchair graphene nanoribbons alter their electronic properties, including potential metal-insulator transitions.

Contribution

It introduces a phenomenological hopping parameter to model chemical edge modifications and analyzes their impact on electronic structures.

Findings

Edge modifications significantly alter band structures.

Chemical addends can induce metal-insulator transitions.

Structural changes near edges are substantial.

Abstract

We report combined first-principle and tight-binding (TB) calculations to simulate the effects of chemical edge modifications on structural and electronic properties. The C-C bond lengths and bond angles near the GNR edge have considerable changes when edge carbon atoms are bounded to different atoms. By introducing a phenomenological hopping parameter $t_{1}$ for nearest-neighboring hopping to represent various chemical edge modifications, we investigated the electronic structural changes of nanoribbons with different widths based on the tight-binding scheme. Theoretical results show that addends can change the band structures of armchair GNRs and even result in observable metal-to-insulator transition.