Role Played by Edge-Defects in the Optical Properties of Armchair Graphene Nanoribbons.

Thi-Nga Do,Godfrey Gumbs,Bui D Hoi,Po-Hsin Shih,Danhong Huang

doi:10.3390/nano11123229

Abstract

We explore the implementation of specific optical properties of armchair graphene nanoribbons (AGNRs) through edge-defect manipulation. This technique employs the tight-binding model in conjunction with the calculated absorption spectral function. Modification of the edge states gives rise to the diverse electronic structures with striking changes in the band gap and special flat bands at low energy. The optical-absorption spectra exhibit unique excitation peaks, and they strongly depend on the type and period of the edge extension. Remarkably, there exist the unusual transition channels associated with the flat bands for selected edge-modified systems. We discovered the special rule governing how the edge-defect influences the electronic and optical properties in AGNRs. Our theoretical prediction demonstrates an efficient way to manipulate the optical properties of AGNRs. This might be of importance in the search for suitable materials designed to have possible technology applications in nano-optical, plasmonic and optoelectronic devices.

Highlights

Seventeen years have passed since the discovery of graphene in 2004 [1], and this has unmistakably inspired a huge amount of research on its fundamental properties as well as those of graphene-related materials
In order to highlight the influence of the edge extension on the electronic properties of armchair graphene nanoribbons (AGNRs), we introduce defects into a narrow ribbon (N = 7)
We found that these essential properties of AGNRs are remarkably enriched by modification of the edge states

Summary

Introduction

Seventeen years have passed since the discovery of graphene in 2004 [1], and this has unmistakably inspired a huge amount of research on its fundamental properties as well as those of graphene-related materials. Graphene nanoribbons (GNRs), which are narrow strips of graphene, possess quasi-one-dimensional properties This material presents rich essential physical properties, including electronic, optical, magnetic, and transport properties [2,3,4,5,6,7]. Methods have been demonstrated to be efficient for the synthesis of GNRs. It is well known that GNRs can be classified into two categories based on their edge-state arrangement, namely, armchair GNR (AGNR) and zigzag GNR (ZGNR) [21,22]. It is well known that GNRs can be classified into two categories based on their edge-state arrangement, namely, armchair GNR (AGNR) and zigzag GNR (ZGNR) [21,22] Both the AGNR and ZGNR can be subjected to edge defects during the fabrication processes, which has been examined to modify remarkably the essential physical properties of the materials.

Methods

Results

Conclusion