Next Article in Journal
Tuning Nanoscale Friction by Applying Weak Magnetic Fields to Reorient Adsorbed Oxygen Molecules
Previous Article in Journal
Fluctuation Theory in Chemical Kinetics
Article Menu

Export Article

Open AccessArticle
Condens. Matter 2018, 3(4), 50; https://doi.org/10.3390/condmat3040050

Effect and Characterization of Stone–Wales Defects on Graphene Quantum Dot: A First-Principles Study

1
Department of Physics, St. Thomas’ College of Engineering Technology, 4, Diamond Harbour Road, Kidderpore, Kolkata 700023, India
2
Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700009, India
*
Author to whom correspondence should be addressed.
Received: 14 November 2018 / Revised: 7 December 2018 / Accepted: 12 December 2018 / Published: 17 December 2018
Full-Text   |   PDF [3881 KB, uploaded 17 December 2018]   |  

Abstract

A first principles based density functional theory (DFT) has been employed to identify the signature of Stone–Wales (SW) defects in semiconducting graphene quantum dot (GQD). Results show that the G mode in the Raman spectra of GQD has been red shifted to 1544.21 cm 1 in the presence of 2.08% SW defect concentration. In addition, the intensity ratio between a robust low intense contraction–elongation mode and G mode is found to be reduced for the defected structure. We have also observed a Raman mode at 1674.04 cm 1 due to the solo contribution of the defected bond. The increase in defect concentration, however, reduces the stability of the structures. As a consequence, the systems undergo structural buckling due to the presence of SW defect generated additional stresses. We have further explored that the 1615.45 cm 1 Raman mode and 1619.29 cm 1 infra-red mode are due to the collective stretching of two distinct SW defects separated at a distance 7.98 Å. Therefore, this is the smallest separation between the SW defects for their distinct existence. The pristine structure possesses maximum electrical conductivity and the same reduces to 0.37 times for 2.08% SW defect. On the other hand, the work function is reduced in the presence of defects except for the structure with SW defects separated at 7.98 Å. All these results will serve as an important reference to facilitate the potential applications of GQD based nano-devices with inherent topological SW defects. View Full-Text
Keywords: density functional theory (DFT); Raman spectroscopy; Stone–Wales defect; electronic properties; infra-red spectra density functional theory (DFT); Raman spectroscopy; Stone–Wales defect; electronic properties; infra-red spectra
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Chakraborti (Banerjee), G.; Bandyopadhyay, A.; Jana, D. Effect and Characterization of Stone–Wales Defects on Graphene Quantum Dot: A First-Principles Study. Condens. Matter 2018, 3, 50.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Condens. Matter EISSN 2410-3896 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top