Numerical simulation of vibrational properties of AGNR with vacancy and stone wales defects

This paper reports the effects of vacancy and stone wales defects on the vibrational properties of armchair graphene nanoribbon (AGNR) using molecular dynamic simulation. The optimized Tersoff and Brenner empirical potential has been used to calculate the phonon density of states (PDOS) using atomistic toolkit (ATK) force-field method, which provides a very good agreement with the Raman spectra of graphene related systems. The calculated results show a downshift of the PDOS peaks with the decrease of AGNR width. The vacancy and stone wales defects strongly affect the PDOS peaks of AGNR. Due to vacancy defects some new peaks are appeared in the low frequency region while stone wales defects produce some new peaks in the high frequency region. However, due to both vacancy and stone wales defects, a localized in-plane optical mode phonon is appeared near the edge and defect sites. This paper also discusses the effects of defects on the phonon transmission spectrum which is responsible for thermal conductivity and electron transport properties of AGNRs.