Vacancy Induced Electron-Phonon Interaction of Single Layer Graphene

Abstract

In graphene honeycomb structure, the phonon particles are strongly coupled with the electrons, therefore any change in the structure of graphene changes the electron-phonon (e-ph) interaction and consequently it has an impressive effect on the electronic and vibrational properties of graphene. Here in this paper, we report the electron-phonon interaction of vacancy defected single layer graphene using first principle calculations based on density functional theory. In this paper, it has been found that vacancy defect introduces a band gap in the graphene structure. In vacancy defected graphene, the ZA phonon modes are shifted downward in the lower frequency region and the el-ph coupling coefficient increases from 0.0035 to 0.30 at Gaussian Broadening of 0.5 Ry which indicates that vacancy defect enhances a ballistic transports of the high-frequency phonons in graphene structure. Again, from Raman spectrum it has found that the G-peak shifts from the frequency of 1607 cm−1to 1704 cm 1due to the presence of vacancy defect and the vibrational modes are IR active in disordered graphene where they are not IR active in case of pristine graphene. Thus this paper gives a deep insight about the electronic and vibrational properties of vacancy induced graphene structure.