An easy approach to reveal the metallic nature of graphene by Breit–Wigner–FanoBreit–Wigner–Fano lineshapes using RamanRaman spectroscopy

摘要

> Electron–phonon coupling enhancement in metal‐doped single‐layer graphene has been investigated. Different metal adatoms were deposited on chemical vapor deposition (CVD) graphene and annealed at high temperature under vacuum. The interaction between these metals and graphene was studied by Raman spectroscopy. A significant variation in peak width has been observed as a function of annealing temperature. This broadening of the Raman features is understood as a consequence of the coupling of phonon with electron–phonon pairs, and its strength depends on the particular metal deposited. A typical softening and broadening of G peak in Raman spectrum is interpreted as Fano resonance, which is an interaction between a phonon and continuum. This asymmetry in G peak is further analyzed and fitted with Breit–Wigner–Fano lineshapes in terms of asymmetric factor type="mathematics"> (1/ q _BWF ) for different metal‐doped samples as a function of annealing temperature. Hence we demonstrated an easy approach to study the transition from semi‐metallic to metallic nature of graphene. This study may extend the interest in electron–phonon coupling as it aims to manipulate the electronic and magnetic properties of graphene and other 2D systems. Copyright ? 2017 John Wiley & Sons, Ltd.