▎ 摘　　要

A phenomenon of phonon anomaly is clearly observed in single-layer graphene (SG) doped chemically with AuCl3 by using electric field effect-induced Raman spectroscopy. The variations of G-mode frequency omega(G) and full-wave half-maximum Gamma(G) in pristine graphene are asymmetric for positive and negative charging, but become more symmetric after the p-type doping due to the softening of the G band. The Gamma(G) shows a steplike variation at doping concentrations of 10 and 20 mM because the AuCl3 doping is uniformly done, thereby making the charge density of graphene uniformly distributed, consistent with theoretical expectation. A flat region of omega(G) between Fermi levels = +/- (h) over bar omega(G)/2, instead of its two logarithmic divergences as theoretically expected, is observed even in doped SG. These results suggest that the observation of the phonon anomaly is facilitated due to the charge uniformity improved by the doping even though it is not enough to show such omega(G) divergences.