Heavy doped ABA stacked trilayer graphene: triple splitting of its Raman G peak

TL;DR

This paper reports the first observation of triple G peak splitting in ABA stacked trilayer graphene, explained by electron-phonon coupling differences and layer interaction variations due to nonuniform doping.

Contribution

It provides the first experimental evidence of triple G peak splitting in ABA trilayer graphene and offers a quantitative understanding of its origin.

Findings

Triple G peak splitting observed in ABA trilayer graphene.

Splitting explained by differences in electron-phonon coupling.

Layer interaction fluctuations linked to nonuniform doping.

Abstract

For the first time, we have observed the obvious triple G peak splitting of ABA stacked trilayer graphene. The G peak splitting can be quantatively understood through the different electron-phonon coupling strength of Ea', Eb' and Ea" modes. In addition, the fluctuation of G peak position at different sample locations can also be understood from the view of the varied interaction strength among graphene layers of TLG, which is induced by nonuniform hole doping at the microscopic level.