Raman signature of electron-electron correlation in chemically doped few-layer graphene

TL;DR

This study uses Raman spectroscopy to investigate how chemical doping affects electron-electron interactions in few-layer graphene, revealing changes in the 2D band related to electron correlation effects.

Contribution

It provides experimental evidence linking electron-electron correlation to Raman spectral features in chemically doped few-layer graphene.

Findings

Reduction in 2D band splitting with doping

Decrease in 2D band area with doping

Electron-electron correlation influences electron-phonon coupling

Abstract

We report an experimental Raman study of few-layer graphene after chemical doping achieved by a plasma process in CHF$_3$ gas. A systematic reduction of both the splitting and the area of the 2D band is observed with increasing the doping level. Both effects can be ascribed to the electron-electron correlation, which on the one hand reduces the electron-phonon coupling strength, and on the other hand affects the probability of the double resonant Raman process.