Ultrafast carrier dynamics in pristine and FeCl3-intercalated bilayer graphene

TL;DR

This study investigates how FeCl3 intercalation alters the ultrafast carrier dynamics in bilayer graphene, revealing significant changes in electronic behavior and relaxation processes due to modifications in electronic structure.

Contribution

It provides new insights into the effects of FeCl3 intercalation on the ultrafast carrier dynamics and electronic structure of bilayer graphene.

Findings

FeCl3 intercalation reverses the sign of delta R/R.

Intercalation results in slower rise times and single exponential relaxation.

Electronic structure changes are linked to Fermi level shifts and Fe d-orbitals.

Abstract

Ultrafast carrier dynamics of pristine bilayer graphene (BLG) and bilayer graphene intercalated with FeCl3 (FeCl3-G), were studied using time-resolved transient differential reflection (delta R/R). Compared to BLG, the FeCl3-G data showed an opposite sign of delta R/R, a slower rise time, and a single (instead of double) exponential relaxation. We attribute these differences in dynamics to the down-shifting of the Fermi level in FeCl3-G, as well as the formation of numerous horizontal bands arising from the d-orbitals of Fe. Our work shows that intercalation can dramatically change the electronic structure of graphene, and its associated carrier dynamics.