Ultrafast carrier dynamics in pristine and FeCl$_{3}$-intercalated bilayer graphene

Ultrafast carrier dynamics of pristine bilayer graphene (BLG) and bilayer graphene intercalated with FeCl$_{3}$ (FeCl$_{3}$-G), were studied using time-resolved transient differential reflection ($\Delta R/R)$. Compared to BLG, the FeCl$_{3}$-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 FeCl$_{3}$-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. Appl. Phys. Lett. \textbf{97, 141910 }(2010)