FeCl₃-based few-layer graphene intercalation compounds: Single linear dispersion electronic band structure and strong charge transfer doping

Graphene has attracted much attention since its first discovery in 2004. Various approaches have been proposed to control its physical and electronic properties. Here, it is reported that graphene-based intercalation is an efficient method to modify the electronic properties of few-layer graphene (FLG). FeCl₃ intercalated FLGs are successfully prepared by the two-zone vapor transport method. This is the first report on full intercalation for graphene samples. The features of the Raman G peak of such FLG intercalation compounds (FLGIC) are in good agreement with their full intercalation structures. The FLGICs present single Lorentzian 2D peaks, similar to that of single-layer graphene, indicating the loss of electronic coupling between adjacent graphene layers. First principle calculations further reveal that the band structure of FLGIC is similar to single-layer graphene but with a strong doping effect due to the charge transfer from graphene to FeCl₃. The successful fabrication of FLGIC opens a new way to modify properties of FLG for fundamental studies and future applications.