Gap Opening of Graphene by Dual FeCl3-Acceptor and K-Donor Doping

The band gap opening of graphene is the most desired property in the device industry because it is vital to the application of graphene as a logical device of semiconductors. Here, we show how to make a reasonably wide band gap in graphene. This is accomplished with bilayer graphene (BLG) dual-doped with FeCl3-acceptor and K-donor. To elucidate this phenomenon, we employed the first-principles method taking into account van der Waals interaction. For the FeCl3 adsorbed BLG, the optimal distance between the adjacent graphene and FeCl3 layers is 4.6-4.8 angstrom, consistent with experiments. Due to the high electronegativity of FeCl3, these graphene layers are hole-doped. The dual-doped BLG gives a band gap of 0.27 eV due to broken symmetry, with a Dirac point shift by -0.09 eV. This increased band gap and proper Dirac point shift could make the dual-doped BLG useful for applications toward future field effect transistor devices.