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

Abstract

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 Å, 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.