There is a tunable band gap in ABC-stacked few-layer graphene (FLG) via applying a vertical electric field, but the operation of FLG-based field effect transistor (FET) requires two gates to create a band gap and tune channel's conductance individually. Using first principle calculations, we propose an alternative scheme to open a band gap in ABC-stacked FLG namely via single-side adsorption. The band gap is generally proportional to the charge transfer density. The capability to open a band gap of metal adsorption decreases in this order: K/Al > Cu/Ag/Au > Pt. Moreover, we find that even the band gap of ABA-stacked FLG can be opened if the bond symmetry is broken. Finally, a single-gated FET based on Cu-adsorbed ABC-stacked trilayer graphene is simulated. A clear transmission gap is observed, which is comparable with the band gap. This renders metal-adsorbed FLG a promising channel in a single-gated FET device.
@article{arxiv.1304.5025,
title = {Tunable band gap in few-layer graphene by surface adsorption},
author = {Ruge Quhe and Jianhua Ma and Zesheng Zeng and Kechao Tang and Jiaxin Zheng and Yangyang Wang and Zeyuan Ni and Lu Wang and Zhengxiang Gao and Junjie Shi and Jing Lu},
journal= {arXiv preprint arXiv:1304.5025},
year = {2013}
}