title: Tunable band gaps and p-type transport properties of boron-doped graphenes by controllable ion doping using reactive microwave plasma.
abstract: We report tunable band gaps and transport properties of B-doped graphenes that were achieved via controllable doping through reaction with the ion atmosphere of trimethylboron decomposed by microwave plasma. Both electron energy loss spectroscopy and X-ray photoemission spectroscopy analyses of the graphene reacted with ion atmosphere showed that B atoms are substitutionally incorporated into graphenes without segregation of B domains. The B content was adjusted over a range of 0-13.85 atom % by controlling the ion reaction time, from which the doping effects on transport properties were quantitatively evaluated. Electrical measurements from graphene field-effect transistors show that the B-doped graphenes have a distinct p-type conductivity with a current on/off ratio higher than 10(2). Especially, the band gap of graphenes is tuned from 0 to ~0.54 eV with increasing B content, leading to a series of modulated transport properties. We believe the controllable doping for graphenes with predictable transport properties may pave a way for the development of graphene-based devices.
authors.affiliation: Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, People's Republic of China.
authors.forename: Yong-Bing
authors.initials: YB
authors.lastname: Tang
authors.forename: Li-Chang
authors.initials: LC
authors.lastname: Yin
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Xiang-Hui
authors.initials: XH
authors.lastname: Bo
authors.forename: Yu-Lin
authors.initials: YL
authors.lastname: Cao
authors.forename: Hong-En
authors.initials: HE
authors.lastname: Wang
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Zhang
authors.forename: Igor
authors.initials: I
authors.lastname: Bello
authors.forename: Shuit-Tong
authors.initials: ST
authors.lastname: Lee
authors.forename: Hui-Ming
authors.initials: HM
authors.lastname: Cheng
authors.forename: Chun-Sing
authors.initials: CS
authors.lastname: Lee