title: Aryl functionalization as a route to band gap engineering in single layer graphene devices.
abstract: Chemical functionalization is a promising route to band gap engineering of graphene. We chemically grafted nitrophenyl groups onto exfoliated single-layer graphene sheets in the form of substrate-supported or free-standing films. Our transport measurements demonstrate that nonsuspended functionalized graphene behaves as a granular metal, with variable range hopping transport and a mobility gap ∼0.1 eV at low temperature. For suspended graphene that allows functionalization on both surfaces, we demonstrate tuning of its electronic properties from a granular metal to a semiconductor in which transport occurs via thermal activation over a transport gap ∼80 meV from 4 to 300 K. This noninvasive and scalable functionalization technique paves the way for CMOS-compatible band gap engineering of graphene electronic devices.
authors.affiliation: Department of Physics and Astronomy, University of California , Riverside, California 92521, United States.
authors.forename: Hang
authors.initials: H
authors.lastname: Zhang
authors.forename: Elena
authors.initials: E
authors.lastname: Bekyarova
authors.forename: Jhao-Wun
authors.initials: JW
authors.lastname: Huang
authors.forename: Zeng
authors.initials: Z
authors.lastname: Zhao
authors.forename: Wenzhong
authors.initials: W
authors.lastname: Bao
authors.forename: Fenglin
authors.initials: F
authors.lastname: Wang
authors.forename: Robert C
authors.initials: RC
authors.lastname: Haddon
authors.forename: Chun Ning
authors.initials: CN
authors.lastname: Lau