title: Gate-Tunable Dirac Point of Molecular Doped Graphene.
abstract: Control of the type and density of charge carriers in graphene is essential for its implementation into various practical applications. Here, we demonstrate the gate-tunable doping effect of adsorbed piperidine on graphene. By gradually increasing the amount of adsorbed piperidine, the graphene doping level can be varied from p- to n-type, with the formation of p-n junctions for intermediate coverages. Moreover, the doping effect of the piperidine can be further tuned by the application of large negative back-gate voltages, which increase the doping level of graphene. In addition, the electronic properties of graphene are well preserved due to the noncovalent nature of the interaction between piperidine and graphene. This gate-tunable doping offers an easy, controllable, and nonintrusive method to alter the electronic structure of graphene.
authors.affiliation: Institute for Materials Chemistry and Engineering, Kyushu University , Fukuoka 816-8580, Japan.
authors.forename: Pablo
authors.initials: P
authors.lastname: Solís-Fernández
authors.affiliation: Graduate School of Pure and Applied Sciences, University of Tsukuba , Ibaraki 305-8571, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Okada
authors.affiliation: Department of Molecular Engineering, School of Engineering, Kyoto University , Kyoto 615-8510, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Sato
authors.affiliation: Institute for Materials Chemistry and Engineering, Kyushu University , Fukuoka 816-8580, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Tsuji
authors.affiliation: Institute for Materials Chemistry and Engineering, Kyushu University , Fukuoka 816-8580, Japan.|PRESTO, Japan Science and Technology Agency (JST) , Saitama 332-0012, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ago
keywords: graphene; molecular doping; p−n junction; transistor