title: Synthesis of Freestanding Graphene on SiC by a Rapid-Cooling Technique.
abstract: Graphene has a negative thermal expansion coefficient; that is, when heated, the graphene lattice shrinks. On the other hand, the substrates typically used for graphene growth, such as silicon carbide, have a positive thermal expansion coefficient. Hence, on cooling graphene on SiC, graphene expands but SiC shrinks. This mismatch will physically break the atomic bonds between graphene and SiC. We have demonstrated that a graphenelike buffer layer on SiC can be converted to a quasifreestanding monolayer graphene by a rapid-cooling treatment. The decoupling of graphene from the SiC substrate was actually effective for reducing the electric carrier scattering due to interfacial phonons. In addition, the rapidly cooled graphene obtained in this way was of high-quality, strain-free, thermally stable, and strongly hole doped. This simple, classical, but quite novel technique for obtaining quasifreestanding graphene could open a new path towards a viable graphene-based semiconductor industry.
authors.affiliation: Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya 464-8603, Japan.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Bao
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Norimatsu
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Iwata
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Matsuda
authors.affiliation: Synchrotron Radiation Research Center, Nagoya University, Nagoya 464-8603, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ito
authors.affiliation: Institute of Materials and Systems for Sustainability, Nagoya University, Nagoya 464-8603, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Kusunoki