title: Characterization of SiC-grown epitaxial graphene microislands using tip-enhanced Raman spectroscopy.
abstract: Single-layer graphene microislands with smooth edges and no visible grain boundary were epitaxially grown on the C-face of 4H-SiC and then characterized at the nanoscale using tip-enhanced Raman spectroscopy (TERS). Although these graphene islands appear highly homogeneous in micro-Raman imaging, TERS reveals the nanoscale strain variation caused by ridge nanostructures. A G' band position shift up to 9 cm(-1) and a band broadening up to 30 cm(-1) are found in TERS spectra obtained from nanoridges, which is explained by the compressive strain relaxation mechanism. The small size and refined nature of the graphene islands help in minimizing the inhomogeneity caused by macroscale factors, and allow a comparative discussion of proposed mechanisms of nanoridge formation.
authors.affiliation: Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan. yoshito@iis.u-tokyo.ac.jp.
authors.forename: Sanpon
authors.initials: S
authors.lastname: Vantasin
authors.affiliation: Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan. ozaki@kwansei.ac.jp.
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan. yoshito@iis.u-tokyo.ac.jp.
authors.forename: Shohei
authors.initials: S
authors.lastname: Uemura
authors.affiliation: UNISOKU Co. Ltd, 2-4-3 Kasugano, Hirakata, Osaka 573-0131, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Physics, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Kutsuma
authors.affiliation: Department of Physics, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan.
authors.forename: Daichi
authors.initials: D
authors.lastname: Doujima
authors.affiliation: Department of Physics, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan.
authors.forename: Tadaaki
authors.initials: T
authors.lastname: Kaneko
authors.affiliation: Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan. yoshito@iis.u-tokyo.ac.jp.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Ozaki