title: Crystal plane dependent growth of aligned single-walled carbon nanotubes on sapphire.
abstract: On single-crystal substrates, such as sapphire (alpha-Al 2O 3) and quartz (SiO 2), single-walled carbon nanotubes (SWNTs) align along specific crystallographic axes of the crystal, indicating that the SWNT growth is influenced by the crystal surface. Here, we show that not only the orientation, but also the diameter and chirality of SWNTs are affected by the crystal plane of the sapphire substrate. The aligned SWNTs grown on the A- and R-planes of sapphire have narrower diameter distributions than randomly oriented tubes produced on the C-plane sapphire and amorphous SiO 2. Photoluminescence measurements reveal a striking difference between the aligned SWNTs: near-zigzag tubes are observed on the A-plane and near-armchair tubes on the R-plane. This study shows the route for the diameter and chirality control of SWNTs by surface atomic arrangements of a single-crystal substrate.
authors.affiliation: Graduate School of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816-8580, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Ishigami
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ago
authors.forename: Kenta
authors.initials: K
authors.lastname: Imamoto
authors.forename: Masaharu
authors.initials: M
authors.lastname: Tsuji
authors.forename: Konstantin
authors.initials: K
authors.lastname: Iakoubovskii
authors.forename: Nobutsugu
authors.initials: N
authors.lastname: Minami