title: Photosensitive function of encapsulated dye in carbon nanotubes.
abstract: Single-wall carbon nanotubes (SWCNTs) exhibit resonant absorption localized in specific spectral regions. To expand the light spectrum that can be utilized by SWCNTs, we have encapsulated squarylium dye into SWCNTs and clarified its microscopic structure and photosensitizing function. X-ray diffraction and polarization-resolved optical absorption measurements revealed that the encapsulated dye molecules are located at an off center position inside the tubes and aligned to the nanotube axis. Efficient energy transfer from the encapsulated dye to SWCNTs was clearly observed in the photoluminescence spectra. Enhancement of transient absorption saturation in the S1 state of the semiconducting SWCNTs was detected after the photoexcitation of the encapsulated dye, which indicates that ultrafast (<190 fs) energy transfer occurred from the dye to the SWCNTs.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki 305-8562, Japan. k-yanagi@aist.go.jp
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yanagi
authors.forename: Konstantin
authors.initials: K
authors.lastname: Iakoubovskii
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsui
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsuzaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Okamoto
authors.forename: Yasumitsu
authors.initials: Y
authors.lastname: Miyata
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Maniwa
authors.forename: Said
authors.initials: S
authors.lastname: Kazaoui
authors.forename: Nobutsugu
authors.initials: N
authors.lastname: Minami
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Kataura