title: Transfer of photoenergy in pi-conjugated polymers. Two types of photoluminescence that involve energy transfer along a polymer chain.
abstract: Two types of energy transfer in pi-conjugated polymers have been investigated using time-resolved photoluminescence (PL) techniques: type i, perpendicular-type energy transfer from the 2,3-di(p-tolyl)quinoxaline unit to the pi-conjugated main chain of poly[2,3-di(p-tolyl)quinoxaline-5,8-diyl], and type ii, parallel-type energy transfer from the oligo(pyridine-2,5-diyl) (O-Py) unit to the oligo(selenophene-2,5-diyl) (O-Se) unit in a block-type copolymer of O-Py and O-Se. Both types of energy transfer were very fast with a time constant shorter than approximately 0.1 ns; in particular, the type ii energy transfer took place with a time constant of approximately 5 ps. Both pi-conjugated polymers were considered to contain segments with various effective pi-conjugation lengths, and the energy transfer to the segment with a larger effective pi-conjugation length and a smaller pi-pi* transition energy required a longer transition time. A polarizing film was obtained by utilizing the perpendicular-type energy transfer.
authors.affiliation: Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.
authors.forename: Takakazu
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Bang-Lin
authors.initials: BL
authors.lastname: Lee
authors.forename: Ismayil
authors.initials: I
authors.lastname: Nurulla
authors.forename: Takuma
authors.initials: T
authors.lastname: Yasuda
authors.forename: Isao
authors.initials: I
authors.lastname: Yamaguchi
authors.forename: Akihide
authors.initials: A
authors.lastname: Wada
authors.forename: Chiaki
authors.initials: C
authors.lastname: Hirose
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Tasumi
authors.forename: Akira
authors.initials: A
authors.lastname: Sakamoto
authors.forename: Eiji
authors.initials: E
authors.lastname: Kobayashi