title: Conjugated Polymer Blend Microspheres for Efficient, Long-Range Light Energy Transfer.
abstract: Highly luminescent π-conjugated polymeric microspheres were fabricated through self-assembly of energy-donating and energy-accepting polymers and their blends. To avoid macroscopic phase separation, the nucleation time and growth rate of each polymer in the solution were properly adjusted. Photoluminescence (PL) studies showed that efficient donor-to-acceptor energy transfer takes place inside the microspheres, revealing that two polymers are well-blended in the microspheres. Focused laser irradiation of a single microsphere excites whispering gallery modes (WGMs), where PL generated inside the sphere is confined and resonates. The wavelengths of the PL lines are finely tuned by changing the blending ratio, accompanying the systematic yellow-to-red color change. Furthermore, when several microspheres are coupled linearly, the confined PL propagates the microspheres through the contact point, and a cascade-like process converts the PL color while maintaining the WGM characteristics. The self-assembly strategy for the formation of polymeric nano- to microstructures with highly miscible polymer blends will be advantageous for optoelectronic and photonic device applications.
authors.affiliation: Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.
authors.forename: Soh
authors.initials: S
authors.lastname: Kushida
authors.affiliation: Faculty of Physics and CENIDE, University of Duisburg-Essen , Lotharstrasse 1, Duisburg D-47048, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Braam
authors.affiliation: International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.|CREST, Japan Science and Technology Agency (JST) , 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Thang Duy
authors.initials: TD
authors.lastname: Dao
authors.affiliation: Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Saito
authors.affiliation: Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Shibasaki
authors.affiliation: International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.|CREST, Japan Science and Technology Agency (JST) , 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ishii
authors.affiliation: International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.|CREST, Japan Science and Technology Agency (JST) , 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Tadaaki
authors.initials: T
authors.lastname: Nagao
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka University , 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Saeki
authors.affiliation: Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.|Tsukuba Research Center for Interdisciplinary Materials Science (TIMS), Faculty of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan.
authors.forename: Junpei
authors.initials: J
authors.lastname: Kuwabara
authors.affiliation: Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.|Tsukuba Research Center for Interdisciplinary Materials Science (TIMS), Faculty of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan.|Center for Integrated Research in Fundamental Science and Technology (CiRfSE), University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.
authors.forename: Takaki
authors.initials: T
authors.lastname: Kanbara
authors.affiliation: Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.|Tsukuba Research Center for Interdisciplinary Materials Science (TIMS), Faculty of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Kijima
authors.affiliation: Faculty of Physics and CENIDE, University of Duisburg-Essen , Lotharstrasse 1, Duisburg D-47048, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Lorke
authors.affiliation: Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.|Tsukuba Research Center for Interdisciplinary Materials Science (TIMS), Faculty of Pure and Applied Sciences, University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan.|Center for Integrated Research in Fundamental Science and Technology (CiRfSE), University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Yamamoto
keywords: conjugated polymer; energy transfer; microsphere; polymer blend; whispering gallery mode