title: Size-dependent spectroscopic properties of conjugated polymer nanoparticles.
abstract: This paper is focused on how the spectroscopic properties of conjugated polymers evolve in the size range between single polymer chains and the bulk material. The measurements used single-particle spectroscopy techniques and include both static and dynamic measurements. The main observation of this work is that the spectroscopic properties of MEH-PPV evolve rapidly as a function of nanoparticle size and achieve bulk-like properties for nanoparticles greater than 10 nm in size. Nanoparticles were assembled by a reprecipitation technique and characterized by fluorescence emission spectroscopy. The physical origin of the size-dependent spectroscopic properties is assigned to the distance dependence of four main processes: electronic energy transfer between blue and red sites, triplet-triplet annihilation, singlet exciton quenching by triplets, and singlet exciton quenching by hole polarons.
authors.affiliation: Center for Nano- and Molecular Science and Technology and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: John K
authors.initials: JK
authors.lastname: Grey
authors.forename: Doo Young
authors.initials: DY
authors.lastname: Kim
authors.forename: Brent C
authors.initials: BC
authors.lastname: Norris
authors.forename: William L
authors.initials: WL
authors.lastname: Miller
authors.forename: Paul F
authors.initials: PF
authors.lastname: Barbara