title: Measurement of interchain and intrachain exciton hopping barriers in luminescent polymer.
abstract: The integrated photoluminescence intensity in thin films of 'Super Yellow' copolymer has been analyzed using a Mott-like temperature dependence. This has enabled us to observe contributions from two emission channels, indicative of exciton recombination proceeding from two distinct origins. At high temperature, interchain thermally activated exciton energy transfer and migration dominates, resulting in large scale quenching of the integrated emission intensity and hence the photoluminescence quantum yield. However, at relatively low temperature, an additional increase of the integrated emission intensity occurs. This new channel of emission has been attributed to recombination from excitons where intrachain exciton energy transfer between adjacent subunits of the copolymer backbone becomes hindered. The activation energy barriers that control both of these emission channels have been obtained and are correlated with chain backbone degrees of freedom.
authors.affiliation: Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: P L
authors.initials: PL
authors.lastname: Santos
authors.forename: B B A
authors.initials: BB
authors.lastname: Costa
authors.forename: K S
authors.initials: KS
authors.lastname: Araujo
authors.forename: L A
authors.initials: LA
authors.lastname: Cury
authors.forename: E W
authors.initials: EW
authors.lastname: Snedden
authors.forename: K N
authors.initials: KN
authors.lastname: Bourdakos
authors.forename: F B
authors.initials: FB
authors.lastname: Dias
authors.forename: A P
authors.initials: AP
authors.lastname: Monkman
mesh_terms: D004583:Electrons; D004735:Energy Transfer; D049408:Luminescent Agents / Q000737:chemistry*; D008163:Luminescent Measurements; D011108:Polymers / Q000737:chemistry*; D013696:Temperature
chemical_list: D049408:Luminescent Agents; D011108:Polymers