title: Phosphorescence quenching of fac-tris(2-phenylpyridyl)iridium(iii) complexes in thin films on dielectric surfaces.
abstract: We study the influence of the film thickness on the time-resolved phosphorescence and the luminescence quantum yield of fac-tris(2-phenylpyridyl)iridium(iii) [Ir(ppy)3]-cored dendrimers deposited on dielectric substrates. A correlation is observed between the surface quenching velocity and the quenching rate by intermolecular interactions in the bulk film, which suggests that both processes are controlled by dipole-dipole interactions between Ir(ppy)3 complexes at the core of the dendrimers. It is also found that the surface quenching velocity decreases as the refractive index of the substrate is increased. This can be explained by partial screening of dipole-dipole interactions by the dielectric environment.
authors.affiliation: Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK. idws@st-andrews.ac.uk.
authors.forename: J C
authors.initials: JC
authors.lastname: Ribierre
authors.forename: A
authors.initials: A
authors.lastname: Ruseckas
authors.forename: S V
authors.initials: SV
authors.lastname: Staton
authors.forename: K
authors.initials: K
authors.lastname: Knights
authors.forename: N
authors.initials: N
authors.lastname: Cumpstey
authors.forename: P L
authors.initials: PL
authors.lastname: Burn
authors.forename: I D W
authors.initials: ID
authors.lastname: Samuel