We have studied energy transfer to a dioxolane-substituted pentacene derivative, 6,14-bis-(triisopropylsilylethynyl)-1,3,9,11-tetraoxa-dicyclopenta[b,m]pentacene (TP-5), from tris(8-hydroxyquin-8-olinato) aluminum(III) (Alq₃) by steady state and time-resolved photoluminescence (PL) spectroscopy. The Förster transfer radius is 27 Å, calculated from the fluorescence spectrum of Alq₃ and the absorption spectrum of TP-5. We find that pentacene emission dominates the PL spectra of TP-5:Alq₃ guest-host films, even at concentrations where the typical guest separation is significantly larger than the Förster transfer radius. Monte Carlo simulations of energy transfer to randomly dispersed guest molecules in the host matrix show that Förster-type energy transfer cannot completely account for the PL dynamics of the guest and host. Exciton diffusion within the Alq₃ host followed by fluorescence of the host molecules or energy transfer to the guest explains the PL spectra and dynamics.

Date Published: 9 October 2005
PDF: 10 pages
Proc. SPIE 5937, Organic Light-Emitting Materials and Devices IX, 593709 (9 October 2005); doi: 10.1117/12.624411

Published in SPIE Proceedings Vol. 5937:
Organic Light-Emitting Materials and Devices IX
Zakya H. Kafafi; Paul A. Lane, Editor(s)