| Abstract
| - We investigate the excitation energy transfer in a guest−host molecular system consisting of a pentacenederivative, namely 6,13-bis(2,6-dimethylphenyl)pentacene (DMPP), doped into tris(8-hydroxyquinolinato)aluminum (Alq3) using steady-state and time-resolved photoluminescence (PL) spectroscopy. The concentrationdependent energy transfer rate and efficiency are calculated and analyzed in terms of the Förster resonanceenergy transfer model. A relatively long excitation transfer time (∼0.6−3.4 ns depending on the DMPPconcentration) and a large transfer radius (31−36 Å) are obtained. The Förster radius calculated directlyfrom the Alq3 PL−DMPP absorption spectral overlap (26 Å) is smaller than the transfer radii obtained fromthe PL studies, which suggests that excitation energy migration within Alq3 plays an important role in theenergy transfer process, effectively elongating the transfer radius and increasing the transfer rate and efficiency.
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