The mechanism of long-range exciton diffusion in a nematically organized porphyrin layer

Annemarie Huijser, Tom J. Savenije, Stefan C.J. Meskers, Martien J. W. Vermeulen, Laurens D. A. Siebbeles

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32 Citations (Scopus)

Abstract

The exciton diffusion length in a nematically organized meso-tetra(4-n-butylphenyl)porphyrin (TnBuPP) layer was found to exceed 40 nm at a temperature of 90 K and to be equal to 22 ± 3 nm at 300 K. The exciton diffusion coefficient decreases from ≥3.1 × 10−6 m2/s at 90 K to (2.5 ± 0.5) × 10−7 m2/s at 300 K. This thermal deactivation is attributed to exciton motion via a band mechanism. The motion of an exciton is not limited by polaronic effects; that is, the deformation of the atomic lattice around the exciton. The absence of polaronic self-trapping implies that the exciton diffusion coefficient can be enhanced by improvement of structural order and rigidity of the material.
Original languageEnglish
Pages (from-to)12496-12500
JournalJournal of the American Chemical Society
Volume130
Issue number37
DOIs
Publication statusPublished - 17 Sep 2008
Externally publishedYes

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