Photoinduced absorption in an alternating polyfluorene copolymer for photovoltaic applications
Journal article, 2006

The authors present a detailed study of a novel alternating polyfluorene copolymer, poly[2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4',7'-di-2-thienyl-2',1',3-benzo-thiadiazole)], and its blends with the fullerene deriv. [6,6]-phenyl-C61-butyric acid Me ester, using continuous wave photoinduced absorption (PA) techniques. The authors also present the use of phase information from the PA measurements for estg. the no. of different photoexcitation types present in the PA spectra as well as their lifetimes. In all blends the PA spectra show a broad high-energy PA band ranging from .apprx.1 to 2 eV as well as a low-energy band at .apprx.0.35 eV. The authors find two kinds of excitations present at 80 DegK, polarons showing dispersive recombination with lifetimes of roughly a millisecond, and a 2nd kind of photoexcitation tentatively assigned to coulombically bound intrachain polaron pairs showing practically nondispersive recombination with a lifetime of .apprx.20 ms. [on SciFinder (R)]


H. Aarnio

M. Westerling

R. Oesterbacka

M. I. Svensson

Mats Andersson

Chalmers, Chemical and Biological Engineering, Polymer Technology

H. Stubb

Chemical Physics

Vol. 321 1-2 127-132

Subject Categories

Polymer Chemistry

Condensed Matter Physics

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