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Photogeneration of free charge carriers in tenuously packed π conjugated polymer chains
Author(s) -
Menšík Miroslav,
Pfleger Jiří,
Rybak Andrzej,
Jung Jaroslaw,
Ulański Jacek,
Halašová Klára,
Vohlídal Jiří
Publication year - 2011
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.1724
Subject(s) - electric field , charge carrier , materials science , chemical physics , polymer , saturation velocity , quantum yield , charge (physics) , electric charge , dielectric , dissociation (chemistry) , exciton , molecular physics , condensed matter physics , optoelectronics , chemistry , optics , physics , drift velocity , quantum mechanics , composite material , fluorescence
A new theoretical insight into the process of free charge carrier photogeneration in polymers is introduced, based on the fact that increasing intensity of electric field may change the charge dynamics during the dissociation process of geminate pairs of photogenerated charge carriers. These changes are reflected in the model by the variation of internal parameters such as permittivity and effective mass of the hole. We used this approach to modify the model recently designed by Arkhipov, Emelianova and Baessler, describing a thermally activated escape of a hole from a quantum well in a Coulombic field of a localized electron. Our approach is particularly suitable for the description of the charge carrier photogeneration process in a polymer consisted of tenuously packed π conjugated polymer chains, as documented by its application to the experimental results of charge carrier photogeneration in poly{1‐[4‐(trimethylsilyl)phenyl]‐2‐phenylacetylene} measured by the photoinduced discharge (PID) technique. Namely, we have observed that the photogeneration yield of free charge carriers does not exhibit a transition to a plateau at the low electric field limit but a steep slope of its dependence on electric field is found. Compared to previously published models, that even consider a limited dimensionality of the process or charge carrier trapping, a marked improvement of the consistency of calculated values with experimental data was achieved. Copyright © 2010 John Wiley & Sons, Ltd.