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dc.contributor.authorSalzner, U.en_US
dc.date.accessioned2016-02-08T10:08:41Z
dc.date.available2016-02-08T10:08:41Z
dc.date.issued2008en_US
dc.identifier.issn1089-5639
dc.identifier.urihttp://hdl.handle.net/11693/23083
dc.description.abstractThe nature of the charge carriers in conducting organic polymers (COPs) is a long standing problem. Polythiophene is one of the prototypes of COPs and intensively studied. Because doping leads to changes in UV/vis spectra that are characteristic of the absorbing species, UV/vis spectra of charged thiophene oligomers with up to 25 rings were calculated with time-dependent density functional theory. The credibility of the method was established by comparing the results with a variety of theoretical levels and with experiment. Effects due to counterions (Cl3-) and solvent (CH 2Cl2) were examined. It was found that TDDFT employing hybrid functionals is accurate enough to distinguish the absorbing species. The findings offer an explanation for the experimentally observed difference in UV-spectra of medium-sized and long oligomers upon doping. As chain lengths of the oligomers increase and energy levels get closer, configuration interaction leads to additional absorption peaks in the high energy sub-band region (at around 1.5-2.5 eV). Thus, long oligomers do not behave differently from medium-sized ones upon doping, only their spectra are different. At low doping levels radical cations (polarons) are produced. At higher doping levels, dications that harbor weakly interacting polaron pairs are formed. Bipolarons are predicted only on very short chains or at high doping levels. There is no bipolaron binding energy and disproportionation of monocations into dications and neutral species is energetically unfavorable. © 2008 American Chemical Society.en_US
dc.language.isoEnglishen_US
dc.source.titleJournal of Physical Chemistry Aen_US
dc.relation.isversionofhttp://dx.doi.org/10.1021/jp800606men_US
dc.subjectABS resinsen_US
dc.subjectCivil aviationen_US
dc.subjectConducting polymersen_US
dc.subjectDensity functional theoryen_US
dc.subjectOligomersen_US
dc.subjectOrganic polymersen_US
dc.subjectPolymersen_US
dc.subjectProbability density functionen_US
dc.subjectSulfur compoundsen_US
dc.subjectThiopheneen_US
dc.subjectConducting organic polymersen_US
dc.subjectCounter-ionsen_US
dc.subjectLong standingen_US
dc.subjectPoly-thiopheneen_US
dc.subjectThiophene oligomersen_US
dc.subjectTime-dependent density functional theoryen_US
dc.subjectUV/Vis spectraen_US
dc.subjectCharge carriersen_US
dc.titleInvestigation of charge carriers in doped thiophene oligomers through theoretical modeling of their UV/Vis spectraen_US
dc.typeArticleen_US
dc.departmentDepartment of Chemistryen_US
dc.citation.spage5458en_US
dc.citation.epage5466en_US
dc.citation.volumeNumber112en_US
dc.citation.issueNumber24en_US
dc.identifier.doi10.1021/jp800606men_US


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