Lowest excited states and optical absorption spectra of donor–acceptor copolymers for organic photovoltaics: a new picture emerging from tuned long-range corrected density functionals

Handle URI:
http://hdl.handle.net/10754/598743
Title:
Lowest excited states and optical absorption spectra of donor–acceptor copolymers for organic photovoltaics: a new picture emerging from tuned long-range corrected density functionals
Authors:
Pandey, Laxman; Doiron, Curtis; Sears, John S.; Brédas, Jean-Luc
Abstract:
Polymers with low optical gaps are of importance to the organic photovoltaics community due to their potential for harnessing a large portion of the solar energy spectrum. The combination along their backbones of electron-rich and electron-deficient fragments contributes to the presence of low-lying excited states that are expected to display significant charge-transfer character. While conventional hybrid functionals are known to provide unsatisfactory results for charge-transfer excitations at the time-dependent DFT level, long-range corrected (LRC) functionals have been reported to give improved descriptions in a number of systems. Here, we use such LRC functionals, considering both tuned and default range-separation parameters, to characterize the absorption spectra of low-optical-gap systems of interest. Our results indicate that tuned LRC functionals lead to simulated optical-absorption properties in good agreement with experimental data. Importantly, the lowest-lying excited states (excitons) are shown to present a much more localized nature than initially anticipated. © 2012 the Owner Societies.
Citation:
Pandey L, Doiron C, Sears JS, Brédas J-L (2012) Lowest excited states and optical absorption spectra of donor–acceptor copolymers for organic photovoltaics: a new picture emerging from tuned long-range corrected density functionals. Physical Chemistry Chemical Physics 14: 14243. Available: http://dx.doi.org/10.1039/c2cp41724c.
Publisher:
Royal Society of Chemistry (RSC)
Journal:
Physical Chemistry Chemical Physics
KAUST Grant Number:
KUS-C1-015-21
Issue Date:
2012
DOI:
10.1039/c2cp41724c
PubMed ID:
22914764
Type:
Article
ISSN:
1463-9076; 1463-9084
Sponsors:
This work has been supported by the National Science Foundation under the STC Program (Award No. DMR-0120967) and under the CRIF Program (Award No. CHE-0946869) and by the Center for Advanced Molecular Photovoltaics (Award No. KUS-C1-015-21 made by King Abdullah University of Science and Technology, KAUST).
Appears in Collections:
Publications Acknowledging KAUST Support

Full metadata record

DC FieldValue Language
dc.contributor.authorPandey, Laxmanen
dc.contributor.authorDoiron, Curtisen
dc.contributor.authorSears, John S.en
dc.contributor.authorBrédas, Jean-Lucen
dc.date.accessioned2016-02-25T13:40:19Zen
dc.date.available2016-02-25T13:40:19Zen
dc.date.issued2012en
dc.identifier.citationPandey L, Doiron C, Sears JS, Brédas J-L (2012) Lowest excited states and optical absorption spectra of donor–acceptor copolymers for organic photovoltaics: a new picture emerging from tuned long-range corrected density functionals. Physical Chemistry Chemical Physics 14: 14243. Available: http://dx.doi.org/10.1039/c2cp41724c.en
dc.identifier.issn1463-9076en
dc.identifier.issn1463-9084en
dc.identifier.pmid22914764en
dc.identifier.doi10.1039/c2cp41724cen
dc.identifier.urihttp://hdl.handle.net/10754/598743en
dc.description.abstractPolymers with low optical gaps are of importance to the organic photovoltaics community due to their potential for harnessing a large portion of the solar energy spectrum. The combination along their backbones of electron-rich and electron-deficient fragments contributes to the presence of low-lying excited states that are expected to display significant charge-transfer character. While conventional hybrid functionals are known to provide unsatisfactory results for charge-transfer excitations at the time-dependent DFT level, long-range corrected (LRC) functionals have been reported to give improved descriptions in a number of systems. Here, we use such LRC functionals, considering both tuned and default range-separation parameters, to characterize the absorption spectra of low-optical-gap systems of interest. Our results indicate that tuned LRC functionals lead to simulated optical-absorption properties in good agreement with experimental data. Importantly, the lowest-lying excited states (excitons) are shown to present a much more localized nature than initially anticipated. © 2012 the Owner Societies.en
dc.description.sponsorshipThis work has been supported by the National Science Foundation under the STC Program (Award No. DMR-0120967) and under the CRIF Program (Award No. CHE-0946869) and by the Center for Advanced Molecular Photovoltaics (Award No. KUS-C1-015-21 made by King Abdullah University of Science and Technology, KAUST).en
dc.publisherRoyal Society of Chemistry (RSC)en
dc.titleLowest excited states and optical absorption spectra of donor–acceptor copolymers for organic photovoltaics: a new picture emerging from tuned long-range corrected density functionalsen
dc.typeArticleen
dc.identifier.journalPhysical Chemistry Chemical Physicsen
dc.contributor.institutionGeorgia Institute of Technology, Atlanta, United Statesen
dc.contributor.institutionKing Abdulaziz University, Jeddah, Saudi Arabiaen
kaust.grant.numberKUS-C1-015-21en
kaust.grant.fundedcenterCenter for Advanced Molecular Photovoltaics (CAMP)en
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