Charge-Transfer States in Organic Solar Cells: Understanding the Impact of Polarization, Delocalization, and Disorder

Handle URI:
http://hdl.handle.net/10754/623702
Title:
Charge-Transfer States in Organic Solar Cells: Understanding the Impact of Polarization, Delocalization, and Disorder
Authors:
Zheng, Zilong; Tummala, Naga Rajesh ( 0000-0001-9957-6330 ) ; Fu, Yao-Tsung; Coropceanu, Veaceslav ( 0000-0003-1693-2315 ) ; Bredas, Jean-Luc ( 0000-0001-7278-4471 )
Abstract:
We investigate the impact of electronic polarization, charge delocalization, and energetic disorder on the charge-transfer (CT) states formed at a planar C60/pentacene interface. The ability to examine large complexes containing up to seven pentacene molecules and three C60 molecules allows us to take explicitly into account the electronic polarization effects. These complexes are extracted from a bilayer architecture modeled by molecular dynamics simulations and evaluated by means of electronic-structure calculations based on long-range-separated functionals (ωB97XD and BNL) with optimized range-separation parameters. The energies of the lowest charge-transfer states derived for the large complexes are in very good agreement with the experimentally reported values. The average singlet-triplet energy splittings of the lowest CT states are calculated not to exceed 10 meV. The rates of geminate recombination as well as of dissociation of the triplet excitons are also evaluated. In line with experiment, our results indicate that the pentacene triplet excitons generated through singlet fission can dissociate into separated charges on a picosecond time scale, despite the fact that their energy in C60/pentacene heterojunctions is slightly lower than the energies of the lowest CT triplet states.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
Zheng Z, Tummala NR, Fu Y-T, Coropceanu V, Brédas J-L (2017) Charge-Transfer States in Organic Solar Cells: Understanding the Impact of Polarization, Delocalization, and Disorder. ACS Applied Materials & Interfaces. Available: http://dx.doi.org/10.1021/acsami.7b02193.
Publisher:
American Chemical Society (ACS)
Journal:
ACS Applied Materials & Interfaces
Issue Date:
8-May-2017
DOI:
10.1021/acsami.7b02193
Type:
Article
ISSN:
1944-8244; 1944-8252
Sponsors:
We acknowledge the financial support of this work at the Georgia Institute of Technology by the Department of the Navy, Office of Naval Research, under the MURI “Center for Advanced Organic Photovoltaics” (Award Nos. N00014-14-1-0580 and N00014-16-1-2520) and by King Abdullah University of Science and Technology (V.C.). A KAUST competitive research funding and the Office of Naval Research – Global (Award No. N62909-15-1-2003) supported the work at King Abdullah University of Science and Technology.
Additional Links:
http://pubs.acs.org/doi/full/10.1021/acsami.7b02193
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorZheng, Zilongen
dc.contributor.authorTummala, Naga Rajeshen
dc.contributor.authorFu, Yao-Tsungen
dc.contributor.authorCoropceanu, Veaceslaven
dc.contributor.authorBredas, Jean-Lucen
dc.date.accessioned2017-05-23T09:30:36Z-
dc.date.available2017-05-23T09:30:36Z-
dc.date.issued2017-05-08en
dc.identifier.citationZheng Z, Tummala NR, Fu Y-T, Coropceanu V, Brédas J-L (2017) Charge-Transfer States in Organic Solar Cells: Understanding the Impact of Polarization, Delocalization, and Disorder. ACS Applied Materials & Interfaces. Available: http://dx.doi.org/10.1021/acsami.7b02193.en
dc.identifier.issn1944-8244en
dc.identifier.issn1944-8252en
dc.identifier.doi10.1021/acsami.7b02193en
dc.identifier.urihttp://hdl.handle.net/10754/623702-
dc.description.abstractWe investigate the impact of electronic polarization, charge delocalization, and energetic disorder on the charge-transfer (CT) states formed at a planar C60/pentacene interface. The ability to examine large complexes containing up to seven pentacene molecules and three C60 molecules allows us to take explicitly into account the electronic polarization effects. These complexes are extracted from a bilayer architecture modeled by molecular dynamics simulations and evaluated by means of electronic-structure calculations based on long-range-separated functionals (ωB97XD and BNL) with optimized range-separation parameters. The energies of the lowest charge-transfer states derived for the large complexes are in very good agreement with the experimentally reported values. The average singlet-triplet energy splittings of the lowest CT states are calculated not to exceed 10 meV. The rates of geminate recombination as well as of dissociation of the triplet excitons are also evaluated. In line with experiment, our results indicate that the pentacene triplet excitons generated through singlet fission can dissociate into separated charges on a picosecond time scale, despite the fact that their energy in C60/pentacene heterojunctions is slightly lower than the energies of the lowest CT triplet states.en
dc.description.sponsorshipWe acknowledge the financial support of this work at the Georgia Institute of Technology by the Department of the Navy, Office of Naval Research, under the MURI “Center for Advanced Organic Photovoltaics” (Award Nos. N00014-14-1-0580 and N00014-16-1-2520) and by King Abdullah University of Science and Technology (V.C.). A KAUST competitive research funding and the Office of Naval Research – Global (Award No. N62909-15-1-2003) supported the work at King Abdullah University of Science and Technology.en
dc.publisherAmerican Chemical Society (ACS)en
dc.relation.urlhttp://pubs.acs.org/doi/full/10.1021/acsami.7b02193en
dc.rightsThis document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials & Interfaces, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/full/10.1021/acsami.7b02193.en
dc.subjectOrganic Photovoltaicsen
dc.subjectCharge-transfer Statesen
dc.subjectElectronic Couplingsen
dc.subjectPentacene-fullerene Blendsen
dc.subjectSinglet−triplet Energy Splittingen
dc.subjectRange-separated Hybrid Functionalsen
dc.titleCharge-Transfer States in Organic Solar Cells: Understanding the Impact of Polarization, Delocalization, and Disorderen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalACS Applied Materials & Interfacesen
dc.eprint.versionPost-printen
dc.contributor.institutionSchool of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology , Atlanta, Georgia 30332-0400, United States.en
kaust.authorBredas, Jean-Lucen
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