Polarization Energies at Organic–Organic Interfaces: Impact on the Charge Separation Barrier at Donor–Acceptor Interfaces in Organic Solar Cells

Handle URI:
http://hdl.handle.net/10754/611771
Title:
Polarization Energies at Organic–Organic Interfaces: Impact on the Charge Separation Barrier at Donor–Acceptor Interfaces in Organic Solar Cells
Authors:
Ryno, Sean; Fu, Yao-Tsung; Risko, Chad; Bredas, Jean-Luc ( 0000-0001-7278-4471 )
Abstract:
We probe the energetic landscape at a model pentacene/fullerene-C60 interface to investigate the interactions between positive and negative charges, which are critical to the processes of charge separation and recombination in organic solar cells. Using a polarizable force field, we find that polarization energy, i.e. the stabilization a charge feels due to its environment, is larger at the interface than in the bulk for both a positive and a negative charge. The combination of the charge being more stabilized at the interface and the Coulomb attraction between the charges, results in a barrier to charge separation at the pentacene-C60 interface that can be in excess of 0.7 eV for static configurations of the donor and acceptor locations. However, the impact of molecular motions, i.e., the dynamics, at the interface at room temperature results in a distribution of polarization energies and in charge separation barriers that can be significantly reduced. The dynamic nature of the interface is thus critical, with the polarization energy distributions indicating that sites along the interface shift in time between favorable and unfavorable configurations for charge separation.
KAUST Department:
Solar and Photovoltaic Engineering Research Center (SPERC)
Citation:
Polarization Energies at Organic–Organic Interfaces: Impact on the Charge Separation Barrier at Donor–Acceptor Interfaces in Organic Solar Cells 2016 ACS Applied Materials & Interfaces
Publisher:
American Chemical Society (ACS)
Journal:
ACS Applied Materials & Interfaces
Issue Date:
31-May-2016
DOI:
10.1021/acsami.6b02851
Type:
Article
ISSN:
1944-8244; 1944-8252
Sponsors:
This work has been supported by King Abdullah University of Science and Technology (KAUST), the KAUST Competitive Research Grant program, and the Office of Naval Research Global (Award N62909-15-1-2003). We acknowledge the IT Research Computing Team and Supercomputing Laboratory at KAUST for providing computational and storage resources. This work has also used the computing resources of the Garnet, Spirit, and Copper supercomputing systems through the DoD HPCMP. C.R. thanks the University of Kentucky Vice President of Research for start-up funds. We wish to thank Mahesh Kumar Ravva and Naga Rajesh Tummala for stimulating discussions and assistance with technical elements of the molecular dynamics simulations.
Additional Links:
http://pubs.acs.org/doi/abs/10.1021/acsami.6b02851
Appears in Collections:
Articles

Full metadata record

DC FieldValue Language
dc.contributor.authorRyno, Seanen
dc.contributor.authorFu, Yao-Tsungen
dc.contributor.authorRisko, Chaden
dc.contributor.authorBredas, Jean-Lucen
dc.date.accessioned2016-06-06T07:40:30Z-
dc.date.available2016-06-06T07:40:30Z-
dc.date.issued2016-05-31-
dc.identifier.citationPolarization Energies at Organic–Organic Interfaces: Impact on the Charge Separation Barrier at Donor–Acceptor Interfaces in Organic Solar Cells 2016 ACS Applied Materials & Interfacesen
dc.identifier.issn1944-8244-
dc.identifier.issn1944-8252-
dc.identifier.doi10.1021/acsami.6b02851-
dc.identifier.urihttp://hdl.handle.net/10754/611771-
dc.description.abstractWe probe the energetic landscape at a model pentacene/fullerene-C60 interface to investigate the interactions between positive and negative charges, which are critical to the processes of charge separation and recombination in organic solar cells. Using a polarizable force field, we find that polarization energy, i.e. the stabilization a charge feels due to its environment, is larger at the interface than in the bulk for both a positive and a negative charge. The combination of the charge being more stabilized at the interface and the Coulomb attraction between the charges, results in a barrier to charge separation at the pentacene-C60 interface that can be in excess of 0.7 eV for static configurations of the donor and acceptor locations. However, the impact of molecular motions, i.e., the dynamics, at the interface at room temperature results in a distribution of polarization energies and in charge separation barriers that can be significantly reduced. The dynamic nature of the interface is thus critical, with the polarization energy distributions indicating that sites along the interface shift in time between favorable and unfavorable configurations for charge separation.en
dc.description.sponsorshipThis work has been supported by King Abdullah University of Science and Technology (KAUST), the KAUST Competitive Research Grant program, and the Office of Naval Research Global (Award N62909-15-1-2003). We acknowledge the IT Research Computing Team and Supercomputing Laboratory at KAUST for providing computational and storage resources. This work has also used the computing resources of the Garnet, Spirit, and Copper supercomputing systems through the DoD HPCMP. C.R. thanks the University of Kentucky Vice President of Research for start-up funds. We wish to thank Mahesh Kumar Ravva and Naga Rajesh Tummala for stimulating discussions and assistance with technical elements of the molecular dynamics simulations.en
dc.language.isoenen
dc.publisherAmerican Chemical Society (ACS)en
dc.relation.urlhttp://pubs.acs.org/doi/abs/10.1021/acsami.6b02851en
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/abs/10.1021/acsami.6b02851.en
dc.titlePolarization Energies at Organic–Organic Interfaces: Impact on the Charge Separation Barrier at Donor–Acceptor Interfaces in Organic Solar Cellsen
dc.typeArticleen
dc.contributor.departmentSolar and Photovoltaic Engineering Research Center (SPERC)en
dc.identifier.journalACS Applied Materials & Interfacesen
dc.eprint.versionPost-printen
dc.contributor.institutionSchool of Chemistry and Biochemistry & Center for Organic Photonics and Electronics Georgia Institute of Technology Atlanta, Georgia 30332-0400en
dc.contributor.institutionDepartment of Chemistry & Center for Applied Energy Research University of Kentucky Lexington, Kentucky 40506-0055en
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorBredas, Jean-Lucen
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