Suppressing Energy Loss due to Triplet Exciton Formation in Organic Solar Cells: The Role of Chemical Structures and Molecular Packing

Handle URI:
http://hdl.handle.net/10754/623395
Title:
Suppressing Energy Loss due to Triplet Exciton Formation in Organic Solar Cells: The Role of Chemical Structures and Molecular Packing
Authors:
Chen, Xiankai; Wang, Tonghui ( 0000-0002-5027-1541 ) ; Bredas, Jean-Luc ( 0000-0001-7278-4471 )
Abstract:
In the most efficient solar cells based on blends of a conjugated polymer (electron donor) and a fullerene derivative (electron acceptor),ultrafast formation of charge-transfer (CT) electronic states at the donor-acceptor interfaces and efficient separation of these CT states into free charges, lead to internal quantum efficiencies near 100%. However, there occur substantial energy losses due to the non-radiative recombinations of the charges, mediated by the loweset-energy (singlet and triplet) CT states; for example, such recombinations can lead to the formation of triplet excited electronic states on the polymer chains, which do not generate free charges. This issue remains a major factor limiting the power conversion efficiencies (PCE) of these devices. The recombination rates are, however, difficult to quantify experimentally. To shed light on these issues, here, an integrated multi-scale theoretical approach that combines molecular dynamics simulations with quantum chemistry calculations is employed in order to establish the relationships among chemical structures, molecular packing, and non-radiative recombination losses mediated by the lowest-energy charge-transfer states.
KAUST Department:
Laboratory for Computational and Theoretical Chemistry of Advanced Materials; Physical Sciences and Engineering (PSE) Division
Citation:
Chen X-K, Wang T, Brédas J-L (2017) Suppressing Energy Loss due to Triplet Exciton Formation in Organic Solar Cells: The Role of Chemical Structures and Molecular Packing. Advanced Energy Materials: 1602713. Available: http://dx.doi.org/10.1002/aenm.201602713.
Publisher:
Wiley-Blackwell
Journal:
Advanced Energy Materials
Issue Date:
21-Apr-2017
DOI:
10.1002/aenm.201602713
Type:
Article
ISSN:
1614-6832
Sponsors:
X.-K.C. and T.W. contributed equally to this work. This work was supported by competitive research funding at the King Abdullah University of Science and Technology (KAUST) and by the ONR Global, Grant N62909-15-1-2003. The authors acknowledge the KAUST IT Research Computing Team and Supercomputing Laboratory for providing precious continuous assistance as well as computational and storage resources.
Additional Links:
http://onlinelibrary.wiley.com/doi/10.1002/aenm.201602713/full
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorChen, Xiankaien
dc.contributor.authorWang, Tonghuien
dc.contributor.authorBredas, Jean-Lucen
dc.date.accessioned2017-05-08T06:49:47Z-
dc.date.available2017-05-08T06:49:47Z-
dc.date.issued2017-04-21en
dc.identifier.citationChen X-K, Wang T, Brédas J-L (2017) Suppressing Energy Loss due to Triplet Exciton Formation in Organic Solar Cells: The Role of Chemical Structures and Molecular Packing. Advanced Energy Materials: 1602713. Available: http://dx.doi.org/10.1002/aenm.201602713.en
dc.identifier.issn1614-6832en
dc.identifier.doi10.1002/aenm.201602713en
dc.identifier.urihttp://hdl.handle.net/10754/623395-
dc.description.abstractIn the most efficient solar cells based on blends of a conjugated polymer (electron donor) and a fullerene derivative (electron acceptor),ultrafast formation of charge-transfer (CT) electronic states at the donor-acceptor interfaces and efficient separation of these CT states into free charges, lead to internal quantum efficiencies near 100%. However, there occur substantial energy losses due to the non-radiative recombinations of the charges, mediated by the loweset-energy (singlet and triplet) CT states; for example, such recombinations can lead to the formation of triplet excited electronic states on the polymer chains, which do not generate free charges. This issue remains a major factor limiting the power conversion efficiencies (PCE) of these devices. The recombination rates are, however, difficult to quantify experimentally. To shed light on these issues, here, an integrated multi-scale theoretical approach that combines molecular dynamics simulations with quantum chemistry calculations is employed in order to establish the relationships among chemical structures, molecular packing, and non-radiative recombination losses mediated by the lowest-energy charge-transfer states.en
dc.description.sponsorshipX.-K.C. and T.W. contributed equally to this work. This work was supported by competitive research funding at the King Abdullah University of Science and Technology (KAUST) and by the ONR Global, Grant N62909-15-1-2003. The authors acknowledge the KAUST IT Research Computing Team and Supercomputing Laboratory for providing precious continuous assistance as well as computational and storage resources.en
dc.publisherWiley-Blackwellen
dc.relation.urlhttp://onlinelibrary.wiley.com/doi/10.1002/aenm.201602713/fullen
dc.rightsThis is the peer reviewed version of the following article: Suppressing Energy Loss due to Triplet Exciton Formation in Organic Solar Cells: The Role of Chemical Structures and Molecular Packing, which has been published in final form at http://doi.org/10.1002/aenm.201602713. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.en
dc.titleSuppressing Energy Loss due to Triplet Exciton Formation in Organic Solar Cells: The Role of Chemical Structures and Molecular Packingen
dc.typeArticleen
dc.contributor.departmentLaboratory for Computational and Theoretical Chemistry of Advanced Materialsen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalAdvanced Energy Materialsen
dc.eprint.versionPost-printen
kaust.authorChen, Xiankaien
kaust.authorWang, Tonghuien
kaust.authorBredas, Jean-Lucen
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