Limits for Recombination in a Low Energy Loss Organic Heterojunction

Handle URI:
http://hdl.handle.net/10754/622740
Title:
Limits for Recombination in a Low Energy Loss Organic Heterojunction
Authors:
Menke, S. Matthew; Sadhanala, Aditya; Nikolka, Mark; Ran, Niva A.; Ravva, Mahesh Kumar ( 0000-0001-9619-0176 ) ; Abdel-Azeim, Safwat ( 0000-0001-8611-1251 ) ; Stern, Hannah L.; Wang, Ming; Sirringhaus, Henning; Nguyen, Thuc-Quyen; Bredas, Jean-Luc ( 0000-0001-7278-4471 ) ; Bazan, Guillermo C.; Friend, Richard H.
Abstract:
Donor-acceptor organic solar cells often show high quantum yields for charge collection, but relatively low open-circuit voltages (VOC) limit power conversion efficiencies to around 12%. We report here the behavior of a system, PIPCP:PC61BM, that exhibits very low electronic disorder (Urbach energy less than 27 meV), very high carrier mobilities in the blend (field-effect mobility for holes >10-2 cm2 V-1 s-1), and a very low driving energy for initial charge separation (50 meV). These characteristics should give excellent performance, and indeed, the VOC is high relative to the donor energy gap. However, we find the overall performance is limited by recombination, with formation of lower-lying triplet excitons on the donor accounting for 90% of the recombination. We find this is a bimolecular process that happens on time scales as short as 100 ps. Thus, although the absence of disorder and the associated high carrier mobility speeds up charge diffusion and extraction at the electrodes, which we measure as early as 1 ns, this also speeds up the recombination channel, giving overall a modest quantum yield of around 60%. We discuss strategies to remove the triplet exciton recombination channel.
KAUST Department:
Physical Sciences and Engineering (PSE) Division; Solar and Photovoltaic Engineering Research Center (SPERC)
Citation:
Menke SM, Sadhanala A, Nikolka M, Ran NA, Ravva MK, et al. (2016) Limits for Recombination in a Low Energy Loss Organic Heterojunction. ACS Nano 10: 10736–10744. Available: http://dx.doi.org/10.1021/acsnano.6b06211.
Publisher:
American Chemical Society (ACS)
Journal:
ACS Nano
Issue Date:
3-Nov-2016
DOI:
10.1021/acsnano.6b06211
Type:
Article
ISSN:
1936-0851; 1936-086X
Sponsors:
S.M.M., R.H.F., M.K.R., S.A.-A., and J.-L.B. acknowledge support from the KAUST Competitive Research Grant Program. M.K.R., S.A.-A., and J.-L.B. also acknowledge generous support of their work by KAUST and the Office of Naval Research Global (Award N629091512003); they thank the KAUST IT Research Computing Team and Supercomputing Laboratory for providing computational and storage resources. N.A.R., M.W., T.-Q.N., and G.C.B. acknowledge support from the Department of the Navy, Office of Naval Research (Award Nos. N00014-14-1-0580 and N00014-16-1-25200. A.S. would like to acknowledge the funding and support from the India–UK APEX project. H.L.S. acknowledges support from the Winton Programme for the Physics of Sustainability. M.N. and H.S. gratefully acknowledge financial support from the Engineering and Physical Sciences Research Council though a Programme Grant (EP/M005141/1).
Additional Links:
http://pubs.acs.org/doi/full/10.1021/acsnano.6b06211
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Solar and Photovoltaic Engineering Research Center (SPERC)

Full metadata record

DC FieldValue Language
dc.contributor.authorMenke, S. Matthewen
dc.contributor.authorSadhanala, Adityaen
dc.contributor.authorNikolka, Marken
dc.contributor.authorRan, Niva A.en
dc.contributor.authorRavva, Mahesh Kumaren
dc.contributor.authorAbdel-Azeim, Safwaten
dc.contributor.authorStern, Hannah L.en
dc.contributor.authorWang, Mingen
dc.contributor.authorSirringhaus, Henningen
dc.contributor.authorNguyen, Thuc-Quyenen
dc.contributor.authorBredas, Jean-Lucen
dc.contributor.authorBazan, Guillermo C.en
dc.contributor.authorFriend, Richard H.en
dc.date.accessioned2017-01-26T13:29:24Z-
dc.date.available2017-01-26T13:29:24Z-
dc.date.issued2016-11-03en
dc.identifier.citationMenke SM, Sadhanala A, Nikolka M, Ran NA, Ravva MK, et al. (2016) Limits for Recombination in a Low Energy Loss Organic Heterojunction. ACS Nano 10: 10736–10744. Available: http://dx.doi.org/10.1021/acsnano.6b06211.en
dc.identifier.issn1936-0851en
dc.identifier.issn1936-086Xen
dc.identifier.doi10.1021/acsnano.6b06211en
dc.identifier.urihttp://hdl.handle.net/10754/622740-
dc.description.abstractDonor-acceptor organic solar cells often show high quantum yields for charge collection, but relatively low open-circuit voltages (VOC) limit power conversion efficiencies to around 12%. We report here the behavior of a system, PIPCP:PC61BM, that exhibits very low electronic disorder (Urbach energy less than 27 meV), very high carrier mobilities in the blend (field-effect mobility for holes >10-2 cm2 V-1 s-1), and a very low driving energy for initial charge separation (50 meV). These characteristics should give excellent performance, and indeed, the VOC is high relative to the donor energy gap. However, we find the overall performance is limited by recombination, with formation of lower-lying triplet excitons on the donor accounting for 90% of the recombination. We find this is a bimolecular process that happens on time scales as short as 100 ps. Thus, although the absence of disorder and the associated high carrier mobility speeds up charge diffusion and extraction at the electrodes, which we measure as early as 1 ns, this also speeds up the recombination channel, giving overall a modest quantum yield of around 60%. We discuss strategies to remove the triplet exciton recombination channel.en
dc.description.sponsorshipS.M.M., R.H.F., M.K.R., S.A.-A., and J.-L.B. acknowledge support from the KAUST Competitive Research Grant Program. M.K.R., S.A.-A., and J.-L.B. also acknowledge generous support of their work by KAUST and the Office of Naval Research Global (Award N629091512003); they thank the KAUST IT Research Computing Team and Supercomputing Laboratory for providing computational and storage resources. N.A.R., M.W., T.-Q.N., and G.C.B. acknowledge support from the Department of the Navy, Office of Naval Research (Award Nos. N00014-14-1-0580 and N00014-16-1-25200. A.S. would like to acknowledge the funding and support from the India–UK APEX project. H.L.S. acknowledges support from the Winton Programme for the Physics of Sustainability. M.N. and H.S. gratefully acknowledge financial support from the Engineering and Physical Sciences Research Council though a Programme Grant (EP/M005141/1).en
dc.publisherAmerican Chemical Society (ACS)en
dc.relation.urlhttp://pubs.acs.org/doi/full/10.1021/acsnano.6b06211en
dc.rightsThis is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited.en
dc.rights.urihttp://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.htmlen
dc.subjectcharge recombinationen
dc.subjectHigh Mobilityen
dc.subjectEnergy Lossen
dc.subjectOrganic Solar Cellen
dc.subjectCharge Transfer Statesen
dc.titleLimits for Recombination in a Low Energy Loss Organic Heterojunctionen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentSolar and Photovoltaic Engineering Research Center (SPERC)en
dc.identifier.journalACS Nanoen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionDepartment of Physics, Cavendish Laboratory, University of Cambridge , J.J. Thompson Avenue, Cambridge CB3 0HE, United Kingdom.en
dc.contributor.institutionCenter for Polymers and Organic Solids, University of California , Santa Barbara, California 93106, United States.en
kaust.authorRavva, Mahesh Kumaren
kaust.authorAbdel-Azeim, Safwaten
kaust.authorBredas, Jean-Lucen
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