Recombination in polymer:Fullerene solar cells with open-circuit voltages approaching and exceeding 1.0 V

Handle URI:
http://hdl.handle.net/10754/562328
Title:
Recombination in polymer:Fullerene solar cells with open-circuit voltages approaching and exceeding 1.0 V
Authors:
Hoke, Eric T.; Vandewal, Koen; Bartelt, Jonathan A.; Mateker, William R.; Douglas, Jessica D.; Noriega, Rodrigo; Graham, Kenneth; Frechet, Jean ( 0000-0001-6419-0163 ) ; Salleo, Alberto; McGehee, Michael D.
Abstract:
Polymer:fullerene solar cells are demonstrated with power conversion efficiencies over 7% with blends of PBDTTPD and PC 61 BM. These devices achieve open-circuit voltages ( V oc ) of 0.945 V and internal quantum efficiencies of 88%, making them an ideal candidate for the large bandgap junction in tandem solar cells. V oc 's above 1.0 V are obtained when the polymer is blended with multiadduct fullerenes; however, the photocurrent and fill factor are greatly reduced. In PBDTTPD blends with multiadduct fullerene ICBA, fullerene emission is observed in the photoluminescence and electroluminescence spectra, indicating that excitons are recombining on ICBA. Voltage-dependent, steady state and time-resolved photoluminescence measurements indicate that energy transfer occurs from PBDTTPD to ICBA and that back hole transfer from ICBA to PBDTTPD is inefficient. By analyzing the absorption and emission spectra from fullerene and charge transfer excitons, we estimate a driving free energy of -0.14 ± 0.06 eV is required for efficient hole transfer. These results suggest that the driving force for hole transfer may be too small for efficient current generation in polymer:fullerene solar cells with V oc values above 1.0 V and that non-fullerene acceptor materials with large optical gaps ( > 1.7 eV) may be required to achieve both near unity internal quantum efficiencies and values of V oc exceeding 1.0 V. © 2013 WILEY-VCH Verlag GmbH and Co.
KAUST Department:
Physical Sciences and Engineering (PSE) Division; Chemical Science Program
Publisher:
Wiley-Blackwell
Journal:
Advanced Energy Materials
Issue Date:
14-Sep-2012
DOI:
10.1002/aenm.201200474
Type:
Article
ISSN:
16146832
Sponsors:
This publication was supported by the Center for Advanced Molecular Photovoltaics (Award No KUS-C1-015-21), made possible by King Abdullah University of Science and Technology (KAUST). Additional support was provided for E.T.H. by the Fannie and John Hertz Foundation and for J.A.B. by the NDSEG fellowship. The authors would like to thank Laxman Pandey and Chad Risko for calculating the PBDTTPD triplet absorption cross section and Ian Howard for helpful discussions.
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Chemical Science Program

Full metadata record

DC FieldValue Language
dc.contributor.authorHoke, Eric T.en
dc.contributor.authorVandewal, Koenen
dc.contributor.authorBartelt, Jonathan A.en
dc.contributor.authorMateker, William R.en
dc.contributor.authorDouglas, Jessica D.en
dc.contributor.authorNoriega, Rodrigoen
dc.contributor.authorGraham, Kennethen
dc.contributor.authorFrechet, Jeanen
dc.contributor.authorSalleo, Albertoen
dc.contributor.authorMcGehee, Michael D.en
dc.date.accessioned2015-08-03T10:01:06Zen
dc.date.available2015-08-03T10:01:06Zen
dc.date.issued2012-09-14en
dc.identifier.issn16146832en
dc.identifier.doi10.1002/aenm.201200474en
dc.identifier.urihttp://hdl.handle.net/10754/562328en
dc.description.abstractPolymer:fullerene solar cells are demonstrated with power conversion efficiencies over 7% with blends of PBDTTPD and PC 61 BM. These devices achieve open-circuit voltages ( V oc ) of 0.945 V and internal quantum efficiencies of 88%, making them an ideal candidate for the large bandgap junction in tandem solar cells. V oc 's above 1.0 V are obtained when the polymer is blended with multiadduct fullerenes; however, the photocurrent and fill factor are greatly reduced. In PBDTTPD blends with multiadduct fullerene ICBA, fullerene emission is observed in the photoluminescence and electroluminescence spectra, indicating that excitons are recombining on ICBA. Voltage-dependent, steady state and time-resolved photoluminescence measurements indicate that energy transfer occurs from PBDTTPD to ICBA and that back hole transfer from ICBA to PBDTTPD is inefficient. By analyzing the absorption and emission spectra from fullerene and charge transfer excitons, we estimate a driving free energy of -0.14 ± 0.06 eV is required for efficient hole transfer. These results suggest that the driving force for hole transfer may be too small for efficient current generation in polymer:fullerene solar cells with V oc values above 1.0 V and that non-fullerene acceptor materials with large optical gaps ( > 1.7 eV) may be required to achieve both near unity internal quantum efficiencies and values of V oc exceeding 1.0 V. © 2013 WILEY-VCH Verlag GmbH and Co.en
dc.description.sponsorshipThis publication was supported by the Center for Advanced Molecular Photovoltaics (Award No KUS-C1-015-21), made possible by King Abdullah University of Science and Technology (KAUST). Additional support was provided for E.T.H. by the Fannie and John Hertz Foundation and for J.A.B. by the NDSEG fellowship. The authors would like to thank Laxman Pandey and Chad Risko for calculating the PBDTTPD triplet absorption cross section and Ian Howard for helpful discussions.en
dc.publisherWiley-Blackwellen
dc.titleRecombination in polymer:Fullerene solar cells with open-circuit voltages approaching and exceeding 1.0 Ven
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentChemical Science Programen
dc.identifier.journalAdvanced Energy Materialsen
dc.contributor.institutionDepartment of Applied Physics, Stanford University, 476 Lomita Mall, Stanford, CA 94305, United Statesen
dc.contributor.institutionDepartment of Material Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, CA 94305, United Statesen
dc.contributor.institutionDepartment of Chemistry, University of California, 727 Latimer Hall, Berkeley, CA 94720-1460, United Statesen
kaust.authorGraham, Kennethen
kaust.authorFrechet, Jeanen
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