From Recombination Dynamics to Device Performance: Quantifying the Efficiency of Exciton Dissociation, Charge Separation, and Extraction in Bulk Heterojunction Solar Cells with Fluorine-Substituted Polymer Donors

Handle URI:
http://hdl.handle.net/10754/625860
Title:
From Recombination Dynamics to Device Performance: Quantifying the Efficiency of Exciton Dissociation, Charge Separation, and Extraction in Bulk Heterojunction Solar Cells with Fluorine-Substituted Polymer Donors
Authors:
Gorenflot, Julien ( 0000-0002-0533-3205 ) ; Paulke, Andreas; Piersimoni, Fortunato; Wolf, Jannic Sebastian; Kan, Zhipeng; Cruciani, Federico ( 0000-0002-0063-2046 ) ; El Labban, Abdulrahman ( 0000-0001-9891-0851 ) ; Neher, Dieter; Beaujuge, Pierre; Laquai, Frederic ( 0000-0002-5887-6158 )
Abstract:
An original set of experimental and modeling tools is used to quantify the yield of each of the physical processes leading to photocurrent generation in organic bulk heterojunction solar cells, enabling evaluation of materials and processing condition beyond the trivial comparison of device performances. Transient absorption spectroscopy, “the” technique to monitor all intermediate states over the entire relevant timescale, is combined with time-delayed collection field experiments, transfer matrix simulations, spectral deconvolution, and parametrization of the charge carrier recombination by a two-pool model, allowing quantification of densities of excitons and charges and extrapolation of their kinetics to device-relevant conditions. Photon absorption, charge transfer, charge separation, and charge extraction are all quantified for two recently developed wide-bandgap donor polymers: poly(4,8-bis((2-ethylhexyl)oxy)benzo[1,2-b:4,5-b′]dithiophene-3,4-difluorothiophene) (PBDT[2F]T) and its nonfluorinated counterpart poly(4,8-bis((2-ethylhexyl)oxy)benzo[1,2-b:4,5-b′]dithiophene-3,4-thiophene) (PBDT[2H]T) combined with PC71BM in bulk heterojunctions. The product of these yields is shown to agree well with the devices' external quantum efficiency. This methodology elucidates in the specific case studied here the origin of improved photocurrents obtained when using PBDT[2F]T instead of PBDT[2H]T as well as upon using solvent additives. Furthermore, a higher charge transfer (CT)-state energy is shown to lead to significantly lower energy losses (resulting in higher VOC) during charge generation compared to P3HT:PCBM.
KAUST Department:
KAUST Solar Center (KSC); Materials Science and Engineering Program; Physical Sciences and Engineering (PSE) Division; Chemical Science Program
Citation:
Gorenflot J, Paulke A, Piersimoni F, Wolf J, Kan Z, et al. (2017) From Recombination Dynamics to Device Performance: Quantifying the Efficiency of Exciton Dissociation, Charge Separation, and Extraction in Bulk Heterojunction Solar Cells with Fluorine-Substituted Polymer Donors. Advanced Energy Materials: 1701678. Available: http://dx.doi.org/10.1002/aenm.201701678.
Publisher:
Wiley-Blackwell
Journal:
Advanced Energy Materials
Issue Date:
28-Sep-2017
DOI:
10.1002/aenm.201701678
Type:
Article
ISSN:
1614-6832
Sponsors:
The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST). A.P. and D.N. acknowledge funding from the BMBF in the project UNVEIL.
Additional Links:
http://onlinelibrary.wiley.com/doi/10.1002/aenm.201701678/full
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Chemical Science Program; Materials Science and Engineering Program; KAUST Solar Center (KSC)

Full metadata record

DC FieldValue Language
dc.contributor.authorGorenflot, Julienen
dc.contributor.authorPaulke, Andreasen
dc.contributor.authorPiersimoni, Fortunatoen
dc.contributor.authorWolf, Jannic Sebastianen
dc.contributor.authorKan, Zhipengen
dc.contributor.authorCruciani, Federicoen
dc.contributor.authorEl Labban, Abdulrahmanen
dc.contributor.authorNeher, Dieteren
dc.contributor.authorBeaujuge, Pierreen
dc.contributor.authorLaquai, Fredericen
dc.date.accessioned2017-10-11T12:04:10Z-
dc.date.available2017-10-11T12:04:10Z-
dc.date.issued2017-09-28en
dc.identifier.citationGorenflot J, Paulke A, Piersimoni F, Wolf J, Kan Z, et al. (2017) From Recombination Dynamics to Device Performance: Quantifying the Efficiency of Exciton Dissociation, Charge Separation, and Extraction in Bulk Heterojunction Solar Cells with Fluorine-Substituted Polymer Donors. Advanced Energy Materials: 1701678. Available: http://dx.doi.org/10.1002/aenm.201701678.en
dc.identifier.issn1614-6832en
dc.identifier.doi10.1002/aenm.201701678en
dc.identifier.urihttp://hdl.handle.net/10754/625860-
dc.description.abstractAn original set of experimental and modeling tools is used to quantify the yield of each of the physical processes leading to photocurrent generation in organic bulk heterojunction solar cells, enabling evaluation of materials and processing condition beyond the trivial comparison of device performances. Transient absorption spectroscopy, “the” technique to monitor all intermediate states over the entire relevant timescale, is combined with time-delayed collection field experiments, transfer matrix simulations, spectral deconvolution, and parametrization of the charge carrier recombination by a two-pool model, allowing quantification of densities of excitons and charges and extrapolation of their kinetics to device-relevant conditions. Photon absorption, charge transfer, charge separation, and charge extraction are all quantified for two recently developed wide-bandgap donor polymers: poly(4,8-bis((2-ethylhexyl)oxy)benzo[1,2-b:4,5-b′]dithiophene-3,4-difluorothiophene) (PBDT[2F]T) and its nonfluorinated counterpart poly(4,8-bis((2-ethylhexyl)oxy)benzo[1,2-b:4,5-b′]dithiophene-3,4-thiophene) (PBDT[2H]T) combined with PC71BM in bulk heterojunctions. The product of these yields is shown to agree well with the devices' external quantum efficiency. This methodology elucidates in the specific case studied here the origin of improved photocurrents obtained when using PBDT[2F]T instead of PBDT[2H]T as well as upon using solvent additives. Furthermore, a higher charge transfer (CT)-state energy is shown to lead to significantly lower energy losses (resulting in higher VOC) during charge generation compared to P3HT:PCBM.en
dc.description.sponsorshipThe research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST). A.P. and D.N. acknowledge funding from the BMBF in the project UNVEIL.en
dc.publisherWiley-Blackwellen
dc.relation.urlhttp://onlinelibrary.wiley.com/doi/10.1002/aenm.201701678/fullen
dc.rightsThis is the peer reviewed version of the following article: From Recombination Dynamics to Device Performance: Quantifying the Efficiency of Exciton Dissociation, Charge Separation, and Extraction in Bulk Heterojunction Solar Cells with Fluorine-Substituted Polymer Donors, which has been published in final form at http://doi.org/10.1002/aenm.201701678. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.en
dc.titleFrom Recombination Dynamics to Device Performance: Quantifying the Efficiency of Exciton Dissociation, Charge Separation, and Extraction in Bulk Heterojunction Solar Cells with Fluorine-Substituted Polymer Donorsen
dc.typeArticleen
dc.contributor.departmentKAUST Solar Center (KSC)en
dc.contributor.departmentMaterials Science and Engineering Programen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentChemical Science Programen
dc.identifier.journalAdvanced Energy Materialsen
dc.eprint.versionPost-printen
dc.contributor.institutionInstitute of Physics and Astronomy, Soft Matter Physics; University of Potsdam; Karl-Liebknecht-Straße 24−25 14476 Potsdam-Golm Germanyen
kaust.authorGorenflot, Julienen
kaust.authorWolf, Jannic Sebastianen
kaust.authorKan, Zhipengen
kaust.authorCruciani, Federicoen
kaust.authorEl Labban, Abdulrahmanen
kaust.authorBeaujuge, Pierreen
kaust.authorLaquai, Fredericen
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