Mechanism of Crystallization and Implications for Charge Transport in Poly(3-ethylhexylthiophene) Thin Films

Handle URI:
http://hdl.handle.net/10754/598789
Title:
Mechanism of Crystallization and Implications for Charge Transport in Poly(3-ethylhexylthiophene) Thin Films
Authors:
Duong, Duc T.; Ho, Victor; Shang, Zhengrong; Mollinger, Sonya; Mannsfeld, Stefan C.B.; Dacuña, Javier; Toney, Michael F.; Segalman, Rachel; Salleo, Alberto
Abstract:
In this work, crystallization kinetics and aggregate growth of poly(3-ethylhexylthiophene) (P3EHT) thin films are studied as a function of film thickness. X-ray diffraction and optical absorption show that individual aggregates and crystallites grow anisotropically and mostly along only two packing directions: the alkyl stacking and the polymer chain backbone direction. Further, it is also determined that crystallization kinetics is limited by the reorganization of polymer chains and depends strongly on the film thickness and average molecular weight. Time-dependent, field-effect hole mobilities in thin films reveal a percolation threshold for both low and high molecular weight P3EHT. Structural analysis reveals that charge percolation requires bridged aggregates separated by a distance of ≈2-3 nm, which is on the order of the polymer persistence length. These results thus highlight the importance of tie molecules and inter-aggregate distance in supporting charge percolation in semiconducting polymer thin films. The study as a whole also demonstrates that P3EHT is an ideal model system for polythiophenes and should prove to be useful for future investigations into crystallization kinetics. Recrystallization kinetics and its relationship to charge transport in poly(3-ethylhexylthiophene) (P3EHT) thin films are investigated using a combination of grazing incidence X-ray diffraction, optical absorption, and field-effect transistor measurements. These results show that thin film crystallization kinetics is limited by polymer chain reorganization and that charge percolation depends strongly on the edge-to-edge distance between aggregates. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Citation:
Duong DT, Ho V, Shang Z, Mollinger S, Mannsfeld SCB, et al. (2014) Mechanism of Crystallization and Implications for Charge Transport in Poly(3-ethylhexylthiophene) Thin Films. Advanced Functional Materials 24: 4515–4521. Available: http://dx.doi.org/10.1002/adfm.201304247.
Publisher:
Wiley-Blackwell
Journal:
Advanced Functional Materials
KAUST Grant Number:
KUS-C1-015-21
Issue Date:
9-Apr-2014
DOI:
10.1002/adfm.201304247
Type:
Article
ISSN:
1616-301X
Sponsors:
A.S. gratefully acknowledges financial support from the National Science Foundation (DMR 1205752 award). D.T.D. is supported by a Stanford Graduate Fellowship and the National Science Foundation Graduate Research Fellowship. S. M. is supported by a Stanford Graduate Fellowship. J.D. was supported by the Center for Advanced Molecular Photovoltaics (Award No. KUS-C1-015-21), made by King Abdullah University of Science and Technology (KAUST). A portion of this research was carried out at the Stanford Synchrotron Radiation Lightsource, a national user facility operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences.
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DC FieldValue Language
dc.contributor.authorDuong, Duc T.en
dc.contributor.authorHo, Victoren
dc.contributor.authorShang, Zhengrongen
dc.contributor.authorMollinger, Sonyaen
dc.contributor.authorMannsfeld, Stefan C.B.en
dc.contributor.authorDacuña, Javieren
dc.contributor.authorToney, Michael F.en
dc.contributor.authorSegalman, Rachelen
dc.contributor.authorSalleo, Albertoen
dc.date.accessioned2016-02-25T13:41:16Zen
dc.date.available2016-02-25T13:41:16Zen
dc.date.issued2014-04-09en
dc.identifier.citationDuong DT, Ho V, Shang Z, Mollinger S, Mannsfeld SCB, et al. (2014) Mechanism of Crystallization and Implications for Charge Transport in Poly(3-ethylhexylthiophene) Thin Films. Advanced Functional Materials 24: 4515–4521. Available: http://dx.doi.org/10.1002/adfm.201304247.en
dc.identifier.issn1616-301Xen
dc.identifier.doi10.1002/adfm.201304247en
dc.identifier.urihttp://hdl.handle.net/10754/598789en
dc.description.abstractIn this work, crystallization kinetics and aggregate growth of poly(3-ethylhexylthiophene) (P3EHT) thin films are studied as a function of film thickness. X-ray diffraction and optical absorption show that individual aggregates and crystallites grow anisotropically and mostly along only two packing directions: the alkyl stacking and the polymer chain backbone direction. Further, it is also determined that crystallization kinetics is limited by the reorganization of polymer chains and depends strongly on the film thickness and average molecular weight. Time-dependent, field-effect hole mobilities in thin films reveal a percolation threshold for both low and high molecular weight P3EHT. Structural analysis reveals that charge percolation requires bridged aggregates separated by a distance of ≈2-3 nm, which is on the order of the polymer persistence length. These results thus highlight the importance of tie molecules and inter-aggregate distance in supporting charge percolation in semiconducting polymer thin films. The study as a whole also demonstrates that P3EHT is an ideal model system for polythiophenes and should prove to be useful for future investigations into crystallization kinetics. Recrystallization kinetics and its relationship to charge transport in poly(3-ethylhexylthiophene) (P3EHT) thin films are investigated using a combination of grazing incidence X-ray diffraction, optical absorption, and field-effect transistor measurements. These results show that thin film crystallization kinetics is limited by polymer chain reorganization and that charge percolation depends strongly on the edge-to-edge distance between aggregates. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.en
dc.description.sponsorshipA.S. gratefully acknowledges financial support from the National Science Foundation (DMR 1205752 award). D.T.D. is supported by a Stanford Graduate Fellowship and the National Science Foundation Graduate Research Fellowship. S. M. is supported by a Stanford Graduate Fellowship. J.D. was supported by the Center for Advanced Molecular Photovoltaics (Award No. KUS-C1-015-21), made by King Abdullah University of Science and Technology (KAUST). A portion of this research was carried out at the Stanford Synchrotron Radiation Lightsource, a national user facility operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences.en
dc.publisherWiley-Blackwellen
dc.subjectcharge transporten
dc.subjectconjugated polymersen
dc.subjectorganic field-effect transistorsen
dc.subjectorganic semiconductorsen
dc.subjectthin filmsen
dc.titleMechanism of Crystallization and Implications for Charge Transport in Poly(3-ethylhexylthiophene) Thin Filmsen
dc.typeArticleen
dc.identifier.journalAdvanced Functional Materialsen
dc.contributor.institutionDepartment of Materials Science and Engineering; Stanford University; Stanford California 94305 USAen
dc.contributor.institutionDepartment of Chemical and Biomolecular Engineering; University of California, Berkeley; Materials Science Division; Lawrence Berkeley National Laboratory; Berkeley California 94720 USAen
dc.contributor.institutionStanford Synchrotron Radiation Lightsource; SLAC National Accelerator Laboratory; Menlo Park California 94025 USAen
dc.contributor.institutionDepartment of Electrical Engineering Stanford University; Stanford California 94305 USAen
kaust.grant.numberKUS-C1-015-21en
kaust.grant.fundedcenterCenter for Advanced Molecular Photovoltaics (CAMP)en
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