Entanglement of conjugated polymer chains influences molecular self-assembly and carrier transport

Handle URI:
http://hdl.handle.net/10754/562825
Title:
Entanglement of conjugated polymer chains influences molecular self-assembly and carrier transport
Authors:
Zhao, Kui ( 0000-0001-9348-7943 ) ; Khan, Hadayat Ullah; Li, Ruipeng; Su, Yisong; Amassian, Aram ( 0000-0002-5734-1194 )
Abstract:
The influence of polymer entanglement on the self-assembly, molecular packing structure, and microstructure of low-Mw (lightly entangled) and high-Mw (highly entangled) poly (3-hexylthiophene) (P3HT), and the carrier transport in thin-film transistors, are investigated. The polymer chains are gradually disentangled in a marginal solvent via ultrasonication of the polymer solution, and demonstrate improved diffusivity of precursor species (coils, aggregates, and microcrystallites), enhanced nucleation and crystallization of P3HT in solution, and self-assembly of well-ordered and highly textured fibrils at the solid-liquid interface. In low-Mw P3HT, reducing chain entanglement enhances interchain and intrachain ordering, but reduces the interconnectivity of ordered domains (tie molecules) due to the presence of short chains, thus deteriorating carrier transport even in the face of improving crystallinity. Reducing chain entanglement in high-Mw P3HT solutions increases carrier mobility up to ≈20-fold, by enhancing interchain and intrachain ordering while maintaining a sufficiently large number of tie molecules between ordered domains. These results indicate that charge carrier mobility is strongly governed by the balancing of intrachain and interchain ordering, on the one hand, and interconnectivity of ordered domains, on the other hand. In high-Mw P3HT, intrachain and interchain ordering appear to be the key bottlenecks to charge transport, whereas in low-Mw P3HT, the limited interconnectivity of the ordered domains acts as the primary bottleneck to charge transport. Conjugated polymer chains of poly(3-hexylthiophene) (P3HT) are gradually disentangled in solution and trends in carrier transport mechanisms in organic thin film transistors for low- and high-molecular weight P3HT are investigated. While intrachain and interchain ordering within ordered domains are the key bottlenecks to charge transport in high-Mw P3HT films, the limited interconnectivity of ordered domains acts as the primary bottleneck to carrier transport in low-Mw P3HT films. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
KAUST Department:
Materials Science and Engineering Program; Physical Sciences and Engineering (PSE) Division; Solar and Photovoltaic Engineering Research Center (SPERC); Organic Electronics and Photovoltaics Group
Publisher:
Wiley-Blackwell
Journal:
Advanced Functional Materials
Issue Date:
26-Jun-2013
DOI:
10.1002/adfm.201301007
Type:
Article
ISSN:
1616301X
Sponsors:
The authors would like to thank Dr. Detlef-M. Smilgies for help with acquisition of GIWAXS data at CHESS, Prof. Yu Han for help with acquisition of UV-Vis spectra at KAUST, and Dr. Misjudeen Raji for help with GPC experiments at KAUST. The authors acknowledge Prof. Carlos Silva, Dr. Natalie Stingelin, Prof. Alberto Salleo, and Dr. Neil Treat for helpful discussions. Part of this work was supported by KAUST's Office of Competitive Research Funds under FIC and AEA awards.
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Materials Science and Engineering Program; Solar and Photovoltaic Engineering Research Center (SPERC)

Full metadata record

DC FieldValue Language
dc.contributor.authorZhao, Kuien
dc.contributor.authorKhan, Hadayat Ullahen
dc.contributor.authorLi, Ruipengen
dc.contributor.authorSu, Yisongen
dc.contributor.authorAmassian, Aramen
dc.date.accessioned2015-08-03T11:11:42Zen
dc.date.available2015-08-03T11:11:42Zen
dc.date.issued2013-06-26en
dc.identifier.issn1616301Xen
dc.identifier.doi10.1002/adfm.201301007en
dc.identifier.urihttp://hdl.handle.net/10754/562825en
dc.description.abstractThe influence of polymer entanglement on the self-assembly, molecular packing structure, and microstructure of low-Mw (lightly entangled) and high-Mw (highly entangled) poly (3-hexylthiophene) (P3HT), and the carrier transport in thin-film transistors, are investigated. The polymer chains are gradually disentangled in a marginal solvent via ultrasonication of the polymer solution, and demonstrate improved diffusivity of precursor species (coils, aggregates, and microcrystallites), enhanced nucleation and crystallization of P3HT in solution, and self-assembly of well-ordered and highly textured fibrils at the solid-liquid interface. In low-Mw P3HT, reducing chain entanglement enhances interchain and intrachain ordering, but reduces the interconnectivity of ordered domains (tie molecules) due to the presence of short chains, thus deteriorating carrier transport even in the face of improving crystallinity. Reducing chain entanglement in high-Mw P3HT solutions increases carrier mobility up to ≈20-fold, by enhancing interchain and intrachain ordering while maintaining a sufficiently large number of tie molecules between ordered domains. These results indicate that charge carrier mobility is strongly governed by the balancing of intrachain and interchain ordering, on the one hand, and interconnectivity of ordered domains, on the other hand. In high-Mw P3HT, intrachain and interchain ordering appear to be the key bottlenecks to charge transport, whereas in low-Mw P3HT, the limited interconnectivity of the ordered domains acts as the primary bottleneck to charge transport. Conjugated polymer chains of poly(3-hexylthiophene) (P3HT) are gradually disentangled in solution and trends in carrier transport mechanisms in organic thin film transistors for low- and high-molecular weight P3HT are investigated. While intrachain and interchain ordering within ordered domains are the key bottlenecks to charge transport in high-Mw P3HT films, the limited interconnectivity of ordered domains acts as the primary bottleneck to carrier transport in low-Mw P3HT films. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.en
dc.description.sponsorshipThe authors would like to thank Dr. Detlef-M. Smilgies for help with acquisition of GIWAXS data at CHESS, Prof. Yu Han for help with acquisition of UV-Vis spectra at KAUST, and Dr. Misjudeen Raji for help with GPC experiments at KAUST. The authors acknowledge Prof. Carlos Silva, Dr. Natalie Stingelin, Prof. Alberto Salleo, and Dr. Neil Treat for helpful discussions. Part of this work was supported by KAUST's Office of Competitive Research Funds under FIC and AEA awards.en
dc.publisherWiley-Blackwellen
dc.subjectentanglementen
dc.subjectmolecular self-assemblyen
dc.subjectorganic transistorsen
dc.subjectP3HTen
dc.subjectthin filmsen
dc.titleEntanglement of conjugated polymer chains influences molecular self-assembly and carrier transporten
dc.typeArticleen
dc.contributor.departmentMaterials Science and Engineering Programen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentSolar and Photovoltaic Engineering Research Center (SPERC)en
dc.contributor.departmentOrganic Electronics and Photovoltaics Groupen
dc.identifier.journalAdvanced Functional Materialsen
kaust.authorZhao, Kuien
kaust.authorKhan, Hadayat Ullahen
kaust.authorLi, Ruipengen
kaust.authorSu, Yisongen
kaust.authorAmassian, Aramen
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