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Abstract
Conjugated polymers have been actively studied as an alternative to inorganic semiconductors for their unique optical and electrical properties and low-cost solution processability. However, typical conjugated polymer films contain numerous defects that negatively affect their transport properties, which remains a major issue despite much effort to develop ways to improve the molecular packing structure. In principle, conjugated block copolymers (BCPs) composed of a rod-type conjugated polymer and a coil-type insulating polymer can assemble into various types of ordered nanostructures based on the microphase segregation of two polymer blocks. However, such assembly typically requires a relatively large volume fraction of the coil block or modification of the rod block, both of which tend to impede charge transport. As an alternative, we and others have fabricated nanoscale assemblies of conjugated BCPs via solution-phase self-assembly, which can be used as building blocks for construction of extended nanoarrays of conjugated polymers. In particular, BCPs containing poly(3-hexylthiophene) (P3HT), a conjugated polymer widely used for its high hole mobility, form highly ordered and technologically relevant one-dimensional (1D) nanowires with controlled lengths. A range of well-defined assembly structures such as square plates, ribbons, vesicles, and helices have been prepared from various conjugated BCPs, resembling those of peptide self-assembly, forming diverse nanostructures through combinations of π-π stacking, hydrogen bonding, and hydrophobic interactions.When the self-assembly of P3HT BCPs takes place at an air-water interface, the initially formed polymer nanowires further assemble into hierarchical two-dimensional (2D) nanoarrays with solvent evaporation. The fluidic nature of the water subphase allows fabrication of highly ordered assembly structures from P3HT BCPs with high P3HT content. The ultrathin free-standing film integrated in a field effect transistor (FET) showed orders of magnitude higher current and hole mobility compared to that fabricated by conventional spin-coating. Furthermore, binary self-assembly of a P3HT BCP and quantum dots (QDs) at the air-water interface generates well-ordered 2D films of alternating P3HT nanowires and 1D QD arrays. Unlike coil-coil BCP systems, QDs reside at the interface between P3HT and coil blocks for a broad range of QD sizes due to the strong P3HT packing interactions and the flexible water subphase, forming tight p-n junctions for enhanced photocurrent. Incorporation of magnetic nanoparticles can further improve the degree of order, enabling fabrication of long-range order and direction-controlled P3HT nanoarrays through magnetic-field induced self-assembly.The conjugated BCP approach is highly modular and can be combined with various types of functional molecules, polymers, and nanoparticles, offering a powerful platform for fabrication of functional polymer nanostructures with desired morphologies and properties. This Account introduces recent advances in the self-assembly of π-conjugated BCPs, describes how they differ from prototypical coil-coil type BCPs, and discusses current issues and future outlooks.
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Affiliation(s)
- Seulki Kang
- Department of Chemistry and Nanoscience, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea
| | - Ga-Hyun Kim
- Department of Chemistry and Nanoscience, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea
| | - So-Jung Park
- Department of Chemistry and Nanoscience, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea
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2
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Peterhans L, Nicolaidou E, Diamantis P, Alloa E, Leclerc M, Surin M, Clément S, Rothlisberger U, Banerji N, Hayes SC. Structural and Photophysical Templating of Conjugated Polyelectrolytes with Single-Stranded DNA. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2020; 32:7347-7362. [PMID: 33122875 PMCID: PMC7587141 DOI: 10.1021/acs.chemmater.0c02251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/06/2020] [Indexed: 06/11/2023]
Abstract
A promising approach to influence and control the photophysical properties of conjugated polymers is directing their molecular conformation by templating. We explore here the templating effect of single-stranded DNA oligomers (ssDNAs) on cationic polythiophenes with the goal to uncover the intermolecular interactions that direct the polymer backbone conformation. We have comprehensively characterized the optical behavior and structure of the polythiophenes in conformationally distinct complexes depending on the sequence of nucleic bases and addressed the effect on the ultrafast excited-state relaxation. This, in combination with molecular dynamics simulations, allowed us a detailed atomistic-level understanding of the structure-property correlations. We find that electrostatic and other noncovalent interactions direct the assembly with the polymer, and we identify that optimal templating is achieved with (ideally 10-20) consecutive cytosine bases through numerous π-stacking interactions with the thiophene rings and side groups of the polymer, leading to a rigid assembly with ssDNA, with highly ordered chains and unique optical signatures. Our insights are an important step forward in an effective approach to structural templating and optoelectronic control of conjugated polymers and organic materials in general.
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Affiliation(s)
- Lisa Peterhans
- Department
of Chemistry and Biochemistry, University
of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Eliana Nicolaidou
- Department
of Chemistry, University of Cyprus, P.O. Box 20537, 1678, Nicosia, Cyprus
| | - Polydefkis Diamantis
- Laboratory
of Computational Chemistry and Biochemistry, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Elisa Alloa
- Department
of Chemistry, University of Cyprus, P.O. Box 20537, 1678, Nicosia, Cyprus
| | - Mario Leclerc
- Department
of Chemistry, Université Laval, G1K 7P4 Quebec
City, Quebec, Canada
| | - Mathieu Surin
- Laboratory
for Chemistry of Novel Materials, Center for Innovation in Materials
and Polymers, University of Mons −
UMONS, 20 Place du Parc, B-7000 Mons, Belgium
| | - Sébastien Clément
- Institut
Charles Gerhardt Montpellier, ICGM, UMR 5253 CNRS, Université de Montpellier, Place Eugène Bataillon, F-34095 Montpellier, Cedex
05, France
| | - Ursula Rothlisberger
- Laboratory
of Computational Chemistry and Biochemistry, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Natalie Banerji
- Department
of Chemistry and Biochemistry, University
of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Sophia C. Hayes
- Department
of Chemistry, University of Cyprus, P.O. Box 20537, 1678, Nicosia, Cyprus
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3
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Colella NS, Labastide JA, Cherniawski BP, Thompson HB, Marques SR, Zhang L, Usluer Ö, Watkins JJ, Briseno AL, Barnes MD. Poly[2,5-bis(3-dodecylthiophen-2-yl)thieno[3,2-b]thiophene] Oligomer Single-Crystal Nanowires from Supercritical Solution and Their Anisotropic Exciton Dynamics. J Phys Chem Lett 2017; 8:2984-2989. [PMID: 28605188 DOI: 10.1021/acs.jpclett.7b01128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Supercritical fluids, exhibiting a combination of liquid-like solvation power and gas-like diffusivity, are a relatively unexplored medium for processing and crystallization of oligomer and polymeric semiconductors whose optoelectronic properties critically depend on the microstructure. Here we report oligomer crystallization from the polymer organic semiconductor, poly[2,5-bis(3-dodecylthiophen-2-yl)thieno[3,2-b]thiophene] (PBTTT) in supercritical hexane, yielding needle-like single crystals up to several microns in length. We characterize the crystals' photophysical properties by time- and polarization-resolved photoluminescence (TPRPL) spectroscopy. These techniques reveal two-dimensional interchromophore coupling facilitated by the high degree of π-stacking order within the crystal. Furthermore, the crystals obtained from supercritical fluid were found to be similar photophysically as the crystallites found in solution-cast thin films and distinct from solution-grown crystals that exhibited spectroscopic signatures indicative of different packing geometries.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Michael D Barnes
- Department of Physics, University of Massachusetts Amherst , Amherst, Massachusetts 01003, United States
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4
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Oh S, Yang M, Bouffard J, Hong S, Park SJ. Air-Liquid Interfacial Self-Assembly of Non-Amphiphilic Poly(3-hexylthiophene) Homopolymers. ACS APPLIED MATERIALS & INTERFACES 2017; 9:12865-12871. [PMID: 28337903 DOI: 10.1021/acsami.7b01058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Here, we demonstrate that the self-assembly of poly(3-hexylthiophene) (P3HT) at the air-water interface can lead to free-standing films of densely packed P3HT nanowires. Interfacial self-assembly on various liquid subphases, such as water, diethylene glycol, and glycerol, indicates that the viscosity of the subphase is an important factor for the formation of well-ordered nanostructures. The thin-film morphology is also sensitive to the concentration of P3HT, its molecular weight (MW), and the presence of oxidative defects. The densely packed nanowire films can be easily transferred to solid substrates for device applications. The ultrathin films of P3HT prepared by the interfacial assembly showed significantly higher hole mobility (∼3.6 × 10-2 cm2/V s) in a field-effect transistor than comparably thin spin-cast films. This work demonstrates that the air-liquid interfacial assembly is not limited to amphiphilic polymers and can, under optimized conditions, be applied to fabricate ultrathin films of widely used conjugated polymers with controlled morphologies.
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Affiliation(s)
- Saejin Oh
- Department of Chemistry and Nano Science, Ewha Womans University , 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea
| | - Myungjae Yang
- Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University , Seoul 151-747, Korea
| | - Jean Bouffard
- Department of Chemistry and Nano Science, Ewha Womans University , 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea
| | - Seunghun Hong
- Department of Physics and Astronomy and Institute of Applied Physics, Seoul National University , Seoul 151-747, Korea
| | - So-Jung Park
- Department of Chemistry and Nano Science, Ewha Womans University , 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea
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Lee D, Lee J, Song KH, Rhee H, Jang DJ. Formation and decay of charge carriers in aggregate nanofibers consisting of poly(3-hexylthiophene)-coated gold nanoparticles. Phys Chem Chem Phys 2016; 18:2087-96. [DOI: 10.1039/c5cp06514c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hybrid nanofibers consisting of poly(3-hexylthiophene)-coated gold nanoparticles have been facilely fabricated and comprehensively investigated by time-resolved emission and transient-absorption spectroscopy.
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Affiliation(s)
- Dongki Lee
- Department of Chemistry
- Seoul National University
- Seoul 08826
- Korea
| | - Jaewon Lee
- Department of Chemistry
- Seoul National University
- Seoul 08826
- Korea
| | - Ki-Hee Song
- Space-Time Resolved Molecular Imaging Team
- Korea Basic Science Institute
- Seoul 02841
- Korea
| | - Hanju Rhee
- Space-Time Resolved Molecular Imaging Team
- Korea Basic Science Institute
- Seoul 02841
- Korea
| | - Du-Jeon Jang
- Department of Chemistry
- Seoul National University
- Seoul 08826
- Korea
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6
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Kim HJ, Skinner M, Yu H, Oh JH, Briseno AL, Emrick T, Kim BJ, Hayward RC. Water Processable Polythiophene Nanowires by Photo-Cross-Linking and Click-Functionalization. NANO LETTERS 2015; 15:5689-5695. [PMID: 26289785 DOI: 10.1021/acs.nanolett.5b01185] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Replacing or minimizing the use of halogenated organic solvents in the processing and manufacturing of conjugated polymer-based organic electronics has emerged as an important issue due to concerns regarding toxicity, environmental impact, and high cost. To date, however, the processing of well-ordered conjugated polymer nanostructures has been difficult to achieve using environmentally benign solvents. In this work, we report the development of water and alcohol processable nanowires (NWs) with well-defined crystalline nanostructure based on the solution assembly of azide functionalized poly(3-hexylthiophene) (P3HT-azide) and subsequent photo-cross-linking and functionalization of these NWs. The solution-assembled P3HT-azide NWs were successfully cross-linked by exposure to UV light, yielding good thermal and chemical stability. Residual azide units on the photo-cross-linked NWs were then functionalized with alkyne terminated polyethylene glycol (PEG-alkyne) using copper catalyzed azide-alkyne cycloaddition chemistry. PEG functionalization of the cross-linked P3HT-azide NWs allowed for stable dispersion in alcohols and water, while maintaining well-ordered NW structures with electronic properties suitable for the fabrication of organic field effect transistors (OFETs).
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Affiliation(s)
- Hyeong Jun Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon, 305-701, Korea
- Department of Polymer Science and Engineering, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Matthew Skinner
- Department of Polymer Science and Engineering, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Hojeong Yu
- Department of Chemical Engineering, Pohang University of Science and Technology , Pohang, Gyeongbuk 790-784, South Korea
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 689-798, South Korea
| | - Joon Hak Oh
- Department of Chemical Engineering, Pohang University of Science and Technology , Pohang, Gyeongbuk 790-784, South Korea
| | - Alejandro L Briseno
- Department of Polymer Science and Engineering, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Todd Emrick
- Department of Polymer Science and Engineering, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Bumjoon J Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon, 305-701, Korea
| | - Ryan C Hayward
- Department of Polymer Science and Engineering, University of Massachusetts , Amherst, Massachusetts 01003, United States
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Yuan Y, Shu J, Liu P, Zhang Y, Duan Y, Zhang J. Study on π–π Interaction in H- and J-Aggregates of Poly(3-hexylthiophene) Nanowires by Multiple Techniques. J Phys Chem B 2015; 119:8446-56. [DOI: 10.1021/acs.jpcb.5b02805] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuan Yuan
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Jie Shu
- Analysis
and Testing Center, Suzhou University, Renai Road 199, 215123 Suzhou, China
| | - Ping Liu
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Yinping Zhang
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Yongxin Duan
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics, Qingdao University of Science & Technology, Qingdao 266042, China
| | - Jianming Zhang
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-plastics, Qingdao University of Science & Technology, Qingdao 266042, China
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McFarland FM, Brickson B, Guo S. Layered Poly(3-hexylthiophene) Nanowhiskers Studied by Atomic Force Microscopy and Kelvin Probe Force Microscopy. Macromolecules 2015. [DOI: 10.1021/ma502411n] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Frederick M. McFarland
- Department
of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi 39406, United States
| | | | - Song Guo
- Department
of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, Mississippi 39406, United States
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Persano L, Camposeo A, Pisignano D. Active polymer nanofibers for photonics, electronics, energy generation and micromechanics. Prog Polym Sci 2015. [DOI: 10.1016/j.progpolymsci.2014.10.001] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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10
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Wang H, Liu J, Xu Y, Yu X, Xing R, Han Y. Ordered fibrillar morphology of donor–acceptor conjugated copolymers at multiple scales via blending with flexible polymers and solvent vapor annealing: insight into photophysics and mechanism. Phys Chem Chem Phys 2014; 16:1441-50. [DOI: 10.1039/c3cp53538j] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Structure and Morphology Control in Thin Films of Conjugated Polymers for an Improved Charge Transport. Polymers (Basel) 2013. [DOI: 10.3390/polym5041272] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Baghgar M, Pentzer E, Wise AJ, Labastide JA, Emrick T, Barnes MD. Cross-linked functionalized poly(3-hexylthiophene) nanofibers with tunable excitonic coupling. ACS NANO 2013; 7:8917-8923. [PMID: 24004252 DOI: 10.1021/nn403392b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We show that mechanically and chemically robust functionalized poly(3-hexylthiophene) (P3HT) nanofibers can be made via chemical cross-linking. Dramatically different photophysical properties are observed depending on the choice of functionalizing moiety and cross-linking strategy. Starting with two different nanofiber families formed from (a) P3HT-b-P3MT or (b) P3HT-b-P3ST diblock copolymers, cross-linking to form robust nanowire structures was readily achieved by either a third-party cross-linking agent (hexamethylene diisocyanate, HDI) which links methoxy side chains on the P3MT system, or direct disulfide cross-link for the P3ST system. Although the nanofiber families have similar gross structure (and almost identical pre-cross-linked absorption spectra), they have completely different photophysics as signaled by ensemble and single nanofiber wavelength- and time-resolved photoluminescence as well as transient absorption (visible and near-IR) probes. For the P3ST diblock nanofibers, excitonic coupling appears to be essentially unchanged before and after cross-linking. In contrast, cross-linked P3MT nanofibers show photoluminescence similar in electronic origin, vibronic structure, and lifetime to unaggregated P3HT molecules, e.g., dissolved in an inert polymer matrix, suggesting almost complete extinction of excitonic coupling. We hypothesize that the different photophysical properties can be understood from structural perturbations resulting from the cross-linking: For the P3MT system, the DIC linker induces a high degree of strain on the P3HT aggregate block, thus disrupting both intra- and interchain coupling. For the P3ST system, the spatial extent of the cross-linking is approximately commensurate with the interlamellar spacing, resulting in a minimally perturbed aggregate structure.
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Affiliation(s)
- Mina Baghgar
- Department of Physics, University of Massachusetts , Amherst, Massachusetts 01003, United States
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Gao J, Grey JK. Resonance Raman overtones reveal vibrational displacements and dynamics of crystalline and amorphous poly(3-hexylthiophene) chains in fullerene blends. J Chem Phys 2013; 139:044903. [DOI: 10.1063/1.4815819] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Erothu H, Sohdi AA, Kumar AC, Sutherland AJ, Dagron-Lartigau C, Allal A, Hiorns RC, Topham PD. Facile synthesis of poly(3-hexylthiophene)-block-poly(ethylene oxide) copolymers via Steglich esterification. Polym Chem 2013. [DOI: 10.1039/c3py00505d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Martin TP, Wise AJ, Busby E, Gao J, Roehling JD, Ford MJ, Larsen DS, Moulé AJ, Grey JK. Packing dependent electronic coupling in single poly(3-hexylthiophene) H- and J-aggregate nanofibers. J Phys Chem B 2012; 117:4478-87. [PMID: 23214454 DOI: 10.1021/jp308586k] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Nanofibers (NFs) of the prototype conjugated polymer, poly(3-hexylthiophene) (P3HT), displaying H- and J-aggregate character are studied using temperature- and pressure-dependent photoluminescence (PL) spectroscopy. Single J-aggregate NF spectra show a decrease of the 0-0/0-1 vibronic intensity ratio from ~2.0 at 300 K to ~1.3 at 4 K. Temperature-dependent PL line shape parameters (i.e., 0-0 energies and 0-0/0-1 intensity ratios) undergo an abrupt change in the range of ~110-130 K suggesting a change in NF chain packing. Pressure-dependent PL lifetimes also show increased contributions from an instrument-limited decay component which is attributed to greater torsional disorder of the P3HT backbone upon decreasing NF volume. It is proposed that the P3HT alkyl side groups change their packing arrangement from a type I to type II configuration causing a decrease in J-aggregate character (lower intrachain order) in both temperature- and pressure-dependent PL spectra. Chain packing dependent exciton and polaron relaxation and recombination dynamics in NF aggregates are next studied using transient absorption spectroscopy (TAS). TAS data reveal faster polaron recombination dynamics in H-type P3HT NFs indicative of interchain delocalization whereas J-type NFs exhibit delayed recombination suggesting that polarons (in addition to excitons) are more delocalized along individual chains. Both time-resolved and steady-state spectra confirm that excitons and polarons in J-type NFs are predominantly intrachain in nature that can acquire interchain character with small structural (chain packing) perturbations.
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Affiliation(s)
- Thomas P Martin
- Department of Chemistry and Chemical Biology, MSC03 2060, University of New Mexico, Albuquerque, New Mexico 87131, USA
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