1
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Liirò-Peluso L, Wrigley J, Amabilino DB, Beton PH. Submolecular Resolution Imaging of P3HT:PCBM Nanostructured Films by Atomic Force Microscopy: Implications for Organic Solar Cells. ACS APPLIED NANO MATERIALS 2022; 5:13794-13804. [PMID: 36338328 PMCID: PMC9623582 DOI: 10.1021/acsanm.2c01399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The efficiency of organic bulk-heterojunction (BHJ) solar cells depends greatly on both the bulk and surface structure of the nanostructured bicontinuous interpenetrating network of materials, known as the active layer. The morphology of the top layer of a coated film is often resolved at the scale of a few nanometers, but fine details of the domains and the order within them are more difficult to identify. Here, we report a high-resolution atomic force microscopy (AFM) investigation of various stoichiometries of the well-studied poly(3-hexylthiophene):[6,6]-phenyl C61 butyric acid methyl ester (P3HT:PCBM) active layer mixture. Images of the surface were obtained using AC-mode AFM exciting higher-order resonance frequencies of a standard silicon probe, a promising technique for acquiring real-space images of organic-based thin films with nanoscale and even submolecular resolution. We provide firm evidence of the nanoscale organization of the P3HT polymer and of the P3HT:PCBM stoichiometric mixtures at the surface-air interface of the BHJ architecture. Our study shows the characteristic periodicity of the regioregular P3HT identified in the nanoscale domain areas with submolecular resolution. Such areas are then distorted in place when adding different quantities of PCBM forming stoichiometric mixtures. When the samples were exposed to ambient light, the morphologies were very different, and submolecular resolution was not achieved. This approach is shown to provide a precise view of the active layer's nanostructure and will be useful for studies of other materials as a function of various parameters, with particular attention to the role of the acceptor in tuning morphology for understanding optimum performance in organic photovoltaic devices.
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Affiliation(s)
- Letizia Liirò-Peluso
- The
GSK Carbon Neutral Laboratories for Sustainable Chemistry, School
of Chemistry, University of Nottingham, Triumph Road, Nottingham NG7 2TU, U.K.
- School
of Physics and Astronomy, University of
Nottingham, University
Park, Nottingham NG7 2RD, U.K.
| | - James Wrigley
- School
of Physics and Astronomy, University of
Nottingham, University
Park, Nottingham NG7 2RD, U.K.
| | - David B. Amabilino
- The
GSK Carbon Neutral Laboratories for Sustainable Chemistry, School
of Chemistry, University of Nottingham, Triumph Road, Nottingham NG7 2TU, U.K.
- Institut
de Ciència de Materials de Barcelona, Consejo Superior de Investigaciones
Científicas, Carrer dels Til.lers, Campus Universitari de Bellaterra, 08193 Cerdanyola del Vallès, Spain
| | - Peter H. Beton
- School
of Physics and Astronomy, University of
Nottingham, University
Park, Nottingham NG7 2RD, U.K.
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2
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Dimitriev OP. Dynamics of Excitons in Conjugated Molecules and Organic Semiconductor Systems. Chem Rev 2022; 122:8487-8593. [PMID: 35298145 DOI: 10.1021/acs.chemrev.1c00648] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The exciton, an excited electron-hole pair bound by Coulomb attraction, plays a key role in photophysics of organic molecules and drives practically important phenomena such as photoinduced mechanical motions of a molecule, photochemical conversions, energy transfer, generation of free charge carriers, etc. Its behavior in extended π-conjugated molecules and disordered organic films is very different and very rich compared with exciton behavior in inorganic semiconductor crystals. Due to the high degree of variability of organic systems themselves, the exciton not only exerts changes on molecules that carry it but undergoes its own changes during all phases of its lifetime, that is, birth, conversion and transport, and decay. The goal of this review is to give a systematic and comprehensive view on exciton behavior in π-conjugated molecules and molecular assemblies at all phases of exciton evolution with emphasis on rates typical for this dynamic picture and various consequences of the above dynamics. To uncover the rich variety of exciton behavior, details of exciton formation, exciton transport, exciton energy conversion, direct and reverse intersystem crossing, and radiative and nonradiative decay are considered in different systems, where these processes lead to or are influenced by static and dynamic disorder, charge distribution symmetry breaking, photoinduced reactions, electron and proton transfer, structural rearrangements, exciton coupling with vibrations and intermediate particles, and exciton dissociation and annihilation as well.
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Affiliation(s)
- Oleg P Dimitriev
- V. Lashkaryov Institute of Semiconductor Physics NAS of Ukraine, pr. Nauki 41, Kyiv 03028, Ukraine
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3
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Kramer SN, Brown J, Rice M, Peteanu LA. Unraveling the Contribution of Residual Monomer to the Emission Spectra of Poly(3-hexylthiophene) Aggregates: Implications for Identifying H- and J-type Coupling. J Phys Chem Lett 2021; 12:5919-5924. [PMID: 34156859 DOI: 10.1021/acs.jpclett.1c01334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Poly(3-hexylthiophene) (P3HT) is a well-studied benchmark system for semiconducting polymers used in optoelectronic devices. In these materials, aggregation can improve charge transport efficiency or enhance emission yields depending on the interchain packing. This may be inferred from the absorption and emission spectra when analyzed using exciton coupling models such as the well-known H- and J-coupling model of Kasha. The more recently developed weakly coupled H-aggregate (WCH) model quantifies the degree of disorder via the ratio of the electronic origin intensity to that of the first vibronic band. Here, the underlying assumptions of this approach are tested experimentally for P3HT aggregates formed by solvent poisoning using bulk and single-molecule-based spectroscopic techniques. Specifically, we show that the contribution of residual monomeric chains to the aggregate spectrum must be accounted for to properly assign the spectra as H- or J-type. A modification of the WCH model is introduced to account for multiple emissive species.
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Affiliation(s)
- Stephanie N Kramer
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Jasper Brown
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Megan Rice
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Linda A Peteanu
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
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4
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Kerfoot J, Svatek SA, Korolkov VV, Taniguchi T, Watanabe K, Antolin E, Beton PH. Fluorescence and Electroluminescence of J-Aggregated Polythiophene Monolayers on Hexagonal Boron Nitride. ACS NANO 2020; 14:13886-13893. [PMID: 32897689 DOI: 10.1021/acsnano.0c06280] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The photophysics of a semiconducting polymer is manipulated through molecular self-assembly on an insulating surface. Adsorption of polythiophene (PT) monolayers on hexagonal boron nitride (hBN) leads to a structurally induced planarization and a rebalancing of inter- and intrachain excitonic coupling. This conformational control results in a dominant 0-0 photoluminescence peak and a reduced Huang-Rhys factor, characteristic of J-type aggregates, and optical properties which are significantly different to both PT thin films and single polymer strands. Adsorption on hBN also provides a route to explore electroluminescence from PT monolayers though incorporation into hybrid van der Waals heterostructures whereby the polymer monolayer is embedded within a hBN tunnel diode. In these structures we observe up-converted singlet electroluminescence from the PT monolayer, with an excitation mechanism based upon inelastic electron scattering. We argue that surface adsorption provides a methodology for the study of fundamental optoelectronic properties of technologically relevant polymers.
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Affiliation(s)
- James Kerfoot
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Simon A Svatek
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, U.K
- Instituto de Energía Solar, Universidad Politécnica de Madrid, Avenida Complutense 30, Madrid 28040, Spain
| | - Vladimir V Korolkov
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Elisa Antolin
- Instituto de Energía Solar, Universidad Politécnica de Madrid, Avenida Complutense 30, Madrid 28040, Spain
| | - Peter H Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, U.K
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5
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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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6
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Camacho R, Täuber D, Scheblykin IG. Fluorescence Anisotropy Reloaded-Emerging Polarization Microscopy Methods for Assessing Chromophores' Organization and Excitation Energy Transfer in Single Molecules, Particles, Films, and Beyond. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1805671. [PMID: 30721532 DOI: 10.1002/adma.201805671] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/12/2018] [Indexed: 06/09/2023]
Abstract
Fluorescence polarization is widely used to assess the orientation/rotation of molecules, and the excitation energy transfer between closely located chromophores. Emerging since the 1990s, single molecule fluorescence spectroscopy and imaging stimulate the application of light polarization for studying molecular organization and energy transfer beyond ensemble averaging. Here, traditional fluorescence polarization and linear dichroism methods used for bulk samples are compared with techniques specially developed for, or inspired by, single molecule fluorescence spectroscopy. Techniques for assessing energy transfer in anisotropic samples, where the traditional fluorescence anisotropy framework is not readily applicable, are discussed in depth. It is shown that the concept of a polarization portrait and the single funnel approximation can lay the foundation for alternative energy transfer metrics. Examples ranging from fundamental studies of photoactive materials (conjugated polymers, light-harvesting aggregates, and perovskite semiconductors) to Förster resonant energy transfer (FRET)-based biomedical imaging are presented. Furthermore, novel uses of light polarization for super-resolution optical imaging are mentioned as well as strategies for avoiding artifacts in polarization microscopy.
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Affiliation(s)
- Rafael Camacho
- Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001, Leuven, Belgium
| | - Daniela Täuber
- Chemical Physics and NanoLund, Lund University, P.O. Box 124, SE-22100, Lund, Sweden
- Biopolarisation, Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, D-07745, Jena, Germany
- Institute of Solid State Physics, FSU Jena, Helmholtzweg 3, D-07743, Jena, Germany
| | - Ivan G Scheblykin
- Chemical Physics and NanoLund, Lund University, P.O. Box 124, SE-22100, Lund, Sweden
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7
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Kim JS, Choi JE, Park H, Kim Y, Kim HJ, Han J, Shin JM, Kim BJ. Synthesis and crystallization behavior of regioregular-block-regiorandom poly(3-hexylthiophene) copolymers. Polym Chem 2019. [DOI: 10.1039/c8py01545g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Regioregular–regiorandom poly(3-hexylthiophene) copolymers, synthesized by chain-transfer polycondensation, show strong crystallinity due to their one-sided distribution of regiodefects.
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Affiliation(s)
- Jin-Seong Kim
- Department of Chemical and Biomolecular Engineering
- Korea Advanced Institute of Science and Technology (KAIST)
- Daejeon 34141
- Korea
| | - Jee-Eun Choi
- Department of Chemical and Biomolecular Engineering
- Korea Advanced Institute of Science and Technology (KAIST)
- Daejeon 34141
- Korea
| | - Hyeonjung Park
- Department of Chemical and Biomolecular Engineering
- Korea Advanced Institute of Science and Technology (KAIST)
- Daejeon 34141
- Korea
| | - Youngkwon Kim
- Department of Chemical and Biomolecular Engineering
- Korea Advanced Institute of Science and Technology (KAIST)
- Daejeon 34141
- Korea
| | - Hyeong Jun Kim
- Department of Polymer Science and Engineering
- University of Massachusetts
- Amherst
- USA
| | - Junghun Han
- Department of Chemical and Biomolecular Engineering
- Korea Advanced Institute of Science and Technology (KAIST)
- Daejeon 34141
- Korea
| | - Jae Man Shin
- Department of Chemical and Biomolecular Engineering
- Korea Advanced Institute of Science and Technology (KAIST)
- Daejeon 34141
- Korea
| | - Bumjoon J. Kim
- Department of Chemical and Biomolecular Engineering
- Korea Advanced Institute of Science and Technology (KAIST)
- Daejeon 34141
- Korea
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8
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Hedley GJ, Steiner F, Vogelsang J, Lupton JM. Fluctuations in the Emission Polarization and Spectrum in Single Chains of a Common Conjugated Polymer for Organic Photovoltaics. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1804312. [PMID: 30444577 DOI: 10.1002/smll.201804312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Indexed: 06/09/2023]
Abstract
Measuring the nanoscale organization of conjugated polymer chains used in organic photovoltaic (OPV) blends is vital if one wants to understand the materials. This is made very difficult with high efficiency OPV polymers such as PTB7 that form aggregates, as a lack of periodicity and a high degree of disorder make understanding of the nanoscale organization challenging. Here, single molecule spectroscopy is used to observe single chains and aggregates of PTB7. Using four detectors the photoluminescence intensity, wavelength, polarization, and lifetime are simultaneously monitored. Fast (milliseconds) and slow (seconds) fluctuations are observed over a time window of 30 s in all of these observables from single aggregates and chains as individual chromophores activate and deactivate, leading to dynamical changes in the emission spectrum and dipole orientation. This information can be used to help reconstruct the spatial and spectral organization of disordered aggregates of PTB7, thereby adding valuable new information on how the chains are arranged in space.
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Affiliation(s)
- Gordon J Hedley
- WestCHEM, School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, D-93040, Regensburg, Germany
| | - Florian Steiner
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, D-93040, Regensburg, Germany
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, D-81377, München, Germany
| | - Jan Vogelsang
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, D-81377, München, Germany
| | - John M Lupton
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, D-93040, Regensburg, Germany
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9
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Jiang Y, McNeill J. Light-Harvesting and Amplified Energy Transfer in Conjugated Polymer Nanoparticles. Chem Rev 2016; 117:838-859. [DOI: 10.1021/acs.chemrev.6b00419] [Citation(s) in RCA: 168] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Yifei Jiang
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634, United States
| | - Jason McNeill
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634, United States
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10
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Raithel D, Baderschneider S, de Queiroz TB, Lohwasser R, Köhler J, Thelakkat M, Kümmel S, Hildner R. Emitting Species of Poly(3-hexylthiophene): From Single, Isolated Chains to Bulk. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b02077] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
| | | | - Thiago B. de Queiroz
- Centro
de Ciências Naturais e Humanas, Universidade Federal do ABC, 09510-580, Santo André-SP, Brazil
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11
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Tsuchiya Y, Noguchi T, Yoshihara D, Roy B, Yamamoto T, Shinkai S. Conformation Control of a Conjugated Polymer through Complexation with Bile Acids Generates Its Novel Spectral and Morphological Properties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:12403-12412. [PMID: 27327101 DOI: 10.1021/acs.langmuir.6b01639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Control of higher-order polymer structures attracts a great deal of interest for many researchers when they lead to the development of materials having various advanced functions. Among them, conjugated polymers that are useful as starting materials in the design of molecular wires are particularly attractive. However, an equilibrium existing between isolated chains and bundled aggregates is inevitable and has made their physical properties very complicated. As an attempt to simplify this situation, we previously reported that a polymer chain of a water-soluble polythiophene could be isolated through complexation with a helix-forming polysaccharide. More recently, a covalently self-threading polythiophene was reported, the main chain of which was physically protected from self-folding and chain-chain π-stacking. In this report, we wish to report a new strategy to isolate a water-soluble polythiophene and to control its higher-order structure by a supramolecular approach: that is, among a few bile acids, lithocholate can form stoichiometric complexes with cationic polythiophene to isolate the polymer chain, and the higher-order structure is changeable by the molar ratio. The optical and morphological studies have been thoroughly performed, and the resultant complex has been applied to the selective recognition of two AMP structural isomers.
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Affiliation(s)
- Youichi Tsuchiya
- Nanotechnology Laboratory, Institute of Systems, Information Technologies and Nanotechnologies (ISIT), Fukuoka Industry-Academia Symphonicity (FiaS), Kyudaishinmachi 4-1, Nishi-ku, Fukuoka 819-0388, Japan
| | | | - Daisuke Yoshihara
- Nanotechnology Laboratory, Institute of Systems, Information Technologies and Nanotechnologies (ISIT), Fukuoka Industry-Academia Symphonicity (FiaS), Kyudaishinmachi 4-1, Nishi-ku, Fukuoka 819-0388, Japan
| | | | - Tatsuhiro Yamamoto
- Nanotechnology Laboratory, Institute of Systems, Information Technologies and Nanotechnologies (ISIT), Fukuoka Industry-Academia Symphonicity (FiaS), Kyudaishinmachi 4-1, Nishi-ku, Fukuoka 819-0388, Japan
| | - Seiji Shinkai
- Nanotechnology Laboratory, Institute of Systems, Information Technologies and Nanotechnologies (ISIT), Fukuoka Industry-Academia Symphonicity (FiaS), Kyudaishinmachi 4-1, Nishi-ku, Fukuoka 819-0388, Japan
- Department of Nanoscience, Faculty of Engineering, Sojo University , Ikeda 4-22-1, Nishi-ku, Kumamoto 860-0082, Japan
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12
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Thiessen A, Würsch D, Jester SS, Aggarwal AV, Idelson A, Bange S, Vogelsang J, Höger S, Lupton JM. Exciton Localization in Extended π-Electron Systems: Comparison of Linear and Cyclic Structures. J Phys Chem B 2015; 119:9949-58. [DOI: 10.1021/acs.jpcb.5b02091] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alexander Thiessen
- Department
of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, United States
| | - Dominik Würsch
- Institut
für Experimentelle und Angewandte Physik, Universität Regensburg, 93040 Regensburg, Germany
| | - Stefan-S. Jester
- Kekulé-Institut
für Organische Chemie und Biochemie der Universität Bonn, 53121 Bonn, Germany
| | - A. Vikas Aggarwal
- Kekulé-Institut
für Organische Chemie und Biochemie der Universität Bonn, 53121 Bonn, Germany
| | - Alissa Idelson
- Kekulé-Institut
für Organische Chemie und Biochemie der Universität Bonn, 53121 Bonn, Germany
| | - Sebastian Bange
- Institut
für Experimentelle und Angewandte Physik, Universität Regensburg, 93040 Regensburg, Germany
| | - Jan Vogelsang
- Institut
für Experimentelle und Angewandte Physik, Universität Regensburg, 93040 Regensburg, Germany
| | - Sigurd Höger
- Kekulé-Institut
für Organische Chemie und Biochemie der Universität Bonn, 53121 Bonn, Germany
| | - John M. Lupton
- Department
of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, United States
- Institut
für Experimentelle und Angewandte Physik, Universität Regensburg, 93040 Regensburg, Germany
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13
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Gong JQ, Parkinson P, Kondratuk D, Gil-Ramírez G, Anderson HL, Herz LM. Structure-Directed Exciton Dynamics in Templated Molecular Nanorings. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2015; 119:6414-6420. [PMID: 25960822 PMCID: PMC4418736 DOI: 10.1021/acs.jpcc.5b00210] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 02/26/2015] [Indexed: 06/04/2023]
Abstract
Conjugated polymers with cyclic structures are interesting because their symmetry leads to unique electronic properties. Recent advances in Vernier templating now allow large shape-persistent fully conjugated porphyrin nanorings to be synthesized, exhibiting unique electronic properties. We examine the impact of different conformations on exciton delocalization and emission depolarization in a range of different porphyrin nanoring topologies with comparable spatial extent. Low photoluminescence anisotropy values are found to occur within the first few hundred femtoseconds after pulsed excitation, suggesting ultrafast delocalization of excitons across the nanoring structures. Molecular dynamics simulations show that further polarization memory loss is caused by out-of-plane distortions associated with twisting and bending of the templated nanoring topologies.
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Affiliation(s)
- Juliane Q. Gong
- Department
of Physics, Clarendon Laboratory, University
of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Patrick Parkinson
- Department
of Physics, Clarendon Laboratory, University
of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Dmitry
V. Kondratuk
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Guzmán Gil-Ramírez
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Harry L. Anderson
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Laura M. Herz
- Department
of Physics, Clarendon Laboratory, University
of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
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14
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Hu Z, Adachi T, Haws R, Shuang B, Ono RJ, Bielawski CW, Landes CF, Rossky PJ, Vanden Bout DA. Excitonic Energy Migration in Conjugated Polymers: The Critical Role of Interchain Morphology. J Am Chem Soc 2014; 136:16023-31. [DOI: 10.1021/ja508112k] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Zhongjian Hu
- Center
for Nano and Molecular Science and Technology, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - Takuji Adachi
- Center
for Nano and Molecular Science and Technology, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - Ryan Haws
- Center
for Nano and Molecular Science and Technology, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - Bo Shuang
- Department
of Chemistry, Rice University, Houston, Texas 77251, United States
| | - Robert J. Ono
- Center
for Nano and Molecular Science and Technology, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - Christopher W. Bielawski
- Center
for Nano and Molecular Science and Technology, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - Christy F. Landes
- Department
of Chemistry, Rice University, Houston, Texas 77251, United States
| | - Peter J. Rossky
- Center
for Nano and Molecular Science and Technology, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
| | - David A. Vanden Bout
- Center
for Nano and Molecular Science and Technology, Department of Chemistry, University of Texas, Austin, Texas 78712, United States
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15
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Haedler AT, Beyer SR, Hammer N, Hildner R, Kivala M, Köhler J, Schmidt HW. Synthesis and photophysical properties of multichromophoric carbonyl-bridged triarylamines. Chemistry 2014; 20:11708-18. [PMID: 25147099 DOI: 10.1002/chem.201403667] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Indexed: 01/16/2023]
Abstract
The synthesis and photophysical properties of two novel multichromophoric compounds is presented. Their molecular design comprises a carbonyl-bridged triarylamine core and either naphthalimides or 4-(5-hexyl-2,2'-bithiophene)naphthalimides as second chromophore in the periphery. The lateral chromophores are attached to the core via an amide linkage and a short alkyl spacer. The synthetic approach demonstrates a straightforward functionalization strategy for carbonyl-bridged triarylamines. Steady-state and time-resolved spectroscopic investigations of these compounds, in combination with three reference compounds, provide clear evidence for energy transfer in both multichromophoric compounds. The direction of the energy transfer depends on the lateral chromophore used. Furthermore, the compound bearing the lateral 4-(bithiophene)naphthaimides is capable of forming fluorescent gels at very low concentrations in the sub-millimolar regime whilst retaining its energy transfer properties.
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Affiliation(s)
- Andreas T Haedler
- Macromolecular Chemistry I, Bayreuther Institut für Makromolekülforschung (BIMF) and Bayreuther Zentrum für Kolloide und Grenzflächen (BZKG), University of Bayreuth, 95440 Bayreuth (Germany), Fax: (+49) 921-55-3206
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16
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Steiner F, Vogelsang J, Lupton JM. Singlet-triplet annihilation limits exciton yield in poly(3-hexylthiophene). PHYSICAL REVIEW LETTERS 2014; 112:137402. [PMID: 24745453 DOI: 10.1103/physrevlett.112.137402] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Indexed: 06/03/2023]
Abstract
Control of chain length and morphology in combination with single-molecule spectroscopy techniques provides a comprehensive photophysical picture of excited-state losses in the prototypical conjugated polymer poly(3-hexylthiophene) (P3HT). Our examination reveals a universal self-quenching mechanism, based on singlet-triplet exciton annihilation, which accounts for the dramatic loss in fluorescence quantum yield of a single P3HT chain between its solution (unfolded) and bulklike (folded) state. Triplet excitons fundamentally limit the fluorescence of organic photovoltaic materials, which impacts the conversion of singlet excitons to separated charge carriers, decreasing the efficiency of energy harvested at high excitation densities. Interexcitonic interactions are so effective that a single P3HT chain of order 100 kDa weight behaves like a 2-level system, exhibiting perfect photon antibunching.
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Affiliation(s)
- Florian Steiner
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Jan Vogelsang
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - John M Lupton
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
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17
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Tapping PC, Kee TW. Optical Pumping of Poly(3-hexylthiophene) Singlet Excitons Induces Charge Carrier Generation. J Phys Chem Lett 2014; 5:1040-1047. [PMID: 26270985 DOI: 10.1021/jz500217f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The dynamics of high-energy excitons of poly(3-hexylthiophene) (P3HT) are shown to consist of torsional relaxation and exciton dissociation to form free carriers. In this work, we use pump-push-probe femtosecond transient absorption spectroscopy to study the highly excited states of P3HT in solution. P3HT excitons are generated using a pump pulse (400 nm) and allowed to relax to the lowest-lying excited state before re-excitation using a push pulse (900 or 1200 nm), producing high-energy excitons that decay back to the original excited state with both subpicosecond (0.16 ps) and picosecond (2.4 ps) time constants. These dynamics are consistent with P3HT torsional relaxation, with the 0.16 ps time constant assigned to ultrafast inertial torsional relaxation. Additionally, the signal exhibits an incomplete recovery, indicating dissociation of high-energy excitons to form charge carriers due to excitation by the push pulse. Our analysis indicates that charge carriers are formed with a yield of 11%.
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Affiliation(s)
- Patrick C Tapping
- Department of Chemistry, The University of Adelaide, South Australia 5005, Australia
| | - Tak W Kee
- Department of Chemistry, The University of Adelaide, South Australia 5005, Australia
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18
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Kang EH, Choi TL. Coil-to-Rod Transition of Conjugated Polymers Prepared by Cyclopolymerization of 1,6-Heptadiynes. ACS Macro Lett 2013; 2:780-784. [PMID: 35606980 DOI: 10.1021/mz400338p] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the conformational change resulting from the coil-to-rod transition in conjugated polymers prepared by the cyclopolymerization of 1,6-heptadiyne derivatives (poly(cyclopentenylene-vinylene), PCPV). By aging a PCPV solution under various conditions, we observed dramatic changes in their absorption spectra (appearance of a 0-0 vibronic peak) and an increase in the Mark-Houwink-Sakurada shape parameter, thereby confirming the coil-to-rod transition of the polymer. Further studies using NMR spectroscopy and various control experiments demonstrated that the coil-to-rod transformation resulted from the cis-to-trans isomerization of the conjugated olefins by a radical mechanism.
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Affiliation(s)
- Eun-Hye Kang
- Department of Chemistry, Seoul National University, Seoul 151-747,
Korea
| | - Tae-Lim Choi
- Department of Chemistry, Seoul National University, Seoul 151-747,
Korea
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19
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Abstract
The spectral breadth of conjugated polymers gives these materials a clear advantage over other molecular compounds for organic photovoltaic applications and is a key factor in recent efficiencies topping 10%. However, why do excitonic transitions, which are inherently narrow, lead to absorption over such a broad range of wavelengths in the first place? Using single-molecule spectroscopy, we address this fundamental question in a model material, poly(3-hexylthiophene). Narrow zero-phonon lines from single chromophores are found to scatter over 200 nm, an unprecedented inhomogeneous broadening that maps the ensemble. The giant red shift between solution and bulk films arises from energy transfer to the lowest-energy chromophores in collapsed polymer chains that adopt a highly ordered morphology. We propose that the extreme energetic disorder of chromophores is structural in origin. This structural disorder on the single-chromophore level may actually enable the high degree of polymer chain ordering found in bulk films: both structural order and disorder are crucial to materials physics in devices.
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20
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Chen PY, Rassamesard A, Chen HL, Chen SA. Conformation and Fluorescence Property of Poly(3-hexylthiophene) Isolated Chains Studied by Single Molecule Spectroscopy: Effects of Solvent Quality and Regioregularity. Macromolecules 2013. [DOI: 10.1021/ma400852q] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Pei-Yin Chen
- Department of Chemical Engineering
and Frontier Research Center on Fundamental and Applied Sciences of
Matters, National Tsing Hua University,
Hsin-Chu 30013, Taiwan
| | - Areefen Rassamesard
- Department of Science (Physics),
Faculty of Science and Technology, Prince of Songkla University, Pattani Campus, Pattani 94000, Thailand
| | - Hsin-Lung Chen
- Department of Chemical Engineering
and Frontier Research Center on Fundamental and Applied Sciences of
Matters, National Tsing Hua University,
Hsin-Chu 30013, Taiwan
| | - Show-An Chen
- Department of Chemical Engineering
and Frontier Research Center on Fundamental and Applied Sciences of
Matters, National Tsing Hua University,
Hsin-Chu 30013, Taiwan
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21
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Danesh CD, Starkweather NS, Zhang S. In Situ Study of Dynamic Conformational Transitions of a Water-Soluble Poly(3-hexylthiophene) Derivative by Surfactant Complexation. J Phys Chem B 2012; 116:12887-94. [DOI: 10.1021/jp307728r] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Cameron D. Danesh
- Department of Chemistry and Biochemistry, California Polytechnic State University, San Luis Obispo,
California 93407, United States
| | - Nathan S. Starkweather
- Department of Chemistry and Biochemistry, California Polytechnic State University, San Luis Obispo,
California 93407, United States
| | - Shanju Zhang
- Department of Chemistry and Biochemistry, California Polytechnic State University, San Luis Obispo,
California 93407, United States
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