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Roy SM, Rao NN, Herissan A, Colbeau-Justin C. Polyaniline film-based wireless photo reactor for hydrogen generation through exciton mediated proton reduction. POLYMER 2017. [DOI: 10.1016/j.polymer.2017.02.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Grußmayer KS, Steiner F, Lupton JM, Herten DP, Vogelsang J. Differentiation between Shallow and Deep Charge Trap States on Single Poly(3-hexylthiophene) Chains through Fluorescence Photon Statistics. Chemphyschem 2015; 16:3578-83. [DOI: 10.1002/cphc.201500719] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Indexed: 01/19/2023]
Affiliation(s)
- Kristin S. Grußmayer
- CellNetworks Cluster und Physikalisch-Chemisches Institut; Universität Heidelberg; Im Neuenheimer Feld 267 69210 Heidelberg Germany
| | - Florian Steiner
- 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
| | - Dirk-Peter Herten
- CellNetworks Cluster und Physikalisch-Chemisches Institut; Universität Heidelberg; Im Neuenheimer Feld 267 69210 Heidelberg Germany
| | - Jan Vogelsang
- Institut für Experimentelle und Angewandte Physik; Universität Regensburg; Universitätsstrasse 31 93053 Regensburg Germany
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Adachi T, Vogelsang J, Lupton JM. Unraveling the Electronic Heterogeneity of Charge Traps in Conjugated Polymers by Single-Molecule Spectroscopy. J Phys Chem Lett 2014; 5:573-577. [PMID: 26276611 DOI: 10.1021/jz402621y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Charge trapping is taken for granted in modeling the characteristics of organic semiconductor devices, but very few techniques actually exist to spectroscopically pinpoint trap states. For example, trap levels are often assumed to be discrete in energy. Using the well-known keto defect in polyfluorene as a model, we demonstrate how single-molecule spectroscopy can directly track the formation of charge and exciton traps in conjugated polymers in real time, providing crucial information on the energetic distribution of trap sites relative to the polymer optical gap. Charge traps with universal spectral fingerprints scatter by almost 1 eV in depth, implying that substantial heterogeneity must be taken into account when modeling devices.
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Affiliation(s)
- Takuji Adachi
- 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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Bolinger JC, Traub MC, Brazard J, Adachi T, Barbara PF, Vanden Bout DA. Conformation and energy transfer in single conjugated polymers. Acc Chem Res 2012; 45:1992-2001. [PMID: 22775295 DOI: 10.1021/ar300012k] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In contrast to the detailed understanding of inorganic materials, researchers lack a comprehensive view of how the properties of bulk organic materials arise from their individual components. For conjugated polymers to eventually serve as low cost semiconductor layers in electronic devices, researchers need to better understand their functionality. For organics, traditional materials science measurements tend to destroy the species of interest, especially at low concentrations. However, fluorescence continues to be a remarkably flexible, relatively noninvasive tool for probing the properties of individual molecules and allows researchers to carry out a broad range of experiments based on a relatively simple concept. In addition, the sensitivity of single-molecule spectroscopy allows researchers to see the properties of an individual component that would be masked in the bulk phase. In this Account, we examine several photophysical properties of different conjugated polymers using single-molecule spectroscopy. In these experiments, we probed the relationship between the conformation of single conjugated polymer chains and the distance scale and efficiency of energy transfer within the polymer. Recent studies used polarization anisotropy measurements on single polymer chains to study chain folding following spin-casting from solution. This Account summarizes the effects of monomer regioregularity and backbone rigidity, by comparing a regiorandom phenylene vinylene (MEH-PPV) with both a regiorandom and regioregular thiophene (P3HT). Synthesis of novel polymers allowed us to explore the role of different conformation-directing inclusions in a PPV backbone. We showed that these inclusions control the conformation of individual chains and that molecular dynamics can predict these structural effects. In situ solvent vapor annealing studies explored the dynamics of polymer chains as well as the effect of solvent evaporation on the structural equilibrium of the polymer. We observed that a slower rate of solvent evaporation results in a narrow population of highly ordered polymer chains. These highly ordered single chains serve as a model system to probe the effect of conformation on energy transfer following excitation in single MEH-PPV polymer chains in two distinct experiments. In the first, we correlated the anisotropy of the fluorescence emission of individual chains with the anisotropy of their fluorescence excitation. Using this data, we derived a model for energy transfer in a conjugated polymer, simulating chromophores along a chain, coupled via Förster energy transfer. In the second experiment, super-resolution measurements demonstrated the ability of single-molecule spectroscopy to directly visualize energy transfer along a polymer chain embedded in a model device environment. A capacitive device allowed for controlled localization of hole polarons onto the polymer chain. These positive charges subsequently quenched local excitations, providing insight into the range of energy transfer in these single polymer molecules. As researchers continue to characterize conjugated polymer films and develop methods for creating multichain systems, single-molecule techniques will provide a greater understanding of how polymer morphology influences interchain interactions and will lead to a richer description of the electronic properties of bulk conjugated polymer films.
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Toušek J, Toušková J, Remeš Z, Čermák J, Kousal J, Kindl D, Kuřitka I. Exciton diffusion length and concentration of holes in MEH-PPV polymer using the surface voltage and surface photovoltage methods. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2012.09.052] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Vogelsang J, Lupton JM. Solvent Vapor Annealing of Single Conjugated Polymer Chains: Building Organic Optoelectronic Materials from the Bottom Up. J Phys Chem Lett 2012; 3:1503-1513. [PMID: 26285629 DOI: 10.1021/jz300294m] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Optoelectronic devices based on organic materials show a strong relationship between the morphological structure of the material and the function of the device. One of the grand challenges in improving the efficiencies of these devices is hence achieving morphological control throughout the entire course of processing. One of the most important postprocessing methods is solvent vapor annealing, which has repeatedly demonstrated its utility in improving the efficiency of organic-material-based devices by changing bulk-film morphology. This Perspective discusses the recent impact of single-molecule spectroscopy techniques in unraveling morphological changes and molecular dynamics and presents solvent vapor annealing as a tool to build organic optoelectronic materials from the bottom up. In particular, we discuss examples of how solvent vapor annealing at the single-chain level can be split into two different regimes, (i) the solvation regime, in which intrachain interactions and molecular dynamics during solvent vapor annealing can be probed, and (ii) the aggregation regime, in which the influence of interchain interactions can be probed. Finally, it will be shown that solvent vapor annealing in the aggregation regime can be used to build highly ordered mesoscopic objects with distinct properties such as long-range energy transfer.
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Affiliation(s)
- 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
- †Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, United States
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Traub MC, Vogelsang J, Plunkett KN, Nuckolls C, Barbara PF, Vanden Bout DA. Unmasking bulk exciton traps and interchain electronic interactions with single conjugated polymer aggregates. ACS NANO 2012; 6:523-529. [PMID: 22208575 DOI: 10.1021/nn203860u] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
For conjugated polymer materials, there is currently a major gap in understanding between the fundamental properties observed in single molecule measurements and the bulk electronic properties extracted from measurements of highly heterogeneous thin films. New materials and methodologies are needed to follow the evolution from single chain to bulk film properties as multiple chains begin to interact. In this work, we used a controlled solvent vapor annealing process to assemble single chains of phenylene-vinylene conjugated polymers into aggregates that can be individually spectroscopically interrogated. This approach allowed us to probe the effects of interchain coupling in isolated conjugated polymer nanodomains of controlled size. By assembling these aggregates from building blocks of both pristine MEH-PPV and MEH-PPV derivatives containing structure-directing ortho- or para-terphenyl inclusions, we were able to control the ordering of these nanodomains as measured by single aggregate polarization anisotropy measurments. Depending on the individual chain constituents, these aggregates varied from highly anisotropic to nearly isotropic, respectively facilitating or inhibiting interchain coupling. From the single chain fluorescence lifetimes, we demonstrated that these structure directing inclusions effectively break the phenylene-vinylene conjugation, allowing us to differentiate interchain electronic effects from those due to hyper-extended conjugation. We observed well-defined bathochromic shifts in the fluorescence spectra of the aggregates containing extensive interchain interactions, indicating that low-energy exciton traps in MEH-PPV are the result of coupling interactions between neighboring chain segments. These results demonstrate the power of the synthetic inclusion approach to control properties at not just the single chain level, but as a comprehensive approach toward ground-up design of bulk electronic properties.
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Affiliation(s)
- Matthew C Traub
- Department of Chemistry and Biochemistry and the Center for Nano and Molecular Science and Technology, The University of Texas at Austin, Austin, Texas 78712, USA
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Hu Z, Gesquiere AJ. Charge Trapping and Storage by Composite P3HT/PC60BM Nanoparticles Investigated by Fluorescence-Voltage/Single Particle Spectroscopy. J Am Chem Soc 2011; 133:20850-6. [DOI: 10.1021/ja207244z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Zhongjian Hu
- NanoScience Technology Center, Department of Chemistry and CREOL, The College of Optics and Photonics, University of Central Florida, 12424 Research Parkway Suite 400, Orlando, Florida 32826, United States
| | - Andre J. Gesquiere
- NanoScience Technology Center, Department of Chemistry and CREOL, The College of Optics and Photonics, University of Central Florida, 12424 Research Parkway Suite 400, Orlando, Florida 32826, United States
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Sai N, Barbara PF, Leung K. Hole localization in molecular crystals from hybrid density functional theory. PHYSICAL REVIEW LETTERS 2011; 106:226403. [PMID: 21702620 DOI: 10.1103/physrevlett.106.226403] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Indexed: 05/13/2023]
Abstract
We use first-principles computational methods to examine hole trapping in organic molecular crystals. We present a computational scheme based on the tuning of the fraction of exact exchange in hybrid density functional theory to eliminate the many-electron self-interaction error. With small organic molecules, we show that this scheme gives accurate descriptions of ionization and dimer dissociation. We demonstrate that the excess hole in perfect molecular crystals forms self-trapped molecular polarons. The predicted absolute ionization potentials of both localized and delocalized holes are consistent with experimental values.
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Affiliation(s)
- Na Sai
- Center for Nano and Molecular Science and Technology, The University of Texas at Austin, Austin, Texas 78712, USA
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Bolinger JC, Traub MC, Adachi T, Barbara PF. Ultralong-Range Polaron-Induced Quenching of Excitons in Isolated Conjugated Polymers. Science 2011; 331:565-7. [DOI: 10.1126/science.1199140] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Joshua C. Bolinger
- Center for Nano and Molecular Science and Technology, University of Texas, Austin, TX 78712, USA
| | - Matthew C. Traub
- Center for Nano and Molecular Science and Technology, University of Texas, Austin, TX 78712, USA
| | - Takuji Adachi
- Center for Nano and Molecular Science and Technology, University of Texas, Austin, TX 78712, USA
| | - Paul F. Barbara
- Center for Nano and Molecular Science and Technology, University of Texas, Austin, TX 78712, USA
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Cohen B, Álvarez CM, Carmona NA, Organero JA, Douhal A. Single molecule photobehavior of a chromophore interacting with silica-based nanomaterials. Phys Chem Chem Phys 2011; 13:1819-26. [DOI: 10.1039/c0cp02240c] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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12
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Cohen B, Sanchez F, Douhal A. Mapping the Distribution of an Individual Chromophore Interacting with Silica-Based Nanomaterials. J Am Chem Soc 2010; 132:5507-14. [DOI: 10.1021/ja100771j] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Boiko Cohen
- Departamento de Química Física, Sección de Químicas, Facultad del Medio Ambiente and INAMOL, Universidad de Castilla−La Mancha, Carlos III S/N 45071 Toledo, Spain, and Instituto de Química Orgánica, CSIC, C/Juan de la Cierva, 3, E-28006, Madrid, Spain
| | - Felix Sanchez
- Departamento de Química Física, Sección de Químicas, Facultad del Medio Ambiente and INAMOL, Universidad de Castilla−La Mancha, Carlos III S/N 45071 Toledo, Spain, and Instituto de Química Orgánica, CSIC, C/Juan de la Cierva, 3, E-28006, Madrid, Spain
| | - Abderrazzak Douhal
- Departamento de Química Física, Sección de Químicas, Facultad del Medio Ambiente and INAMOL, Universidad de Castilla−La Mancha, Carlos III S/N 45071 Toledo, Spain, and Instituto de Química Orgánica, CSIC, C/Juan de la Cierva, 3, E-28006, Madrid, Spain
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Palacios RE, Chang WS, Grey JK, Chang YL, Miller WL, Lu CY, Henkelman G, Zepeda D, Ferraris J, Barbara PF. Detailed Single-Molecule Spectroelectrochemical Studies of the Oxidation of Conjugated Polymers. J Phys Chem B 2009; 113:14619-28. [DOI: 10.1021/jp906740n] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rodrigo E. Palacios
- Department of Chemistry and Biochemistry and the Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, Texas 78712, and Department of Chemistry and the Alan G. McDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, Texas 75083-0688
| | - Wei-Shun Chang
- Department of Chemistry and Biochemistry and the Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, Texas 78712, and Department of Chemistry and the Alan G. McDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, Texas 75083-0688
| | - John K. Grey
- Department of Chemistry and Biochemistry and the Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, Texas 78712, and Department of Chemistry and the Alan G. McDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, Texas 75083-0688
| | - Ya-Lan Chang
- Department of Chemistry and Biochemistry and the Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, Texas 78712, and Department of Chemistry and the Alan G. McDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, Texas 75083-0688
| | - William L. Miller
- Department of Chemistry and Biochemistry and the Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, Texas 78712, and Department of Chemistry and the Alan G. McDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, Texas 75083-0688
| | - Chun-Yaung Lu
- Department of Chemistry and Biochemistry and the Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, Texas 78712, and Department of Chemistry and the Alan G. McDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, Texas 75083-0688
| | - Graeme Henkelman
- Department of Chemistry and Biochemistry and the Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, Texas 78712, and Department of Chemistry and the Alan G. McDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, Texas 75083-0688
| | - Danny Zepeda
- Department of Chemistry and Biochemistry and the Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, Texas 78712, and Department of Chemistry and the Alan G. McDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, Texas 75083-0688
| | - John Ferraris
- Department of Chemistry and Biochemistry and the Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, Texas 78712, and Department of Chemistry and the Alan G. McDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, Texas 75083-0688
| | - Paul F. Barbara
- Department of Chemistry and Biochemistry and the Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, Texas 78712, and Department of Chemistry and the Alan G. McDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, Texas 75083-0688
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