1
|
LeCroy G, Ghosh R, Sommerville P, Burke C, Makki H, Rozylowicz K, Cheng C, Weber M, Khelifi W, Stingelin N, Troisi A, Luscombe C, Spano FC, Salleo A. Using Molecular Structure to Tune Intrachain and Interchain Charge Transport in Indacenodithiophene-Based Copolymers. J Am Chem Soc 2024. [PMID: 39058936 DOI: 10.1021/jacs.4c06006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
Abstract
In this work, we compare two structurally near-amorphous rigid-rod polymers─poly(indacenodithiophene-co-benzothiadiazole), p(IDT-BT), and poly(indacenodithiophene-co-benzopyrollodione), p(IDT-BPD)─with orders of magnitude different mobilities to understand the effect charge carrier intrachain delocalization has on electronic transport. Quantum chemical calculations show that p(IDT-BPD) has a barrier to torsion that is significantly lower than that of p(IDT-BT) and is thus more likely to have reduced conjugation lengths. We utilize absorption and photoluminescence spectroscopy to characterize energetic disorder and show that p(IDT-BPD) has higher energetic disorder. Charge modulation spectroscopy (CMS) and model calculations are used to show that charge carriers are substantially delocalized in p(IDT-BT) and occupy near-uniform energetic environments. We find that mobility activated hopping barriers are similar in these two materials. Electronic structure calculations show that both intrachain and interchain couplings of monomer units are poor enough in p(IDT-BPD) that charge carriers collapse to single IDT units and transport via a through-space tunneling mechanism. This work highlights the remarkable charge transport properties of p(IDT-BT) by showing that high mobilities are achievable on device-relevant length scales with only 1D carrier delocalization.
Collapse
Affiliation(s)
- Garrett LeCroy
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| | - Raja Ghosh
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Parker Sommerville
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Colm Burke
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - Hesam Makki
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - Kalee Rozylowicz
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| | - Christina Cheng
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| | - Mark Weber
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Wissem Khelifi
- pi-Conjugated Polymers Unit, Okinawa Institute of Science and Technology, Onna, Okinawa 904-0495, Japan
| | - Natalie Stingelin
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Alessandro Troisi
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, United Kingdom
| | - Christine Luscombe
- pi-Conjugated Polymers Unit, Okinawa Institute of Science and Technology, Onna, Okinawa 904-0495, Japan
| | - Frank C Spano
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Alberto Salleo
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| |
Collapse
|
2
|
Reiker T, Liu Z, Winter C, Cappellari MV, Abradelo DG, Strassert CA, Zhang D, Zacharias H. Ultrafast electron dynamics in excited states of conjugated thiophene-fluorene organic polymer (pF8T2) thin films. Phys Chem Chem Phys 2024; 26:4736-4751. [PMID: 38251969 DOI: 10.1039/d3cp00502j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
The electronic states of poly(9,9-dioctylfluorenyl-alt-bithiophene) pF8T2 on H/Si(100) substrates, prototypical for organic photovoltaics, were investigated by ultrafast photoelectron spectroscopy and by time-resolved fluorescence studies. Occupied and unoccupied electronic states were analysed by ultraviolet photoelectron spectroscopy (UPS), static and dynamic femtosecond two-photon photoemission (2PPE), and time-correlated single photon counting (TCSPC). Time-resolved measurements allow assessment of population lifetimes of intermediate states. The combination of time-resolved photoelectron spectroscopy and fluorescence excitation allows following the electronic dynamics in excited states from the femtosecond to the nanosecond time scale. For this prototypical material the electron kinetic energy resolved lifetimes range from about a few tens of femtoseconds up to hundreds of picoseconds. After annealing these types of organic thin films the efficiency of organic solar cells usually increases. We show that annealing does not influence the initial ultrafast charge generation processes, but the long-lived states. However, the nanosecond scale fluorescence lifetimes measured by TCSPC are prolonged after annealing, which therefore is identified as the cause of a greater exciton diffusion range and thus is beneficial for charge carrier extraction.
Collapse
Affiliation(s)
- T Reiker
- Center for Soft Nanoscience, University of Münster, 48149 Münster, Germany.
- Physics Institute, University of Münster, 48149 Münster, Germany
| | - Z Liu
- Organic Solids Laboratory, Institute of Chemistry, Chinese Academy of Science, Beijing 100190, P. R. China
| | - C Winter
- Physics Institute, University of Münster, 48149 Münster, Germany
| | - M V Cappellari
- Center for Nanotechnology and Institute for Inorganic and Analytical Chemistry, University of Münster, Heisenbergstraße 11, 48149 Münster, Germany
| | - D Gonzalez Abradelo
- Center for Nanotechnology and Institute for Inorganic and Analytical Chemistry, University of Münster, Heisenbergstraße 11, 48149 Münster, Germany
| | - C A Strassert
- Center for Nanotechnology and Institute for Inorganic and Analytical Chemistry, University of Münster, Heisenbergstraße 11, 48149 Münster, Germany
| | - D Zhang
- Organic Solids Laboratory, Institute of Chemistry, Chinese Academy of Science, Beijing 100190, P. R. China
| | - H Zacharias
- Center for Soft Nanoscience, University of Münster, 48149 Münster, Germany.
- Physics Institute, University of Münster, 48149 Münster, Germany
| |
Collapse
|
3
|
Schötz K, Panzer F, Sommer M, Bässler H, Köhler A. A spectroscopic assessment of static and dynamic disorder in a film of a polythiophene with a planarized backbone. MATERIALS HORIZONS 2023; 10:5538-5546. [PMID: 37853812 DOI: 10.1039/d3mh01262j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
The optoelectronic performance of organic semiconductor devices is related to the static and dynamic disorder in the film. The disorder can be assessed by considering the linewidth of its optical spectra. We focus on identifying the effect of conjugation length distribution on the static energetic disorder. Hence, we disentangle the contributions of static and dynamic disorder to the absorption and emission spectra of poly(3-(2,5-dioctylphenyl)-thiophene) (PDOPT) by exploring how the linewidth and energy of the spectra evolve upon cooling the sample from 300 K to 5 K. PDOPT has sterically hindered side chains that arrange such as to cause a planarized polymer backbone. This makes it a suitable model for a quasi-one-dimensional molecular system. By modelling the conjugated segments as coupled oscillators we find that the linewidth contribution resulting from the variation of conjugation length decreases linearly with decreasing exciton energy and extrapolates to zero at the energy corresponding to an infinite chain. These results provide a new avenue to the design of low disorder and hence high mobility polymeric semiconductors.
Collapse
Affiliation(s)
- Konstantin Schötz
- Soft Matter Optoelectronics and Bavarian Polymer Institute (BPI), University of Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany
| | - Fabian Panzer
- Soft Matter Optoelectronics and Bavarian Polymer Institute (BPI), University of Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany
| | - Michael Sommer
- Institute for Chemistry, Chemnitz University of Technology, Straße der Nationen 62, 09111 Chemnitz, Germany
| | - Heinz Bässler
- Bayreuth Institute of Macromolecular Research (BIMF), University of Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany.
| | - Anna Köhler
- Soft Matter Optoelectronics and Bavarian Polymer Institute (BPI), University of Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany
- Bayreuth Institute of Macromolecular Research (BIMF), University of Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany.
| |
Collapse
|
4
|
Eder T, Kraus D, Höger S, Vogelsang J, Lupton JM. Vibrations Responsible for Luminescence from HJ-Aggregates of Conjugated Polymers Identified by Cryogenic Spectroscopy of Single Nanoparticles. ACS NANO 2022; 16:6382-6393. [PMID: 35394735 DOI: 10.1021/acsnano.2c00472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A single polymer chain can be thought of as a covalently bound J-aggregate, where the microscopic transition-dipole moments line up to emit in phase. Packing polymer chains into a bulk film can result in the opposite effect, inducing H-type coupling between chains. Cofacial transition-dipole moments oscillate out of phase, canceling each other out, so that the lowest-energy excited state turns dark. H-aggregates of conjugated polymers can, in principle, be coaxed into emitting light by mixing purely electronic and vibronic transitions. However, it is challenging to characterize this electron-phonon coupling experimentally. In a bulk film, many different conformations exist with varying degrees of intrachain J-type and interchain H-type coupling strengths, giving rise to broad and featureless aggregate absorption and emission spectra. Even if single nanoparticles consisting of only a few single chains are grown in a controlled fashion, the luminescence spectra remain broad, owing to the underlying molecular dynamics and structural heterogeneity at room temperature. At cryogenic temperatures, emission from H-type aggregates should be suppressed because, in the absence of thermal energy, internal conversion drives the aggregate to the lowest-energy dark state. At the same time, electronic and vibronic transitions narrow substantially, facilitating the attribution of spectral signatures to distinct vibrational modes. We demonstrate how to distinguish signatures of interchain H-type aggregate species from those of intramolecular J-type coupling. Whereas all dominant vibronic modes revealed in the photoluminescence (PL) and surface-enhanced resonance Raman scattering spectra of a single chromophore within a single polymer chain are identified in the J-type aggregate luminescence spectra, they are not all present at once in the H-type spectra. Universal spectral features are found for the luminescence from strongly HJ-coupled chains, clearly resolving the vibrations responsible for the nonadiabatic excited-state molecular dynamics that enable light emission. We discuss the possible combinations of vibrational modes responsible for H-type aggregate PL and demonstrate that only one, mainly the lowest energy one, of the three dominant vibrational modes contributes to the 0-1 transition, whereas combinations of all three are found in the 0-2 transition. From this analysis, we can distinguish between energy shifts due to either J-type intrachain coupling or H-type interchain interactions, offering a means to directly discriminate between structural and energetic disorder.
Collapse
Affiliation(s)
- Theresa Eder
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93040 Regensburg, Germany
| | - Daniel Kraus
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93040 Regensburg, Germany
| | - Sigurd Höger
- Kekulé-Institut für Organische Chemie und Biochemie der Universität Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn, Germany
| | - Jan Vogelsang
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93040 Regensburg, Germany
| | - John M Lupton
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, 93040 Regensburg, Germany
| |
Collapse
|
5
|
Chang X, Balooch Qarai M, Spano FC. HJ-aggregates of donor-acceptor-donor oligomers and polymers. J Chem Phys 2021; 155:034905. [PMID: 34293903 DOI: 10.1063/5.0054877] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
A vibronic exciton model is developed to account for the spectral signatures of HJ-aggregates of oligomers and polymers containing donor-acceptor-donor (DAD) repeat units. In (DAD)N π-stacks, J-aggregate-promoting intrachain interactions compete with H-aggregate-promoting interchain interactions. The latter includes Coulombic coupling, which arises from "side-by-side" fragment transition dipole moments as well as intermolecular charge transfer (ICT), which is enhanced in geometries with substantial overlap between donors on one chain and acceptors on a neighboring chain. J-behavior is dominant in single (DAD)N chains with enhanced intrachain order as evidenced by an increased red-shift in the low-energy absorption band along with a heightened A1/A2 peak ratio, where A1 and A2 are the oscillator strengths of the first two vibronic peaks in the progression sourced by the symmetric quinoidal-aromatic vibration. By contrast, the positive H-promoting interchain Coulomb interactions operative in aggregates cause the vibronic ratio to attenuate, similar to what has been established in H-aggregates of homopolymers such as P3HT. An attenuated A1/A2 ratio can also be caused by H-promoting ICT which occurs when the electron and hole transfer integrals are out-of-phase. In this case, the A1 peak is red-shifted, in contrast to conventional Kasha H-aggregates. With slight modifications, the ratio formula derived previously for P3HT aggregates is shown to apply to (DAD)N aggregates as well, allowing one to determine the effective free-exciton interchain coupling from the A1/A2 ratio. Applications are made to polymers based on 2T-DPP-2T and 2T-BT-2T repeat units, where the importance of the admixture of the excited acceptor state in the lowest energy band is emphasized.
Collapse
Affiliation(s)
- Xin Chang
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
| | | | - Frank C Spano
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
| |
Collapse
|
6
|
Nematiaram T, Padula D, Troisi A. Bright Frenkel Excitons in Molecular Crystals: A Survey. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2021; 33:3368-3378. [PMID: 34526736 PMCID: PMC8432684 DOI: 10.1021/acs.chemmater.1c00645] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/14/2021] [Indexed: 05/12/2023]
Abstract
We computed the optical properties of a large set of molecular crystals (∼2200 structures) composed of molecules whose lowest excited states are strongly coupled and generate wide excitonic bands. Such bands are classified in terms of their dimensionality (1-, 2-, and 3-dimensional), the position of the optically allowed state in relation with the excitonic density of states, and the presence of Davydov splitting. The survey confirms that one-dimensional aggregates are rare in molecular crystals highlighting the need to go beyond the simple low-dimensional models. Furthermore, this large set of data is used to search for technologically interesting and less common properties. For instance, we considered the largest excitonic bandwidth that is achievable within known molecular crystals and identified materials with strong super-radiant states. Finally, we explored the possibility that strong excitonic coupling can be used to generate emissive states in the near-infrared region in materials formed by molecules with bright visible absorption and we could identify the maximum allowable red shift in this material class. These insights with the associated searchable database provide practical guidelines for designing materials with interesting optical properties.
Collapse
Affiliation(s)
- Tahereh Nematiaram
- Department
of Chemistry and Materials Innovation Factory, University of Liverpool, Liverpool L69 7ZD, U.K.
| | - Daniele Padula
- Dipartimento
di Biotecnologie, Chimica e Farmacia, Università
di Siena, via A. Moro 2, Siena 53100, Italy
| | - Alessandro Troisi
- Department
of Chemistry and Materials Innovation Factory, University of Liverpool, Liverpool L69 7ZD, U.K.
| |
Collapse
|
7
|
Balooch Qarai M, Chang X, Spano FC. Vibronic exciton model for low bandgap donor–acceptor polymers. J Chem Phys 2020; 153:244901. [DOI: 10.1063/5.0029193] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
| | - Xin Chang
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - F. C. Spano
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
| |
Collapse
|
8
|
Intrinsically distinct hole and electron transport in conjugated polymers controlled by intra and intermolecular interactions. Nat Commun 2019; 10:5226. [PMID: 31745091 PMCID: PMC6863910 DOI: 10.1038/s41467-019-13155-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/16/2019] [Indexed: 11/08/2022] Open
Abstract
It is still a matter of controversy whether the relative difference in hole and electron transport in solution-processed organic semiconductors is either due to intrinsic properties linked to chemical and solid-state structure or to extrinsic factors, as device architecture. We here isolate the intrinsic factors affecting either electron or hole transport within the same film microstructure of a model copolymer semiconductor. Relatively, holes predominantly bleach inter-chain interactions with H-type electronic coupling character, while electrons' relaxation more strongly involves intra-chain interactions with J-type character. Holes and electrons mobility correlates with the presence of a charge transfer state, while their ratio is a function of the relative content of intra- and inter-molecular interactions. Such fundamental observation, revealing the specific role of the ground-state intra- and inter-molecular coupling in selectively assisting charge transport, allows predicting a more favorable hole or electron transport already from screening the polymer film ground state optical properties.
Collapse
|
9
|
Guerrini M, Calzolari A, Corni S. Solid-State Effects on the Optical Excitation of Push-Pull Molecular J-Aggregates by First-Principles Simulations. ACS OMEGA 2018; 3:10481-10486. [PMID: 30288457 PMCID: PMC6166226 DOI: 10.1021/acsomega.8b01457] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 08/17/2018] [Indexed: 05/26/2023]
Abstract
J-aggregates are a class of low-dimensional molecular crystals which display enhanced interaction with light. These systems show interesting optical properties as an intense and narrow red-shifted absorption peak (J-band) with respect to the spectrum of the corresponding monomer. The need to theoretically investigate optical excitations in J-aggregates is twofold: a thorough first-principles description is still missing and a renewed interest is rising recently in understanding the nature of the J-band, in particular regarding the collective mechanisms involved in its formation. In this work, we investigate the electronic and optical properties of a J-aggregate molecular crystal made of ordered arrangements of organic push-pull chromophores. By using a time-dependent density functional theory approach, we assess the role of the molecular packing in the enhancement and red shift of the J-band along with the effects of confinement in the optical absorption, when moving from bulk to low-dimensional crystal structures. We simulate the optical absorption of different configurations (i.e., monomer, dimers, a polymer chain, and a monolayer sheet) extracted from the bulk crystal. By analyzing the induced charge density associated with the J-band, we conclude that it is a longitudinal excitation, delocalized along parallel linear chains and that its overall red shift results from competing coupling mechanisms, some giving red shift and others giving blue shift, which derive from both coupling between transition densities and renormalization of the single-particle energy levels.
Collapse
Affiliation(s)
- Michele Guerrini
- Dipartimento
FIM, Università di Modena e Reggio
Emilia, 41125 Modena, Italy
- CNR
Nano Istituto Nanoscienze, Centro S3, 41125 Modena, Italy
| | | | - Stefano Corni
- CNR
Nano Istituto Nanoscienze, Centro S3, 41125 Modena, Italy
- Dipartimento
di Scienze Chimiche, Università di
Padova, 35131 Padova, Italy
| |
Collapse
|
10
|
Milward JD, Marcus M, Köhler A, Barford W. Extracting structural information from MEH-PPV optical spectra. J Chem Phys 2018; 149:044903. [PMID: 30068188 DOI: 10.1063/1.5041938] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The Frenkel-Holstein model in the Born-Oppenheimer regime is used to interpret temperature-dependent photoluminescence spectra of solutions made with the poly(p-phenylene vinylene) derivative MEH-PPV. Using our recently developed structural optimization method and assuming only intrachain electronic coupling, we predict the structure of emissive MEH-PPV chromophores in terms of a mean torsional angle ϕ0 and its static fluctuations σϕ, assuming no cis-trans defects. This allows us to fully account for the observed changes in spectra, and the chromophore structures obtained are consistent with the known phase transition at 180 K between a "red" and "blue" phase.
Collapse
Affiliation(s)
- Jonathan D Milward
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Max Marcus
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Anna Köhler
- Experimental Physics II, University of Bayreuth, 95447 Bayreuth, Germany and Bayreuth Institute of Macromolecular Research (BIMF), University of Bayreuth, 95447 Bayreuth, Germany
| | - William Barford
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| |
Collapse
|
11
|
Hestand NJ, Spano FC. Expanded Theory of H- and J-Molecular Aggregates: The Effects of Vibronic Coupling and Intermolecular Charge Transfer. Chem Rev 2018; 118:7069-7163. [PMID: 29664617 DOI: 10.1021/acs.chemrev.7b00581] [Citation(s) in RCA: 719] [Impact Index Per Article: 119.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The electronic excited states of molecular aggregates and their photophysical signatures have long fascinated spectroscopists and theoreticians alike since the advent of Frenkel exciton theory almost 90 years ago. The influence of molecular packing on basic optical probes like absorption and photoluminescence was originally worked out by Kasha for aggregates dominated by Coulombic intermolecular interactions, eventually leading to the classification of J- and H-aggregates. This review outlines advances made in understanding the relationship between aggregate structure and photophysics when vibronic coupling and intermolecular charge transfer are incorporated. An assortment of packing geometries is considered from the humble molecular dimer to more exotic structures including linear and bent aggregates, two-dimensional herringbone and "HJ" aggregates, and chiral aggregates. The interplay between long-range Coulomb coupling and short-range charge-transfer-mediated coupling strongly depends on the aggregate architecture leading to a wide array of photophysical behaviors.
Collapse
Affiliation(s)
- Nicholas J Hestand
- Department of Chemistry , Temple University , Philadelphia , Pennsylvania 19122 , United States
| | - Frank C Spano
- Department of Chemistry , Temple University , Philadelphia , Pennsylvania 19122 , United States
| |
Collapse
|
12
|
Marcus M, Milward JD, Köhler A, Barford W. Structural Information for Conjugated Polymers from Optical Modeling. J Phys Chem A 2018; 122:3621-3625. [PMID: 29565593 DOI: 10.1021/acs.jpca.8b01585] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We use a Frenkel-Holstein model of uncoupled chains in the adiabatic limit to simulate the optical spectra of the conjugated polymer ladder-type poly( p-phenylene) derivative (MeLPPP), which is a planar conjugated polymer with especially low interchain interactions. The theoretical calculations correctly reproduce the vibronic spectra and yield reasonable torsion angles between adjacent phenyl rings. The success of this approach indicates that, in contrast to interchain coupling, the strong electronic coupling along a polymer chain is more appropriately described in the adiabatic limit.
Collapse
Affiliation(s)
- Max Marcus
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory , University of Oxford , Oxford , OX1 3QZ , U.K.,Magdalen College , University of Oxford , Oxford , OX1 4AU , U.K
| | - Jonathan D Milward
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory , University of Oxford , Oxford , OX1 3QZ , U.K.,University College , University of Oxford , Oxford , OX1 4BH , U.K
| | - Anna Köhler
- Experimental Physics II , University of Bayreuth , 95447 Bayreuth , Germany.,Bayreuth Institut of Macromulecular Research (BIMF) , University of Bayreuth , 95447 Bayreuth , Germany
| | - William Barford
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory , University of Oxford , Oxford , OX1 3QZ , U.K
| |
Collapse
|
13
|
Gudnason D, Madsen M, Krissanaprasit A, Gothelf KV, Birkedal V. Controlled aggregation of DNA functionalized poly(phenylene-vinylene). Chem Commun (Camb) 2018; 54:5534-5537. [DOI: 10.1039/c8cc00943k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We show that aggregation of DNA-functionalized poly(phenylene-vinylene) can be controlled in solution through ion and DNA interactions.
Collapse
Affiliation(s)
- Daniel Gudnason
- Center for DNA Nanotechnology
- Interdisciplinary Nanoscience Center
- iNANO
- Aarhus University
- Aarhus C
| | - Mikael Madsen
- Center for DNA Nanotechnology
- Interdisciplinary Nanoscience Center
- iNANO
- Aarhus University
- Aarhus C
| | | | - Kurt V. Gothelf
- Center for DNA Nanotechnology
- Interdisciplinary Nanoscience Center
- iNANO
- Aarhus University
- Aarhus C
| | - Victoria Birkedal
- Center for DNA Nanotechnology
- Interdisciplinary Nanoscience Center
- iNANO
- Aarhus University
- Aarhus C
| |
Collapse
|
14
|
Eder T, Stangl T, Gmelch M, Remmerssen K, Laux D, Höger S, Lupton JM, Vogelsang J. Switching between H- and J-type electronic coupling in single conjugated polymer aggregates. Nat Commun 2017; 8:1641. [PMID: 29158508 PMCID: PMC5696370 DOI: 10.1038/s41467-017-01773-0] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 10/13/2017] [Indexed: 11/21/2022] Open
Abstract
The aggregation of conjugated polymers and electronic coupling of chromophores play a central role in the fundamental understanding of light and charge generation processes. Here we report that the predominant coupling in isolated aggregates of conjugated polymers can be switched reversibly between H-type and J-type coupling by partially swelling and drying the aggregates. Aggregation is identified by shifts in photoluminescence energy, changes in vibronic peak ratio, and photoluminescence lifetime. This experiment unravels the internal electronic structure of the aggregate and highlights the importance of the drying process in the final spectroscopic properties. The electronic coupling after drying is tuned between H-type and J-type by changing the side chains of the conjugated polymer, but can also be entirely suppressed. The types of electronic coupling correlate with chain morphology, which is quantified by excitation polarization spectroscopy and the efficiency of interchromophoric energy transfer that is revealed by the degree of single-photon emission.
Collapse
Affiliation(s)
- Theresa Eder
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Thomas Stangl
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Max Gmelch
- Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Klaas Remmerssen
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Dirk Laux
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Sigurd Höger
- Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - John M Lupton
- 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.
| |
Collapse
|
15
|
Yu SH, Park KH, Kim YH, Chung DS, Kwon SK. Fine Molecular Tuning of Diketopyrrolopyrrole-Based Polymer Semiconductors for Efficient Charge Transport: Effects of Intramolecular Conjugation Structure. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b00624] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Seong Hoon Yu
- Department of Energy Systems Engineering, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu 42988, Republic of Korea
| | | | | | - Dae Sung Chung
- Department of Energy Systems Engineering, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu 42988, Republic of Korea
| | | |
Collapse
|
16
|
Barford W, Marcus M. Perspective: Optical spectroscopy in π-conjugated polymers and how it can be used to determine multiscale polymer structures. J Chem Phys 2017; 146:130902. [DOI: 10.1063/1.4979495] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
17
|
Braendle A, Perevedentsev A, Cheetham NJ, Stavrinou PN, Schachner JA, Mösch-Zanetti NC, Niederberger M, Caseri WR. Homoconjugation in poly(phenylene methylene)s: A case study of non-π-conjugated polymers with unexpected fluorescent properties. ACTA ACUST UNITED AC 2017. [DOI: 10.1002/polb.24305] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Andreas Braendle
- Department of Materials; Multifunctional Materials, ETH Zürich; Vladimir-Prelog-Weg 5 Zürich 8093 Switzerland
| | - Aleksandr Perevedentsev
- Department of Materials; Polymer Technology, ETH Zürich; Vladimir-Prelog-Weg 5 Zürich 8093 Switzerland
| | - Nathan J. Cheetham
- Department of Physics and Centre for Plastic Electronics; Imperial College London; London SW7 2AZ United Kingdom
| | - Paul N. Stavrinou
- Department of Engineering Science; University of Oxford; Oxford OX1 3PJ United Kingdom
| | - Jörg A. Schachner
- Institute of Chemistry, Inorganic Chemistry, University of Graz; Schubertstrasse 1 Graz 8010 Austria
| | - Nadia C. Mösch-Zanetti
- Institute of Chemistry, Inorganic Chemistry, University of Graz; Schubertstrasse 1 Graz 8010 Austria
| | - Markus Niederberger
- Department of Materials; Multifunctional Materials, ETH Zürich; Vladimir-Prelog-Weg 5 Zürich 8093 Switzerland
| | - Walter R. Caseri
- Department of Materials; Multifunctional Materials, ETH Zürich; Vladimir-Prelog-Weg 5 Zürich 8093 Switzerland
| |
Collapse
|
18
|
Panzer F, Bässler H, Köhler A. Temperature Induced Order-Disorder Transition in Solutions of Conjugated Polymers Probed by Optical Spectroscopy. J Phys Chem Lett 2017; 8:114-125. [PMID: 27966973 DOI: 10.1021/acs.jpclett.6b01641] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The aggregation of π-conjugated materials significantly impacts the photophysics and performance of optoelectronic devices. Nevertheless, little is known about the laws governing aggregate formation of π-conjugated materials from solution. In this Perspective, we compare, discuss, and summarize how aggregates form for three different types of compounds, that is, homopolymers, donor-acceptor type polymers, and low molecular weight compounds. To this end, we employ temperature-dependent optical spectroscopy, which is a simple yet powerful tool to investigate aggregate formation. We show how optical spectra can be analyzed to identify distinct conformational states. We find aggregate formation to proceed the same in all these compounds by a coil-to-globule-like first-order phase transition. Notably, the chain expands before it collapses into a highly ordered dense state. The role of side chains and the impact of changes in environmental polarization are addressed.
Collapse
Affiliation(s)
- Fabian Panzer
- Experimental Physics II, ‡Department of Functional Materials, and §Bayreuth Institute of Macromolecular Research (BIMF), University of Bayreuth , 95540 Bayreuth, Germany
| | - Heinz Bässler
- Experimental Physics II, ‡Department of Functional Materials, and §Bayreuth Institute of Macromolecular Research (BIMF), University of Bayreuth , 95540 Bayreuth, Germany
| | - Anna Köhler
- Experimental Physics II, ‡Department of Functional Materials, and §Bayreuth Institute of Macromolecular Research (BIMF), University of Bayreuth , 95540 Bayreuth, Germany
| |
Collapse
|
19
|
Hader K, Consani C, Brixner T, Engel V. Mapping of exciton–exciton annihilation in MEH-PPV by time-resolved spectroscopy: experiment and microscopic theory. Phys Chem Chem Phys 2017; 19:31989-31996. [DOI: 10.1039/c7cp05168a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Transient absorption traces taken on samples of the polymer MEH-PPV are measured as a function of the laser intensity.
Collapse
Affiliation(s)
- Kilian Hader
- Institut für Physikalische und Theoretische Chemie
- Universität Würzburg
- 97074 Würzburg
- Germany
| | - Cristina Consani
- Institut für Physikalische und Theoretische Chemie
- Universität Würzburg
- 97074 Würzburg
- Germany
- Center for Nanosystems Chemistry (CNC)
| | - Tobias Brixner
- Institut für Physikalische und Theoretische Chemie
- Universität Würzburg
- 97074 Würzburg
- Germany
- Center for Nanosystems Chemistry (CNC)
| | - Volker Engel
- Institut für Physikalische und Theoretische Chemie
- Universität Würzburg
- 97074 Würzburg
- Germany
| |
Collapse
|
20
|
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
| |
Collapse
|
21
|
Yoon S, Ji S, Yoo Y, Jeong JE, Kim J, Woo HY, Park B, Hwang I. Enhanced Polarization Ratio of Electrospun Nanofibers with Increased Intrachain Order by Postsolvent Treatments. J Phys Chem B 2016; 120:12981-12987. [DOI: 10.1021/acs.jpcb.6b08277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | - Youngjun Yoo
- Department
of Chemistry, Inha University, Incheon 22212, Republic of Korea
| | - Ji-Eun Jeong
- Department
of Chemistry, Korea University, Seoul 02841, Republic of Korea
| | - Jeongho Kim
- Department
of Chemistry, Inha University, Incheon 22212, Republic of Korea
| | - Han Young Woo
- Department
of Chemistry, Korea University, Seoul 02841, Republic of Korea
| | | | | |
Collapse
|
22
|
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
| | | | | | | | | | | |
Collapse
|
23
|
Camposeo A, Pensack RD, Moffa M, Fasano V, Altamura D, Giannini C, Pisignano D, Scholes GD. Anisotropic Conjugated Polymer Chain Conformation Tailors the Energy Migration in Nanofibers. J Am Chem Soc 2016; 138:15497-15505. [PMID: 27933935 PMCID: PMC5133673 DOI: 10.1021/jacs.6b10761] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Indexed: 01/22/2023]
Abstract
Conjugated polymers are complex multichromophore systems, with emission properties strongly dependent on the electronic energy transfer through active subunits. Although the packing of the conjugated chains in the solid state is known to be a key factor to tailor the electronic energy transfer and the resulting optical properties, most of the current solution-based processing methods do not allow for effectively controlling the molecular order, thus making the full unveiling of energy transfer mechanisms very complex. Here we report on conjugated polymer fibers with tailored internal molecular order, leading to a significant enhancement of the emission quantum yield. Steady state and femtosecond time-resolved polarized spectroscopies evidence that excitation is directed toward those chromophores oriented along the fiber axis, on a typical time scale of picoseconds. These aligned and more extended chromophores, resulting from the high stretching rate and electric field applied during the fiber spinning process, lead to improved emission properties. Conjugated polymer fibers are relevant to develop optoelectronic plastic devices with enhanced and anisotropic properties.
Collapse
Affiliation(s)
- Andrea Camposeo
- Istituto
Nanoscienze-CNR, Euromediterranean Center
for Nanomaterial Modelling and Technology (ECMT), via Arnesano, I-73100 Lecce, Italy
| | - Ryan D. Pensack
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Maria Moffa
- Istituto
Nanoscienze-CNR, Euromediterranean Center
for Nanomaterial Modelling and Technology (ECMT), via Arnesano, I-73100 Lecce, Italy
| | - Vito Fasano
- Dipartimento
di Matematica e Fisica “Ennio De Giorgi”, Università del Salento, via Arnesano, I-73100 Lecce, Italy
| | - Davide Altamura
- Istituto
di Cristallografia (IC-CNR), via Amendola 122/O, I-70126 Bari, Italy
| | - Cinzia Giannini
- Istituto
di Cristallografia (IC-CNR), via Amendola 122/O, I-70126 Bari, Italy
| | - Dario Pisignano
- Istituto
Nanoscienze-CNR, Euromediterranean Center
for Nanomaterial Modelling and Technology (ECMT), via Arnesano, I-73100 Lecce, Italy
- Dipartimento
di Matematica e Fisica “Ennio De Giorgi”, Università del Salento, via Arnesano, I-73100 Lecce, Italy
| | - Gregory D. Scholes
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| |
Collapse
|
24
|
Surface-Enhanced Impulsive Coherent Vibrational Spectroscopy. Sci Rep 2016; 6:36471. [PMID: 27812020 PMCID: PMC5095601 DOI: 10.1038/srep36471] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 10/14/2016] [Indexed: 12/28/2022] Open
Abstract
Surface-enhanced Raman spectroscopy (SERS) has attracted a lot of attention in molecular sensing because of the remarkable ability of plasmonic metal nanostructures to enhance the weak Raman scattering process. On the other hand, coherent vibrational spectroscopy triggered by impulsive excitation using ultrafast laser pulses provides complete information about the temporal evolution of molecular vibrations, allowing dynamical processes in molecular systems to be followed in "real time". Here, we combine these two concepts and demonstrate surface-enhanced impulsive vibrational spectroscopy. The vibrational modes of the ground and excited states of poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), spin-coated on a substrate covered with monodisperse silver nanoparticles, are impulsively excited with a sub-10 fs pump pulse and characterized with a delayed broad-band probe pulse. The maximum enhancement in the spectrally and temporally resolved vibrational signatures averaged over the whole sample is about 4.6, while the real-time information about the instantaneous vibrational amplitude together with the initial vibrational phase is preserved. The phase is essential to determine the vibrational contributions from the ground and excited states.
Collapse
|
25
|
Sosorev AY, Parashchuk OD, Zapunidi SA, Kashtanov GS, Golovnin IV, Kommanaboyina S, Perepichka IF, Paraschuk DY. Threshold-like complexation of conjugated polymers with small molecule acceptors in solution within the neighbor-effect model. Phys Chem Chem Phys 2016; 18:4684-96. [PMID: 26799407 DOI: 10.1039/c5cp05266a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In some donor-acceptor blends based on conjugated polymers, a pronounced charge-transfer complex (CTC) forms in the electronic ground state. In contrast to small-molecule donor-acceptor blends, the CTC concentration in polymer:acceptor solution can increase with the acceptor content in a threshold-like way. This threshold-like behavior was earlier attributed to the neighbor effect (NE) in the polymer complexation, i.e., next CTCs are preferentially formed near the existing ones; however, the NE origin is unknown. To address the factors affecting the NE, we record the optical absorption data for blends of the most studied conjugated polymers, poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) and poly(3-hexylthiophene) (P3HT), with electron acceptors of fluorene series, 1,8-dinitro-9,10-antraquinone (), and 7,7,8,8-tetracyanoquinodimethane () in different solvents, and then analyze the data within the NE model. We have found that the NE depends on the polymer and acceptor molecular skeletons and solvent, while it does not depend on the acceptor electron affinity and polymer concentration. We conclude that the NE operates within a single macromolecule and stems from planarization of the polymer chain involved in the CTC with an acceptor molecule; as a result, the probability of further complexation with the next acceptor molecules at the adjacent repeat units increases. The steric and electronic microscopic mechanisms of NE are discussed.
Collapse
Affiliation(s)
- Andrey Yu Sosorev
- Faculty of Physics and International Laser Center, M.V. Lomonosov Moscow State University, Moscow 119991, Russia.
| | - Olga D Parashchuk
- Faculty of Physics and International Laser Center, M.V. Lomonosov Moscow State University, Moscow 119991, Russia.
| | - Sergey A Zapunidi
- Faculty of Physics and International Laser Center, M.V. Lomonosov Moscow State University, Moscow 119991, Russia.
| | - Grigoriy S Kashtanov
- Faculty of Physics and International Laser Center, M.V. Lomonosov Moscow State University, Moscow 119991, Russia.
| | - Ilya V Golovnin
- Faculty of Physics and International Laser Center, M.V. Lomonosov Moscow State University, Moscow 119991, Russia.
| | | | | | - Dmitry Yu Paraschuk
- Faculty of Physics and International Laser Center, M.V. Lomonosov Moscow State University, Moscow 119991, Russia.
| |
Collapse
|
26
|
Marcus M, Coonjobeeharry J, Barford W. Theory of optical transitions in π-conjugated macrocycles. J Chem Phys 2016; 144:154102. [DOI: 10.1063/1.4946794] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
27
|
Chakraborty R, Rothberg LJ. Role of Aggregates in the Luminescence Decay Dynamics of Conjugated Polymers. J Phys Chem A 2016; 120:551-5. [DOI: 10.1021/acs.jpca.5b11349] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rajarshi Chakraborty
- Materials
Science Program, University of Rochester, Rochester, New York 14627, United States
| | - Lewis J Rothberg
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
| |
Collapse
|
28
|
Scharsich C, Fischer FSU, Wilma K, Hildner R, Ludwigs S, Köhler A. Revealing structure formation in PCPDTBT by optical spectroscopy. ACTA ACUST UNITED AC 2015. [DOI: 10.1002/polb.23780] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Christina Scharsich
- Bayreuth Institute of Macromolecular Research (BIMF), University of Bayreuth; Bayreuth 95440 Germany
- Experimental Physics II, University of Bayreuth; Bayreuth 95440 Germany
| | | | - Kevin Wilma
- Bayreuth Institute of Macromolecular Research (BIMF), University of Bayreuth; Bayreuth 95440 Germany
- Experimental Physics IV, University of Bayreuth; Bayreuth 95440 Germany
| | - Richard Hildner
- Bayreuth Institute of Macromolecular Research (BIMF), University of Bayreuth; Bayreuth 95440 Germany
- Experimental Physics IV, University of Bayreuth; Bayreuth 95440 Germany
| | - Sabine Ludwigs
- IPOC-Functional Polymers, University of Stuttgart; Stuttgart 70569 Germany
| | - Anna Köhler
- Bayreuth Institute of Macromolecular Research (BIMF), University of Bayreuth; Bayreuth 95440 Germany
- Experimental Physics II, University of Bayreuth; Bayreuth 95440 Germany
| |
Collapse
|
29
|
Spano FC. Optical microcavities enhance the exciton coherence length and eliminate vibronic coupling in J-aggregates. J Chem Phys 2015; 142:184707. [DOI: 10.1063/1.4919348] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- F. C. Spano
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
| |
Collapse
|
30
|
Unger T, Panzer F, Consani C, Koch F, Brixner T, Bässler H, Köhler A. Ultrafast Energy Transfer between Disordered and Highly Planarized Chains of Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV). ACS Macro Lett 2015; 4:412-416. [PMID: 35596330 DOI: 10.1021/acsmacrolett.5b00133] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Upon cooling a solution of poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), a phase transition occurs, leading to the formation of aggregates. We have studied the dynamics of singlet excitons in MEH-PPV solution below the critical temperature of the phase transition using steady-state photoluminescence measurements and pump-probe fs-spectroscopy at different temperatures. Spectral analysis indicates the coexistence of disordered chromophores with highly planarized chromophores. The high planarity is evidenced by a remarkably high 0-0/0-1 peak ratio in the spectra. By spectrally separating the contributions of either type of chromophore to the pump-probe signal we find that energy transfer takes place within less than 1 ps from disordered, unaggregated chain segments to highly planarized, aggregated chain segments. The short time scale of the energy transfer indicates intimate intermixing of the planarized and disordered polymeric chromophores.
Collapse
Affiliation(s)
- Thomas Unger
- Experimental
Physics II, University of Bayreuth, 95540 Bayreuth, Germany
- Bayreuth
Institute of Macromolecular Research (BIMF), University of Bayreuth, 95440 Bayreuth, Germany
| | - Fabian Panzer
- Experimental
Physics II, University of Bayreuth, 95540 Bayreuth, Germany
- Bayreuth
Institute of Macromolecular Research (BIMF), University of Bayreuth, 95440 Bayreuth, Germany
| | | | | | | | - Heinz Bässler
- Bayreuth
Institute of Macromolecular Research (BIMF), University of Bayreuth, 95440 Bayreuth, Germany
| | - Anna Köhler
- Experimental
Physics II, University of Bayreuth, 95540 Bayreuth, Germany
- Bayreuth
Institute of Macromolecular Research (BIMF), University of Bayreuth, 95440 Bayreuth, Germany
| |
Collapse
|
31
|
Panzer F, Sommer M, Bässler H, Thelakkat M, Köhler A. Spectroscopic Signature of Two Distinct H-Aggregate Species in Poly(3-hexylthiophene). Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b00129] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Fabian Panzer
- Experimental Physics II, ‡Bayreuth Institute of Macromolecular
Research (BIMF), and §Applied Functional
Polymers, Macromolecular Chemistry I, University of Bayreuth, 95540 Bayreuth, Germany
| | - Michael Sommer
- Experimental Physics II, ‡Bayreuth Institute of Macromolecular
Research (BIMF), and §Applied Functional
Polymers, Macromolecular Chemistry I, University of Bayreuth, 95540 Bayreuth, Germany
| | - Heinz Bässler
- Experimental Physics II, ‡Bayreuth Institute of Macromolecular
Research (BIMF), and §Applied Functional
Polymers, Macromolecular Chemistry I, University of Bayreuth, 95540 Bayreuth, Germany
| | - Mukundan Thelakkat
- Experimental Physics II, ‡Bayreuth Institute of Macromolecular
Research (BIMF), and §Applied Functional
Polymers, Macromolecular Chemistry I, University of Bayreuth, 95540 Bayreuth, Germany
| | - Anna Köhler
- Experimental Physics II, ‡Bayreuth Institute of Macromolecular
Research (BIMF), and §Applied Functional
Polymers, Macromolecular Chemistry I, University of Bayreuth, 95540 Bayreuth, Germany
| |
Collapse
|
32
|
Bässler H, Köhler A. “Hot or cold”: how do charge transfer states at the donor–acceptor interface of an organic solar cell dissociate? Phys Chem Chem Phys 2015; 17:28451-62. [DOI: 10.1039/c5cp04110d] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This perspective discusses concepts to understand efficient photogeneration of charges in organic semiconductors, with particular emphasis on the role of excess energy.
Collapse
Affiliation(s)
- Heinz Bässler
- Bayreuth Institute of Macromolecular Research
- Universität Bayreuth
- 95440 Bayreuth
- Germany
| | - Anna Köhler
- Bayreuth Institute of Macromolecular Research
- Universität Bayreuth
- 95440 Bayreuth
- Germany
- Experimentalphysik II (Organic Semiconductors)
| |
Collapse
|
33
|
Merdasa A, Jiménez ÁJ, Camacho R, Meyer M, Würthner F, Scheblykin IG. Single Lévy states-disorder induced energy funnels in molecular aggregates. NANO LETTERS 2014; 14:6774-6781. [PMID: 25349900 DOI: 10.1021/nl5021188] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Using fluorescence super-resolution microscopy we studied simultaneous spectral, spatial localization, and blinking behavior of individual 1D J-aggregates. Excitons migrating 100 nm are funneled to a trap appearing as an additional red-shifted blinking fluorescence band. We propose that the trap is a Frenkel exciton state formed much below the main exciton band edge due to an environmentally induced heavy-tailed Lévy disorder. This points to disorder engineering as a new avenue in controlling light-harvesting in molecular ensembles.
Collapse
Affiliation(s)
- Aboma Merdasa
- Chemical Physics, Lund University , P.O. Box 124, 22100 Lund, Sweden
| | | | | | | | | | | |
Collapse
|
34
|
Marcus M, Tozer OR, Barford W. Theory of optical transitions in conjugated polymers. II. Real systems. J Chem Phys 2014; 141:164102. [DOI: 10.1063/1.4897985] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Max Marcus
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
- Magdalen College, University of Oxford, Oxford OX1 4AU, United Kingdom
| | - Oliver Robert Tozer
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
- University College, University of Oxford, Oxford OX1 4BH, United Kingdom
| | - William Barford
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
- Balliol College, University of Oxford, Oxford OX1 3BJ, United Kingdom
| |
Collapse
|
35
|
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
| |
Collapse
|
36
|
Zhu X, Plunkett KN. Controlled Regioregularity in Oligo(2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylenes. J Org Chem 2014; 79:7093-102. [DOI: 10.1021/jo501266g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xinju Zhu
- Department
of Chemistry and
Biochemistry and the Materials Technology Center, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Kyle N. Plunkett
- Department
of Chemistry and
Biochemistry and the Materials Technology Center, Southern Illinois University, Carbondale, Illinois 62901, United States
| |
Collapse
|
37
|
Binder R, Römer S, Wahl J, Burghardt I. An analytic mapping of oligomer potential energy surfaces to an effective Frenkel model. J Chem Phys 2014; 141:014101. [DOI: 10.1063/1.4880415] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
|
38
|
Blayney AJ, Perepichka IF, Wudl F, Perepichka DF. Advances and Challenges in the Synthesis of Poly(p-phenylene vinylene)-Based Polymers. Isr J Chem 2014. [DOI: 10.1002/ijch.201400067] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
39
|
Hestand NJ, Spano FC. The Effect of Chain Bending on the Photophysical Properties of Conjugated Polymers. J Phys Chem B 2014; 118:8352-63. [DOI: 10.1021/jp501857n] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Nicholas J. Hestand
- Department
of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Frank C. Spano
- Department
of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, United States
| |
Collapse
|
40
|
Yamagata H, Spano FC. Strong Photophysical Similarities between Conjugated Polymers and J-aggregates. J Phys Chem Lett 2014; 5:622-32. [PMID: 26276619 DOI: 10.1021/jz402450m] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The photophysical properties of emissive conjugated polymer (CP) chains are compared to those of linear J-aggregates. The two systems share many properties in common, including a red-shifted absorption spectrum with increasing chain/aggregate length, enhanced radiative decay rates (superradiance) relative to a single monomer/molecule, and several vibronic signatures involving the vinyl-stretching mode common to many conjugated molecules. In particular, the scaling of the 0-0/0-1 photoluminescence ratio and radiative decay rate with the inverse square root of temperature in red-phase polydiacetylene is also characteristic of linear, disorder-free J-aggregates. The strong photophysical resemblance is traced to the excitonic band structure; in one-dimensional direct band gap semiconductors as well as J-aggregates, the exciton band curvature is positive at the gamma point (k = 0).
Collapse
Affiliation(s)
- Hajime Yamagata
- Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - Frank C Spano
- Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
| |
Collapse
|
41
|
Abstract
Aggregates of conjugated polymers exhibit two classes of fundamental electronic interactions: those occurring within a given chain and those occurring between chains. The impact of such excitonic interactions on the photophysics of polymer films can be understood using concepts of J- and H-aggregation originally developed by Kasha and coworkers to treat aggregates of small molecules. In polymer assemblies, intrachain through-bond interactions lead to J-aggregate behavior, whereas interchain Coulombic interactions lead to H-aggregate behavior. The photophysics of common emissive conjugated polymer films are determined by a competition between intrachain, J-favoring interactions and interchain, H-favoring interactions. We review formalisms describing absorption and photoluminescence lineshapes, based on intra- and intermolecular excitonic coupling, electron-vibrational coupling, and correlated energetic disorder. Examples include regioregular polythiophenes, pheneylene-vinylenes, and polydiacetylene.
Collapse
Affiliation(s)
- Frank C Spano
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122;
| | | |
Collapse
|