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Durbin M, Balzer AH, Reynolds JR, Ratcliff EL, Stingelin N, Österholm AM. Role of Side-Chain Free Volume on the Electrochemical Behavior of Poly(propylenedioxythiophenes). CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2024; 36:2634-2641. [PMID: 38558922 PMCID: PMC10976628 DOI: 10.1021/acs.chemmater.3c02122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 02/25/2024] [Accepted: 02/26/2024] [Indexed: 04/04/2024]
Abstract
Mixed ionic/electronic conducting polymers are versatile systems for, e.g., energy storage, heat management (exploiting electrochromism), and biosensing, all of which require electrochemical doping, i.e., the electrochemical oxidation or reduction of their macromolecular backbones. Electrochemical doping is achieved via electro-injection of charges (i.e., electronic carriers), stabilized via migration of counterions from a supporting electrolyte. Since the choice of the polymer side-chain functionalization influences electrolyte and/or ion sorption and desorption, it in turn affects redox properties, and, thus, electrochemically induced mixed conduction. However, our understanding of how side-chain versus backbone design can increase ion flow while retaining high electronic transport remains limited. Hence, heuristic design approaches have typically been followed. Herein, we consider the redox and swelling behavior of three poly(propylenedioxythiophene) derivatives, P(ProDOT)s, substituted with different side-chain motifs, and demonstrate that passive swelling is controlled by the surface polarity of P(ProDOT) films. In contrast, active swelling under operando conditions (i.e., under an applied bias) is dictated by the local side-chain free volume on the length scale of a monomer unit. Such insights deliver important design criteria toward durable soft electrochemical systems for diverse energy and biosensing platforms and new understanding into electrochemical conditioning ("break-in") in many conducting polymers.
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Affiliation(s)
- Marlow
M. Durbin
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Alex H. Balzer
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - John R. Reynolds
- School
of Materials Science and Engineering, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, Atlanta, Georgia 30332, United States
| | - Erin L. Ratcliff
- Department
of Chemical and Environmental Engineering, The University of Arizona, Tucson, Arizona 85721-0012, United States
| | - Natalie Stingelin
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- School
of Materials Science and Engineering, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Anna M. Österholm
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, Atlanta, Georgia 30332, United States
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2
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Kashani S, Wang Z, Risko C, Ade H. Relating reorganization energies, exciton diffusion length and non-radiative recombination to the room temperature UV-vis absorption spectra of NF-SMA. MATERIALS HORIZONS 2023; 10:443-453. [PMID: 36515185 DOI: 10.1039/d2mh01228f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Understanding excited-state reorganization energies, exciton diffusion lengths and non-radiative (NR) recombination, and the overall optoelectronic responses of nonfullerene small molecule acceptors (NF-SMAs) is important in order to rationally design new materials with controlled properties. While the effects of structural modifications on the optical gaps and electron affinities of NF-SMAs have been studied extensively, analyses of their absorption spectra that carefully characterize electronic and vibrational contributions that allow comparisons of reorganization energies and their implications for exciton diffusion lengths and NR recombination have yet to be reported. Here, we study the room temperature absorption spectra of three structural classes of NF-SMAs in dilute solutions through multiparameter Franck Condon (MFC) analyses and density functional theory (DFT) calculations. We show that the absorption spectra of these NF-SMAs can be categorized based on molecular structure-spectra correlation. The absorption spectra of curved, Y6-like structures can be described using an MFC model with two electronic transitions and two effective vibrational modes. The results of MFC/DFT analyses reveal that Y6 exhibits the smallest intra-molecular reorganization energy among the materials studied. Linear ITIC-like molecular structures reveal larger reorganization energies and reduced conformational uniformity compared to Y6. Meanwhile structures such as IDTBR and IEICO, which have an extra π-conjugated moiety between the donor and acceptor moieties, have large excited-state reorganization energies and low degrees of conformational uniformity. Since the intra-molecular reorganization energy is correlated with exciton diffusion length and nonradiative voltage losses (ΔVnr), our results highlight the power of RT absorption spectroscopy and DFT calculations as simple tools to designing improved OSCs materials with small reorganization energies, small ΔVnr, large exciton diffusion length and low energetic disorder (due to a strongly dominant conformation).
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Affiliation(s)
- Somayeh Kashani
- Department of Physics and Organic and Carbon Electronics Laboratories (ORaCEL), North Carolina State University, Raleigh, NC, 27695, USA.
| | - Zhen Wang
- Department of Physics and Organic and Carbon Electronics Laboratories (ORaCEL), North Carolina State University, Raleigh, NC, 27695, USA.
| | - Chad Risko
- Department of Chemistry and Center for Applied Energy Research (CAER), University of Kentucky, Lexington, Kentucky, 40506, USA
| | - Harald Ade
- Department of Physics and Organic and Carbon Electronics Laboratories (ORaCEL), North Carolina State University, Raleigh, NC, 27695, USA.
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3
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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.
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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
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4
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Kim HJ, Perera K, Liang Z, Bowen B, Mei J, Boudouris BW. Radical Polymer-Based Organic Electrochemical Transistors. ACS Macro Lett 2022; 11:243-250. [PMID: 35574776 DOI: 10.1021/acsmacrolett.1c00695] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Organic electrochemical transistors (OECTs) are an emerging platform for bioelectronic applications. Significant effort has been placed in designing advanced polymers that simultaneously transport both charge and ions (i.e., macromolecules that are mixed conductors). However, the considerations for mixed organic conductors are often different from the established principles that are well-known in the solid-state organic electronics field; thus, the discovery of new OECT macromolecular systems is highly desired. Here, we demonstrate a new materials system by blending a radical polymer (i.e., a macromolecule with a nonconjugated backbone and with stable open-shell sites at its pendant group) with a frequently used conjugated polymer. Specifically, poly(4-glycidyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl) (PTEO) was blended with poly(3-hexylthiophene) (P3HT) to create thin films with distinct closed-shell and open-shell domains. Importantly, the sharp and unique oxidation-reduction (redox) potential associated with the radical moieties of the PTEO chain provided a distinct actuation feature to the blended films that modulated the ionic transport of the OECT devices. In turn, this led to controlled regulation of the doping of the P3HT phase in the composite film. By decoupling the ionic and electronic transport into two distinct phases and by using an ion transport phase with well-controlled redox activity, never-before-seen performance for a P3HT-based OECT was observed. That is, at loadings as low as 5% PTEO (by weight) OECTs achieved figure-of-merit (i.e., μC*) values >150 F V-1 cm-1 s-1, which place the performance on the same order as state-of-the-art conjugated polymers despite the relatively common conjugated macromolecular moiety implemented. As such, this effort presents a design platform by which to readily create a tailored OECT response through strategic macromolecular selection and polymer processing.
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Affiliation(s)
- Ho Joong Kim
- Charles D. Davidson School of Chemical Engineering, Purdue University, 480 Stadium Avenue, West Lafayette, Indiana 47907, United States
| | - Kuluni Perera
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Zihao Liang
- Charles D. Davidson School of Chemical Engineering, Purdue University, 480 Stadium Avenue, West Lafayette, Indiana 47907, United States
| | - Brennen Bowen
- Charles D. Davidson School of Chemical Engineering, Purdue University, 480 Stadium Avenue, West Lafayette, Indiana 47907, United States
| | - Jianguo Mei
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Bryan W. Boudouris
- Charles D. Davidson School of Chemical Engineering, Purdue University, 480 Stadium Avenue, West Lafayette, Indiana 47907, United States
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
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5
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Gutiérrez-Meza E, Malatesta R, Li H, Bargigia I, Srimath Kandada AR, Valverde-Chávez DA, Kim SM, Li H, Stingelin N, Tretiak S, Bittner ER, Silva-Acuña C. Frenkel biexcitons in hybrid HJ photophysical aggregates. SCIENCE ADVANCES 2021; 7:eabi5197. [PMID: 34890231 PMCID: PMC8664265 DOI: 10.1126/sciadv.abi5197] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 10/25/2021] [Indexed: 06/13/2023]
Abstract
Frenkel excitons are unequivocally responsible for the optical properties of organic semiconductors and are predicted to form bound exciton pairs (biexcitons). These are key intermediates, ubiquitous in many photophysical processes such as the exciton bimolecular annihilation dynamics in such systems. Because of their spectral ambiguity, there has been, to date, only scant direct evidence of bound biexcitons. By using nonlinear coherent spectroscopy, we identify here bound biexcitons in a model polymeric semiconductor. We find, unexpectedly, that excitons with interchain vibronic dispersion reveal intrachain biexciton correlations and vice versa. Moreover, using a Frenkel exciton model, we relate the biexciton binding energy to molecular parameters quantified by quantum chemistry, including the magnitude and sign of the exciton-exciton interaction the intersite hopping energies. Therefore, our work promises general insights into the many-body electronic structure in polymeric semiconductors and beyond, e.g., other excitonic systems such as organic semiconductor crystals, molecular aggregates, photosynthetic light-harvesting complexes, or DNA.
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Affiliation(s)
- Elizabeth Gutiérrez-Meza
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, GA 30332, USA
| | - Ravyn Malatesta
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, GA 30332, USA
| | - Hongmo Li
- School of Materials Science and Engineering, Georgia Institute of Technology, North Avenue, Atlanta, GA 30332, USA
| | - Ilaria Bargigia
- Department of Physics and Center for Functional Materials, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, NC 27109, USA
| | - Ajay Ram Srimath Kandada
- Department of Physics and Center for Functional Materials, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, NC 27109, USA
| | - David A. Valverde-Chávez
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, GA 30332, USA
| | - Seong-Min Kim
- School of Materials Science and Engineering, Georgia Institute of Technology, North Avenue, Atlanta, GA 30332, USA
| | - Hao Li
- Department of Chemistry, University of Houston, Houston, TX 77204, USA
| | - Natalie Stingelin
- School of Materials Science and Engineering, Georgia Institute of Technology, North Avenue, Atlanta, GA 30332, USA
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, GA 30332, USA
| | - Sergei Tretiak
- Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Eric R. Bittner
- Department of Chemistry, University of Houston, Houston, TX 77204, USA
| | - Carlos Silva-Acuña
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, GA 30332, USA
- School of Materials Science and Engineering, Georgia Institute of Technology, North Avenue, Atlanta, GA 30332, USA
- School of Physics, Georgia Institute of Technology, 837 State Street, Atlanta, GA 30332, USA
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6
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Li M, Leenaers PJ, Li J, Wienk MM, Janssen RAJ. Polymorphism of a semi-crystalline diketopyrrolopyrrole-terthiophene polymer. JOURNAL OF POLYMER SCIENCE 2021; 59:1285-1292. [PMID: 34223180 PMCID: PMC8246555 DOI: 10.1002/pol.20200673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 10/26/2020] [Accepted: 10/28/2020] [Indexed: 11/26/2022]
Abstract
Few semiconducting polymers are known that possess more than one semi-crystalline structure. Guidelines for rationalizing or creating polymorphism in these materials do not exist. Two different semi-crystalline polymorphs, β 1 and β 2, and an amorphous α phase have recently been identified for alternating diketopyrrolopyrrole-quaterthiophene copolymers (PDPP4T). The polymorphs differ structurally by the π-π stacking distance, and electronically by the optical bandgap and charge carrier mobility. Here we investigate the corresponding terthiophene (PDPP3T) derivatives, to study the effect of the relative orientation of adjacent DPP units on the polymorphism. In PDPP3T, the relative orientation of DPP units alternates along the chain, while in PDPP4T it is constant. We show that the two polymorphs, β 1 and β 2, can also be generated for a PDPP3T polymer in solution and thin film. Interestingly, compared to PDPP4T, more solvents can induce the two distinct semi-crystalline polymorphs for PDPP3T via a β 1 → α → β 2 polymorphic transition.
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Affiliation(s)
- Mengmeng Li
- Key Laboratory of Microelectronic Devices and Integrated Technology, Institute of MicroelectronicsChinese Academy of SciencesBeijingChina
- Molecular Materials and Nanosystems, Institute for Complex Molecular SystemsEindhoven University of TechnologyEindhovenThe Netherlands
- Dutch Institute For Fundamental Energy ResearchEindhovenThe Netherlands
- School of Electronic, Electrical and Communication EngineeringUniversity of Chinese Academy of SciencesBeijingChina
| | - Pieter J. Leenaers
- Molecular Materials and Nanosystems, Institute for Complex Molecular SystemsEindhoven University of TechnologyEindhovenThe Netherlands
| | - Junyu Li
- Molecular Materials and Nanosystems, Institute for Complex Molecular SystemsEindhoven University of TechnologyEindhovenThe Netherlands
| | - Martijn M. Wienk
- Molecular Materials and Nanosystems, Institute for Complex Molecular SystemsEindhoven University of TechnologyEindhovenThe Netherlands
| | - René A. J. Janssen
- Molecular Materials and Nanosystems, Institute for Complex Molecular SystemsEindhoven University of TechnologyEindhovenThe Netherlands
- Dutch Institute For Fundamental Energy ResearchEindhovenThe Netherlands
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7
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Ware W, Wright T, Mao Y, Han S, Guffie J, Danilov EO, Rech J, You W, Luo Z, Gautam B. Aggregation Controlled Charge Generation in Fullerene Based Bulk Heterojunction Polymer Solar Cells: Effect of Additive. Polymers (Basel) 2020; 13:polym13010115. [PMID: 33396672 PMCID: PMC7795443 DOI: 10.3390/polym13010115] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 12/22/2020] [Accepted: 12/28/2020] [Indexed: 11/16/2022] Open
Abstract
Optimization of charge generation in polymer blends is crucial for the fabrication of highly efficient polymer solar cells. While the impacts of the polymer chemical structure, energy alignment, and interface on charge generation have been well studied, not much is known about the impact of polymer aggregation on charge generation. Here, we studied the impact of aggregation on charge generation using transient absorption spectroscopy, neutron scattering, and atomic force microscopy. Our measurements indicate that the 1,8-diiodooctane additive can change the aggregation behavior of poly(benzodithiophene-alt-dithienyl difluorobenzotriazole (PBnDT-FTAZ) and phenyl-C61-butyric acid methyl ester (PCBM)polymer blends and impact the charge generation process. Our observations show that the charge generation can be optimized by tuning the aggregation in polymer blends, which can be beneficial for the design of highly efficient fullerene-based organic photovoltaic devices.
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Affiliation(s)
- Washat Ware
- Department of Chemistry, Physics and Materials Science, Fayetteville State University, Fayetteville, NC 28301, USA; (W.W.); (T.W.); (S.H.); (J.G.); (Z.L.)
| | - Tia Wright
- Department of Chemistry, Physics and Materials Science, Fayetteville State University, Fayetteville, NC 28301, USA; (W.W.); (T.W.); (S.H.); (J.G.); (Z.L.)
| | - Yimin Mao
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA;
- Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA
| | - Shubo Han
- Department of Chemistry, Physics and Materials Science, Fayetteville State University, Fayetteville, NC 28301, USA; (W.W.); (T.W.); (S.H.); (J.G.); (Z.L.)
| | - Jessa Guffie
- Department of Chemistry, Physics and Materials Science, Fayetteville State University, Fayetteville, NC 28301, USA; (W.W.); (T.W.); (S.H.); (J.G.); (Z.L.)
| | - Evgeny O. Danilov
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA;
| | - Jeromy Rech
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (J.R.); (W.Y.)
| | - Wei You
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (J.R.); (W.Y.)
| | - Zhiping Luo
- Department of Chemistry, Physics and Materials Science, Fayetteville State University, Fayetteville, NC 28301, USA; (W.W.); (T.W.); (S.H.); (J.G.); (Z.L.)
| | - Bhoj Gautam
- Department of Chemistry, Physics and Materials Science, Fayetteville State University, Fayetteville, NC 28301, USA; (W.W.); (T.W.); (S.H.); (J.G.); (Z.L.)
- Correspondence:
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8
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Eom S, Sim JH, Kim J, Tran NB, Sung MM, Kang Y. Eutectic friction transfer lithography: a facile solid-state route for highly crystalline semiconducting polymers. NANOSCALE 2020; 12:23514-23520. [PMID: 33216110 DOI: 10.1039/d0nr06411d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Herein, we report a solid-state lithography technique utilizing eutectic friction transfer lithography (EFTL). The EFTL technique employs eutectic pellets made of semiconducting polymers and volatile organic solid matrices. Using frictional heating and eutectic melting, various semiconducting polymer crystals were formed by a simple rubbing process under mild conditions. The strong anisotropic optical properties suggest that J-type packing is dominant in EFTL microwires because of the highly extended and planarized crystal structures.
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Affiliation(s)
- Sangwon Eom
- Department of Chemistry, Hanyang University, Seoul, 04763, Korea.
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9
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Angunawela I, Nahid MM, Ghasemi M, Amassian A, Ade H, Gadisa A. The Critical Role of Materials' Interaction in Realizing Organic Field-Effect Transistors Via High-Dilution Blending with Insulating Polymers. ACS APPLIED MATERIALS & INTERFACES 2020; 12:26239-26249. [PMID: 32410453 DOI: 10.1021/acsami.0c04208] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
High-performance low-band-gap polymer semiconductors are visibly colored, making them unsuitable for transparent and imperceptible electronics without reducing film thickness to the nanoscale range. Herein, we demonstrate polymer/insulator blends exhibiting favorable miscibility that improves the transparency and carrier transport in an organic field-effect transistor (OFET) device. The mesoscale structures leading to more efficient charge transport in ultrathin films relevant to the realization of transparent and flexible electronic applications are explored based on thermodynamic material interaction principles in conjunction with optical and morphological studies. By blending the commodity polymer polystyrene (PS) with two high-performing polymers, PDPP3T and P (NDI2OD-T2) (known as N2200), a drastic difference in morphology and fiber network are observed due to considerable differences in the degree of thermodynamic interaction between the conjugated polymers and PS. Intrinsic material interaction behavior establishes a long-range intermolecular interaction in the PDPP3T polymer fibrillar network dispersed in the majority (80%) PS matrix resulting in a ca. 3-fold increased transistor hole mobility of 1.15 cm2 V-1 s-1 (highest = 1.5 cm2 V-1 s-1) as compared to the pristine material, while PS barely affects the electron mobility in N2200. These basic findings provide important guidelines to achieve high mobility in transparent OFETs.
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Affiliation(s)
- Indunil Angunawela
- Department of Physics, Organic and Carbon Electronics Labs (ORaCEL), North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Masrur M Nahid
- Department of Physics, Organic and Carbon Electronics Labs (ORaCEL), North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Masoud Ghasemi
- Department of Materials Science and Engsineering, Organic and Carbon Electronics Labs (ORaCEL), North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Aram Amassian
- Department of Materials Science and Engsineering, Organic and Carbon Electronics Labs (ORaCEL), North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Harald Ade
- Department of Physics, Organic and Carbon Electronics Labs (ORaCEL), North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Abay Gadisa
- Department of Physics, Organic and Carbon Electronics Labs (ORaCEL), North Carolina State University, Raleigh, North Carolina 27695, United States
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10
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Dou F, Li J, Men H, Zhang X. Controlling Molecule Aggregation and Electronic Spatial Coherence in the H-Aggregate and J-Aggregate Regime at Room Temperature. Polymers (Basel) 2020; 12:polym12040786. [PMID: 32252243 PMCID: PMC7240476 DOI: 10.3390/polym12040786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 11/16/2022] Open
Abstract
Controlling molecule aggregation in polymer films is one of the key factors in understanding the links between properties and structures in organic semiconductors. Here, we used poly(3-hexylthiophene-2,5-diyl) (P3HT) as the model system. By doping the insulating polar additive poly (ethylene oxide) (PEO) into P3HT film and controlling the processing methods, we achieved the side-to-side H-aggregate and head-to-tail J-aggregate of P3HT molecules with different extents at room temperature. We have demonstrated that the solvent solidification rate plays an important role in the controlling of molecule aggregation, which finally influenced the solid-state phase separation in the film. Furthermore, based on a series of spectroscopy investigations, we quantified the electronic spatial coherence in different aggregations combined with the modified Franck-Condon model. Subsequently, we established the relationship between the processing method, the molecule aggregation, and the electronic spatial coherence.
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11
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Impact of polymorphism on the optoelectronic properties of a low-bandgap semiconducting polymer. Nat Commun 2019; 10:2867. [PMID: 31253772 PMCID: PMC6599012 DOI: 10.1038/s41467-019-10519-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 05/15/2019] [Indexed: 01/08/2023] Open
Abstract
Polymorphism of organic semiconducting materials exerts critical effects on their physical properties such as optical absorption, emission and electrical conductivity, and provides an excellent platform for investigating structure–property relations. It is, however, challenging to efficiently tune the polymorphism of conjugated polymers in aggregated, semi-crystalline phases due to their conformational freedom and anisotropic nature. Here, two distinctly different semi-crystalline polymorphs (β1 and β2) of a low-bandgap diketopyrrolopyrrole polymer are formed through controlling the solvent quality, as evidenced by spectroscopic, structural, thermal and charge transport studies. Compared to β1, the β2 polymorph exhibits a lower optical band gap, an enhanced photoluminescence, a reduced π-stacking distance, a higher hole mobility in field-effect transistors and improved photocurrent generation in polymer solar cells. The β1 and β2 polymorphs provide insights into the control of polymer self-organization for plastic electronics and hold potential for developing programmable ink formulations for next-generation electronic devices. Tuning polymorphism of conjugated polymers, though a promising method for studying and controlling the structure-property relations in these materials remains a challenge. Here, the authors identify two aggregated semi-crystalline polymorphs of a low-bandgap diketopyrrolopyrrole-based polymer.
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12
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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.
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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.
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13
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Dimitriev OP. Effect of Confinement on Photophysical Properties of P3HT Chains in PMMA Matrix. NANOSCALE RESEARCH LETTERS 2017; 12:510. [PMID: 28853046 PMCID: PMC5574825 DOI: 10.1186/s11671-017-2270-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 08/09/2017] [Indexed: 06/07/2023]
Abstract
The influence of arrangement of poly(3-hexylthiophene) (P3HT) chains embedded into poly(methyl methacrylate) (PMMA) matrix on photophysical properties, such as electronic absorption spectrum, band gap, and photoluminescence quantum yield, of the formed P3HT aggregates have been studied. It has been found that variation of P3HT fraction in PMMA matrix from 25 to 2 wt% is accompanied with the increasing quantum yield of photoluminescence, red shift of the band gap, and structural change of P3HT crystallites. The above changes are accompanied with disruption of the continuous network of P3HT fraction into smaller P3HT particles with size ranged from several microns to several tens of nanometers. The results are interpreted in terms of the changing intermolecular packing and reduced intramolecular torsional disorder. It is discussed that the most contribution to the above changes comes from P3HT molecules at the interface of P3HT cluster and PMMA environment.
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Affiliation(s)
- Oleg P Dimitriev
- V. Lashkaryov Institute of Semiconductor Physics, Natl. Acad. of Sci. of Ukraine, Prospect Nauki, 41, Kiev, 03028, Ukraine.
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14
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Impact of backbone fluorination on nanoscale morphology and excitonic coupling in polythiophenes. Proc Natl Acad Sci U S A 2017; 114:5113-5118. [PMID: 28465439 DOI: 10.1073/pnas.1620722114] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Fluorination represents an important strategy in developing high-performance conjugated polymers for photovoltaic applications. Here, we use regioregular poly(3-ethylhexylthiophene) (P3EHT) and poly(3-ethylhexyl-4-fluorothiophene) (F-P3EHT) as simplified model materials, using single-molecule/aggregate spectroscopy and molecular dynamic simulations, to elucidate the impacts of backbone fluorination on morphology and excitonic coupling on the molecular scale. Despite its high regioregularity, regioregular P3EHT exhibits a rather broad distribution in polymer chain conformation due to the strong steric hindrance of bulky ethylhexyl side chains. This conformational variability results in disordered interchain morphology even between a few chains, prohibiting long-range effective interchain coupling. In stark contrast, the experimental and molecular dynamic calculations reveal that backbone fluorination of F-P3EHT leads to an extended rod-like single-chain conformation and hence highly ordered interchain packing in aggregates. Surprisingly, the ordered and close interchain packing in F-P3EHT does not lead to strong excitonic coupling between the chains but rather to dominant intrachain excitonic coupling that greatly reduces the molecular energetic heterogeneity.
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15
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Kiefer D, Yu L, Fransson E, Gómez A, Primetzhofer D, Amassian A, Campoy‐Quiles M, Müller C. A Solution-Doped Polymer Semiconductor:Insulator Blend for Thermoelectrics. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2017; 4:1600203. [PMID: 28105396 PMCID: PMC5238747 DOI: 10.1002/advs.201600203] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Indexed: 05/02/2023]
Abstract
Poly(ethylene oxide) is demonstrated to be a suitable matrix polymer for the solution-doped conjugated polymer poly(3-hexylthiophene). The polarity of the insulator combined with carefully chosen processing conditions permits the fabrication of tens of micrometer-thick films that feature a fine distribution of the F4TCNQ dopant:semiconductor complex. Changes in electrical conductivity from 0.1 to 0.3 S cm-1 and Seebeck coefficient from 100 to 60 μV K-1 upon addition of the insulator correlate with an increase in doping efficiency from 20% to 40% for heavily doped ternary blends. An invariant bulk thermal conductivity of about 0.3 W m-1 K-1 gives rise to a thermoelectric Figure of merit ZT ∼ 10-4 that remains unaltered for an insulator content of more than 60 wt%. Free-standing, mechanically robust tapes illustrate the versatility of the developed dopant:semiconductor:insulator ternary blends.
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Affiliation(s)
- David Kiefer
- Department of Chemistry and Chemical EngineeringChalmers University of Technology41296GöteborgSweden
| | - Liyang Yu
- Department of Chemistry and Chemical EngineeringChalmers University of Technology41296GöteborgSweden
- Physical Sciences & Engineering Division, and KAUST Solar Center (KSC)King Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Erik Fransson
- Department of PhysicsChalmers University of Technology41296GöteborgSweden
| | - Andrés Gómez
- Institut de Ciència de Materials de Barcelona (ICMAB‐CSIC)Esfera de la UAB08193BellaterraSpain
| | | | - Aram Amassian
- Physical Sciences & Engineering Division, and KAUST Solar Center (KSC)King Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Mariano Campoy‐Quiles
- Institut de Ciència de Materials de Barcelona (ICMAB‐CSIC)Esfera de la UAB08193BellaterraSpain
| | - Christian Müller
- Department of Chemistry and Chemical EngineeringChalmers University of Technology41296GöteborgSweden
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16
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Schwarz KN, Farley SB, Smith TA, Ghiggino KP. Charge generation and morphology in P3HT:PCBM nanoparticles prepared by mini-emulsion and reprecipitation methods. NANOSCALE 2015; 7:19899-19904. [PMID: 26567986 DOI: 10.1039/c5nr06244f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Organic semiconductor nanoparticles provide a potentially scalable approach for photovoltaics that can be processed from aqueous media. Particles of poly(3-hexylthiophene) (P3HT):phenyl-C61-butyric acid methyl ester (PCBM) were prepared using two techniques; those produced by a mini-emulsion method contained greater amounts of crystalline P3HT domains with charge generation resembling phase-separated annealed solvent-cast films.
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Affiliation(s)
- Kyra N Schwarz
- School of Chemistry, University of Melbourne, Victoria, 3010, Australia.
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17
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Wang F, Hashimoto K, Tajima K. Optical anisotropy and strong H-aggregation of poly(3-alkylthiophene) in a surface monolayer. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:6014-6020. [PMID: 26310575 DOI: 10.1002/adma.201502339] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Revised: 07/03/2015] [Indexed: 06/04/2023]
Abstract
Slab optical waveguide absorption spectra reveal that surface segregated monolayers of a vertically oriented poly(3-buthylthiophene) derivative have large optical anisotropy, and that confinement of the polymer chains in the isolated monolayer causes strong H-aggregation.
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Affiliation(s)
- Fanji Wang
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Kazuhito Hashimoto
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Keisuke Tajima
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
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18
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Wang H, Chen L, Xing R, Liu J, Han Y. Simultaneous control over both molecular order and long-range alignment in films of the donor-acceptor copolymer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:469-479. [PMID: 25435158 DOI: 10.1021/la5037772] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Control over both molecular order and long-range alignment order in films of the donor-acceptor copolymer of 3,6-bis(thiophen-2-yl)-N,N'-bis(2-octyl-1-dodecyl)-1,4-dioxo-pyrrolo[3,4-c]pyrrole and thieno[3,2-b]thiophene (PDBT-TT) was demonstrated via off-center spin-coating (OCSC) from its blend solution with polystyrene (PS). It was found that the dichroic ratio (DR) of OCSC blend films was dependent on both the physical process of spin-coating and the effect of PS chains. The highest DR of 2.75 was obtained via OCSC from the blend solution in oDCB at 1500 rpm. Meanwhile, both the intrachain and interchain molecular order were improved in blend films compared with neat ones, which were indicated by the red-shift of the max absorption, enhanced J-aggregation absorption, and smaller π-π stacking distance (from 3.77 to 3.70 Å). According to the results of the investigation into the macro anisotropy, micro morphology, solution rheology properties, and photophysics features of films, an overall mechanism of simultaneous control over molecular and long-range order of D-A copolymer films was proposed. On the one hand, a larger viscosity and the pseudoplastic nature of the solution tuned by choosing good solvents with high boiling points and adding PS resulted in a better chain disentanglement, better shear transfer, and a slower contact line receding velocity to induce an enhanced alignment of chains and thus fibrillar aggregates. Also, the critical contact line receding velocity for alignment dominated by the solvent evaporation rate accounted for the variation of DR with OCSC rates. A vertical phase separation accompanying the formation of aligned fibrils during OCSC was also confirmed due to the friction shear between air and solution surface. On the other hand, the negligible dependence of the blend OCSC film's photophysical and morphological features on the solvent suggested the critical role of PS in determining the better intrachain conjugation in blend films, which was attributed to multiple reasons, like limited phase separation room, a coil-toward conformation promotion, and a high surface energy. Furthermore, the enhanced π-attraction and smaller steric hindrance induced by improved intrachain conjugation accounted for the smaller π-π stacking distance in the blend films than that in the neat ones.
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Affiliation(s)
- Haiyang Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , 5625 Renmin Street, Changchun 130022, People's Republic of China
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19
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Fukumatsu T, Saeki A, Seki S. Modulation and evaluation of the charge carrier mobility in a polymer alloy of polythiophene and an insulating matrix with an electron accepting molecule. Polym Chem 2015. [DOI: 10.1039/c5py00796h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Non-contact measurements with time-resolved microwave conductivity and absorption spectroscopy offer direct access to the charge carrier mobility in conjugated backbones.
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Affiliation(s)
- Takahiro Fukumatsu
- Department of Applied Chemistry
- Graduate School of Engineering
- Osaka University
- Suita
- Japan
| | - Akinori Saeki
- Department of Applied Chemistry
- Graduate School of Engineering
- Osaka University
- Suita
- Japan
| | - Shu Seki
- Department of Applied Chemistry
- Graduate School of Engineering
- Osaka University
- Suita
- Japan
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20
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Hellmann C, Treat ND, Scaccabarozzi AD, Razzell Hollis J, Fleischli FD, Bannock JH, de Mello J, Michels JJ, Kim JS, Stingelin N. Solution processing of polymer semiconductor: Insulator blends-Tailored optical properties through liquid-liquid phase separation control. ACTA ACUST UNITED AC 2014. [DOI: 10.1002/polb.23656] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Christoph Hellmann
- Department of Materials and Centre for Plastic Electronics; Imperial College London; London SW7 2AZ United Kingdom
| | - Neil D. Treat
- Department of Materials and Centre for Plastic Electronics; Imperial College London; London SW7 2AZ United Kingdom
| | - Alberto D. Scaccabarozzi
- Department of Materials and Centre for Plastic Electronics; Imperial College London; London SW7 2AZ United Kingdom
| | - Joseph Razzell Hollis
- Department of Physics and Centre for Plastic Electronics; Imperial College London; London SW7 2AZ United Kingdom
| | - Franziska D. Fleischli
- Department of Materials and Centre for Plastic Electronics; Imperial College London; London SW7 2AZ United Kingdom
| | - James H. Bannock
- Department of Chemistry and Centre for Plastic Electronics; Imperial College London; London SW7 2AZ United Kingdom
| | - John de Mello
- Department of Chemistry and Centre for Plastic Electronics; Imperial College London; London SW7 2AZ United Kingdom
| | - Jasper J. Michels
- Max Planck Institute for Polymer Research; Ackermannweg 10 55128 Mainz Germany
| | - Ji-Seon Kim
- Department of Physics and Centre for Plastic Electronics; Imperial College London; London SW7 2AZ United Kingdom
| | - Natalie Stingelin
- Department of Materials and Centre for Plastic Electronics; Imperial College London; London SW7 2AZ United Kingdom
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21
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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.
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Affiliation(s)
- Frank C Spano
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122;
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22
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Rahimi K, Botiz I, Agumba JO, Motamen S, Stingelin N, Reiter G. Light absorption of poly(3-hexylthiophene) single crystals. RSC Adv 2014. [DOI: 10.1039/c3ra47064d] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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