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Guo J, Chen SE, Giridharagopal R, Bischak CG, Onorato JW, Yan K, Shen Z, Li CZ, Luscombe CK, Ginger DS. Understanding asymmetric switching times in accumulation mode organic electrochemical transistors. Nat Mater 2024; 23:656-663. [PMID: 38632374 DOI: 10.1038/s41563-024-01875-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 03/19/2024] [Indexed: 04/19/2024]
Abstract
Understanding the factors underpinning device switching times is crucial for the implementation of organic electrochemical transistors in neuromorphic computing, bioelectronics and real-time sensing applications. Existing models of device operation cannot explain the experimental observations that turn-off times are generally much faster than turn-on times in accumulation mode organic electrochemical transistors. Here, using operando optical microscopy, we image the local doping level of the transistor channel and show that turn-on occurs in two stages-propagation of a doping front, followed by uniform doping-while turn-off occurs in one stage. We attribute the faster turn-off to a combination of engineering as well as physical and chemical factors including channel geometry, differences in doping and dedoping kinetics and the phenomena of carrier-density-dependent mobility. We show that ion transport limits the operation speed in our devices. Our study provides insights into the kinetics of organic electrochemical transistors and guidelines for engineering faster organic electrochemical transistors.
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Affiliation(s)
- Jiajie Guo
- Molecular Engineering and Sciences Institute, University of Washington, Seattle, WA, USA
| | - Shinya E Chen
- Molecular Engineering and Sciences Institute, University of Washington, Seattle, WA, USA
| | | | - Connor G Bischak
- Department of Chemistry, University of Washington, Seattle, WA, USA
| | - Jonathan W Onorato
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
| | - Kangrong Yan
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, P. R. China
| | - Ziqiu Shen
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, P. R. China
| | - Chang-Zhi Li
- State Key Laboratory of Silicon and Advanced Semiconductor Materials, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, P. R. China
| | - Christine K Luscombe
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
- pi-Conjugated Polymers Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Japan
| | - David S Ginger
- Department of Chemistry, University of Washington, Seattle, WA, USA.
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Yu H, Nelson J. Slow on, fast off. Nat Mater 2024; 23:585-586. [PMID: 38702547 DOI: 10.1038/s41563-024-01885-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2024]
Affiliation(s)
- Hang Yu
- Department of Physics and Centre for Processable Electronics, Imperial College London, London, UK
| | - Jenny Nelson
- Department of Physics and Centre for Processable Electronics, Imperial College London, London, UK.
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Organic mixed ionic-electronic conductors progress at pace. Nat Mater 2024; 23:577. [PMID: 38702548 DOI: 10.1038/s41563-024-01902-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2024]
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Wu R, Ji X, Ma Q, Paulsen BD, Tropp J, Rivnay J. Direct quantification of ion composition and mobility in organic mixed ionic-electronic conductors. Sci Adv 2024; 10:eadn8628. [PMID: 38657078 PMCID: PMC11042751 DOI: 10.1126/sciadv.adn8628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 03/19/2024] [Indexed: 04/26/2024]
Abstract
Ion transport in organic mixed ionic-electronic conductors (OMIECs) is crucial due to its direct impact on device response time and operating mechanisms but is often assessed indirectly or necessitates extra assumptions. Operando x-ray fluorescence (XRF) is a powerful, direct probe for elemental characterization of bulk OMIECs and was used to directly quantify ion composition and mobility in a model OMIEC, poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS), during device operation. The first cycle revealed slow electrowetting and cation-proton exchange. Subsequent cycles showed rapid response with minor cation fluctuation (~5%). Comparison with optical-tracked electrochromic fronts revealed mesoscale structure-dependent proton transport. The calculated effective ion mobility demonstrated thickness-dependent behavior, emphasizing an interfacial ion transport pathway with a higher mobile ion density. The decoupling of interfacial effects on bulk ion mobility and the decoupling of cation and proton migration elucidate ion transport in conventional and emerging OMIEC-based devices and has broader implications for other ionic conductors writ large.
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Affiliation(s)
- Ruiheng Wu
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
| | - Xudong Ji
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Qing Ma
- DND-CAT, Synchrotron Research Center, Northwestern University, Evanston, IL 60208, USA
| | - Bryan D. Paulsen
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Joshua Tropp
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Jonathan Rivnay
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
- Department of Material Science and Engineering, Northwestern University, Evanston, IL 60611, USA
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Yang Y, Lin E, Wang S, Wang T, Wang Z, Zhang Z. Single-Crystal One-Dimensional Porous Ladder Covalent Polymers. J Am Chem Soc 2024; 146:782-790. [PMID: 38165084 DOI: 10.1021/jacs.3c10812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
The synthesis of single-crystal, one-dimensional (1D) polymers is of great importance but a formidable challenge. Herein, we report the synthesis of single-crystal 1D ladder polymers in solution by dynamic covalent chemistry. The three-dimensional electron diffraction technique was used to rigorously solve the structure of the crystalline polymers, unveiling that each polymer chain is connected by double covalent bridges and all polymer chains are packed in a staggered and interlaced manner by π-π stacking and hydrogen bonding interactions, making the crystalline polymers highly robust in both thermal and chemical stability. The synthesized single-crystal polymers possess permanent micropores and can efficiently remove CO2 from the C2H2/CO2 mixture to obtain high-purity C2H2, validated by dynamic breakthrough experiments. This work demonstrates the first example of constructing single-crystal 1D porous ladder polymers with double covalent bridges in solution for efficient C2H2/CO2 separation.
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Affiliation(s)
- Yi Yang
- State Key Laboratory of Medicine Chemistry Biology, College of Chemistry, Nankai University, Tianjin 300071, China
| | - En Lin
- State Key Laboratory of Medicine Chemistry Biology, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Sa Wang
- State Key Laboratory of Medicine Chemistry Biology, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Ting Wang
- State Key Laboratory of Medicine Chemistry Biology, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Zhifang Wang
- State Key Laboratory of Medicine Chemistry Biology, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Zhenjie Zhang
- State Key Laboratory of Medicine Chemistry Biology, College of Chemistry, Nankai University, Tianjin 300071, China
- Key Laboratory of Advanced Energy Materials Chemistry, Ministry of Education, Nankai University, Tianjin 300071, China
- Frontiers Science Center for New Organic Matter, Tianjin 300071, China
- Renewable Energy Conversion and Storage Center, Nankai University, Tianjin 300071, China
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Osazuwa PO, Lo CY, Feng X, Nolin A, Dhong C, Kayser LV. Surface Functionalization with (3-Glycidyloxypropyl)trimethoxysilane (GOPS) as an Alternative to Blending for Enhancing the Aqueous Stability and Electronic Performance of PEDOT:PSS Thin Films. ACS Appl Mater Interfaces 2023; 15:54711-54720. [PMID: 37962428 DOI: 10.1021/acsami.3c09452] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Organic mixed ionic-electronic conductors, such as poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), are essential materials for the fabrication of bioelectronic devices due to their unique ability to couple and transport ionic and electronic charges. The growing interest in bioelectronic devices has led to the development of organic electrochemical transistors (OECTs) that can operate in aqueous solutions and transduce ionic signals of biological origin into measurable electronic signals. A common challenge with OECTs is maintaining the stability and performance of the PEDOT:PSS films operating under aqueous conditions. Although the conventional approach of blending the PEDOT:PSS dispersions with a cross-linker such as (3-glycidyloxypropyl)trimethoxysilane (GOPS) helps to ensure strong adhesion of the films to device substrates, it also impacts the morphology and thus electrical properties of the PEDOT:PSS films, which leads to a significant reduction in the performance of OECTs. In this study, we instead functionalize only the surface of the device substrates with GOPS to introduce a silane monolayer before spin-coating the PEDOT:PSS dispersion on the substrate. In all cases, having a GOPS monolayer instead of a blend leads to increased electronic performance metrics, such as three times higher electronic conductivity, volumetric capacitance, and mobility-capacitance product [μC*] value in OECT devices, ultimately leading to a record value of 406 ± 39 F cm-1 V-1 s-1 for amorphous PEDOT:PSS. This increased performance does not come at the expense of operational stability, as both the blend and surface functionalization show similar performance when subjected to pulsed gate bias stress, long-term electrochemical cycling tests, and aging over 150 days. Overall, this study establishes a novel approach to using GOPS as a surface monolayer instead of a blended cross-linker, for achieving high-performance organic mixed ionic-electronic conductors that are stable in water for bioelectronics.
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Affiliation(s)
- Peter O Osazuwa
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Chun-Yuan Lo
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Xu Feng
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Abigail Nolin
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Charles Dhong
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Laure V Kayser
- Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
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Zahabi N, Baryshnikov G, Linares M, Zozoulenko I. Charge carrier dynamics in conducting polymer PEDOT using ab initio molecular dynamics simulations. J Chem Phys 2023; 159:154801. [PMID: 37843059 DOI: 10.1063/5.0169363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 10/01/2023] [Indexed: 10/17/2023] Open
Abstract
As conducting polymers become increasingly important in electronic devices, understanding their charge transport is essential for material and device development. Various semi-empirical approaches have been used to describe temporal charge carrier dynamics in these materials, but there have yet to be any theoretical approaches utilizing ab initio molecular dynamics. In this work, we develop a computational technique based on ab initio Car-Parrinello molecular dynamics to trace charge carrier temporal motion in archetypical conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT). Particularly, we analyze charge dynamics in a single PEDOT chain and in two coupled chains with different degrees of coupling and study the effect of temperature. In our model we first initiate a positively charged polaron (compensated by a negative counterion) at one end of the chain, and subsequently displace the counterion to the other end of the chain and trace polaron dynamics in the system by monitoring bond length alternation in the PEDOT backbone and charge density distribution. We find that at low temperature (T = 1 K) the polaron distortion gradually disappears from its initial location and reappears near the new position of the counterion. At the room temperature (T = 300 K), we find that the distortions induced by polaron, and atomic vibrations are of the same magnitude, which makes tracking the polaron distortion challenging because it is hidden behind the temperature-induced vibrations. The novel approach developed in this work can be used to study polaron mobility along and between the chains, investigate charge transport in highly doped polymers, and explore other flexible polymers, including n-doped ones.
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Affiliation(s)
- Najmeh Zahabi
- Laboratory of Organic Electronics (LOE), Department of Science and Technology (ITN), Campus Norrköping, Linköping University, SE-60174 Norrköping, Sweden
| | - Glib Baryshnikov
- Laboratory of Organic Electronics (LOE), Department of Science and Technology (ITN), Campus Norrköping, Linköping University, SE-60174 Norrköping, Sweden
| | - Mathieu Linares
- Group of Scientific Visualization, Department of Science and Technology (ITN), Campus Norrköping, Linköping University, SE-60174 Norrköping, Sweden
- Swedish e-Science Center (SeRC), Linköping University, SE-581 83 Linköping, Sweden
| | - Igor Zozoulenko
- Laboratory of Organic Electronics (LOE), Department of Science and Technology (ITN), Campus Norrköping, Linköping University, SE-60174 Norrköping, Sweden
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Keene ST, Rao A, Malliaras GG. The relationship between ionic-electronic coupling and transport in organic mixed conductors. Sci Adv 2023; 9:eadi3536. [PMID: 37647402 PMCID: PMC10468126 DOI: 10.1126/sciadv.adi3536] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 07/28/2023] [Indexed: 09/01/2023]
Abstract
Organic mixed ionic-electronic conductors (OMIECs) directly convert between ionic and electronic charge through electrochemical (de)doping, enabling a wide range of applications in bioelectronics, neuromorphic computing, and energy storage and conversion. While both ionic and electronic transport are individually well characterized, their combined transport has been difficult to describe self-consistently. We use in situ measurements of electrochemical (de)doping of an archetypal OMIEC to inform a quasi-field drift-diffusion model, which accurately captures experimentally measured ion transport across a range of potentials. We find that the chemical potential of holes, which is modulated by changes in doping level, represents a major driving force for mixed charge transport. Using numerical simulations at device-relevant time scales and potentials, we find that the competition between hole drift and diffusion leads to diffuse space charge regions despite high charge densities. This effect is unique to mixed conducting systems where mobile ionic charges can compensate the accumulation or depletion of electronic charge, thereby screening electrostatic driving forces.
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Affiliation(s)
- Scott T. Keene
- Department of Engineering, Electrical Engineering Division, University of Cambridge, Cambridge, CB3 0FA, UK
- Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, CB3 0HE, UK
| | - Akshay Rao
- Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, CB3 0HE, UK
| | - George G. Malliaras
- Department of Engineering, Electrical Engineering Division, University of Cambridge, Cambridge, CB3 0FA, UK
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Wu R, Meli D, Rivnay J. The hole truth. Nat Mater 2023; 22:1055-1056. [PMID: 37644224 DOI: 10.1038/s41563-023-01643-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Affiliation(s)
- Ruiheng Wu
- Department of Chemistry, Northwestern University, Evanston, IL, USA
| | - Dilara Meli
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA
| | - Jonathan Rivnay
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA.
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA.
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