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Memon WA, Zhang Y, Zhang J, Yan Y, Wang Y, Wei Z. Alignment of organic conjugated molecules for high-performance device applications. Macromol Rapid Commun 2022; 43:e2100931. [PMID: 35338681 DOI: 10.1002/marc.202100931] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 03/17/2022] [Indexed: 11/11/2022]
Abstract
High-performance organic semiconductor materials as the electroactive components of optoelectronic devices have attracted much attention and made them ideal candidates for solution-processable, large-area, and low-cost flexible electronics. Especially, organic field-effect transistors (OFETs) based on conjugated semiconductor materials have experienced stunning progress in device performance. To make these materials economically viable, comprehensive knowledge of charge transport mechanisms is required. The alignment of organic conjugated molecules in the active layer is vital to charge transport properties of devices. The present review highlights the recent progress of processing-structure-transport correlations that allow the precise and uniform alignment of organic conjugated molecules over large areas for multiple electronic applications, including OFETs, organic thermoelectric devices (OTEs), and organic phototransistors (OPTs). Different strategies for regulating crystallinity and macroscopic orientation of conjugated molecules are introduced to correlate the molecular packing, the device performance and charge transport anisotropy in multiple organic electronic devices. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Waqar Ali Memon
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Yajie Zhang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Jianqi Zhang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Yangjun Yan
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Yuheng Wang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Zhixiang Wei
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
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Improving the Micropore Capacity of Activated Carbon by Preparation under a High Magnetic Field of 10 T. Sci Rep 2019; 9:7489. [PMID: 31097744 PMCID: PMC6522527 DOI: 10.1038/s41598-019-43818-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 05/01/2019] [Indexed: 11/30/2022] Open
Abstract
The influence of an applied magnetic field on the formation of carbon materials from coal tar pitch is investigated. Under an applied magnetic field, crystallites in a mesophase resembling liquid crystals are magnetically oriented during the carbonization process. Compared with that under a nonmagnetic field, carbonized coal tar pitch under a strong magnetic field of 10 T, generated by a superconducting magnet, has a highly oriented structure of carbon crystallites. The orientation of samples prepared under 2 T, which can easily be supplied by an electromagnet, was insufficient. Activation by potassium hydroxide is effective for affording a precursor for activated carbon. The activated carbon obtained under a strong magnetic field has a unique adsorption ability, which arises from its increase in relative surface area and total pore volume compared with those of an activated carbon sample prepared from a precursor produced under zero magnetic field. The precursor carbonized under a magnetic field of 10 T contains a larger number of crystallites than that carbonized under a 0-T magnetic field, which leads to high-performance activated carbon.
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Chen W, Zhu Y, Cui F, Liu L, Sun Z, Chen J, Li Y. GPU-Accelerated Molecular Dynamics Simulation to Study Liquid Crystal Phase Transition Using Coarse-Grained Gay-Berne Anisotropic Potential. PLoS One 2016; 11:e0151704. [PMID: 26986851 PMCID: PMC4795799 DOI: 10.1371/journal.pone.0151704] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 03/02/2016] [Indexed: 12/26/2022] Open
Abstract
Gay-Berne (GB) potential is regarded as an accurate model in the simulation of anisotropic particles, especially for liquid crystal (LC) mesogens. However, its computational complexity leads to an extremely time-consuming process for large systems. Here, we developed a GPU-accelerated molecular dynamics (MD) simulation with coarse-grained GB potential implemented in GALAMOST package to investigate the LC phase transitions for mesogens in small molecules, main-chain or side-chain polymers. For identical mesogens in three different molecules, on cooling from fully isotropic melts, the small molecules form a single-domain smectic-B phase, while the main-chain LC polymers prefer a single-domain nematic phase as a result of connective restraints in neighboring mesogens. The phase transition of side-chain LC polymers undergoes a two-step process: nucleation of nematic islands and formation of multi-domain nematic texture. The particular behavior originates in the fact that the rotational orientation of the mesogenes is hindered by the polymer backbones. Both the global distribution and the local orientation of mesogens are critical for the phase transition of anisotropic particles. Furthermore, compared with the MD simulation in LAMMPS, our GPU-accelerated code is about 4 times faster than the GPU version of LAMMPS and at least 200 times faster than the CPU version of LAMMPS. This study clearly shows that GPU-accelerated MD simulation with GB potential in GALAMOST can efficiently handle systems with anisotropic particles and interactions, and accurately explore phase differences originated from molecular structures.
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Affiliation(s)
- Wenduo Chen
- Key Laboratory of Synthetic Rubber & Laboratory of Advanced Power Sources, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, PR China
| | - Youliang Zhu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, PR China
| | - Fengchao Cui
- Key Laboratory of Synthetic Rubber & Laboratory of Advanced Power Sources, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, PR China
| | - Lunyang Liu
- Key Laboratory of Synthetic Rubber & Laboratory of Advanced Power Sources, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, PR China
| | - Zhaoyan Sun
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, PR China
| | - Jizhong Chen
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, PR China
| | - Yunqi Li
- Key Laboratory of Synthetic Rubber & Laboratory of Advanced Power Sources, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, PR China
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Alvarez Fernandez A, Keshavarz M, Christianen PCM, Kouwer PHJ. Maximizing Orientational Order in Polymer-Stabilized Liquid Crystals Using High Magnetic Fields. Macromolecules 2015. [DOI: 10.1021/ma501867f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alexandra Alvarez Fernandez
- Institute for Molecules and
Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Masoumeh Keshavarz
- Institute for Molecules and
Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Peter C. M. Christianen
- Institute for Molecules and
Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Paul H. J. Kouwer
- Institute for Molecules and
Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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Takazawa K, Inoue JI, Mitsuishi K. Self-assembled coronene nanofibers: optical waveguide effect and magnetic alignment. NANOSCALE 2014; 6:4174-4181. [PMID: 24608753 DOI: 10.1039/c3nr06760b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
To fabricate organic nanofibers that function as active optical waveguides with semiconductor properties, a facile procedure was developed to grow single crystalline nanofibers via π-π stacking of the polycyclic aromatic molecule, coronene, through solution evaporation on a substrate. The fabricated nanofibers with millimeter-scale lengths have well-defined shapes, smooth surfaces, and low-defect structures. The nanofibers are demonstrated to function as efficient active waveguides that propagate their fluorescence (FL) along the fiber axis over their entire length. We further demonstrate that the nanofibers can be highly aligned on the substrate when solution evaporation is conducted in a magnetic field of 12 T. The mechanism of the magnetic alignment can be elucidated by considering the anisotropy of the diamagnetic susceptibility of a single coronene molecule and the crystal structure of a nanofiber. Owing to the high degree of alignment, the nanofibers rarely cross each other, allowing for measurement of the waveguiding properties of single isolated nanofibers. The nanofibers propagate their FL of λ > 500 nm with a low propagation loss of 0-3 dB per 100 μm, indicating that the nanofibers function as sub-wavelength scale, low-loss waveguides. Thus, they are promising building blocks for miniaturized optoelectronic circuits.
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Affiliation(s)
- Ken Takazawa
- National Institute for Materials Science, 3-13 Sakura, Tsukuba, 305-0003, Japan.
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Gopinadhan M, Majewski PW, Choo Y, Osuji CO. Order-disorder transition and alignment dynamics of a block copolymer under high magnetic fields by in situ x-ray scattering. PHYSICAL REVIEW LETTERS 2013; 110:078301. [PMID: 25166413 DOI: 10.1103/physrevlett.110.078301] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Indexed: 06/03/2023]
Abstract
We examine the influence of magnetic fields on the order-disorder transition (ODT) in a liquid crystalline block copolymer. This is motivated by a desire to understand the dynamics of microstructure alignment during field annealing as potentially dictated by selective destabilization of nonaligned material. Temperature resolved scattering across the ODT and time-resolved measurements during isothermal field annealing at sub-ODT temperatures were performed in situ. Strongly textured mesophases resulted in each case but no measurable field-induced shift in T(ODT) was observed. This suggests that selective melting does not play a discernable role in the system's field response. Our data indicate instead that alignment occurs by slow grain rotation within the mesophase. We identify an optimum subcooling that maximizes alignment during isothermal field annealing. This is corroborated by a simple model incorporating the competing effects of an exponentially decreasing mobility and divergent, increasing magnetic anisotropy on cooling below T(ODT). The absence of measurable field effects on T(ODT) is consistent with estimates based on the relative magnitudes of the field interaction energy and the enthalpy associated with the ODT.
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Affiliation(s)
- Manesh Gopinadhan
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, USA
| | - Paweł W Majewski
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, USA
| | - Youngwoo Choo
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, USA
| | - Chinedum O Osuji
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, USA
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Sakaguchi A, Hamasaki A, Sadatou T, Nishihara Y, Yamamoto S, Sekinuma Y, Ozeki S. Magnetic Orientation of Hexagonal Carbon Layers at High Temperatures. CHEM LETT 2012. [DOI: 10.1246/cl.2012.1576] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Ayumi Sakaguchi
- Department of Chemistry, Faculty of Science, Shinshu University
| | - Atom Hamasaki
- Department of Chemistry, Faculty of Science, Shinshu University
| | | | | | - Shou Yamamoto
- Department of Chemistry, Faculty of Science, Shinshu University
| | - Yuya Sekinuma
- Department of Chemistry, Faculty of Science, Shinshu University
| | - Sumio Ozeki
- Department of Chemistry, Faculty of Science, Shinshu University
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Wen Y, Liu Y, Guo Y, Yu G, Hu W. Experimental Techniques for the Fabrication and Characterization of Organic Thin Films for Field-Effect Transistors. Chem Rev 2011; 111:3358-406. [DOI: 10.1021/cr1001904] [Citation(s) in RCA: 214] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yugeng Wen
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Yunqi Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Yunlong Guo
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Gui Yu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Wenping Hu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
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Shklyarevskiy IO, Jonkheijm P, Stutzmann N, Wasserberg D, Wondergem HJ, Christianen PCM, Schenning APHJ, de Leeuw DM, Tomović Z, Wu J, Müllen K, Maan JC. High Anisotropy of the Field-Effect Transistor Mobility in Magnetically Aligned Discotic Liquid-Crystalline Semiconductors. J Am Chem Soc 2005; 127:16233-7. [PMID: 16287314 DOI: 10.1021/ja054694t] [Citation(s) in RCA: 183] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A magnetic field has been utilized for producing highly oriented films of a substituted hexabenzocoronene (HBC). Optical microscopy studies revealed large area HBC monodomains that covered the entire film, while wide-angle X-ray measurements showed that the HBC molecules are aligned with their planes along the applied field. On the basis of this method, solution-processed field-effect transistors (FET) have been constructed with charge carrier mobilities of up to 10(-3) cm2/V.s, which are significantly enhanced with respect to the unaligned material. Exceptionally high mobility anisotropies of 25-75 for current flow parallel and perpendicular to the alignment direction have been measured as a function of the channel length. Atomic force microscopy performed on the FET structures reveals fibril superstructures that are oriented perpendicularly to the magnetic field direction, consisting of molecular columns with a slippage angle of 40 degrees between the molecules. For channel lengths larger than 2.5 mum, the fibrils are smaller than the electrode spacing, which adversely affects the device performance.
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Affiliation(s)
- Igor O Shklyarevskiy
- High Field Magnet Laboratory, Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
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Boamfa MI, Viertler K, Wewerka A, Stelzer F, Christianen PCM, Maan JC. Magnetic-field-induced changes of the isotropic-nematic phase transition in side-chain polymer liquid crystals. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2003; 67:050701. [PMID: 12786124 DOI: 10.1103/physreve.67.050701] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2002] [Indexed: 05/24/2023]
Abstract
The isotropic-nematic (I-N) phase transition of side-chain polymer liquid crystals is intrinsically a weak first-order transition with a biphasic region spread over a wide temperature interval. In the presence of high magnetic fields we find the I-N transition to become a strong first order. The I-N biphasic region shrinks its temperature window as larger magnetic fields are applied, until it completely disappears and the transition completes at a fixed temperature. We interpret this behavior as a consequence of the nonlinear coupling of the magnetic field to the system free energy, via the suppression of the order fluctuations in the nematic mesophase at the I-N transition crossing.
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Affiliation(s)
- M I Boamfa
- Research Institute for Materials, High Field Magnet Laboratory, University of Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands.
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