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O'Connor JP, Schultz JD, Tcyrulnikov NA, Kim T, Young RM, Wasielewski MR. Distinct vibrational motions promote disparate excited-state decay pathways in cofacial perylenediimide dimers. J Chem Phys 2024; 161:074306. [PMID: 39145558 DOI: 10.1063/5.0218752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Accepted: 07/29/2024] [Indexed: 08/16/2024] Open
Abstract
A complex interplay of structural, electronic, and vibrational degrees of freedom underpins the fate of molecular excited states. Organic assemblies exhibit a myriad of excited-state decay processes, such as symmetry-breaking charge separation (SB-CS), excimer (EX) formation, singlet fission, and energy transfer. Recent studies of cofacial and slip-stacked perylene-3,4:9,10-bis(dicarboximide) (PDI) multimers demonstrate that slight variations in core substituents and H- or J-type aggregation can determine whether the system follows an SB-CS pathway or an EX one. However, questions regarding the relative importance of structural properties and molecular vibrations in driving the excited-state dynamics remain. Here, we use a combination of two-dimensional electronic spectroscopy, femtosecond stimulated Raman spectroscopy, and quantum chemistry computations to compare the photophysics of two PDI dimers. The dimer with 1,7-bis(pyrrolidin-1'-yl) substituents (5PDI2) undergoes ultrafast SB-CS from a photoexcited mixed state, while the dimer with bis-1,7-(3',5'-di-t-butylphenoxy) substituents (PPDI2) rapidly forms an EX state. Examination of their quantum beating features reveals that SB-CS in 5PDI2 is driven by the collective vibronic coupling of two or more excited-state vibrations. In contrast, we observe signatures of low-frequency vibrational coherence transfer during EX formation by PPDI2, which aligns with several previous studies. We conclude that key electronic and structural differences between 5PDI2 and PPDI2 determine their markedly different photophysics.
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Affiliation(s)
- James P O'Connor
- Department of Chemistry and Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Jonathan D Schultz
- Department of Chemistry and Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Nikolai A Tcyrulnikov
- Department of Chemistry and Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Taeyeon Kim
- Department of Chemistry and Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Ryan M Young
- Department of Chemistry and Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Michael R Wasielewski
- Department of Chemistry and Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, USA
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2
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Zhan S, Gelin MF, Huang X, Sun K. Ab initio simulation of peak evolutions and beating maps for electronic two-dimensional signals of a polyatomic chromophore. J Chem Phys 2023; 158:2890773. [PMID: 37191214 DOI: 10.1063/5.0150387] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 04/28/2023] [Indexed: 05/17/2023] Open
Abstract
By employing the doorway-window (DW) on-the-fly simulation protocol, we performed ab initio simulations of peak evolutions and beating maps of electronic two-dimensional (2D) spectra of a polyatomic molecule in the gas phase. As the system under study, we chose pyrazine, which is a paradigmatic example of photodynamics dominated by conical intersections (CIs). From the technical perspective, we demonstrate that the DW protocol is a numerically efficient methodology suitable for simulations of 2D spectra for a wide range of excitation/detection frequencies and population times. From the information content perspective, we show that peak evolutions and beating maps not only reveal timescales of transitions through CIs but also pinpoint the most relevant coupling and tuning modes active at these CIs.
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Affiliation(s)
- Siying Zhan
- School of Sciences, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Maxim F Gelin
- School of Sciences, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Xiang Huang
- Department of Chemistry, Technical University of Munich, D-85747 Garching, Germany
| | - Kewei Sun
- School of Sciences, Hangzhou Dianzi University, Hangzhou 310018, China
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3
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Sil S, Tilluck RW, Mohan T M N, Leslie CH, Rose JB, Domínguez-Martín MA, Lou W, Kerfeld CA, Beck WF. Excitation energy transfer and vibronic coherence in intact phycobilisomes. Nat Chem 2022; 14:1286-1294. [PMID: 36123451 DOI: 10.1038/s41557-022-01026-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 07/21/2022] [Indexed: 11/09/2022]
Abstract
The phycobilisome is an oligomeric chromoprotein complex that serves as the principal mid-visible light-harvesting system in cyanobacteria. Here we report the observation of excitation-energy-transfer pathways involving delocalized optical excitations of the bilin (linear tetrapyrrole) chromophores in intact phycobilisomes isolated from Fremyella diplosiphon. By using broadband multidimensional electronic spectroscopy with 6.7-fs laser pulses, we are able to follow the progress of excitation energy from the phycoerythrin disks at the ends of the phycobilisome's rods to the C-phycocyanin disks along their length in <600 fs. Oscillation maps show that coherent wavepacket motions prominently involving the hydrogen out-of-plane vibrations of the bilins mediate non-adiabatic relaxation of a manifold of vibronic exciton states. However, the charge-transfer character of the bilins in the allophycocyanin-containing segments localizes the excitations in the core of the phycobilisome, yielding a kinetic bottleneck that enables photoregulatory mechanisms to operate efficiently on the >10-ps timescale.
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Affiliation(s)
- Sourav Sil
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | - Ryan W Tilluck
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | - Nila Mohan T M
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | - Chase H Leslie
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | - Justin B Rose
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | | | - Wenjing Lou
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Warren F Beck
- Department of Chemistry, Michigan State University, East Lansing, MI, USA.
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4
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Wang Z, Hedse A, Amarotti E, Lenngren N, Žídek K, Zheng K, Zigmantas D, Pullerits T. Beating signals in CdSe quantum dots measured by low-temperature 2D spectroscopy. J Chem Phys 2022; 157:014201. [DOI: 10.1063/5.0089798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Advances in ultrafast spectroscopy can provide access to dynamics involving nontrivial quantum correlations and their evolutions. In coherent 2D spectroscopy, the oscillatory time dependence of a signal is a signature of such quantum dynamics. Here we study such beating signals in electronic coherent 2D spectroscopy of CdSe quantum dots (CdSe QDs) at 77 K. The beating signals are analyzed in terms of their positive and negative Fourier components. We conclude that the beatings originate from coherent LO-phonons of CdSe QDs. No evidence for the quantum dot size dependence of the LO-phonon frequency was identified.
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Affiliation(s)
- Zhengjun Wang
- Division of Chemical Physics, Lund Univeristy, Sweden
| | | | | | | | - Karel Žídek
- TOPTEC Research Center, Institute of Plasma Physics Czech Academy of Sciences, Czech Republic
| | - Kaibo Zheng
- Department of Chemical Physics, Lund University, Sweden
| | | | - Tonu Pullerits
- Department of Chemical Physics, Lund University Faculty of Science, Sweden
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5
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Biswas S, Kim J, Zhang X, Scholes GD. Coherent Two-Dimensional and Broadband Electronic Spectroscopies. Chem Rev 2022; 122:4257-4321. [PMID: 35037757 DOI: 10.1021/acs.chemrev.1c00623] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Over the past few decades, coherent broadband spectroscopy has been widely used to improve our understanding of ultrafast processes (e.g., photoinduced electron transfer, proton transfer, and proton-coupled electron transfer reactions) at femtosecond resolution. The advances in femtosecond laser technology along with the development of nonlinear multidimensional spectroscopy enabled further insights into ultrafast energy transfer and carrier relaxation processes in complex biological and material systems. New discoveries and interpretations have led to improved design principles for optimizing the photophysical properties of various artificial systems. In this review, we first provide a detailed theoretical framework of both coherent broadband and two-dimensional electronic spectroscopy (2DES). We then discuss a selection of experimental approaches and considerations of 2DES along with best practices for data processing and analysis. Finally, we review several examples where coherent broadband and 2DES were employed to reveal mechanisms of photoinitiated ultrafast processes in molecular, biological, and material systems. We end the review with a brief perspective on the future of the experimental techniques themselves and their potential to answer an even greater range of scientific questions.
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Affiliation(s)
- Somnath Biswas
- Department of Chemistry, Princeton University, Princeton, New Jersey 08 544, United States
| | - JunWoo Kim
- Department of Chemistry, Princeton University, Princeton, New Jersey 08 544, United States
| | - Xinzi Zhang
- Department of Chemistry, Princeton University, Princeton, New Jersey 08 544, United States
| | - Gregory D Scholes
- Department of Chemistry, Princeton University, Princeton, New Jersey 08 544, United States
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6
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Tilluck RW, Mohan T M N, Hetherington CV, Leslie CH, Sil S, Frazier J, Zhang M, Levine BG, Van Patten PG, Beck WF. Vibronic Excitons and Conical Intersections in Semiconductor Quantum Dots. J Phys Chem Lett 2021; 12:9677-9683. [PMID: 34590846 DOI: 10.1021/acs.jpclett.1c02630] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Surface defects and organic surface-capping ligands affect the photoluminescence properties of semiconductor quantum dots (QDs) by altering the rates of competing nonradiative relaxation processes. In this study, broadband two-dimensional electronic spectroscopy reveals that absorption of light by QDs prepares vibronic excitons, excited states derived from quantum coherent mixing of the core electronic and ligand vibrational states. Rapidly damped coherent wavepacket motions of the ligands are observed during hot-carrier cooling, with vibronic coherence transferred to the photoluminescent state. These findings suggest a many-electron, molecular theory for the electronic structure of QDs, which is supported by calculations of the structures of conical intersections between the exciton potential surfaces of a small ammonia-passivated model CdSe nanoparticle.
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Affiliation(s)
- Ryan W Tilluck
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Nila Mohan T M
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Caitlin V Hetherington
- Institute for Advanced Computational Science and Department of Chemistry, Stony Brook University, Stony Brook, New York 11733, United States
| | - Chase H Leslie
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Sourav Sil
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Jared Frazier
- Department of Chemistry, Middle Tennessee State University, Murfreesboro, Tennessee 37132, United States
| | - Mengliang Zhang
- Department of Chemistry, Middle Tennessee State University, Murfreesboro, Tennessee 37132, United States
| | - Benjamin G Levine
- Institute for Advanced Computational Science and Department of Chemistry, Stony Brook University, Stony Brook, New York 11733, United States
| | - P Gregory Van Patten
- Department of Chemistry, Middle Tennessee State University, Murfreesboro, Tennessee 37132, United States
| | - Warren F Beck
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
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7
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Mohan T M N, Leslie CH, Sil S, Rose JB, Tilluck RW, Beck WF. Broadband 2DES detection of vibrational coherence in the S x state of canthaxanthin. J Chem Phys 2021; 155:035103. [PMID: 34293883 DOI: 10.1063/5.0055598] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The nonadiabatic mechanism that mediates nonradiative decay of the bright S2 state to the dark S1 state of carotenoids involves population of a bridging intermediate state, Sx, in several examples. The nature of Sx remains to be determined definitively, but it has been recently suggested that Sx corresponds to conformationally distorted molecules evolving along out-of-plane coordinates of the isoprenoid backbone near a low barrier between planar and distorted conformations on the S2 potential surface. In this study, the electronic and vibrational dynamics accompanying the formation of Sx in toluene solutions of the ketocarotenoid canthaxanthin (CAN) are characterized with broadband two-dimensional electronic spectroscopy (2DES) with 7.8 fs excitation pulses and detection of the linear polarization components of the third-order nonlinear optical signal. A stimulated-emission cross peak in the 2DES spectrum accompanies the formation of Sx in <20 fs following excitation of the main absorption band. Sx is prepared instantaneously, however, with excitation of hot-band transitions associated with distorted conformations of CAN's isoprenoid backbone in the low frequency onset of the main absorption band. Vibrational coherence oscillation maps and modulated anisotropy transients show that Sx undergoes displacements from the Franck-Condon S2 state along out-of-plane coordinates as it passes to the S1 state. The results are consistent with the conclusion that CAN's carbonyl-substituted β-ionone rings impart an intramolecular charge-transfer character that frictionally slows the passage from Sx to S1 compared to carotenoids lacking carbonyl substitution. Despite the longer lifetime, the S1 state of CAN is formed with retention of vibrational coherence after passing through a conical intersection seam with the Sx state.
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Affiliation(s)
- Nila Mohan T M
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, USA
| | - Chase H Leslie
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, USA
| | - Sourav Sil
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, USA
| | - Justin B Rose
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, USA
| | - Ryan W Tilluck
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, USA
| | - Warren F Beck
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, Michigan 48824, USA
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8
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Arpin PC, Turner DB. Signatures of Vibrational and Electronic Quantum Beats in Femtosecond Coherence Spectra. J Phys Chem A 2021; 125:2425-2435. [PMID: 33724844 PMCID: PMC8023717 DOI: 10.1021/acs.jpca.0c10807] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Indexed: 11/29/2022]
Abstract
Femtosecond laser pulses can produce oscillatory signals in transient-absorption spectroscopy measurements. The quantum beats are often studied using femtosecond coherence spectra (FCS), the Fourier domain amplitude, and phase profiles at individual oscillation frequencies. In principle, one can identify the mechanism that gives rise to each quantum-beat signal by comparing its measured FCS to those arising from microscopic models. To date, however, most measured FCS deviate from the ubiquitous harmonic oscillator model. Here, we expand the inventory of models to which the measured spectra can be compared. We develop quantum-mechanical models of the fundamental, overtone, and combination-band FCS arising from harmonic potentials, the FCS of anharmonic potentials, and the FCS of a purely electronic dimer. This work solidifies the use of FCS for identifying electronic coherences that can arise in measurements of molecular aggregates including photosynthetic proteins. Furthermore, future studies can use the derived expressions to fit the measured FCS and thereby extract microscopic parameters of molecular potential-energy surfaces.
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Affiliation(s)
- Paul C. Arpin
- Department
of Physics, California State University,
Chico, Chico, California 95929, United States
| | - Daniel B. Turner
- Micron
School for Materials Science and Engineering, Boise State University, Boise, Idaho 83725, United States
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9
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Begušić T, Vaníček J. Finite-Temperature, Anharmonicity, and Duschinsky Effects on the Two-Dimensional Electronic Spectra from Ab Initio Thermo-Field Gaussian Wavepacket Dynamics. J Phys Chem Lett 2021; 12:2997-3005. [PMID: 33733773 PMCID: PMC8006135 DOI: 10.1021/acs.jpclett.1c00123] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 03/08/2021] [Indexed: 05/28/2023]
Abstract
Accurate description of finite-temperature vibrational dynamics is indispensable in the computation of two-dimensional electronic spectra. Such simulations are often based on the density matrix evolution, statistical averaging of initial vibrational states, or approximate classical or semiclassical limits. While many practical approaches exist, they are often of limited accuracy and difficult to interpret. Here, we use the concept of thermo-field dynamics to derive an exact finite-temperature expression that lends itself to an intuitive wavepacket-based interpretation. Furthermore, an efficient method for computing finite-temperature two-dimensional spectra is obtained by combining the exact thermo-field dynamics approach with the thawed Gaussian approximation for the wavepacket dynamics, which is exact for any displaced, distorted, and Duschinsky-rotated harmonic potential but also accounts partially for anharmonicity effects in general potentials. Using this new method, we directly relate a symmetry breaking of the two-dimensional signal to the deviation from the conventional Brownian oscillator picture.
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10
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Zhu R, Zou J, Wang Z, Chen H, Weng Y. Electronic State-Resolved Multimode-Coupled Vibrational Wavepackets in Oxazine 720 by Two-Dimensional Electronic Spectroscopy. J Phys Chem A 2020; 124:9333-9342. [PMID: 33136407 DOI: 10.1021/acs.jpca.0c06559] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The difference between the excited- and ground-state vibrational wavepackets remains to be fully explored when multiple vibrational modes are coherently excited simultaneously by femtosecond pulses. In this work, we present a series of one- and two-dimensional electronic spectroscopy for studying multimode wavepackets of oxazine 720 in solution. Fourier transform (FT) maps combined with time-frequency transform (TFT) are employed to unambiguously distinguish the origin of low-frequency vibrational wavepackets, that is, an excited-state vibrational wavepacket of 586 cm-1 with a dephasing time of 0.7 ps and a ground-state vibrational wavepacket of 595 cm-1 with a dephasing time of 1.3-1.7 ps. We also found the additional low-frequency vibrational wavepackets resulting from the coupling of the 595 cm-1 mode to a series of high-frequency modes centered at 1150 cm-1 via electronic transitions. The combined use of FT maps and TFT analysis allows us to reveal the potential vibrational coupling of wavepackets and offers the possibility of disentangling the coupling between the electronic and vibrational degrees of freedom in condensed-phase systems.
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Affiliation(s)
- Ruidan Zhu
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiading Zou
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhuan Wang
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Hailong Chen
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Yuxiang Weng
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China.,Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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