1
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Alvertis AM, Haber JB, Engel EA, Sharifzadeh S, Neaton JB. Phonon-Induced Localization of Excitons in Molecular Crystals from First Principles. Phys Rev Lett 2023; 130:086401. [PMID: 36898125 DOI: 10.1103/physrevlett.130.086401] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 01/20/2023] [Accepted: 01/23/2023] [Indexed: 06/18/2023]
Abstract
The spatial extent of excitons in molecular systems underpins their photophysics and utility for optoelectronic applications. Phonons are reported to lead to both exciton localization and delocalization. However, a microscopic understanding of phonon-induced (de)localization is lacking, in particular, how localized states form, the role of specific vibrations, and the relative importance of quantum and thermal nuclear fluctuations. Here, we present a first-principles study of these phenomena in solid pentacene, a prototypical molecular crystal, capturing the formation of bound excitons, exciton-phonon coupling to all orders, and phonon anharmonicity, using density functional theory, the ab initio GW-Bethe-Salpeter equation approach, finite-difference, and path integral techniques. We find that for pentacene zero-point nuclear motion causes uniformly strong localization, with thermal motion providing additional localization only for Wannier-Mott-like excitons. Anharmonic effects drive temperature-dependent localization, and, while such effects prevent the emergence of highly delocalized excitons, we explore the conditions under which these might be realized.
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Affiliation(s)
- Antonios M Alvertis
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Physics, University of California Berkeley, Berkeley, 94720 California, USA
| | - Jonah B Haber
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Physics, University of California Berkeley, Berkeley, 94720 California, USA
| | - Edgar A Engel
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Sahar Sharifzadeh
- Division of Materials Science and Engineering, Boston University, Boston, 02215 Massachusetts, USA
- Department of Electrical and Computer Engineering, Boston University, Boston, 02215 Massachusetts, USA
| | - Jeffrey B Neaton
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Physics, University of California Berkeley, Berkeley, 94720 California, USA
- Kavli Energy NanoScience Institute at Berkeley, Berkeley, 94720 California, USA
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2
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Gillett AJ, Pershin A, Pandya R, Feldmann S, Sneyd AJ, Alvertis AM, Evans EW, Thomas TH, Cui LS, Drummond BH, Scholes GD, Olivier Y, Rao A, Friend RH, Beljonne D. Dielectric control of reverse intersystem crossing in thermally activated delayed fluorescence emitters. Nat Mater 2022; 21:1150-1157. [PMID: 35927434 PMCID: PMC7613666 DOI: 10.1038/s41563-022-01321-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 06/13/2022] [Indexed: 05/22/2023]
Abstract
Thermally activated delayed fluorescence enables organic semiconductors with charge transfer-type excitons to convert dark triplet states into bright singlets via reverse intersystem crossing. However, thus far, the contribution from the dielectric environment has received insufficient attention. Here we study the role of the dielectric environment in a range of thermally activated delayed fluorescence materials with varying changes in dipole moment upon optical excitation. In dipolar emitters, we observe how environmental reorganization after excitation triggers the full charge transfer exciton formation, minimizing the singlet-triplet energy gap, with the emergence of two (reactant-inactive) modes acting as a vibrational fingerprint of the charge transfer product. In contrast, the dielectric environment plays a smaller role in less dipolar materials. The analysis of energy-time trajectories and their free-energy functions reveals that the dielectric environment substantially reduces the activation energy for reverse intersystem crossing in dipolar thermally activated delayed fluorescence emitters, increasing the reverse intersystem crossing rate by three orders of magnitude versus the isolated molecule.
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Affiliation(s)
| | - Anton Pershin
- Laboratory for Chemistry of Novel Materials, Université de Mons, Mons, Belgium
- Wigner Research Centre for Physics, Budapest, Hungary
| | - Raj Pandya
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Sascha Feldmann
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | | | | | - Emrys W Evans
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- Department of Chemistry, Swansea University, Swansea, UK
| | - Tudor H Thomas
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Lin-Song Cui
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, China
| | | | | | - Yoann Olivier
- Unité de Chimie Physique Théorique et Structurale & Laboratoire de Physique du Solide, Namur Institute of Structured Matter, Université de Namur, Namur, Belgium
| | - Akshay Rao
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | | | - David Beljonne
- Laboratory for Chemistry of Novel Materials, Université de Mons, Mons, Belgium.
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3
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Lambropoulos K, Alvertis AM, Morphis A, Simserides C. Cyclo[18]carbon including zero-point motion: ground state, first singlet and triplet excitations, and hole transfer. Phys Chem Chem Phys 2022; 24:7779-7787. [PMID: 35293921 DOI: 10.1039/d2cp00343k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Recent synthesis of cyclo[18]carbon has spurred increasing interest in carbon rings. We focus on a comparative inspection of ground and excited states, as well as of hole transfer properties of cumulenic and polyynic cyclo[18]carbon via Density Functional Theory (DFT), time-dependent DFT (TD-DFT) and real-time time-dependent DFT (RT-TDDFT). Zero-point vibrations are also accounted for, using a Monte Carlo sampling technique and a less exact, yet mode-resolved, quadratic approximation. The inclusion of zero-point vibrations leads to a red-shift on the HOMO-LUMO gap and the first singlet and triplet excitation energies of both conformations, correcting the values of the 'static' configurations by 9% to 24%. Next, we oxidize the molecule, creating a hole at one carbon atom. Hole transfer along polyynic cyclo[18]carbon is decreased in magnitude compared to its cumulenic counterpart and lacks the symmetric features the latter displays. Contributions by each mode to energy changes and hole transfer between diametrically opposed atoms vary, with specific bond-stretching modes being dominant.
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Affiliation(s)
- Konstantinos Lambropoulos
- Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos GR-15784, Athens, Greece.
| | - Antonios M Alvertis
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, UK.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA. .,Department of Physics, University of California Berkeley, Berkeley, California 94720, USA
| | - Andreas Morphis
- Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos GR-15784, Athens, Greece.
| | - Constantinos Simserides
- Department of Physics, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos GR-15784, Athens, Greece.
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4
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Pandya R, Chen RYS, Gu Q, Sung J, Schnedermann C, Ojambati OS, Chikkaraddy R, Gorman J, Jacucci G, Onelli OD, Willhammar T, Johnstone DN, Collins SM, Midgley PA, Auras F, Baikie T, Jayaprakash R, Mathevet F, Soucek R, Du M, Alvertis AM, Ashoka A, Vignolini S, Lidzey DG, Baumberg JJ, Friend RH, Barisien T, Legrand L, Chin AW, Yuen-Zhou J, Saikin SK, Kukura P, Musser AJ, Rao A. Microcavity-like exciton-polaritons can be the primary photoexcitation in bare organic semiconductors. Nat Commun 2021; 12:6519. [PMID: 34764252 PMCID: PMC8585971 DOI: 10.1038/s41467-021-26617-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/29/2021] [Indexed: 11/12/2022] Open
Abstract
Strong-coupling between excitons and confined photonic modes can lead to the formation of new quasi-particles termed exciton-polaritons which can display a range of interesting properties such as super-fluidity, ultrafast transport and Bose-Einstein condensation. Strong-coupling typically occurs when an excitonic material is confided in a dielectric or plasmonic microcavity. Here, we show polaritons can form at room temperature in a range of chemically diverse, organic semiconductor thin films, despite the absence of an external cavity. We find evidence of strong light-matter coupling via angle-dependent peak splittings in the reflectivity spectra of the materials and emission from collective polariton states. We additionally show exciton-polaritons are the primary photoexcitation in these organic materials by directly imaging their ultrafast (5 × 106 m s-1), ultralong (~270 nm) transport. These results open-up new fundamental physics and could enable a new generation of organic optoelectronic and light harvesting devices based on cavity-free exciton-polaritons.
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Affiliation(s)
- Raj Pandya
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE Cambridge, UK
| | - Richard Y. S. Chen
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE Cambridge, UK
| | - Qifei Gu
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE Cambridge, UK
| | - Jooyoung Sung
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE Cambridge, UK
| | - Christoph Schnedermann
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE Cambridge, UK
| | - Oluwafemi S. Ojambati
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE Cambridge, UK
| | - Rohit Chikkaraddy
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE Cambridge, UK
| | - Jeffrey Gorman
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE Cambridge, UK
| | - Gianni Jacucci
- grid.5335.00000000121885934Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Olimpia D. Onelli
- grid.5335.00000000121885934Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Tom Willhammar
- grid.10548.380000 0004 1936 9377Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden
| | - Duncan N. Johnstone
- grid.5335.00000000121885934Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, CB3 0FS Cambridge, UK
| | - Sean M. Collins
- grid.5335.00000000121885934Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, CB3 0FS Cambridge, UK
| | - Paul A. Midgley
- grid.5335.00000000121885934Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, CB3 0FS Cambridge, UK
| | - Florian Auras
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE Cambridge, UK
| | - Tomi Baikie
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE Cambridge, UK
| | - Rahul Jayaprakash
- grid.11835.3e0000 0004 1936 9262Department of Physics & Astronomy, University of Sheffield, S3 7RH Sheffield, UK
| | - Fabrice Mathevet
- grid.462019.80000 0004 0370 0168Institut Parisien de Chimie Moléculaire (IPCM), Sorbonne Université, 4 Place Jussieu, 75005 Paris, France
| | - Richard Soucek
- grid.462844.80000 0001 2308 1657Institut des NanoSciences de Paris (INSP), Sorbonne Université, 4 place Jussieu, 75005 Paris, France
| | - Matthew Du
- grid.266100.30000 0001 2107 4242Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093 USA
| | - Antonios M. Alvertis
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE Cambridge, UK
| | - Arjun Ashoka
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE Cambridge, UK
| | - Silvia Vignolini
- grid.5335.00000000121885934Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - David G. Lidzey
- grid.11835.3e0000 0004 1936 9262Department of Physics & Astronomy, University of Sheffield, S3 7RH Sheffield, UK
| | - Jeremy J. Baumberg
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE Cambridge, UK
| | - Richard H. Friend
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE Cambridge, UK
| | - Thierry Barisien
- grid.462844.80000 0001 2308 1657Institut des NanoSciences de Paris (INSP), Sorbonne Université, 4 place Jussieu, 75005 Paris, France
| | - Laurent Legrand
- grid.462844.80000 0001 2308 1657Institut des NanoSciences de Paris (INSP), Sorbonne Université, 4 place Jussieu, 75005 Paris, France
| | - Alex W. Chin
- grid.462844.80000 0001 2308 1657Institut des NanoSciences de Paris (INSP), Sorbonne Université, 4 place Jussieu, 75005 Paris, France
| | - Joel Yuen-Zhou
- grid.266100.30000 0001 2107 4242Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093 USA
| | - Semion K. Saikin
- grid.38142.3c000000041936754XDepartment of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138 USA ,grid.510678.dKebotix Inc., 501 Massachusetts Avenue, Cambridge, MA 02139 USA
| | - Philipp Kukura
- grid.4991.50000 0004 1936 8948Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QZ UK
| | - Andrew J. Musser
- grid.5386.8000000041936877XDepartment of Chemistry and Chemical Biology, Cornell University, Baker Laboratory, Ithaca, NY 14853 USA
| | - Akshay Rao
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE, Cambridge, UK.
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5
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Hele TJH, Monserrat B, Alvertis AM. Systematic improvement of molecular excited state calculations by inclusion of nuclear quantum motion: A mode-resolved picture and the effect of molecular size. J Chem Phys 2021; 154:244109. [PMID: 34241372 DOI: 10.1063/5.0052247] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The energies of molecular excited states arise as solutions to the electronic Schrödinger equation and are often compared to experiment. At the same time, nuclear quantum motion is known to be important and to induce a redshift of excited state energies. However, it is thus far unclear whether incorporating nuclear quantum motion in molecular excited state calculations leads to a systematic improvement of their predictive accuracy, making further investigation necessary. Here, we present such an investigation by employing two first-principles methods for capturing the effect of quantum fluctuations on excited state energies, which we apply to the Thiel set of organic molecules. We show that accounting for zero-point motion leads to much improved agreement with experiment, compared to "static" calculations that only account for electronic effects, and the magnitude of the redshift can become as large as 1.36 eV. Moreover, we show that the effect of nuclear quantum motion on excited state energies largely depends on the molecular size, with smaller molecules exhibiting larger redshifts. Our methodology also makes it possible to analyze the contribution of individual vibrational normal modes to the redshift of excited state energies, and in several molecules, we identify a limited number of modes dominating this effect. Overall, our study provides a foundation for systematically quantifying the shift of excited state energies due to nuclear quantum motion and for understanding this effect at a microscopic level.
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Affiliation(s)
- Timothy J H Hele
- Department of Chemistry, University College London, 20, Gordon Street, London WC1H 0AJ, United Kingdom
| | - Bartomeu Monserrat
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - Antonios M Alvertis
- Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, United Kingdom
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6
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Pandya R, Alvertis AM, Gu Q, Sung J, Legrand L, Kréher D, Barisien T, Chin AW, Schnedermann C, Rao A. Exciton Diffusion in Highly-Ordered One Dimensional Conjugated Polymers: Effects of Back-Bone Torsion, Electronic Symmetry, Phonons and Annihilation. J Phys Chem Lett 2021; 12:3669-3678. [PMID: 33829788 PMCID: PMC8154834 DOI: 10.1021/acs.jpclett.1c00193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
Many optoelectronic devices based on organic materials require rapid and long-range singlet exciton transport. Key factors controlling exciton transport include material structure, exciton-phonon coupling and electronic state symmetry. Here, we employ femtosecond transient absorption microscopy to study the influence of these parameters on exciton transport in one-dimensional conjugated polymers. We find that excitons with 21Ag- symmetry and a planar backbone exhibit a significantly higher diffusion coefficient (34 ± 10 cm2 s-1) compared to excitons with 11Bu+ symmetry (7 ± 6 cm2 s-1) with a twisted backbone. We also find that exciton transport in the 21Ag- state occurs without exciton-exciton annihilation. Both 21Ag- and 11Bu+ states are found to exhibit subdiffusive behavior. Ab initio GW-BSE calculations reveal that this is due to the comparable strengths of the exciton-phonon interaction and exciton coupling. Our results demonstrate the link between electronic state symmetry, backbone torsion and phonons in exciton transport in π-conjugated polymers.
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Affiliation(s)
- Raj Pandya
- Cavendish
Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE, Cambridge, United Kingdom
| | - Antonios M. Alvertis
- Cavendish
Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE, Cambridge, United Kingdom
| | - Qifei Gu
- Cavendish
Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE, Cambridge, United Kingdom
| | - Jooyoung Sung
- Cavendish
Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE, Cambridge, United Kingdom
| | - Laurent Legrand
- Sorbonne
Université, CNRS, Institut
des NanoSciences de Paris, INSP, 4 place Jussieu, F-75005 Paris, France
| | - David Kréher
- Sorbonne
Université, CNRS, Institut
Parisien de Chimie Moléculaire (IPCM) UMR 8232, Chimie des
Polymères, 4 Place
Jussieu, 75005 Paris, France
| | - Thierry Barisien
- Sorbonne
Université, CNRS, Institut
des NanoSciences de Paris, INSP, 4 place Jussieu, F-75005 Paris, France
| | - Alex W. Chin
- Sorbonne
Université, CNRS, Institut
des NanoSciences de Paris, INSP, 4 place Jussieu, F-75005 Paris, France
| | - Christoph Schnedermann
- Cavendish
Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE, Cambridge, United Kingdom
| | - Akshay Rao
- Cavendish
Laboratory, University of Cambridge, J.J. Thomson Avenue, CB3 0HE, Cambridge, United Kingdom
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7
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Gray V, Zhang Z, Dowland S, Allardice JR, Alvertis AM, Xiao J, Greenham NC, Anthony JE, Rao A. Thiol-Anchored TIPS-Tetracene Ligands with Quantitative Triplet Energy Transfer to PbS Quantum Dots and Improved Thermal Stability. J Phys Chem Lett 2020; 11:7239-7244. [PMID: 32787302 DOI: 10.1021/acs.jpclett.0c02031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Triplet energy transfer between inorganic quantum dots (QDs) and organic materials plays a fundamental role in many optoelectronic applications based on these nanocomposites. Attaching organic molecules to the QD as transmitter ligands has been shown to facilitate transfer both to and from QDs. Here we show that the often disregarded thiol anchoring group can achieve quantitative triplet energy transfer yields in a PbS QD system with 6,11-bis[(triisopropylsilyl)ethynyl]tetracene-2-methylthiol (TET-SH) ligands. We demonstrate efficient triplet transfer in a singlet fission-based photon multiplication system with 5,12-bis[(triisopropylsilyl)ethynyl]tetracene generating triplets in solution that transfer to the PbS QDs via the thiol ligand TET-SH. Importantly, we demonstrate the increased thermal stability of the PbS/TET-SH system, compared to the traditional carboxylic acid counterpart, allowing for higher photoluminescence quantum yields.
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Affiliation(s)
- Victor Gray
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, U.K
- Ångström Laboratory, Department of Chemistry, Uppsala University, Box 523, 751 20 Uppsala, Sweden
| | - Zhilong Zhang
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, U.K
| | - Simon Dowland
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, U.K
| | - Jesse R Allardice
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, U.K
| | - Antonios M Alvertis
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, U.K
| | - James Xiao
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, U.K
| | - Neil C Greenham
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, U.K
| | - John E Anthony
- University of Kentucky Center for Applied Energy Research, 2582 Research Park Drive, Lexington, Kentucky 40511, United States
| | - Akshay Rao
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, U.K
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8
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Alvertis AM, Pandya R, Quarti C, Legrand L, Barisien T, Monserrat B, Musser AJ, Rao A, Chin AW, Beljonne D. First principles modeling of exciton-polaritons in polydiacetylene chains. J Chem Phys 2020; 153:084103. [PMID: 32872885 DOI: 10.1063/5.0019009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Exciton-polaritons in organic materials are hybrid states that result from the strong interaction of photons and the bound excitons that these materials host. Organic polaritons hold great interest for optoelectronic applications; however, progress toward this end has been impeded by the lack of a first principles approach that quantifies light-matter interactions in these systems, which would allow the formulation of molecular design rules. Here, we present a theoretical framework that combines first principles calculations for excitons with classical electrodynamics in order to quantify light-matter interactions. We exemplify our approach by studying variants of the conjugated polymer polydiacetylene, and we show that a large polymer conjugation length is critical toward strong exciton-photon coupling, hence underlying the importance of pure structures without static disorder. By comparing to our experimental reflectivity measurements, we show that the coupling of excitons to vibrations, manifested by phonon side bands in the absorption, has a strong impact on the magnitude of light-matter coupling over a range of frequencies. Our approach opens the way toward a deeper understanding of polaritons in organic materials, and we highlight that a quantitatively accurate calculation of the exciton-photon interaction would require accounting for all sources of disorder self-consistently.
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Affiliation(s)
- Antonios M Alvertis
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Raj Pandya
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Claudio Quarti
- Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc, 20, B-7000 Mons, Belgium
| | - Laurent Legrand
- Sorbonne Universite, CNRS-UMR 7588, Institut des NanoSciences de Paris, INSP, 4 Place Jussieu, F-75005 Paris, France
| | - Thierry Barisien
- Sorbonne Universite, CNRS-UMR 7588, Institut des NanoSciences de Paris, INSP, 4 Place Jussieu, F-75005 Paris, France
| | - Bartomeu Monserrat
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Andrew J Musser
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA
| | - Akshay Rao
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Alex W Chin
- Sorbonne Universite, CNRS-UMR 7588, Institut des NanoSciences de Paris, INSP, 4 Place Jussieu, F-75005 Paris, France
| | - David Beljonne
- Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc, 20, B-7000 Mons, Belgium
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9
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Alvertis AM, Lukman S, Hele TJH, Fuemmeler EG, Feng J, Wu J, Greenham NC, Chin AW, Musser AJ. Switching between Coherent and Incoherent Singlet Fission via Solvent-Induced Symmetry Breaking. J Am Chem Soc 2019; 141:17558-17570. [DOI: 10.1021/jacs.9b05561] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Antonios M. Alvertis
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Steven Lukman
- Institute of Materials Research and Engineering, Agency for Science Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Timothy J. H. Hele
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Eric G. Fuemmeler
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Jiaqi Feng
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543 Singapore
| | - Jishan Wu
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543 Singapore
| | - Neil C. Greenham
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Alex W. Chin
- CNRS & Institut des NanoSciences de Paris, Sorbonne Université, 4 place Jussieu boite courrier 840, 75252 Paris Cedex 05, France
| | - Andrew J. Musser
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
- Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield S3 7RH, U.K
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Schnedermann C, Alvertis AM, Wende T, Lukman S, Feng J, Schröder FAYN, Turban DHP, Wu J, Hine NDM, Greenham NC, Chin AW, Rao A, Kukura P, Musser AJ. A molecular movie of ultrafast singlet fission. Nat Commun 2019; 10:4207. [PMID: 31527736 PMCID: PMC6746807 DOI: 10.1038/s41467-019-12220-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 08/26/2019] [Indexed: 11/09/2022] Open
Abstract
The complex dynamics of ultrafast photoinduced reactions are governed by their evolution along vibronically coupled potential energy surfaces. It is now often possible to identify such processes, but a detailed depiction of the crucial nuclear degrees of freedom involved typically remains elusive. Here, combining excited-state time-domain Raman spectroscopy and tree-tensor network state simulations, we construct the full 108-atom molecular movie of ultrafast singlet fission in a pentacene dimer, explicitly treating 252 vibrational modes on 5 electronic states. We assign the tuning and coupling modes, quantifying their relative intensities and contributions, and demonstrate how these modes coherently synchronise to drive the reaction. Our combined experimental and theoretical approach reveals the atomic-scale singlet fission mechanism and can be generalized to other ultrafast photoinduced reactions in complex systems. This will enable mechanistic insight on a detailed structural level, with the ultimate aim to rationally design molecules to maximise the efficiency of photoinduced reactions. Ultrafast photo-induced processes in complex systems require theoretical models and their experimental validation which are still lacking. Here the authors investigate singlet fission in a pentacene dimer by a combined experimental and theoretical approach providing a real-time visualisation of the process.
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Affiliation(s)
- Christoph Schnedermann
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK. .,Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, UK.
| | - Antonios M Alvertis
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Torsten Wende
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, UK
| | - Steven Lukman
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK.,Institute of Materials Research and Engineering, Agency for Science Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore, 138634, Singapore
| | - Jiaqi Feng
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
| | - Florian A Y N Schröder
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK
| | - David H P Turban
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Jishan Wu
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
| | - Nicholas D M Hine
- Department of Physics, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK
| | - Neil C Greenham
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Alex W Chin
- Centre National de la Recherce Scientifique, Institute des Nanosciences de Paris, Sorbonne Universite, Paris, France
| | - Akshay Rao
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Philipp Kukura
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, UK
| | - Andrew J Musser
- Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield, S3 7RH, UK. .,Department of Chemistry and Chemical Biology, Cornell University, Baker Laboratory, Ithaca, NY, 14853, USA.
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Alvertis AM, Schröder FAYN, Chin AW. Non-equilibrium relaxation of hot states in organic semiconductors: Impact of mode-selective excitation on charge transfer. J Chem Phys 2019; 151:084104. [PMID: 31470711 DOI: 10.1063/1.5115239] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The theoretical study of open quantum systems strongly coupled to a vibrational environment remains computationally challenging due to the strongly non-Markovian characteristics of the dynamics. We study this problem in the case of a molecular dimer of the organic semiconductor tetracene, the exciton states of which are strongly coupled to a few hundreds of molecular vibrations. To do so, we employ a previously developed tensor network approach, based on the formalism of matrix product states. By analyzing the entanglement structure of the system wavefunction, we can expand it in a tree tensor network state, which allows us to perform a fully quantum mechanical time evolution of the exciton-vibrational system, including the effect of 156 molecular vibrations. We simulate the dynamics of hot states, i.e., states resulting from excess energy photoexcitation, by constructing various initial bath states, and show that the exciton system indeed has a memory of those initial configurations. In particular, the specific pathway of vibrational relaxation is shown to strongly affect the quantum coherence between exciton states in time scales relevant for the ultrafast dynamics of application-relevant processes such as charge transfer. The preferential excitation of low-frequency modes leads to a limited number of relaxation pathways, thus "protecting" quantum coherence and leading to a significant increase in the charge transfer yield in the dimer structure.
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Affiliation(s)
- Antonios M Alvertis
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Florian A Y N Schröder
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Alex W Chin
- CNRS, Institut des NanoSciences de Paris, Sorbonne Université, 4 place Jussieu boite courrier 840, 75252 Paris Cedex 05, France
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