1
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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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Feng J, Hosseinabadi P, de Clercq DM, Carwithen BP, Nielsen MP, Brett MW, Prasad SKK, Farahani AAD, Li HL, Sanders SN, Beves JE, Ekins-Daukes NJ, Cole JH, Thordarson P, Huang DM, Tayebjee MJY, Schmidt TW. Magnetic fields reveal signatures of triplet-pair multi-exciton photoluminescence in singlet fission. Nat Chem 2024:10.1038/s41557-024-01591-0. [PMID: 39054380 DOI: 10.1038/s41557-024-01591-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 07/01/2024] [Indexed: 07/27/2024]
Abstract
The photophysical processes of singlet fission and triplet fusion have numerous emerging applications. They involve the separation of a photo-generated singlet exciton into two dark triplet excitons and the fusion of two dark triplet excitons into an emissive singlet exciton, respectively. The role of the excimer state and the nature of the triplet-pair state in these processes have been a matter of contention. Here we analyse the room temperature time-resolved emission of a neat liquid singlet fission chromophore and show that it exhibits three spectral components: two that correspond to the bright singlet and excimer states and a third component that becomes more prominent during triplet fusion. This spectrum is enhanced by magnetic fields, confirming its origins in the recombination of weakly coupled triplet pairs. It is thus attributed to a strongly coupled triplet pair state. These observations unite the view that there is an emissive intermediate in singlet fission and triplet fusion, distinct from the broad, unstructured excimer emission.
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Affiliation(s)
- Jiale Feng
- ARC Centre of Excellence in Exciton Science, School of Chemistry, UNSW Sydney, Sydney, New South Wales, Australia
| | - Parisa Hosseinabadi
- School of Photovoltaic and Renewable Energy Engineering, UNSW Sydney, Sydney, New South Wales, Australia
| | - Damon M de Clercq
- ARC Centre of Excellence in Exciton Science, School of Chemistry, UNSW Sydney, Sydney, New South Wales, Australia
| | - Ben P Carwithen
- ARC Centre of Excellence in Exciton Science, School of Chemistry, UNSW Sydney, Sydney, New South Wales, Australia
| | - Michael P Nielsen
- School of Photovoltaic and Renewable Energy Engineering, UNSW Sydney, Sydney, New South Wales, Australia
| | - Matthew W Brett
- ARC Centre of Excellence in Exciton Science, School of Chemistry, UNSW Sydney, Sydney, New South Wales, Australia
| | - Shyamal K K Prasad
- ARC Centre of Excellence in Exciton Science, School of Chemistry, UNSW Sydney, Sydney, New South Wales, Australia
| | - Adam A D Farahani
- The UNSW RNA Institute, The Australian Centre for Nanomedicine, School of Chemistry, UNSW Sydney, Sydney, New South Wales, Australia
| | - Hsiu L Li
- The UNSW RNA Institute, The Australian Centre for Nanomedicine, School of Chemistry, UNSW Sydney, Sydney, New South Wales, Australia
| | | | - Jonathon E Beves
- ARC Centre of Excellence in Exciton Science, School of Chemistry, UNSW Sydney, Sydney, New South Wales, Australia
| | - N J Ekins-Daukes
- School of Photovoltaic and Renewable Energy Engineering, UNSW Sydney, Sydney, New South Wales, Australia
| | - Jared H Cole
- ARC Centre of Excellence in Exciton Science, School of Science, RMIT University, Melbourne, Victoria, Australia
| | - Pall Thordarson
- The UNSW RNA Institute, The Australian Centre for Nanomedicine, School of Chemistry, UNSW Sydney, Sydney, New South Wales, Australia
| | - David M Huang
- Department of Chemistry, School of Physics, Chemistry and Earth Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Murad J Y Tayebjee
- School of Photovoltaic and Renewable Energy Engineering, UNSW Sydney, Sydney, New South Wales, Australia
| | - Timothy W Schmidt
- ARC Centre of Excellence in Exciton Science, School of Chemistry, UNSW Sydney, Sydney, New South Wales, Australia.
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3
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Kim J, Bain DC, Ding V, Majumder K, Windemuller D, Feng J, Wu J, Patil S, Anthony J, Kim W, Musser AJ. Coherent photoexcitation of entangled triplet pair states. Nat Chem 2024:10.1038/s41557-024-01556-3. [PMID: 38898214 DOI: 10.1038/s41557-024-01556-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 05/13/2024] [Indexed: 06/21/2024]
Abstract
The functional properties of organic semiconductors are defined by the interplay between optically bright and dark states. Organic devices require rapid conversion between these bright and dark manifolds for maximum efficiency, and one way to achieve this is through multiexciton generation (S1→1TT). The dark state 1TT is typically generated from bright S1 after optical excitation; however, the mechanistic details are hotly debated. Here we report a 1TT generation pathway in which it can be coherently photoexcited, without any involvement of bright S1. Using <10-fs transient absorption spectroscopy and pumping sub-resonantly, 1TT is directly generated from the ground state. Applying this method to a range of pentacene dimers and thin films of various aggregation types, we determine the critical material properties that enable this forbidden pathway. Through a strikingly simple technique, this result opens the door for new mechanistic insights into 1TT and other dark states in organic materials.
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Affiliation(s)
- Juno Kim
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - David C Bain
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Vivian Ding
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Kanad Majumder
- Solid State and Structural Chemistry Unit, Indian Institute of Sciences, Bangalore, Republic of India
| | - Dean Windemuller
- Center for Applied Energy Research, University of Kentucky, Lexington, KY, USA
| | - Jiaqi Feng
- Department of Chemistry, National University of Singapore, Singapore, Republic of Singapore
| | - Jishan Wu
- Department of Chemistry, National University of Singapore, Singapore, Republic of Singapore
| | - Satish Patil
- Solid State and Structural Chemistry Unit, Indian Institute of Sciences, Bangalore, Republic of India
| | - John Anthony
- Center for Applied Energy Research, University of Kentucky, Lexington, KY, USA
| | - Woojae Kim
- Department of Chemistry, Yonsei University, Seoul, Republic of Korea.
| | - Andrew J Musser
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA.
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4
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Reddy SR, Coto PB, Thoss M. Intramolecular singlet fission: Quantum dynamical simulations including the effect of the laser field. J Chem Phys 2024; 160:194306. [PMID: 38767260 DOI: 10.1063/5.0209546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Accepted: 04/30/2024] [Indexed: 05/22/2024] Open
Abstract
In the previous work [Reddy et al., J. Chem. Phys. 151, 044307 (2019)], we have analyzed the dynamics of the intramolecular singlet fission process in a series of prototypical pentacene-based dimers, where the pentacene monomers are covalently bonded to a phenylene linker in ortho, meta, and para positions. The results obtained were qualitatively consistent with the experimental data available, showing an ultrafast population of the multiexcitonic state that mainly takes place via a mediated (superexchange-like) mechanism involving charge transfer and doubly excited states. Our results also highlighted the instrumental role of molecular vibrations in the process as a sizable population of the multiexcitonic state could only be obtained through vibronic coupling. Here, we extend these studies and investigate the effect of the laser field on the dynamics of intramolecular singlet fission by explicitly including the coupling to the laser field in our model. In this manner, and by selectively tuning the laser field to the different low-lying absorption bands of the systems investigated, we analyze the wavelength dependence of the intramolecular singlet fission process. In addition, we have also analyzed how the nature of the initially photoexcited electronic state (either localized or delocalized) affects its dynamics. Altogether, our results provide new insights into the design of intramolecular singlet fission-active molecules.
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Affiliation(s)
- S Rajagopala Reddy
- Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan 305817, India
| | - Pedro B Coto
- Materials Physics Center (CFM), Spanish National Research Council (CSIC) and Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 5, 20018 Donostia-San Sebastián, Spain
| | - Michael Thoss
- Institute of Physics, Albert-Ludwigs University Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
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5
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Kim J, Teo HT, Hong Y, Cha H, Kim W, Chi C, Kim D. Elucidating Singlet-Fission-Born Multiexciton Dynamics via Molecular Engineering: A Dilution Principle Extended to Quintet Triplet Pair. J Am Chem Soc 2024; 146:10833-10846. [PMID: 38578848 DOI: 10.1021/jacs.4c01326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2024]
Abstract
Multiexciton in singlet exciton fission represents a critical quantum state with significant implications for both solar cell applications and quantum information science. Two distinct fields of interest explore contrasting phenomena associated with the geminate triplet pair: one focusing on the persistence of long-lived correlation and the other emphasizing efficient decorrelation. Despite the pivotal nature of multiexciton processes, a comprehensive understanding of their dependence on the structural and spin properties of materials is currently lacking in experimental realizations. To address this gap in knowledge, molecular engineering was employed to modify the TIPS-tetracene structures, enabling an investigation of the structure-property relationships in spin-related multiexciton processes. In lieu of the time-resolved electron paramagnetic resonance technique, two time-resolved magneto-optical spectroscopies were implemented for quantitative analysis of spin-dependent multiexciton dynamics. The utilization of absorption and fluorescence signals as complementary optical readouts, in the presence of a magnetic field, provided crucial insights into geminate triplet pair dynamics. These insights encompassed the duration of multiexciton correlation and the involvement of the spin state in multiexciton decorrelation. Furthermore, simulations based on our kinetic models suggested a role for quintet dilution in multiexciton dynamics, surpassing the singlet dilution principle established by the Merrifield model. The integration of intricate model structures and time-resolved magneto-optical spectroscopies served to explicitly elucidate the interplay between structural and spin properties in multiexciton processes. This comprehensive approach not only contributes to the fundamental understanding of these processes but also aligns with and reinforces previous experimental studies of solid states and theoretical assessments.
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Affiliation(s)
- Juno Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, Seoul 03722, Korea
| | - Hao Ting Teo
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Yongseok Hong
- Department of Chemistry, Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, Seoul 03722, Korea
| | - Hyojung Cha
- Department of Hydrogen and Renewable Energy, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Woojae Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, Seoul 03722, Korea
| | - Chunyan Chi
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Dongho Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, Seoul 03722, Korea
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6
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Cohen G, Haber JB, Neaton JB, Qiu DY, Refaely-Abramson S. Phonon-Driven Femtosecond Dynamics of Excitons in Crystalline Pentacene from First Principles. PHYSICAL REVIEW LETTERS 2024; 132:126902. [PMID: 38579218 DOI: 10.1103/physrevlett.132.126902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 08/24/2023] [Accepted: 02/11/2024] [Indexed: 04/07/2024]
Abstract
Nonradiative exciton relaxation processes are critical for energy transduction and transport in optoelectronic materials, but how these processes are connected to the underlying crystal structure and the associated electron, exciton, and phonon band structures, as well as the interactions of all these particles, is challenging to understand. Here, we present a first-principles study of exciton-phonon relaxation pathways in pentacene, a paradigmatic molecular crystal and optoelectronic semiconductor. We compute the momentum- and band-resolved exciton-phonon interactions, and use them to analyze key scattering channels. We find that both exciton intraband scattering and interband scattering to parity-forbidden dark states occur on the same ∼100 fs timescale as a direct consequence of the longitudinal-transverse splitting of the bright exciton band. Consequently, exciton-phonon scattering exists as a dominant nonradiative relaxation channel in pentacene. We further show how the propagation of an exciton wave packet is connected with crystal anisotropy, which gives rise to the longitudinal-transverse exciton splitting and concomitant anisotropic exciton and phonon dispersions. Our results provide a framework for understanding the role of exciton-phonon interactions in exciton nonradiative lifetimes in molecular crystals and beyond.
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Affiliation(s)
- Galit Cohen
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Jonah B Haber
- Department of Physics, University of California Berkeley, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Jeffrey B Neaton
- Department of Physics, University of California Berkeley, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Kavli Energy Nanosciences Institute at Berkeley, Berkeley, California 94720, USA
| | - Diana Y Qiu
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06520, USA
| | - Sivan Refaely-Abramson
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
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7
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Kefer O, Kolesnichenko PV, Buckup T. Two-dimensional coherent electronic spectrometer with switchable multi-color configurations. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:023003. [PMID: 38416044 DOI: 10.1063/5.0186915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 02/05/2024] [Indexed: 02/29/2024]
Abstract
Broadband implementation of two-dimensional electronic spectroscopy (2DES) is a desirable goal for numerous research groups, yet achieving it presents considerable challenges. An effective strategy to mitigate these challenges is the utilization of two-color approaches, effectively broadening the spectral bandwidth accessible with 2DES. Here, we present a simple approach to include multi-color configurations based on adjustable mirror mounts. This enables seamless toggling between single-color, two-color, and transient 2DES within the same spectroscopic apparatus, which is benchmarked on two common laser dyes, Rhodamine 6G and Nile blue. Upon mixing the dyes, single-color 2DES shows overlapping signals, whereas a high selectivity toward Nile blue responses is maintained in two-color and transient 2DES, owing to the fully resonant excitation that is spectrally shifted relative to the detection window. This method is readily implemented in other setups with similar experimental layouts and can be used as a simple solution to overcome existing bandwidth limitations. With the inclusion of transient 2DES, additional insights into excited-state processes can be gained due to its increased sensitivity toward excited-state coherences.
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Affiliation(s)
- Oskar Kefer
- Physikalisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, D-69120 Heidelberg, Germany
| | - Pavel V Kolesnichenko
- Physikalisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, D-69120 Heidelberg, Germany
| | - Tiago Buckup
- Physikalisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, D-69120 Heidelberg, Germany
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8
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Timmer D, Lünemann DC, Riese S, Sio AD, Lienau C. Full visible range two-dimensional electronic spectroscopy with high time resolution. OPTICS EXPRESS 2024; 32:835-847. [PMID: 38175103 DOI: 10.1364/oe.511906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 12/14/2023] [Indexed: 01/05/2024]
Abstract
Two-dimensional electronic spectroscopy (2DES) is a powerful method to study coherent and incoherent interactions and dynamics in complex quantum systems by correlating excitation and detection energies in a nonlinear spectroscopy experiment. Such dynamics can be probed with a time resolution limited only by the duration of the employed laser pulses and in a spectral range defined by the pulse spectrum. In the blue spectral range (<500 nm), the generation of sufficiently broadband ultrashort pulses with pulse durations of 10 fs or less has been challenging so far. Here, we present a 2DES setup based on a hollow-core fiber supercontinuum covering the full visible range (400-700 nm). Pulse compression via custom-made chirped mirrors yields a time resolution of <10 fs. The broad spectral coverage, in particular the extension of the pulse spectra into the blue spectral range, unlocks new possibilities for coherent investigations of blue-light absorbing and multichromophoric compounds, as demonstrated by a 2DES measurement of chlorophyll a.
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9
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Bhattacharyya A, Sahu A, Patra S, Tiwari V. Low- and high-frequency vibrations synergistically enhance singlet exciton fission through robust vibronic resonances. Proc Natl Acad Sci U S A 2023; 120:e2310124120. [PMID: 38019862 PMCID: PMC10710028 DOI: 10.1073/pnas.2310124120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 10/14/2023] [Indexed: 12/01/2023] Open
Abstract
Singlet exciton fission (SEF) is initiated by ultrafast internal conversion of a singlet exciton into a correlated triplet pair [Formula: see text]. The "reaction coordinates" for ultrafast SEF even in archetypal systems such as pentacene thin film remain unclear. Couplings between fast electrons and slow nuclei are ubiquitous across a range of phenomena in chemistry. Accordingly, spectroscopic detection of vibrational coherences in the [Formula: see text] photoproduct motivated investigations into a possible role of vibronic coupling, akin to that reported in several photosynthetic proteins. However, acenes are very different from chlorophylls with 10× larger vibrational displacements upon photoexcitation and low-frequency vibrations modulating intermolecular orbital overlaps. Whether (and if so how) these unique features carry any mechanistic significance for SEF remains a poorly understood question. Accordingly, synthetic design of new molecules aiming to mimic this process across the solar spectrum has broadly relied on tuning electronic couplings. We address this gap and identify previously unrecognized synergistic interplay of vibrations, which in striking contrast to photosynthesis, vitally enhances SEF across a broad, nonselective and, therefore, unavoidable range of vibrational frequencies. We argue that attaching mechanistic significance to spectroscopically observed prominent quantum beats is misleading. Instead, we show that vibronic mixing leads to anisotropic quantum beats and propose readily implementable polarization-based two-dimensional electronic spectroscopy experiments which uniquely distinguish vibrations which drive vibronic mixing and promote SEF, against spectator vibrations simply accompanying ultrafast internal conversion. Our findings introduce crucial ingredients in synthetic design of SEF materials and spectroscopy experiments aiming to decipher mechanistic details from quantum beats.
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Affiliation(s)
- Atandrita Bhattacharyya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore560012, India
| | - Amitav Sahu
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore560012, India
| | - Sanjoy Patra
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore560012, India
| | - Vivek Tiwari
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore560012, India
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10
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Kim J, Teo HT, Hong Y, Liau YC, Yim D, Han Y, Oh J, Kim H, Chi C, Kim D. Leveraging Charge-Transfer Interactions in Through-Space-Coupled Pentacene Dendritic Oligomer for Singlet Exciton Fission. J Am Chem Soc 2023; 145:19812-19823. [PMID: 37656929 DOI: 10.1021/jacs.3c05660] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/03/2023]
Abstract
Singlet exciton fission in organic chromophores has received much attention during the past decade. Inspired by numerous spectroscopic studies in the solid state, there have been vigorous efforts to study singlet exciton fission dynamics in covalently bonded oligomers, which aims to investigate underlying mechanisms of this intriguing process in simplified model systems. In terms of through-space orbital interactions, however, most of covalently bonded pentacene oligomers studied so far fall into weakly interacting systems since they manifest chain-like structures based on various (non)conjugated linkers. Therefore, it remains as a compelling question to answer how through-space interactions in the solid state intervene this photophysical process since it is hypersensitive to displacements and orientations between neighboring chromophores. Herein, as one of experimental studies to answer this question, we introduced a tight-packing dendritic structure whose mesityl-pentacene constituents are coupled via moderate through-space orbital interactions. Based on the comparison with a suitably controlled dendritic structure, which is in a weak coupling regime, important mechanistic viewpoints are tackled such as configurational mixings between singlet, charge-transfer, and triplet pair states and the role of chromophore multiplication. We underscore that our through-space-coupled dendritic oligomer in a quasi-intermediate coupling regime provides a hint on the interplay of multiconfigurational excited-states, which might have drawn complexity in singlet exciton fission kinetics throughout numerous solid-state morphologies.
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Affiliation(s)
- Juno Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, Seoul 03722, Korea
| | - Hao Ting Teo
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Yongseok Hong
- Department of Chemistry, Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, Seoul 03722, Korea
| | - Yuan Cheng Liau
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Daniel Yim
- Department of Chemistry, Incheon National University, Incheon 22012, Korea
| | - Yi Han
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Juwon Oh
- Department of ICT Environmental Health System and Department of Chemistry, Soonchunhyang University, Asan 31538, Korea
| | - Hyungjun Kim
- Department of Chemistry, Incheon National University, Incheon 22012, Korea
| | - Chunyan Chi
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Dongho Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional π-Electronic Systems, Yonsei University, Seoul 03722, Korea
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11
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Deckert T, Vanderhaegen A, Brida D. Sub-8-fs pulses in the visible to near-infrared by a degenerate optical parametric amplifier. OPTICS LETTERS 2023; 48:4496-4499. [PMID: 37656537 DOI: 10.1364/ol.498291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 08/03/2023] [Indexed: 09/03/2023]
Abstract
This work presents a single-stage optical parametric amplifier (OPA) operating at degeneracy (DOPA) and pumped by the third harmonic of a Yb:KGW laser system. This DOPA exploits the broad amplification bandwidth that occurs with type-I phase-matching in β-barium borate (BBO) when signal and idler overlap in the spectrum. The output pulses span from 590 to 780 nm (1.59-2.10 eV) with 7.75-fs duration after compression. Ultrashort pulses with similar bandwidths in this spectral window complement the existing array of optical parametric amplifiers that cover either the visible or the near-IR spectral regions with sub-10-fs pulses. This source of ultrashort optical pulses will enable the application of sophisticated spectroscopy techniques to the study of electronic coherences and energy migration pathways in biological, chemical, and condensed matter systems.
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12
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Terry Weatherly CK, Provazza J, Weiss EA, Tempelaar R. Theory predicts UV/vis-to-IR photonic down conversion mediated by excited state vibrational polaritons. Nat Commun 2023; 14:4804. [PMID: 37558658 PMCID: PMC10412565 DOI: 10.1038/s41467-023-40400-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 07/25/2023] [Indexed: 08/11/2023] Open
Abstract
This work proposes a photophysical phenomenon whereby ultraviolet/visible (UV/vis) excitation of a molecule involving a Franck-Condon (FC) active vibration yields infrared (IR) emission by strong coupling to an optical cavity. The resulting UV/vis-to-IR photonic down conversion process is mediated by vibrational polaritons in the electronic excited state potential. It is shown that the formation of excited state vibrational polaritons (ESVP) via UV/vis excitation only involve vibrational modes with both a non-zero FC activity and IR activity in the excited state. Density functional theory calculations are used to identify 1-Pyreneacetic acid as a molecule with this property and the dynamics of ESVP are modeled. Overall, this work introduces an avenue of polariton chemistry where excited state dynamics are influenced by the formation of vibrational polaritons. Along with this, the UV/vis-to-IR photonic down conversion is potentially useful in both sensing excited state vibrations and quantum transduction schemes.
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Affiliation(s)
| | - Justin Provazza
- Department of Chemistry, Northwestern University, Evanston, IL, 60208-3113, USA.
| | - Emily A Weiss
- Department of Chemistry, Northwestern University, Evanston, IL, 60208-3113, USA.
| | - Roel Tempelaar
- Department of Chemistry, Northwestern University, Evanston, IL, 60208-3113, USA.
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13
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Theurer CP, Laible F, Tang J, Broch K, Fleischer M, Schreiber F. Strong light-matter coupling in pentacene thin films on plasmonic arrays. NANOSCALE 2023. [PMID: 37387269 DOI: 10.1039/d3nr01108a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/01/2023]
Abstract
Utilizing strong light-matter coupling is an elegant and powerful way to modify the energy landscapes of excited states of organic semiconductors. Consequently, the chemical and photophysical properties of these organic semiconductors can be influenced without the need of chemical modification but simply by implementing them in optical microcavities. This has so far mostly been shown in Fabry-Pérot cavities and with organic single crystals or diluted molecules in a host matrix. Here, we demonstrate strong, simultaneous coupling of the two Davydov transitions in polycrystalline pentacene thin films to surface lattice resonances supported by open cavities made of silver nanoparticle arrays. Such thin films are more easily fabricated and, together with the open architecture, more suitable for device applications.
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Affiliation(s)
- Christoph P Theurer
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
| | - Florian Laible
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
| | - Jia Tang
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
| | - Katharina Broch
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
- Center for Light-Matter Interaction, Sensors & Analytics (LISA+), Universität Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Monika Fleischer
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
- Center for Light-Matter Interaction, Sensors & Analytics (LISA+), Universität Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Frank Schreiber
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
- Center for Light-Matter Interaction, Sensors & Analytics (LISA+), Universität Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
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14
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Yoneda Y, Kuramochi H. Rapid-Scan Resonant Two-Dimensional Impulsive Stimulated Raman Spectroscopy of Excited States. J Phys Chem A 2023. [PMID: 37289973 DOI: 10.1021/acs.jpca.3c02489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Photochemical reactions occur in the electronically excited state, which is effectively represented by a multidimensional potential energy surface (PES) with a vast degree of freedom of nuclear coordinates. The elucidation of the intricate shape of the PES constitutes an important topic in the field of photochemistry and has long been studied both experimentally and theoretically. Recently, fully time-domain resonant two-dimensional Raman spectroscopy has emerged as a potentially powerful tool to provide unique information about the coupling between vibrational manifolds in the excited state. However, the wide application of this technique has been significantly hampered by the technical difficulties associated with experimental implementation and remains challenging. Herein, we demonstrate time-domain resonant two-dimensional impulsive stimulated Raman spectroscopy (2D-ISRS) of excited states using sub-10 fs pulses based on the rapid scan of the time delay, which facilitates the efficient collection of time-domain vibrational signals with high sensitivity. As a proof-of-principle experiment, we performed 2D-ISRS of 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) in solution. Through 2D Fourier transformation of the high-quality time-time oscillatory signal, we obtained a 2D frequency-frequency correlation map of excited-state TIPS-pentacene in the broad frequency window of 0-2000 cm-1. The data clearly resolve a number of cross peaks that signify the correlations among excited-state vibrational manifolds. The high capability of the rapid-scan-based 2D-ISRS spectrometer presented in this study enables the systematic investigation of various photochemical reaction systems, thereby further promoting the understanding and applications of this new multidimensional spectroscopy.
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Affiliation(s)
- Yusuke Yoneda
- Research Center of Integrative Molecular Systems (CIMoS), Institute for Molecular Science, National Institutes of Natural Sciences, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan
- Graduate Institute for Advanced Studies, SOKENDAI, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan
| | - Hikaru Kuramochi
- Research Center of Integrative Molecular Systems (CIMoS), Institute for Molecular Science, National Institutes of Natural Sciences, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan
- Graduate Institute for Advanced Studies, SOKENDAI, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan
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15
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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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16
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Wu Y, Lu L, Yu B, Zhang S, Luo P, Chen M, He J, Li Y, Zhang C, Zhu J, Yao J, Fu H. Dynamic Evolving Exothermicity Steers Ultrafast Formation of a Correlated Triplet Pair State. J Phys Chem Lett 2023; 14:4233-4240. [PMID: 37126526 DOI: 10.1021/acs.jpclett.3c00193] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Singlet fission (SF) presents an attractive solution to overcome the Shockley-Queisser limit of single-junction solar cells. The conversion from an initial singlet state to final triplet is mediated by the correlated triplet pair state 1(T1T1). Despite significant advancement on 1(T1T1) properties and its role in SF, a comprehensive understanding of the energetic landscape during SF is still unclear. Here, we study an unconventional SF system with excited-state aromaticity, i.e., cyano-substituted dipyrrolonaphtheridinedione derivative (DPND-CN), using time-resolved spectroscopy as a function of the temperature. We demonstrate that the population transfer from S1 to 1(T1T1) is driven by a time-dependent exothermicity resulting from the coherent coupling between electronic and spin degrees of freedom. This is followed by thermal-activated dissociation of 1(T1T1) to yield free triplets. Our results provide some new insight into the SF mechanism, which may guide the development of new efficient and stable SF materials for practical applications.
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Affiliation(s)
- Yishi Wu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, People's Republic of China
| | - Lina Lu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, People's Republic of China
| | - Buyang Yu
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing, Jiangsu 210093, People's Republic of China
| | - San Zhang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing, Jiangsu 210093, People's Republic of China
| | - Pengdong Luo
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, People's Republic of China
| | - Mingxing Chen
- Analytical Instrumentation Center, Peking University, Beijing 100871, People's Republic of China
| | - Jingping He
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, People's Republic of China
| | - Yongyao Li
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, People's Republic of China
| | - Chunfeng Zhang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing, Jiangsu 210093, People's Republic of China
| | - Jun Zhu
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, People's Republic of China
| | - Jiannian Yao
- Beijing National Laboratory for Molecules Science (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, People's Republic of China
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17
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Bylinkin A, Calavalle F, Barra-Burillo M, Kirtaev RV, Nikulina E, Modin E, Janzen E, Edgar JH, Casanova F, Hueso LE, Volkov VS, Vavassori P, Aharonovich I, Alonso-Gonzalez P, Hillenbrand R, Nikitin AY. Dual-Band Coupling of Phonon and Surface Plasmon Polaritons with Vibrational and Electronic Excitations in Molecules. NANO LETTERS 2023; 23:3985-3993. [PMID: 37116103 DOI: 10.1021/acs.nanolett.3c00768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Strong coupling (SC) between light and matter excitations bears intriguing potential for manipulating material properties. Typically, SC has been achieved between mid-infrared (mid-IR) light and molecular vibrations or between visible light and excitons. However, simultaneously achieving SC in both frequency bands remains unexplored. Here, we introduce polaritonic nanoresonators (formed by h-BN layers on Al ribbons) hosting surface plasmon polaritons (SPPs) at visible frequencies and phonon polaritons (PhPs) at mid-IR frequencies, which simultaneously couple to excitons and molecular vibrations in an adjacent layer of CoPc molecules, respectively. Employing near-field optical nanoscopy, we demonstrate the colocalization of near fields at both visible and mid-IR frequencies. Far-field transmission spectroscopy of the nanoresonator structure covered with a layer of CoPc molecules shows clear mode splittings in both frequency ranges, revealing simultaneous SPP-exciton and PhP-vibron coupling. Dual-band SC may offer potential for manipulating coupling between exciton and molecular vibration in future optoelectronics, nanophotonics, and quantum information applications.
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Affiliation(s)
- Andrei Bylinkin
- CIC nanoGUNE BRTA, Donostia - San Sebastian 20018, Spain
- Donostia International Physics Center (DIPC), Donostia - San Sebastián 20018, Spain
| | | | | | - Roman V Kirtaev
- Emerging Technologies Research Center, XPANCEO, Dubai, DIP 00000, UAE
| | | | - Evgeny Modin
- CIC nanoGUNE BRTA, Donostia - San Sebastian 20018, Spain
| | - Eli Janzen
- Tim Taylor Department of Chemical Engineering, Kansas State University, Manhattan, Kansas 66506, USA
| | - James H Edgar
- Tim Taylor Department of Chemical Engineering, Kansas State University, Manhattan, Kansas 66506, USA
| | - Fèlix Casanova
- CIC nanoGUNE BRTA, Donostia - San Sebastian 20018, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao 48009, Spain
| | - Luis E Hueso
- CIC nanoGUNE BRTA, Donostia - San Sebastian 20018, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao 48009, Spain
| | - Valentyn S Volkov
- Emerging Technologies Research Center, XPANCEO, Dubai, DIP 00000, UAE
| | - Paolo Vavassori
- CIC nanoGUNE BRTA, Donostia - San Sebastian 20018, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao 48009, Spain
| | - Igor Aharonovich
- School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
- ARC Centre of Excellence for Transformative Meta-Optical Systems, Faculty of Science, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Pablo Alonso-Gonzalez
- Departamento de Fisica, Universidad de Oviedo, Oviedo 33006, Spain
- Nanomaterials and Nanotechnology Research Center (CINN), El Entego 33940, Spain
| | - Rainer Hillenbrand
- CIC nanoGUNE BRTA and EHU/UPV, Donostia - San Sebastián 20018, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao 48009, Spain
| | - Alexey Y Nikitin
- Donostia International Physics Center (DIPC), Donostia - San Sebastián 20018, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao 48009, Spain
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18
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Liu Z, Jha A, Liang XT, Duan HG. Transient chiral dynamics revealed by two-dimensional circular dichroism spectroscopy. Phys Rev E 2023; 107:054119. [PMID: 37329099 DOI: 10.1103/physreve.107.054119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 05/05/2023] [Indexed: 06/18/2023]
Abstract
Chirality has been considered as one of the key factors in the evolution of life in nature. It is important to uncover how chiral potentials of molecular systems play vital role in fundamental photochemical processes. Here, we investigate the role of chirality in photoinduced energy transfer in a model dimeric system, where the monomers are excitonically coupled. To observe transient chiral dynamics and energy transfer, we employ circularly polarized laser pulses in two-dimensional electronic spectroscopy to construct the two-dimensional circular dichroism (2DCD) spectral maps. Tracking time-resolved peak magnitudes in 2DCD spectra allows one to identify chirality induced population dynamics. The dynamics of energy transfer is revealed by the time-resolved kinetics of cross peaks. However, the differential signal of 2DCD spectra shows the magnitude of cross peaks is dramatically reduced at initial waiting time, which indicates the weak chiral interactions between two monomers. The downhill energy transfer is resolved by presenting a strong magnitude of cross peak in 2DCD spectra after long waiting time. The chiral contribution towards coherent and incoherent energy-transfer pathways in the model dimer system is further examined via control of excitonic couplings between two monomers. Applications are made to study the energy-transfer process in the Fenna-Matthews-Olson complex. Our work uncovers the potential of 2DCD spectroscopy to resolve the chiral-induced interactions and population transfers in excitonically coupled systems.
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Affiliation(s)
- Zihui Liu
- Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, P.R. China
| | - Ajay Jha
- Rosalind Franklin Institute, Harwell, Oxfordshire OX11 0QX, United Kingdom
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, United Kingdom
- Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | - Xian-Ting Liang
- Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, P.R. China
| | - Hong-Guang Duan
- Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, P.R. China
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19
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Wang JX, Yin J, Gutiérrez-Arzaluz L, Thomas S, Shao W, Alshareef HN, Eddaoudi M, Bakr OM, Mohammed OF. Singlet Fission-Based High-Resolution X-Ray Imaging Scintillation Screens. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023:e2300406. [PMID: 37083237 DOI: 10.1002/advs.202300406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/02/2023] [Indexed: 05/03/2023]
Abstract
X-ray imaging technology is critical to numerous different walks of daily life, ranging from medical radiography and security screening all the way to high-energy physics. Although several organic chromophores are fabricated and tested as X-ray imaging scintillators, they generally show poor scintillation performance due to their weak X-ray absorption cross-section and inefficient exciton utilization efficiency. Here, a singlet fission-based high-performance organic X-ray imaging scintillator with near unity exciton utilization efficiency is presented. Interestingly, it is found that the X-ray sensitivity and imaging resolution of the singlet fission-based scintillator are dramatically improved by an efficient energy transfer from a thermally activated delayed fluorescence (TADF) sensitizer, in which both singlet and triplet excitons can be efficiently harnessed. The fabricated singlet fission-based scintillator exhibits a high X-ray imaging resolution of 27.5 line pairs per millimeter (lp mm-1 ), which exceeds that of most commercial scintillators, demonstrating its high potential use in medical radiography and security inspection.
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Affiliation(s)
- Jian-Xin Wang
- Advanced Membranes and Porous Materials Center, Division of Physical Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Jun Yin
- Advanced Membranes and Porous Materials Center, Division of Physical Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
- KAUST Catalysis Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
- Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, 999077, P. R. China
| | - Luis Gutiérrez-Arzaluz
- Advanced Membranes and Porous Materials Center, Division of Physical Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
- KAUST Catalysis Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Simil Thomas
- Advanced Membranes and Porous Materials Center, Division of Physical Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
- Materials Science and Engineering, Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Wenyi Shao
- Advanced Membranes and Porous Materials Center, Division of Physical Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Husam N Alshareef
- Materials Science and Engineering, Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Mohamed Eddaoudi
- Advanced Membranes and Porous Materials Center, Division of Physical Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Osman M Bakr
- KAUST Catalysis Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Omar F Mohammed
- Advanced Membranes and Porous Materials Center, Division of Physical Science and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Kingdom of Saudi Arabia
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20
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Musser AJ, Stern H. Elusive excited states identified from cutting-edge molecular movies. Nature 2023; 616:255-256. [PMID: 37045916 DOI: 10.1038/d41586-023-00980-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
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21
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Neef A, Beaulieu S, Hammer S, Dong S, Maklar J, Pincelli T, Xian RP, Wolf M, Rettig L, Pflaum J, Ernstorfer R. Orbital-resolved observation of singlet fission. Nature 2023; 616:275-279. [PMID: 37045918 PMCID: PMC10097594 DOI: 10.1038/s41586-023-05814-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 02/06/2023] [Indexed: 04/14/2023]
Abstract
Singlet fission1-13 may boost photovoltaic efficiency14-16 by transforming a singlet exciton into two triplet excitons and thereby doubling the number of excited charge carriers. The primary step of singlet fission is the ultrafast creation of the correlated triplet pair17. Whereas several mechanisms have been proposed to explain this step, none has emerged as a consensus. The challenge lies in tracking the transient excitonic states. Here we use time- and angle-resolved photoemission spectroscopy to observe the primary step of singlet fission in crystalline pentacene. Our results indicate a charge-transfer mediated mechanism with a hybridization of Frenkel and charge-transfer states in the lowest bright singlet exciton. We gained intimate knowledge about the localization and the orbital character of the exciton wave functions recorded in momentum maps. This allowed us to directly compare the localization of singlet and bitriplet excitons and decompose energetically overlapping states on the basis of their orbital character. Orbital- and localization-resolved many-body dynamics promise deep insights into the mechanics governing molecular systems18-20 and topological materials21-23.
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Affiliation(s)
- Alexander Neef
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin, Germany.
| | - Samuel Beaulieu
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin, Germany
- CELIA, University of Bordeaux-CNRS-CEA, Bordeaux, France
| | - Sebastian Hammer
- Experimental Physics VI, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
- Center for the Physics of Materials, Departments of Physics and Chemistry, McGill University, Montréal, Quebec, Canada
| | - Shuo Dong
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin, Germany
| | - Julian Maklar
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin, Germany
| | - Tommaso Pincelli
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin, Germany
- Institute for Optics and Atomic Physics, Technical University Berlin, Berlin, Germany
| | - R Patrick Xian
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin, Germany
- Department of Statistical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Martin Wolf
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin, Germany
| | - Laurenz Rettig
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin, Germany
| | - Jens Pflaum
- Experimental Physics VI, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
- Barvarian Centre for Applied Energy Research, Wuerzburg, Germany
| | - Ralph Ernstorfer
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Berlin, Germany.
- Institute for Optics and Atomic Physics, Technical University Berlin, Berlin, Germany.
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22
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Huang CH, Wu CC, Li EY, Chou PT. Quest for singlet fission of organic sulfur-containing systems in the higher lying singlet excited state: application prospects of anti-Kasha's rule. Phys Chem Chem Phys 2023; 25:9115-9122. [PMID: 36928330 DOI: 10.1039/d3cp00298e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
In this study, we explore the possibilities of the deactivating pathways of organic thione containing systems through first-principles calculations. We particularly pay attention to the second lying singlet excited state, S2, due to its large energy difference from the lowest lying S1 state in the sulfur-containing systems. Several theoretical models including the previously synthesized thiones and the strategically designed molecules are investigated to search for the basic conjugation unit that exhibits the prospect of S2 fission. Various molecular motifs and different substituents are combined to maneuver the relative alignment of the relevant low excited energy states. The results lead us to conclude that the thione derivatives, under rational and delicate molecular designs, may be engineered to possess a sufficiently high S2-S1 energy gap as high as 2 eV and that these systems may exhibit S2 fission to triplet excitons in the red to near infrared region.
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Affiliation(s)
- Chun-Hao Huang
- Department of Chemistry, National Taiwan Normal University, Taipei, 11677, Taiwan.
| | - Chi-Chi Wu
- Department of Chemistry, National Taiwan Normal University, Taipei, 11677, Taiwan. .,Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan.
| | - Elise Y Li
- Department of Chemistry, National Taiwan Normal University, Taipei, 11677, Taiwan.
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan.
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23
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Tonami T, Miyamoto H, Nakano M, Kishi R, Kitagawa Y. Theoretical Study on Thermal Structural Fluctuation Effects of Intermolecular Configurations on Singlet Fission in Pentacene Crystal Models. J Phys Chem A 2023; 127:1883-1893. [PMID: 36799732 DOI: 10.1021/acs.jpca.2c08864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Singlet fission (SF) occurs as a result of complex excited state relaxation dynamics in molecular aggregates, where a singlet exciton (FE) state is converted into a double-triplet exciton (TT) state through the interactions with several other degrees of freedom, such as nuclear motions. In this study, we combined quantum dynamics simulation based on the quantum master equation approach with all-atom-based classical molecular mechanics/molecular dynamics to examine the thermal structural fluctuation (i.e., static disorder) effects of intermolecular configuration on SF in pentacene crystal models. In particular, we considered two types of static-disordered models, in which excited states are assumed to interact with nuclear motions of intermolecular modes in the classical mechanical/statistical manner. We found that the introduction of static disorder effects leads to a faster decay of coherence between the FE and charge transfer (CT) states in the early stage of SF, contributing to the accelerations of several FE → TT relaxation pathways. Such acceleration in these models is shown to be attributed to fluctuations in the energies and electronic coupling of the CT states based on relative relaxation factor analysis. The present study is expected to contribute to further development of bottom-up materials design for efficient SF in condensed phases where the exitonic system interacts with nuclear motions in various coupling strengths.
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Affiliation(s)
- Takayoshi Tonami
- Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Hajime Miyamoto
- Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Masayoshi Nakano
- Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Ryohei Kishi
- Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.,Research Center for Solar Energy Chemistry (RCSEC), Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.,Center for Quantum Information and Quantum Biology (QIQB), Osaka University, Toyonaka, Osaka 560-8531, Japan.,Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka 565-0871, Japan
| | - Yasutaka Kitagawa
- Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.,Research Center for Solar Energy Chemistry (RCSEC), Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.,Center for Quantum Information and Quantum Biology (QIQB), Osaka University, Toyonaka, Osaka 560-8531, Japan.,Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka 565-0871, Japan.,Spintronics Research Network Division, Institute for Open and Transdisciplinary Research Initiatives (SRN-OTRI), Osaka University, Toyonaka, Osaka 560-8531, Japan
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24
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Singlet fission as a polarized spin generator for dynamic nuclear polarization. Nat Commun 2023; 14:1056. [PMID: 36859419 PMCID: PMC9977948 DOI: 10.1038/s41467-023-36698-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 02/09/2023] [Indexed: 03/03/2023] Open
Abstract
Singlet fission (SF), converting a singlet excited state into a spin-correlated triplet-pair state, is an effective way to generate a spin quintet state in organic materials. Although its application to photovoltaics as an exciton multiplier has been extensively studied, the use of its unique spin degree of freedom has been largely unexplored. Here, we demonstrate that the spin polarization of the quintet multiexcitons generated by SF improves the sensitivity of magnetic resonance of water molecules through dynamic nuclear polarization (DNP). We form supramolecular assemblies of a few pentacene chromophores and use SF-born quintet spins to achieve DNP of water-glycerol, the most basic biological matrix, as evidenced by the dependence of nuclear polarization enhancement on magnetic field and microwave power. Our demonstration opens a use of SF as a polarized spin generator in bio-quantum technology.
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25
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Zhao Y. The hierarchy of Davydov's Ansätze: From guesswork to numerically "exact" many-body wave functions. J Chem Phys 2023; 158:080901. [PMID: 36859105 DOI: 10.1063/5.0140002] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
This Perspective presents an overview of the development of the hierarchy of Davydov's Ansätze and a few of their applications in many-body problems in computational chemical physics. Davydov's solitons originated in the investigation of vibrational energy transport in proteins in the 1970s. Momentum-space projection of these solitary waves turned up to be accurate variational ground-state wave functions for the extended Holstein molecular crystal model, lending unambiguous evidence to the absence of formal quantum phase transitions in Holstein systems. The multiple Davydov Ansätze have been proposed, with increasing Ansatz multiplicity, as incremental improvements of their single-Ansatz parents. For a given Hamiltonian, the time-dependent variational formalism is utilized to extract accurate dynamic and spectroscopic properties using Davydov's Ansätze as its trial states. A quantity proven to disappear for large multiplicities, the Ansatz relative deviation is introduced to quantify how closely the Schrödinger equation is obeyed. Three finite-temperature extensions to the time-dependent variation scheme are elaborated, i.e., the Monte Carlo importance sampling, the method of thermofield dynamics, and the method of displaced number states. To demonstrate the versatility of the methodology, this Perspective provides applications of Davydov's Ansätze to the generalized Holstein Hamiltonian, variants of the spin-boson model, and systems of cavity-assisted singlet fission, where accurate dynamic and spectroscopic properties of the many-body systems are given by the Davydov trial states.
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Affiliation(s)
- Yang Zhao
- Division of Materials Science, Nanyang Technological University, Singapore 639798, Singapore
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26
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Leng X, Yan Y, Zhu R, Zou J, Zhang W, Shi Q. Revealing Intermolecular Electronic and Vibronic Coherence with Polarization-Dependent Two-Dimensional Beating Maps. J Phys Chem Lett 2023; 14:838-845. [PMID: 36656105 DOI: 10.1021/acs.jpclett.2c03413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Two-dimensional electronic spectroscopy (2DES) has been widely employed as an efficient tool to reveal the impact of intermolecular electronic and/or vibronic quantum coherence on excitation energy transfer in light-harvesting complexes. However, intramolecular vibrational coherence would also contribute to oscillating signals in 2D spectra, along with the intermolecular coherence signals that are directly related to energy transfer. In this work, the possibility of screening the vibrational coherence signals is explored through polarization-dependent 2DES. The all-parallel (AP) and double-crossed (DC) polarization-dependent two-dimensional rephasing spectra (2DRS) are simulated for a minimalist heterodimer model with vibrational coupling. By combining the DC-2DRS and the 2D beating maps, we demonstrate that the population and vibrational coherence signals can be largely suppressed, resulting in highlighted intermolecular electronic and vibronic coherence signals. Moreover, the AP- and DC-2DBMs show rather different patterns at the vibrational frequency, indicating a possible way to identify pure vibrational coherence.
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Affiliation(s)
- Xuan Leng
- Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
| | - Yaming Yan
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, China
| | - Ruidan Zhu
- Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, 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
| | - Wenzhao Zhang
- Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
| | - Qiang Shi
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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27
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Unger F, Moretti L, Hausch J, Bredehoeft J, Zeiser C, Haug S, Tempelaar R, Hestand NJ, Cerullo G, Broch K. Modulating Singlet Fission by Scanning through Vibronic Resonances in Pentacene-Based Blends. J Am Chem Soc 2022; 144:20610-20619. [DOI: 10.1021/jacs.2c07237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Frederik Unger
- Institute for Applied Physics, University of Tuebingen, Auf der Morgenstelle 10, Tuebingen, 72076, Germany
| | - Luca Moretti
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milan 20133, Italy
| | - Julian Hausch
- Institute for Applied Physics, University of Tuebingen, Auf der Morgenstelle 10, Tuebingen, 72076, Germany
| | - Jona Bredehoeft
- Institute for Applied Physics, University of Tuebingen, Auf der Morgenstelle 10, Tuebingen, 72076, Germany
| | - Clemens Zeiser
- Institute for Applied Physics, University of Tuebingen, Auf der Morgenstelle 10, Tuebingen, 72076, Germany
| | - Sara Haug
- Institute for Applied Physics, University of Tuebingen, Auf der Morgenstelle 10, Tuebingen, 72076, Germany
| | - Roel Tempelaar
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Nicholas J. Hestand
- Department of Natural and Applied Sciences, Evangel University, 1111 North Glenstone Avenue, Springfield, Missouri 65802, United States
| | - Giulio Cerullo
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milan 20133, Italy
| | - Katharina Broch
- Institute for Applied Physics, University of Tuebingen, Auf der Morgenstelle 10, Tuebingen, 72076, Germany
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28
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Ashoka A, Gauriot N, Girija AV, Sawhney N, Sneyd AJ, Watanabe K, Taniguchi T, Sung J, Schnedermann C, Rao A. Direct observation of ultrafast singlet exciton fission in three dimensions. Nat Commun 2022; 13:5963. [PMID: 36216826 PMCID: PMC9551063 DOI: 10.1038/s41467-022-33647-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 09/26/2022] [Indexed: 11/06/2022] Open
Abstract
We present quantitative ultrafast interferometric pump-probe microscopy capable of tracking of photoexcitations with sub-10 nm spatial precision in three dimensions with 15 fs temporal resolution, through retrieval of the full transient photoinduced complex refractive index. We use this methodology to study the spatiotemporal dynamics of the quantum coherent photophysical process of ultrafast singlet exciton fission. Measurements on microcrystalline pentacene films grown on glass (SiO2) and boron nitride (hBN) reveal a 25 nm, 70 fs expansion of the joint-density-of-states along the crystal a,c-axes accompanied by a 6 nm, 115 fs change in the exciton density along the crystal b-axis. We propose that photogenerated singlet excitons expand along the direction of maximal orbital π-overlap in the crystal a,c-plane to form correlated triplet pairs, which subsequently electronically decouples into free triplets along the crystal b-axis due to molecular sliding motion of neighbouring pentacene molecules. Our methodology lays the foundation for the study of three dimensional transport on ultrafast timescales.
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Affiliation(s)
- Arjun Ashoka
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE UK
| | - Nicolas Gauriot
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE UK
| | - Aswathy V. Girija
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE UK
| | - Nipun Sawhney
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE UK
| | - Alexander J. Sneyd
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE UK
| | - Kenji Watanabe
- grid.21941.3f0000 0001 0789 6880Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044 Japan
| | - Takashi Taniguchi
- grid.21941.3f0000 0001 0789 6880International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044 Japan
| | - Jooyoung Sung
- grid.417736.00000 0004 0438 6721Department of Emerging Materials Science, DGIST, Daegu, 42988 Republic of Korea
| | - Christoph Schnedermann
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE UK
| | - Akshay Rao
- grid.5335.00000000121885934Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE UK
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29
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Parker KA, Schultz JD, Singh N, Wasielewski MR, Beratan DN. Mapping Simulated Two-Dimensional Spectra to Molecular Models Using Machine Learning. J Phys Chem Lett 2022; 13:7454-7461. [PMID: 35930790 DOI: 10.1021/acs.jpclett.2c01913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Two-dimensional (2D) spectroscopy encodes molecular properties and dynamics into expansive spectral data sets. Translating these data into meaningful chemical insights is challenging because of the many ways chemical properties can influence the spectra. To address the task of extracting chemical information from 2D spectroscopy, we study the capacity of simple feedforward neural networks (NNs) to map simulated 2D electronic spectra to underlying physical Hamiltonians. We examined hundreds of simulated 2D spectra corresponding to monomers and dimers with varied Franck-Condon active vibrations and monomer-monomer electronic couplings. We find the NNs are able to correctly characterize most Hamiltonian parameters in this study with an accuracy above 90%. Our results demonstrate that NNs can aid in interpreting 2D spectra, leading from spectroscopic features to underlying effective Hamiltonians.
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Affiliation(s)
- Kelsey A Parker
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Jonathan D Schultz
- Department of Chemistry and Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Niven Singh
- Program in Computational Biology and Bioinformatics, Center for Genomics and Computational Biology, Duke University School of Medicine, Durham, North Carolina 27710, United States
| | - Michael R Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - David N Beratan
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
- Department of Biochemistry, Duke University, Durham, North Carolina 27710, United States
- Department of Physics, Duke University, Durham, North Carolina 27708, United States
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30
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Silori Y, Yadav A, Chawla S, De AK. Effect of nanoscale confinement on ultrafast dynamics of singlet fission in TIPS-pentacene. Chemphyschem 2022; 23:e202200454. [PMID: 35830606 DOI: 10.1002/cphc.202200454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 07/12/2022] [Indexed: 11/06/2022]
Abstract
Singlet fission (SF) is a phenomenon for the generation of a pair of triplet excitons from a singlet excited molecule interacting with another adjacent molecule in its ground electronic state. By increasing the effective number of charge carriers and reducing thermal dissipation of excess energy, SF is promised to enhance light-harvesting efficiency for photovoltaic applications. While SF has been extensively studied in thin films and crystals, the same has not been explored much within a confined medium. Here, we report the ultrafast SF dynamics of triisopropylsilylethynyl pentacene (TIPS-Pn) in micellar nanocavity of varying sizes (prepared from TX-100, CTAB, and SDS surfactants). The nanoparticle with a smaller size contains weakly coupled chromophores and is shown to be more efficient for SF followed by triplet generation as compared to the nanoparticles of larger size which contain strongly coupled chromophores and are less efficient due to the presence of singlet exciton traps. Through these studies, we delineate how a subtle interplay between short-range and long-range interaction among chromophores confined within nanoparticles, fine-tuned by the curvature of the micellar interface but irrespective of the nature of the micelle (cationic or anionic or neutral), play a crucial role in SF through and generation of triplets.
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Affiliation(s)
- Yogita Silori
- IISER Mohali: Indian Institute of Science Education and Research Mohali, Chemical Sciences, INDIA
| | - Anita Yadav
- IISER Mohali: Indian Institute of Science Education and Research Mohali, Chemical Sciences, INDIA
| | - Sakshi Chawla
- IISER Mohali: Indian Institute of Science Education and Research Mohali, Chemical Sciences, INDIA
| | - Arijit Kumar De
- Indian Institute of Science Education and Research Mohali, Chemical Sciences, Knowledge City, Sector 81, 140306, SAS Nagar,, INDIA
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31
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Kim T, Lin C, Schultz JD, Young RM, Wasielewski MR. π-Stacking-Dependent Vibronic Couplings Drive Excited-State Dynamics in Perylenediimide Assemblies. J Am Chem Soc 2022; 144:11386-11396. [PMID: 35699940 DOI: 10.1021/jacs.2c03993] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Vibronic coupling, the interplay of electronic and nuclear vibrational motion, is considered a critical mechanism in photoinduced reactions such as energy transfer, charge transfer, and singlet fission. However, our understanding of how particular vibronic couplings impact excited-state dynamics is lacking due to the limited number of experimental studies of model molecular systems. Herein, we use two-dimensional electronic spectroscopy (2DES) to launch and interrogate a range of vibronic coherences in two distinct types of perylenediimide slip stacks─along the short and long molecular axes, which form either an excimer or a mixed state between the Frenkel exciton (FE) and charge transfer states. We explore the functionality of these vibronic coherences using quantum beatmaps, which display the Fourier amplitude signal oscillations as a function of pump and probe frequencies, along with knowledge of the characteristic signatures of the FE, ionic, and excimer species. We find that a low-frequency vibrational mode of the short-axis slip stack appears concomitantly with the formation of the excimer state, survives 2-fold longer than in the FE state in the reference monomer, and shows a phase shift compared to other modes. For the long-axis slip stacks, a pair of low-frequency modes coupled to a high-frequency coordinate of the FE state were found to play a critical role in mixed-state generation. Our findings thus experimentally reveal the complex and varying roles of vibronic couplings in tightly packed multimers undergoing a range of photoinduced processes.
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Affiliation(s)
- Taeyeon Kim
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Chenjian Lin
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Jonathan D Schultz
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Ryan M Young
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Michael R Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
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32
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High-resolution two-dimensional electronic spectroscopy reveals the homogeneous line profile of chromophores solvated in nanoclusters. Nat Commun 2022; 13:3350. [PMID: 35688839 PMCID: PMC9187667 DOI: 10.1038/s41467-022-31021-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 05/24/2022] [Indexed: 11/16/2022] Open
Abstract
Doped clusters in the gas phase provide nanoconfined model systems for the study of system-bath interactions. To gain insight into interaction mechanisms between chromophores and their environment, the ensemble inhomogeneity has to be lifted and the homogeneous line profile must be accessed. However, such measurements are very challenging at the low particle densities and low signal levels in cluster beam experiments. Here, we dope cryogenic rare-gas clusters with phthalocyanine molecules and apply action-detected two-dimensional electronic spectroscopy to gain insight into the local molecule-cluster environment for solid and superfluid cluster species. The high-resolution homogeneous linewidth analysis provides a benchmark for the theoretical modelling of binding configurations and shows a promising route for high-resolution molecular two-dimensional spectroscopy. Understanding the interaction of single chromophores with nanoparticles remains a challenging task in nanoscience. Here the authors provide insight into the interaction between isolated base-free phthalocyanine molecules and He and Ne nanoclusters in the gas phase using high-resolution two-dimensional spectroscopy.
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33
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Solowan HP, Malý P, Brixner T. Direct comparison of molecular-beam versus liquid-phase pump-probe and two-dimensional spectroscopy on the example of azulene. J Chem Phys 2022; 157:044201. [DOI: 10.1063/5.0088365] [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
Although azulene's anomalous fluorescence originating from S2 rather than from S1 is the textbook example for the violation of Kasha's rule, the understanding of the underlying processes is still a subject of investigation. Here, we use action-based coherent two-dimensional electronic spectroscopy (2DES) to measure a single Liouville-space response pathway from S0 via S1 to the S2 state of azulene. We directly compare this sequential excitation in liquid phase detecting S2 fluorescence and in a molecular beam detecting photoionized cations, using the S2 anomalous emission to our advantage. We complement the 2DES study by pump-probe measurements of S1 excitation dynamics, including vibrational relaxation and passage through a conical intersection. The direct comparison of liquid and gas phase allows us to assess the effect of the solvent and the interplay of intra- and inter-molecular energy relaxation.
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Affiliation(s)
| | - Pavel Malý
- Institute of Physical and Theoretical Chemistry, Julius-Maximilians-Universität Würzburg, Germany
| | - Tobias Brixner
- Institut fuer Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg, Germany
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34
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Patra S, Tiwari V. Vibronic resonance along effective modes mediates selective energy transfer in excitonically coupled aggregates. J Chem Phys 2022; 156:184115. [PMID: 35568533 DOI: 10.1063/5.0088855] [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
We recently proposed effective normal modes for excitonically coupled aggregates that exactly transform the energy transfer Hamiltonian into a sum of one-dimensional Hamiltonians along the effective normal modes. Identifying physically meaningful vibrational motions that maximally promote vibronic mixing suggested an interesting possibility of leveraging vibrational-electronic resonance for mediating selective energy transfer. Here, we expand on the effective mode approach, elucidating its iterative nature for successively larger aggregates, and extend the idea of mediated energy transfer to larger aggregates. We show that energy transfer between electronically uncoupled but vibronically resonant donor-acceptor sites does not depend on the intermediate site energy or the number of intermediate sites. The intermediate sites simply mediate electronic coupling such that vibronic coupling along specific promoter modes leads to direct donor-acceptor energy transfer, bypassing any intermediate uphill energy transfer steps. We show that the interplay between the electronic Hamiltonian and the effective mode transformation partitions the linear vibronic coupling along specific promoter modes to dictate the selectivity of mediated energy transfer with a vital role of interference between vibronic couplings and multi-particle basis states. Our results suggest a general design principle for enhancing energy transfer through synergistic effects of vibronic resonance and weak mediated electronic coupling, where both effects individually do not promote efficient energy transfer. The effective mode approach proposed here paves a facile route toward four-wavemixing spectroscopy simulations of larger aggregates without severely approximating resonant vibronic coupling.
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Affiliation(s)
- Sanjoy Patra
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Vivek Tiwari
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
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35
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Accelerating symmetry-breaking charge separation in a perylenediimide trimer through a vibronically coherent dimer intermediate. Nat Chem 2022; 14:786-793. [PMID: 35469005 DOI: 10.1038/s41557-022-00927-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 03/10/2022] [Indexed: 11/08/2022]
Abstract
Understanding the photophysics and photochemistry of molecular π-stacked chromophores is important for utilizing them as functional photonic materials. However, these investigations have been mostly limited to covalent molecular dimers, which can only approximate the electronic and vibronic interactions present in the higher oligomers typical of functional organic materials. Here we show that a comparison of the excited-state dynamics of a covalent slip-stacked perylenediimide dimer (2) and trimer (3) provides fundamental insights into electronic state mixing and symmetry-breaking charge separation (SB-CS) beyond the dimer limit. We find that coherent vibronic coupling to high-frequency modes facilitates ultrafast state mixing between the Frenkel exciton (FE) and charge-transfer (CT) states. Subsequently, solvent fluctuations and interchromophore low-frequency vibrations promote CT character in the coherent FE/CT mixed state. The coherent FE/CT mixed state persists in 2, but, in 3, low-frequency vibronic coupling collapses the coherence, resulting in ultrafast SB-CS between the distal perylenediimide units.
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36
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37
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Yan Y, Zhang Y, Memon WA, Wang M, Zhang X, Wei Z. The role of entropy gains in the exciton separation in organic solar cells. Macromol Rapid Commun 2022; 43:e2100903. [PMID: 35338684 DOI: 10.1002/marc.202100903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/16/2022] [Indexed: 11/06/2022]
Abstract
In organic solar cell (OSC), the lower dielectric constant of organic semiconductor material induces a strong Coulomb attraction between electron-hole pairs, which leads to a low exciton separation efficiency, especially the charge transfer (CT) state. The CT state formed at the electron-donor (D) and electron-acceptor (A) interface is regarded as an unfavorable property of organic photovoltaic devices. Since the OSC works in a nonzero temperature condition, the entropy effect would be one of the main reasons to overcome the Coulomb energy barrier and must be taken into account. In this review, we review the present understanding of the entropy-driven charge separation and describe how factors such as the dimensionality of the organic semiconductor, energy disorder effect, the morphology of the active layer, and the nonequilibrium effect affect the entropy contribution in compensating the Coulomb dissociation barrier for CT exciton separation and charge generation process. We focus on the investigation of the entropy effect on exciton dissociation mechanism from both theoretical and experimental aspects, which provides pathways for understanding the underlying mechanisms of exciton separation and further enhancing the efficiency of OSCs. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Yangjun Yan
- School of Science, Beijing Jiaotong University, Beijing, 100044, China.,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
| | - 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
| | - Mengni Wang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Xinghua Zhang
- School of Science, Beijing Jiaotong University, Beijing, 100044, 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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38
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Dostál J. Nonresonant coherent two-dimensional spectroscopy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 267:120441. [PMID: 34678717 DOI: 10.1016/j.saa.2021.120441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 09/03/2021] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
Coherent electronic two-dimensional spectroscopy is nowadays a matured experimental technique that monitors the time evolution of the studied sample after its resonant optical excitation. However, the experimental experience shows that even nonresonant interactions can provide detectable spectral contributions. These are often present as a weak parasitic signals originating in the solvent and/or cuvette walls underlying the resonant spectrum of the actual sample and as such they are usually discarded from the analysis. In this work, we adapt the formalism of double-sided Feynman diagrams for the needs of coherent two-dimensional spectroscopy in the nonresonant regime. We analytically calculate the third-order polarization of a two-level and several variants of three-level systems. As a result, we demonstrate the typical appearance of the optical Kerr-effect, cross-phase modulation, excited-state coherence, two-photon absorption and stimulated Raman scattering in the 2D spectrum. This provides a framework for studying these effects by means of coherent two-dimensional spectroscopy.
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Affiliation(s)
- Jakub Dostál
- Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, Prague 121 16, Czech Republic; ELI Beamlines, Institute of Physics, Czech Academy of Sciences, Za Radnicí 835, Dolní Břežany 252 41, Czech Republic.
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39
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Altman AR, Refaely-Abramson S, da Jornada FH. Identifying Hidden Intracell Symmetries in Molecular Crystals and Their Impact for Multiexciton Generation. J Phys Chem Lett 2022; 13:747-753. [PMID: 35029407 DOI: 10.1021/acs.jpclett.1c03540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Organic molecular crystals are appealing for next-generation optoelectronic applications due to their multiexciton generation processes that can increase the efficiency of photovoltaic devices. However, a general understanding of how crystal structures affect these processes is lacking, requiring computationally demanding calculations for each material. Here we present an approach to understand and classify organic crystals and elucidate multiexciton processes. We show that organic crystals that are composed of two sublattices are well-approximated by effective fictitious systems of higher translational symmetry. Within this framework, we derive hidden selection rules in crystal pentacene and predict that the bulk polymorph supports fast Coulomb-mediated singlet fission with a transition rate about 2 orders of magnitude faster than that of the thin-film polymorph, a result confirmed with many-body perturbation theory calculations. Our approach is based on density-functional theory calculations and provides design principles for the experimental and computational discovery of new materials with tailored excitonic properties.
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Affiliation(s)
- Aaron R Altman
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
| | - Sivan Refaely-Abramson
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Felipe H da Jornada
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
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40
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Policht VR, Niedringhaus A, Willow R, Laible PD, Bocian DF, Kirmaier C, Holten D, Mančal T, Ogilvie JP. Hidden vibronic and excitonic structure and vibronic coherence transfer in the bacterial reaction center. SCIENCE ADVANCES 2022; 8:eabk0953. [PMID: 34985947 PMCID: PMC8730630 DOI: 10.1126/sciadv.abk0953] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We report two-dimensional electronic spectroscopy (2DES) experiments on the bacterial reaction center (BRC) from purple bacteria, revealing hidden vibronic and excitonic structure. Through analysis of the coherent dynamics of the BRC, we identify multiple quasi-resonances between pigment vibrations and excitonic energy gaps, and vibronic coherence transfer processes that are typically neglected in standard models of photosynthetic energy transfer and charge separation. We support our assignment with control experiments on bacteriochlorophyll and simulations of the coherent dynamics using a reduced excitonic model of the BRC. We find that specific vibronic coherence processes can readily reveal weak exciton transitions. While the functional relevance of such processes is unclear, they provide a spectroscopic tool that uses vibrations as a window for observing excited state structure and dynamics elsewhere in the BRC via vibronic coupling. Vibronic coherence transfer reveals the upper exciton of the “special pair” that was weakly visible in previous 2DES experiments.
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Affiliation(s)
- Veronica R. Policht
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
| | - Andrew Niedringhaus
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
| | - Rhiannon Willow
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
| | - Philip D. Laible
- Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - David F. Bocian
- Department of Chemistry, University of California, Riverside, CA 92521, USA
| | - Christine Kirmaier
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA
| | - Dewey Holten
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA
| | - Tomáš Mančal
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, CZ-12116 Prague 2, Czech Republic
| | - Jennifer P. Ogilvie
- Department of Physics, University of Michigan, 450 Church St, Ann Arbor, MI 48109, USA
- Corresponding author.
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41
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Zhao Y, Sun K, Chen L, Gelin M. The hierarchy of Davydov's Ansätze and its applications. WIRES COMPUTATIONAL MOLECULAR SCIENCE 2021. [DOI: 10.1002/wcms.1589] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Yang Zhao
- Division of Materials Science Nanyang Technological University Singapore Singapore
| | - Kewei Sun
- Division of Materials Science Nanyang Technological University Singapore Singapore
- School of Science, Hanghzhou Dianzi University Hangzhou China
| | - Lipeng Chen
- Max Planck Institute for the Physics of Complex Systems Dresden Germany
| | - Maxim Gelin
- School of Science, Hanghzhou Dianzi University Hangzhou China
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42
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Zhou L, Tian L, Liu J, Zhang W. Scattering elimination of two-dimensional electronic spectroscopy using phase and amplitude modulation. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.139098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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43
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Mardazad S, Xu Y, Yang X, Grundner M, Schollwöck U, Ma H, Paeckel S. Quantum dynamics simulation of intramolecular singlet fission in covalently linked tetracene dimer. J Chem Phys 2021; 155:194101. [PMID: 34800955 DOI: 10.1063/5.0068292] [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
In this work, we study singlet fission in tetracene para-dimers, covalently linked by a phenyl group. In contrast to most previous studies, we account for the full quantum dynamics of the combined excitonic and vibrational system. For our simulations, we choose a numerically unbiased representation of the molecule's wave function, enabling us to compare with experiments, exhibiting good agreement. Having access to the full wave function allows us to study in detail the post-quench dynamics of the excitons. Here, one of our main findings is the identification of a time scale t0 ≈ 35 fs dominated by coherent dynamics. It is within this time scale that the larger fraction of the singlet fission yield is generated. We also report on a reduced number of phononic modes that play a crucial role in the energy transfer between excitonic and vibrational systems. Notably, the oscillation frequency of these modes coincides with the observed electronic coherence time t0. We extend our investigations by also studying the dependency of the dynamics on the excitonic energy levels that, for instance, can be experimentally tuned by means of the solvent polarity. Here, our findings indicate that the singlet fission yield can be doubled, while the electronic coherence time t0 is mainly unaffected.
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Affiliation(s)
- Sam Mardazad
- Department of Physics, Arnold Sommerfeld Center of Theoretical Physics, University of Munich, Theresienstrasse 37, 80333 Munich, Germany
| | - Yihe Xu
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Xuexiao Yang
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Martin Grundner
- Department of Physics, Arnold Sommerfeld Center of Theoretical Physics, University of Munich, Theresienstrasse 37, 80333 Munich, Germany
| | - Ulrich Schollwöck
- Department of Physics, Arnold Sommerfeld Center of Theoretical Physics, University of Munich, Theresienstrasse 37, 80333 Munich, Germany
| | - Haibo Ma
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Sebastian Paeckel
- Department of Physics, Arnold Sommerfeld Center of Theoretical Physics, University of Munich, Theresienstrasse 37, 80333 Munich, Germany
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44
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Bera K, Douglas CJ, Frontiera RR. Femtosecond stimulated Raman spectroscopy - guided library mining leads to efficient singlet fission in rubrene derivatives. Chem Sci 2021; 12:13825-13835. [PMID: 34760168 PMCID: PMC8549787 DOI: 10.1039/d1sc04251c] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 09/22/2021] [Indexed: 12/04/2022] Open
Abstract
Chromophores undergoing singlet fission are promising candidates for harnessing solar energy as they can generate a pair of charge carriers by the absorption of one photon. However, photovoltaic devices employing singlet fission are still lacking practical applications due to the limitations within the existing molecules undergoing singlet fission. Chemical modifications to acenes can lead to efficient singlet fission devices, but the influence of changes to molecular structure on the rate of singlet fission is challenging to model and predict. Using femtosecond stimulated Raman spectroscopy we have previously demonstrated that the triplet separation process during singlet fission in crystalline rubrene is associated with the loss of electron density from its tetracene core. Based on this knowledge, we mined a library of new rubrene derivatives with electron withdrawing substituents that prime the molecules for efficient singlet fission, without impacting their crystal packing. Our rationally chosen crystalline chromophores exhibit significantly improved singlet fission rates. This study demonstrates the utility and strength of a structurally sensitive spectroscopic technique in providing insights to spectroscopy-guided materials selection and design guidelines that go beyond energy arguments to design new singlet fission-capable chromophores. In the race to find efficient singlet fission materials, picking a winner is not easy. Femtosecond stimulated Raman spectroscopy can help us choose the best candidates, as demonstrated here in choosing from a library of rubrene derivatives.![]()
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Affiliation(s)
- Kajari Bera
- Department of Chemistry, University of Minnesota Minneapolis MN 55455 USA +1612-624-2501
| | - Christopher J Douglas
- Department of Chemistry, University of Minnesota Minneapolis MN 55455 USA +1612-624-2501
| | - Renee R Frontiera
- Department of Chemistry, University of Minnesota Minneapolis MN 55455 USA +1612-624-2501
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45
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Walia R, Deng Z, Yang J. Towards multistate multimode landscapes in singlet fission of pentacene: the dual role of charge-transfer states. Chem Sci 2021; 12:12928-12938. [PMID: 34745523 PMCID: PMC8514007 DOI: 10.1039/d1sc01703a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 08/30/2021] [Indexed: 12/03/2022] Open
Abstract
Singlet fission duplicates triplet excitons for improving light harvesting efficiency. The presence of the interaction between electronic and nuclear degrees of freedom complicates the interpretation of correlated triplet pairs. We report a quantum chemistry study on the significance and subtleties of multistate and multimode pathways in forming triplet pair states of the pentacene dimer through a six-state vibronic-coupling Hamiltonian derived from many-electron adiabatic wavefunctions of an ab initio density matrix renormalization group. The resulting spin values of the singlet manifolds on each pentacene center are computed, and the varying spin nature can be distinguished clearly with respect to dimer stacking and vibronic progression. Our monomer spin assignments reveal the coexistence of both lower-lying weak and higher-lying strong charge transfer states which interact vibronically with the triplet pair state, providing important implications for its generation and separation occurring in vibronic regions. This work conveys the importance of the many-electron process requiring close low-lying singlet manifolds to determine the subtle fission details, and represents an important step for understanding vibronically resolved spin states and conversions underlying efficient singlet fission.
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Affiliation(s)
- Rajat Walia
- Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong P. R. China
| | - Zexiang Deng
- Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong P. R. China
| | - Jun Yang
- Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong P. R. China
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46
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Vacancy control in acene blends links exothermic singlet fission to coherence. Nat Commun 2021; 12:5149. [PMID: 34446726 PMCID: PMC8390483 DOI: 10.1038/s41467-021-25395-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 07/20/2021] [Indexed: 11/09/2022] Open
Abstract
The fission of singlet excitons into triplet pairs in organic materials holds great technological promise, but the rational application of this phenomenon is hampered by a lack of understanding of its complex photophysics. Here, we use the controlled introduction of vacancies by means of spacer molecules in tetracene and pentacene thin films as a tuning parameter complementing experimental observables to identify the operating principles of different singlet fission pathways. Time-resolved spectroscopic measurements in combination with microscopic modelling enables us to demonstrate distinct scenarios, resulting from different singlet-to-triplet pair energy alignments. For pentacene, where fission is exothermic, coherent mixing between the photoexcited singlet and triplet-pair states is promoted by vibronic resonances, which drives the fission process with little sensitivity to the vacancy concentration. Such vibronic resonances do not occur for endothermic materials such as tetracene, for which we find fission to be fully incoherent; a process that is shown to slow down with increasing vacancy concentration.
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47
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Zeiser C, Moretti L, Reicherter F, Bettinger HF, Maiuri M, Cerullo G, Broch K. Singlet Fission in Dideuterated Tetracene and Pentacene. CHEMPHOTOCHEM 2021. [DOI: 10.1002/cptc.202000284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Clemens Zeiser
- Institute for Applied Physics University of Tübingen Auf der Morgenstelle 10 72076 Tübingen Germany
| | - Luca Moretti
- IFN-CNR Dipartimento di Fisica Politecnico di Milano Piazza Leonardo da Vinci 32 20133 Milan Italy
| | - Florian Reicherter
- Institute for Organic Chemistry University of Tübingen Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Holger F. Bettinger
- Institute for Organic Chemistry University of Tübingen Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Margherita Maiuri
- IFN-CNR Dipartimento di Fisica Politecnico di Milano Piazza Leonardo da Vinci 32 20133 Milan Italy
| | - Giulio Cerullo
- IFN-CNR Dipartimento di Fisica Politecnico di Milano Piazza Leonardo da Vinci 32 20133 Milan Italy
| | - Katharina Broch
- Institute for Applied Physics University of Tübingen Auf der Morgenstelle 10 72076 Tübingen Germany
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48
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Mewes L, Ingle RA, Al Haddad A, Chergui M. Broadband visible two-dimensional spectroscopy of molecular dyes. J Chem Phys 2021; 155:034201. [PMID: 34293898 DOI: 10.1063/5.0053554] [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
Two-dimensional Fourier transform spectroscopy is a promising technique to study ultrafast molecular dynamics. Similar to transient absorption spectroscopy, a more complete picture of the dynamics requires broadband laser pulses to observe transient changes over a large enough bandwidth, exceeding the inhomogeneous width of electronic transitions, as well as the separation between the electronic or vibronic transitions of interest. Here, we present visible broadband 2D spectra of a series of dye molecules and report vibrational coherences with frequencies up to ∼1400 cm-1 that were obtained after improvements to our existing two-dimensional Fourier transform setup [Al Haddad et al., Opt. Lett. 40, 312-315 (2015)]. The experiment uses white light from a hollow core fiber, allowing us to acquire 2D spectra with a bandwidth of 200 nm, in a range between 500 and 800 nm, and with a temporal resolution of 10-15 fs. 2D spectra of nile blue, rhodamine 800, terylene diimide, and pinacyanol iodide show vibronic spectral features with at least one vibrational mode and reveal information about structural motion via coherent oscillations of the 2D signals during the population time. For the case of pinacyanol iodide, these observations are complemented by its Raman spectrum, as well as the calculated Raman activity at the ground- and excited-state geometry.
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Affiliation(s)
- Lars Mewes
- Laboratoire de Spectroscopie Ultrarapide and LACUS, Ecole Polytechnique Fédérale de Lausanne, ISIC, FSB-BSP, CH-1015 Lausanne, Switzerland
| | - Rebecca A Ingle
- Laboratoire de Spectroscopie Ultrarapide and LACUS, Ecole Polytechnique Fédérale de Lausanne, ISIC, FSB-BSP, CH-1015 Lausanne, Switzerland
| | - Andre Al Haddad
- Laboratoire de Spectroscopie Ultrarapide and LACUS, Ecole Polytechnique Fédérale de Lausanne, ISIC, FSB-BSP, CH-1015 Lausanne, Switzerland
| | - Majed Chergui
- Laboratoire de Spectroscopie Ultrarapide and LACUS, Ecole Polytechnique Fédérale de Lausanne, ISIC, FSB-BSP, CH-1015 Lausanne, Switzerland
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49
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Chen L, Borrelli R, Shalashilin DV, Zhao Y, Gelin MF. Simulation of Time- and Frequency-Resolved Four-Wave-Mixing Signals at Finite Temperatures: A Thermo-Field Dynamics Approach. J Chem Theory Comput 2021; 17:4359-4373. [PMID: 34107216 DOI: 10.1021/acs.jctc.1c00259] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We propose a new approach to simulate four-wave-mixing signals of molecular systems at finite temperatures by combining the multiconfigurational Ehrenfest method with the thermo-field dynamics theory. In our approach, the four-time correlation functions at finite temperatures are mapped onto those at zero temperature in an enlarged Hilbert space with twice the vibrational degrees of freedom. As an illustration, we have simulated three multidimensional spectroscopic signals, time- and frequency-resolved fluorescence spectra, transient-absorption pump-probe spectra, and electronic two-dimensional (2D) spectra at finite temperatures, for a conical intersection-mediated singlet fission model of a rubrene crystal. It is shown that a detailed dynamical picture of the singlet fission process can be extracted from the three spectroscopic signals. An increasing temperature leads to lower intensities of the signals and broadened vibrational peaks, which can be attributed to faster singlet-triplet population transfer and stronger bath-induced electronic dephasing at higher temperatures.
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Affiliation(s)
- Lipeng Chen
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Str 38, 01187 Dresden, Germany
| | - Raffaele Borrelli
- Department of Agricultural, Forestry and Food Science, Universitá di Torino, I-10095 Grugliasco, TO, Italy
| | | | - Yang Zhao
- Division of Materials Science, Nanyang Technological University, Singapore 639798, Singapore
| | - Maxim F Gelin
- School of Science, Hangzhou Dianzi University, Hangzhou 310018, China
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50
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Le DV, de la Perrelle JM, Do TN, Leng X, Tapping PC, Scholes GD, Kee TW, Tan HS. Characterization of the ultrafast spectral diffusion and vibronic coherence of TIPS-pentacene using 2D electronic spectroscopy. J Chem Phys 2021; 155:014302. [PMID: 34241376 DOI: 10.1063/5.0055528] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
TIPS-pentacene is a small-molecule organic semiconductor that is widely used in optoelectronic devices. It has been studied intensely owing to its ability to undergo singlet fission. In this study, we aim to develop further understanding of the coupling between the electronic and nuclear degrees of freedom of TIPS-pentacene (TIPS-Pn). We measured and analyzed the 2D electronic spectra of TIPS-Pn in solutions. Using center line slope (CLS) analysis, we characterized the frequency-fluctuation correlation function of the 0-0 vibronic transition. Strong oscillations in the CLS values were observed for up to 5 ps with a frequency of 264 cm-1, which are attributable to a large vibronic coupling with the TIPS-Pn ring-breathing vibrational mode. In addition, detailed analysis of the CLS values allowed us to retrieve two spectral diffusion lifetimes, which are attributed to the inertial and diffusive dynamics of solvent molecules. Amplitude beating analysis also uncovered couplings with another vibrational mode at 1173 cm-1. The experimental results can be described using the displaced harmonic oscillator model. By comparing the CLS values of the simulated data with the experimental CLS values, we estimated a Huang-Rhys factor of 0.1 for the ring-breathing vibrational mode. The results demonstrated how CLS analysis can be a useful method for characterizing the strength of vibronic coupling.
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Affiliation(s)
- Duc Viet Le
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | | | - Thanh Nhut Do
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Xuan Leng
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Patrick C Tapping
- Department of Chemistry, University of Adelaide, Adelaide SA 5005, Australia
| | - Gregory D Scholes
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
| | - Tak W Kee
- Department of Chemistry, University of Adelaide, Adelaide SA 5005, Australia
| | - Howe-Siang Tan
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
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