1
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Wang K, You X, Miao X, Yi Y, Peng S, Wu D, Chen X, Xu J, Sfeir MY, Xia J. Activated Singlet Fission Dictated by Anti-Kasha Property in a Rylene Imide Dye. J Am Chem Soc 2024; 146:13326-13335. [PMID: 38693621 DOI: 10.1021/jacs.4c01732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
A key challenge in the search of new materials capable of singlet fission (SF) arises from the primary energy conservation criterion, i.e., the energy of the triplet exciton has to be half that of the singlet (E(S1) ≥ 2E(T1)), which excludes most photostable organic materials from consideration and confines the design strategy to materials with low energy triplet states. One potential way to overcome this energy requirement and improve the triplet energy is to enable a SF channel from higher energy ("hot") excitonic states (Sn) in a process called activated SF. Herein, we demonstrate that efficient activated SF is achieved in a rylene imide-based derivative acenaphth[l, 2-a]acenaphthylene diimide (AADI). This process is enabled by an increase in the energy gap to greater than 1.0 eV between the S3 and S1 states due to the incorporation of an antiaromatic pentalene unit, which leads to the emergence of anti-Kasha properties in the isolated molecule. Transient spectroscopy studies show that AADI undergoes ultrafast SF from higher singlet excited states in thin film, with excitation wavelength-dependent SF yields. The SF yield of ∼200% is observed upon higher energy excitation, and long-lived free triplets persist on the μs time scale suggesting that AADI can be used in SF-enhanced devices. Our results suggest that enlarging the Sn-S1 energy gap is an effective way to turn on the activated SF channel and shed light on the development of novel, stable SF materials with high triplet energies.
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Affiliation(s)
- Kangwei Wang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
| | - Xiaoxiao You
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
| | - Xiaodan Miao
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy Sciences, Beijing 100049, China
| | - Yuanping Yi
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy Sciences, Beijing 100049, China
| | - Shaoqian Peng
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
| | - Di Wu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, China
| | - Xingyu Chen
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, China
| | - Jingwen Xu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, China
| | - Matthew Y Sfeir
- Photonics Initiative, Advanced Science Research Center, City University of New York, New York 10016, United States
- Department of Physics, Graduate Center, City University of New York, New York 10031, United States
| | - Jianlong Xia
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, China
- International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
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2
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Zheng Y, Venkatesh R, Rojas-Gatjens E, Reichmanis E, Silva-Acuña C. Exciton Bimolecular Annihilation Dynamics in Push-Pull Semiconductor Polymers. J Phys Chem Lett 2024; 15:272-280. [PMID: 38166236 PMCID: PMC10788955 DOI: 10.1021/acs.jpclett.3c03094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/17/2023] [Accepted: 12/28/2023] [Indexed: 01/04/2024]
Abstract
Exciton-exciton annihilation is a ubiquitous nonlinear dynamic phenomenon in materials hosting Frenkel excitons. In this work, we investigate the nonlinear exciton dynamics of an electron push-pull conjugated polymer by fluence-dependent transient absorption and excitation-correlation photoluminescence spectroscopy, where we can quantitatively show the latter to be a more selective probe of the nonlinear dynamics. Simulations based on a time-independent exciton annihilation model show a decreasing trend for the extracted annihilation rates with excitation fluence. Further investigation of the fluence-dependent transients suggests that the exciton-exciton annihilation bimolecular rates are not constant in time, displaying a t-1/2 time dependence, which we rationalize as reflective of one-dimensional exciton diffusion, with a diffusion length estimated to be 9 ± 2 nm. In addition, exciton annihilation gives rise to a long-lived species that recombines on a nanosecond time scale. Our conclusions shed broad light onto nonlinear exciton dynamics in push-pull conjugated polymers.
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Affiliation(s)
- Yulong Zheng
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, 901 Atlantic Drive, Atlanta, Georgia 30332, United States
| | - Rahul Venkatesh
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332, United States
| | - Esteban Rojas-Gatjens
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, 901 Atlantic Drive, Atlanta, Georgia 30332, United States
| | - Elsa Reichmanis
- Department
of Chemical & Biomolecular Engineering, Lehigh University, 124 E. Morton Street, Bethlehem, Pennsylvania 18015, United States
| | - Carlos Silva-Acuña
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, 901 Atlantic Drive, Atlanta, Georgia 30332, United States
- Institut
Courtois & Département de physique, Université de Montréal, 1375 Avenue Thérèse-Lavoie-Roux, Montréal H2V 0B3, Québec, Canada
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3
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Wang K, Chen X, Xu J, Peng S, Wu D, Xia J. Recent Advance in the Development of Singlet-Fission-Capable Polymeric Materials. Macromol Rapid Commun 2024; 45:e2300241. [PMID: 37548255 DOI: 10.1002/marc.202300241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/24/2023] [Indexed: 08/08/2023]
Abstract
Singlet fission (SF) is a spin-allowed process in which a higher-energy singlet exciton is converted into two lower-energy triplet excitons via a triplet pair intermediate state. Implementing SF in photovoltaic devices holds the potential to exceed the Shockley-Queisser limit of conventional single-junction solar cells. Although great progress has been made in exploiting the underlying mechanism of SF over the past decades, the scope of materials capable of SF, particularly polymeric materials, remains poor. SF-capable polymer is one of the most potential candidates in the implementation of SF into devices due to their distinct superiorities in flexibility, solution processability and self-assembly behavior. Notably, recent advancements have demonstrated high-performance SF in isolated donor-acceptor (D-A) copolymer chains. This review provides an overview of recent progress in the development of SF-capable polymeric materials, with a significant focus on elucidating the mechanisms of SF in polymers and optimizing the design strategies for SF-capable polymers. Additionally, the paper discusses the challenges encountered in this field and presents future perspectives. It is expected that this comprehensive review will offer valuable insights into the design of novel SF-capable polymeric materials, further advancing the potential for SF implementation in photovoltaic devices.
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Affiliation(s)
- Kangwei Wang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan, 430070, China
| | - Xingyu Chen
- International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, China
| | - Jingwen Xu
- International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, China
| | - Shaoqian Peng
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan, 430070, China
| | - Di Wu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan, 430070, China
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan, 430070, China
| | - Jianlong Xia
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan, 430070, China
- International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, China
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan, 430070, China
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4
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Barford W. Singlet Fission in Lycopene H-Aggregates. J Phys Chem Lett 2023; 14:9842-9847. [PMID: 37890074 PMCID: PMC10641873 DOI: 10.1021/acs.jpclett.3c02435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/09/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023]
Abstract
A theory of singlet fission (SF) in carotenoid dimers is applied to explain the SF in lycopene H-aggregates observed after high-energy photoexcitation. The explanation proposed here is that a high energy, delocalized bright 1Bu+ state first relaxes and localizes onto a single lycopene monomer. The high-energy intramonomer state then undergoes internal conversion to the 11Bu- state. Once populated, the 11Bu- state allows exothermic bimolecular singlet fission, while its internal conversion to the 21Ag- state is symmetry forbidden. The simulation of SF predicts that the intramonomer triplet-pair state undergoes almost complete population transfer to the intermonomer singlet-pair state within 100 ps. Simultaneously, ZFS interactions begin to partially populate the intermonomer quintet triplet-pair state up to ca. 2 ns, after which hyperfine interactions thermally equilibrate the triplet-pair states, thus forming free single triplets within 50 ns.
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Affiliation(s)
- William Barford
- Department of Chemistry, Physical and
Theoretical Chemistry Laboratory,University
of Oxford, Oxford, OX1 3QZ, United
Kingdom
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5
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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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6
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Barford W, Chambers CA. Theory of singlet fission in carotenoid dimers. J Chem Phys 2023; 159:084116. [PMID: 37646371 DOI: 10.1063/5.0155476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 07/03/2023] [Indexed: 09/01/2023] Open
Abstract
We develop a theory of singlet fission in carotenoid dimers. Following photoexcitation of the "bright" state (i.e., a singlet electron-hole pair) in a single carotenoid, the first step in the singlet fission process is ultrafast intramolecular conversion into the highly correlated "dark" (or 2Ag) state. This state has both entangled singlet triplet-pair and charge-transfer character. Our theory is predicated on the assumption that it is the singlet triplet-pair component of the "dark" state that undergoes bimolecular singlet fission. We use valence bond theory to develop a minimal two-chain model of the triplet-pair states. The single and double chain triplet-pair spectra are described, as this helps explain the dynamics and the equilibrated populations. We simulate the dynamics of the initial entangled pair state using the quantum Liouville equation, including both spin-conserving and spin-nonconserving dephasing processes. By computing the intrachain and interchain singlet, triplet, and quintet triplet-pair populations, we show that singlet fission critically depends on the interchain coupling and the driving potential (that determines endothermic vs exothermic fission).
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Affiliation(s)
- William Barford
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, OX1 3QZ, United Kingdom
- Balliol College, University of Oxford, Oxford, OX1 3BJ, United Kingdom
| | - Cameron A Chambers
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, OX1 3QZ, United Kingdom
- Lincoln College, University of Oxford, Oxford, OX1 3DR, United Kingdom
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7
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Mencaroni L, Alebardi M, Elisei F, Škorić I, Spalletti A, Carlotti B. Unveiling the double triplet nature of the 2Ag state in conjugated stilbenoid compounds to achieve efficient singlet fission. Phys Chem Chem Phys 2023; 25:21089-21099. [PMID: 37527269 DOI: 10.1039/d3cp02805d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
In this investigation, the excited-state evolution in a series of all-trans stilbenoid compounds, displaying a low-lying dark singlet state of 2Ag-like symmetry nearly degenerate with the bright 1Bu state, was unveiled by employing advanced ultrafast spectroscopies while probing the effect of solvent polarizability. Together with the dual emission, femtosecond transient absorption and broadband fluorescence up-conversion disclosed the double nature of the 2Ag-like state showing both singlet features, a lifetime typical of a singlet and the ability to emit, and a triplet character, exhibiting a triplet-like absorption spectrum. The ultrafast formation (in hundreds of femtoseconds) from the non-relaxed upper singlet state led to the identification of 2Ag as the correlated triplet pair of singlet fission. The spectral difference obtained by comparison of transient absorption peaks of the 2Ag (1TT) and the triplet states was found to be in remarkable agreement with the observed triplet yield and the 1(TT) separation rate constant. Indeed, this spectral shift provided an experimental method to gain qualitative insight into the ease of separation of the 1(TT) and the relative SF efficiency. The highly conjugated polyene-like structures enable the ultrafast formation of the double triplet, but then the large binding energy prevents the triplet separation and thus the effective completion of singlet fission. Even though thermodynamically feasible for all the investigated stilbenoids according to TD-DFT calculations, singlet fission resulted to occur efficiently in the case of 1-(pyridyl-4-ylethenyl)-4-(p-nitrostyryl)benzene and nitro-styrylfuran with the triplet yield reaching 120% and 140%, respectively, triggered by their greatly enhanced intramolecular charge transfer character relative to the other compounds in the series.
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Affiliation(s)
- Letizia Mencaroni
- Department of Chemistry, Biology and Biotechnology, University of Perugia, via elce di sotto 8, 06123 Perugia, Italy.
| | - Martina Alebardi
- Department of Chemistry, Biology and Biotechnology, University of Perugia, via elce di sotto 8, 06123 Perugia, Italy.
| | - Fausto Elisei
- Department of Chemistry, Biology and Biotechnology, University of Perugia, via elce di sotto 8, 06123 Perugia, Italy.
| | - Irena Škorić
- Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, 10000 Zagreb, Croatia
| | - Anna Spalletti
- Department of Chemistry, Biology and Biotechnology, University of Perugia, via elce di sotto 8, 06123 Perugia, Italy.
| | - Benedetta Carlotti
- Department of Chemistry, Biology and Biotechnology, University of Perugia, via elce di sotto 8, 06123 Perugia, Italy.
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8
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Sutherland GA, Pidgeon JP, Lee HKH, Proctor MS, Hitchcock A, Wang S, Chekulaev D, Tsoi WC, Johnson MP, Hunter CN, Clark J. Twisted Carotenoids Do Not Support Efficient Intramolecular Singlet Fission in the Orange Carotenoid Protein. J Phys Chem Lett 2023:6135-6142. [PMID: 37364284 DOI: 10.1021/acs.jpclett.3c01139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
Singlet exciton fission is the spin-allowed generation of two triplet electronic excited states from a singlet state. Intramolecular singlet fission has been suggested to occur on individual carotenoid molecules within protein complexes provided that the conjugated backbone is twisted out of plane. However, this hypothesis has been forwarded only in protein complexes containing multiple carotenoids and bacteriochlorophylls in close contact. To test the hypothesis on twisted carotenoids in a "minimal" one-carotenoid system, we study the orange carotenoid protein (OCP). OCP exists in two forms: in its orange form (OCPo), the single bound carotenoid is twisted, whereas in its red form (OCPr), the carotenoid is planar. To enable room-temperature spectroscopy on canthaxanthin-binding OCPo and OCPr without laser-induced photoconversion, we trap them in a trehalose glass. Using transient absorption spectroscopy, we show that there is no evidence of long-lived triplet generation through intramolecular singlet fission despite the canthaxanthin twist in OCPo.
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Affiliation(s)
- George A Sutherland
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
| | - James P Pidgeon
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, U.K
| | - Harrison Ka Hin Lee
- SPECIFIC, Faculty of Science and Engineering, Swansea University, Swansea SA1 8EN, U.K
| | - Matthew S Proctor
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
| | - Andrew Hitchcock
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
| | - Shuangqing Wang
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, U.K
| | - Dimitri Chekulaev
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, U.K
| | - Wing Chung Tsoi
- SPECIFIC, Faculty of Science and Engineering, Swansea University, Swansea SA1 8EN, U.K
| | - Matthew P Johnson
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
| | - C Neil Hunter
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
| | - Jenny Clark
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, U.K
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9
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Wang K, Huang H, Xu K, Peng S, You X, Chen X, Xu J, Wu D, Xia J. Veil of the Charge Transfer State in Bay-Annulated Indigo-Based Donor-Acceptor Systems: Charge Separation versus Singlet Fission. J Phys Chem Lett 2023; 14:4822-4829. [PMID: 37191450 DOI: 10.1021/acs.jpclett.3c00798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Bay-annulated indigo (BAI) is a new potential SF-active building block, which has aroused great interest in the design of highly stable singlet fission materials. However, singlet fission of unfunctionalized BAI is inactive due to the inappropriate energy levels. Herein, we seek to develop a new design strategy by introducing the charge transfer interaction to tune the exciton dynamics of BAI derivatives. A new donor-acceptor molecule (TPA-2BAI) and two control molecules (TPA-BAI and 2TPA-BAI) were designed and synthesized to unravel the veil of CT states in tuning the excited-state dynamics of BAI derivatives. Transient absorption spectroscopy studies show that CT states are generated immediately following the excitation. However, the low-lying CT states induced by strong donor-acceptor interactions result in them acting as trap states and inhibiting the SF process. These results show that the low-lying CT state is detrimental to SF and provide insight into the design of CT-mediated BAI-based SF materials.
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Affiliation(s)
- Kangwei Wang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
| | - Huaxi Huang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
| | - Ke Xu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
| | - Shaoqian Peng
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
| | - Xiaoxiao You
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
| | - Xingyu Chen
- International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Jingwen Xu
- International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Di Wu
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, China
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
| | - Jianlong Xia
- International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, China
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan 430070, China
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10
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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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11
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Tsuneda T, Taketsugu T. Singlet fission initiating triplet generations of BODIPY derivatives through [Formula: see text]-stacking: a theoretical study. Sci Rep 2022; 12:19714. [PMID: 36385479 PMCID: PMC9668823 DOI: 10.1038/s41598-022-23370-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 10/31/2022] [Indexed: 11/17/2022] Open
Abstract
The role of singlet fission (SF) in the triplet-state generation mechanism of 1,3,5,7-tetramethyl-boron-dipyrromethene derivatives is revealed by exploring the cause for the solvent dependence of the generation rate. Comparing the adsorption energy calculations of solvent molecules, i.e., cyclohexane, chloroform and acetonitrile molecules, to the derivatives with the [Formula: see text]-stacking energies of these derivatives surprisingly show that the hierarchy of the solvation energies and [Formula: see text]-stacking energies strongly correlates with the experimentally-suggested solvent dependence of the triplet-state generation of these derivatives for five and more adsorbing solvent molecules. Following this finding, the excitation spectra of these derivatives in acetonitrile solvent are explored using the proprietary spin-flip long-range corrected time-dependent density functional theory. It is, consequently, confirmed that the [Formula: see text]-stacking activates the second lowest singlet excitation to trigger the spin-allowed transition to the singlet doubly-excited tetraradical (TT)[Formula: see text] state, which generates the long-lived quintet (TT)[Formula: see text] state causing the SF. However, it is also found that the [Formula: see text]-stacking also get a slow intersystem crossing active around the intersections of the lowest singlet excitations with the lowest triplet T[Formula: see text] excitations in parallel with the SF due to the charge transfer characters of the lowest singlet excitations. These results suggest that SF initiates the triplet-state generations through near-degenerate low-lying singlet and (TT) excitations with a considerable singlet-triplet energy gap after the [Formula: see text]-stacking of chromophores stronger than but not far from the solvation. Since these derivatives are organic photosensitizers, this study proposes that SF should be taken into consideration in developing novel heavy atom-free organic photosensitizers, which will contribute to a variety of research fields such as medical care, photobiology, energy science, and synthetic chemistry.
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Affiliation(s)
- Takao Tsuneda
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, 060-0810 Japan
- Graduate School of Science Technology and Innovation, Kobe University, Nada-ku, Kobe, Hyogo 657-8501 Japan
| | - Tetsuya Taketsugu
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, 060-0810 Japan
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo, 001-0021 Japan
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12
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Bansal D, Kundu A, Singh VP, Pal AK, Datta A, Dasgupta J, Mukhopadhyay P. A highly contorted push-pull naphthalenediimide dimer and evidence of intramolecular singlet exciton fission. Chem Sci 2022; 13:11506-11512. [PMID: 36320404 PMCID: PMC9555572 DOI: 10.1039/d2sc04187a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 09/05/2022] [Indexed: 08/05/2023] Open
Abstract
Singlet fission is a process by which two molecular triplet excitons are generated subsequent to the absorption of one photon. Molecules that enable singlet fission have triplet state energy at least half of the bright singlet state energy. This stringent energy criteria have challenged chemists to device new molecular and supramolecular design principles to modulate the singlet-triplet energy gap and build singlet fission systems from a wide range of organic chromophores. Herein, we report for the first time intramolecular singlet fission in the seminal naphthalenediimide (NDI) scaffold constrained in a push-pull cyclophane architecture, while individually the NDI chromophore does not satisfy the energy criterion. The challenging synthesis of this highly contorted push-pull cyclophane is possible from the preorganized pincer-like precursor. The special architecture establishes the shortest co-facial NDI⋯NDI contacts (3.084 Å) realized to date. Using broadband femtosecond transient absorption, we find that the correlated T-T pair forms rapidly within 380 fs of photoexcitation. Electronic structure calculations at the level of state-averaged CASSCF (ne,mo)/XMCQDPT2 support the existence of the multi-excitonic T-T pair state, thereby confirming the first example of singlet exciton fission in a NDI scaffold.
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Affiliation(s)
- Deepak Bansal
- School of Physical Sciences, Jawaharlal Nehru University New Delhi 110067 India
| | - Arup Kundu
- Department of Chemical Sciences, Tata Institute of Fundamental Research Mumbai 400005 India
| | - Vijay Pal Singh
- School of Physical Sciences, Jawaharlal Nehru University New Delhi 110067 India
| | - Arun K Pal
- School of Chemical Sciences, Indian Association for the Cultivation of Science Kolkata 700032 West Bengal India
| | - Ayan Datta
- School of Chemical Sciences, Indian Association for the Cultivation of Science Kolkata 700032 West Bengal India
| | - Jyotishman Dasgupta
- Department of Chemical Sciences, Tata Institute of Fundamental Research Mumbai 400005 India
| | - Pritam Mukhopadhyay
- School of Physical Sciences, Jawaharlal Nehru University New Delhi 110067 India
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13
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Xu X, Gunasekaran S, Renken S, Ripani L, Schollmeyer D, Kim W, Marcaccio M, Musser A, Narita A. Synthesis and Characterizations of 5,5'-Bibenzo[rst]pentaphene with Axial Chirality and Symmetry-Breaking Charge Transfer. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2200004. [PMID: 35156332 PMCID: PMC9259715 DOI: 10.1002/advs.202200004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 01/23/2022] [Indexed: 05/31/2023]
Abstract
Exploration of novel biaryls consisting of two polycyclic aromatic hydrocarbon (PAH) units can be an important strategy toward further developments of organic materials with unique properties. In this study, 5,5'-bibenzo[rst]pentaphene (BBPP) with two benzo[rst]pentaphene (BPP) units is synthesized in an efficient and versatile approach, and its structure is unambiguously elucidated by X-ray crystallography. BBPP exhibits axial chirality, and the (M)- and (P)-enantiomers are resolved by chiral high-performance liquid chromatography and studied by circular dichroism spectroscopy. These enantiomers have a relatively high isomerization barrier of 43.6 kcal mol-1 calculated by density functional theory. The monomer BPP and dimer BBPP are characterized by UV-vis absorption and fluorescence spectroscopy, cyclic voltammetry, and femtosecond transient absorption spectroscopy. The results indicate that both BPP and BBPP fluoresce from a formally dark S1 electronic state that is enabled by Herzberg-Teller intensity borrowing from a neighboring bright S2 state. While BPP exhibits a relatively low photoluminescence quantum yield (PLQY), BBPP exhibits a significantly enhanced PLQY due to a greater S2 intensity borrowing. Moreover, symmetry-breaking charge transfer in BBPP is demonstrated by spectroscopic investigations in solvents of different polarity. This suggests high potential for singlet fission in such π-extended biaryls through appropriate molecular design.
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Affiliation(s)
- Xiushang Xu
- Max Planck Institute for Polymer ResearchAckermannweg 10Mainz55128Germany
- Organic and Carbon Nanomaterials UnitOkinawa Institute of Science and Technology Graduate University1919‐1 Tancha, Onna‐sonKunigami‐gunOkinawa904‐0495Japan
| | - Suman Gunasekaran
- Department of Chemistry & Chemical BiologyCornell UniversityIthacaNY14853USA
| | - Scott Renken
- Department of Chemistry & Chemical BiologyCornell UniversityIthacaNY14853USA
| | - Lorenzo Ripani
- Dipartimento di Chimica “Giacomo Ciamician”Università di Bolognavia Selmi 2Bologna40126Italy
| | - Dieter Schollmeyer
- Department of ChemistryJohannes Gutenberg University MainzDuesbergweg 10–14Mainz55128Germany
| | - Woojae Kim
- Department of Chemistry & Chemical BiologyCornell UniversityIthacaNY14853USA
| | - Massimo Marcaccio
- Dipartimento di Chimica “Giacomo Ciamician”Università di Bolognavia Selmi 2Bologna40126Italy
| | - Andrew Musser
- Department of Chemistry & Chemical BiologyCornell UniversityIthacaNY14853USA
| | - Akimitsu Narita
- Max Planck Institute for Polymer ResearchAckermannweg 10Mainz55128Germany
- Organic and Carbon Nanomaterials UnitOkinawa Institute of Science and Technology Graduate University1919‐1 Tancha, Onna‐sonKunigami‐gunOkinawa904‐0495Japan
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14
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Wang T, Zhang BY, Zhang HL. Singlet Fission Materials for Photovoltaics: from Small Molecules to Macromolecules. Macromol Rapid Commun 2022; 43:e2200326. [PMID: 35703581 DOI: 10.1002/marc.202200326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/29/2022] [Indexed: 11/08/2022]
Abstract
Singlet fission (SF) is a spin-allowed process in which a singlet state splits into two triplet states. Materials that enable SF have attracted great attention in the last decade, mainly stemming from the potential of overcoming the Shockley-Queisser (SQ) limit in photoenergy conversion. In the past decade, a large number of new molecules exhibiting SF have been explored and many devices based on SF materials have been studied, though the mechanistic understanding is still obscure. This review focuses on the recent developments of SF materials, including small molecules, oligomers and polymers. The molecular design strategies and related mechanisms of SF are discussed. Then the dynamics of charge transfer and energy transfer between SF materials and other materials are introduced. Further, we discuss the progresses of implementing SF in photovoltaics. It is hoped that a comprehensive understanding to the SF materials, devices and mechanism may pave a new way for the design of next generation photovoltaics. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Ting Wang
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Special Function Materials and Structure Design, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, P. R. China
| | - Bo-Yang Zhang
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Special Function Materials and Structure Design, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, P. R. China
| | - Hao-Li Zhang
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Special Function Materials and Structure Design, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, P. R. China.,Prof. H. L. Zhang, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072, P. R. China
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15
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Dimitriev OP. Dynamics of Excitons in Conjugated Molecules and Organic Semiconductor Systems. Chem Rev 2022; 122:8487-8593. [PMID: 35298145 DOI: 10.1021/acs.chemrev.1c00648] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The exciton, an excited electron-hole pair bound by Coulomb attraction, plays a key role in photophysics of organic molecules and drives practically important phenomena such as photoinduced mechanical motions of a molecule, photochemical conversions, energy transfer, generation of free charge carriers, etc. Its behavior in extended π-conjugated molecules and disordered organic films is very different and very rich compared with exciton behavior in inorganic semiconductor crystals. Due to the high degree of variability of organic systems themselves, the exciton not only exerts changes on molecules that carry it but undergoes its own changes during all phases of its lifetime, that is, birth, conversion and transport, and decay. The goal of this review is to give a systematic and comprehensive view on exciton behavior in π-conjugated molecules and molecular assemblies at all phases of exciton evolution with emphasis on rates typical for this dynamic picture and various consequences of the above dynamics. To uncover the rich variety of exciton behavior, details of exciton formation, exciton transport, exciton energy conversion, direct and reverse intersystem crossing, and radiative and nonradiative decay are considered in different systems, where these processes lead to or are influenced by static and dynamic disorder, charge distribution symmetry breaking, photoinduced reactions, electron and proton transfer, structural rearrangements, exciton coupling with vibrations and intermediate particles, and exciton dissociation and annihilation as well.
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Affiliation(s)
- Oleg P Dimitriev
- V. Lashkaryov Institute of Semiconductor Physics NAS of Ukraine, pr. Nauki 41, Kyiv 03028, Ukraine
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16
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He G, Yablon LM, Parenti KR, Fallon KJ, Campos LM, Sfeir MY. Quantifying Exciton Transport in Singlet Fission Diblock Copolymers. J Am Chem Soc 2022; 144:3269-3278. [PMID: 35166107 DOI: 10.1021/jacs.1c13456] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Singlet fission (SF) is a mechanism of exciton multiplication in organic chromophores, which has potential to drive highly efficient optoelectronic devices. Creating effective device architectures that operate by SF critically depends on electronic interactions across multiple length scales─from individual molecules to interchromophore interactions that facilitate multiexciton dephasing and exciton diffusion toward donor-acceptor interfaces. Therefore, it is imperative to understand the underpinnings of multiexciton transport and interfacial energy transfer in multichromophore systems. Interestingly, block copolymers (BCPs) can be designed to control multiscale interactions by tailoring the nature of the building blocks, yet SF dynamics are not well understood in these macromolecules. Here, we designed diblock copolymers comprising an inherent energy cleft at the interface between a block with pendent pentacene chromophores and an additional block with pendent tetracene chromophores. The singlet and triplet energy offset between the two blocks creates a driving force for exciton transport along the BCP chain in dilute solution. Using time-resolved optical spectroscopy, we have quantified the yields of key energy transfer steps, including both singlet and triplet energy transfer processes across the pentacene-tetracene interface. From this modular BCP architecture, we correlate the energy transfer time scales and relative yields with the length of each block. The ability to quantify these energy transfer processes provides valuable insights into exciton transport at critical length scales between bulk crystalline systems and small-molecule dimers─an area that has been underexplored.
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Affiliation(s)
- Guiying He
- Department of Physics, Graduate Center, City University of New York, New York, New York 10016, United States.,Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, United States
| | - Lauren M Yablon
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Kaia R Parenti
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Kealan J Fallon
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Luis M Campos
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Matthew Y Sfeir
- Department of Physics, Graduate Center, City University of New York, New York, New York 10016, United States.,Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, United States
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17
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Manawadu D, Valentine DJ, Marcus M, Barford W. Singlet Triplet-Pair Production and Possible Singlet-Fission in Carotenoids. J Phys Chem Lett 2022; 13:1344-1349. [PMID: 35108016 PMCID: PMC9084603 DOI: 10.1021/acs.jpclett.1c03812] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 02/01/2022] [Indexed: 05/19/2023]
Abstract
Internal conversion from the photoexcited state to a correlated singlet triplet-pair state is believed to be the precursor of singlet fission in carotenoids. We present numerical simulations of this process using a π-electron model that fully accounts for electron-electron interactions and electron-nuclear coupling. The time-evolution of the electrons is determined rigorously using the time-dependent density matrix renormalization group method, while the nuclei are evolved via the Ehrenfest equations of motion. We apply this to zeaxanthin, a carotenoid chain with 18 fully conjugated carbon atoms. We show that the internal conversion of the primary photoexcited state, S2, to the singlet triplet-pair state occurs adiabatically via an avoided crossing within ∼50 fs with a yield of ∼60%. We further discuss whether this singlet triplet-pair state will undergo exothermic versus endothermic intra- or interchain singlet fission.
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Affiliation(s)
- Dilhan Manawadu
- Department
of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
- Linacre College, University of Oxford, Oxford OX1 3JA, United Kingdom
| | - Darren J. Valentine
- Department
of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
- Balliol College, University of Oxford, Oxford OX1 3BJ, United Kingdom
| | - Max Marcus
- Department
of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - William Barford
- Department
of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
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18
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Xie X, Troisi A. Evaluating the Electronic Structure of Coexisting Excitonic and Multiexcitonic States in Periodic Systems: Significance for Singlet Fission. J Chem Theory Comput 2021; 18:394-405. [PMID: 34902251 DOI: 10.1021/acs.jctc.1c00831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Singlet fission (SF) in organic molecular solids is an example of a process that is challenging to describe with the most common electronic structure approaches. It involves optically bright singlet excited states delocalized over many molecules, which could be efficiently treated by density functional theory, and multiexcitonic localized states that have to be studied with wavefunction methods, usually with small clusters considering their expensive computational costs. In this work, we propose a methodology to combine multiconfigurational wavefunction calculations with reduced Hamiltonian to investigate the electronic structure of large clusters or fully periodic systems. The method is applied to the prototypical SF materials tetracene and pentacene. The results allow one to study how states of different natures (excitonic, charge-transfer, and multiexcitonic) coexist and are contaminated by their couplings in large or periodic systems. Novel insights are therefore possible. For example, because the excitonic bands are relatively broad with respect to the multiexcitonic states, there are limited regions of the crystal momentum space where the transition between the two is more likely.
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Affiliation(s)
- Xiaoyu Xie
- Department of Chemistry, University of Liverpool, Liverpool L69 3BX, U.K
| | - Alessandro Troisi
- Department of Chemistry, University of Liverpool, Liverpool L69 3BX, U.K
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19
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Bader YMK, Guan C, Qin Y. Regio‐regular
and
cross‐conjugated
poly(thienylene vinylene)s through acyclic diene metathesis. JOURNAL OF POLYMER SCIENCE 2021. [DOI: 10.1002/pol.20210778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yousef M. Katba Bader
- Department of Chemistry & Chemical Biology University of New Mexico Albuquerque New Mexico USA
| | - Chao Guan
- Institute of Materials Science University of Connecticut Storrs Connecticut USA
| | - Yang Qin
- Department of Chemistry & Chemical Biology University of New Mexico Albuquerque New Mexico USA
- Institute of Materials Science University of Connecticut Storrs Connecticut USA
- Department of Chemical & Biomolecular Engineering University of Connecticut Storrs Connecticut USA
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20
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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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21
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Katba-Bader YM, Meng L, Guan C, Qin Y. Regio-regular poly(thienylene vinylene)s (rr-PTVs) through acyclic diene metathesis (ADMET) polymerization and the impact of alkyl side-chains on polymer molecular weight and solubility. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.124150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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22
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Stoycheva J, Romanova J, Tadjer A. Women in the Singlet Fission World: Pearls in a Semi-Open Shell. Molecules 2021; 26:molecules26102922. [PMID: 34069036 PMCID: PMC8156465 DOI: 10.3390/molecules26102922] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 04/27/2021] [Accepted: 04/30/2021] [Indexed: 11/16/2022] Open
Abstract
Singlet fission, a multiple exciton generation process, can revolutionize existing solar cell technologies. Offering the possibility to double photocurrent, the process has become a focal point for physicists, chemists, software developers, and engineers. The following review is dedicated to the female investigators, predominantly theorists, who have contributed to the field of singlet fission. We highlight their most significant advances in the subject, from deciphering the mechanism of the process to designing coveted singlet fission materials.
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Affiliation(s)
- Joanna Stoycheva
- Correspondence: (J.S.); (J.R.); (A.T.); Tel.: +359-2-8161374 (A.T.)
| | - Julia Romanova
- Correspondence: (J.S.); (J.R.); (A.T.); Tel.: +359-2-8161374 (A.T.)
| | - Alia Tadjer
- Correspondence: (J.S.); (J.R.); (A.T.); Tel.: +359-2-8161374 (A.T.)
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23
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Manna B, Nandi A, Vats BG. Role of nanosize and defect trapping upon singlet fission yield and singlet fission dynamics of 1,6-Diphenyl-1,3,5-hexatriene nanoaggregates. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2021.113262] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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24
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Manna B, Nandi A. Singlet fission in nanoaggregate of bis(phenylethynyl) derivative of benzene (BPEB): High energy triplet exciton generation with >100 % yield. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2021.113251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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25
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Wang L, Zhang TS, Fu L, Xie S, Wu Y, Cui G, Fang WH, Yao J, Fu H. High-Lying 3 1A g Dark-State-Mediated Singlet Fission. J Am Chem Soc 2021; 143:5691-5697. [PMID: 33843229 DOI: 10.1021/jacs.0c11681] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Singlet fission (SF), the conversion of one high-energy singlet to two low-energy triplets, provides the potential to increase the efficiency of photovoltaic devices. In the SF chromophores with C2h symmetry, exemplified by polyenes, singlet-to-triplet conversion generally involves a low-lying 21Ag dark state, which serves as either a multiexciton (ME) intermediate to promote the SF process or a parasitic trap state to shunt excited-state populations via internal conversion. This controversial behavior calls for a deep understanding of dark-state-related photophysics involving the higher-lying singlet state. However, the optical "dark" and "transient" nature of these dark states and strong correlation feature of double exciton species make their characterization and interpretation challenging from both experimental and computational perspectives. In the present work combining transient spectroscopy and multireference electronic structure calculations (XDW-CASPT2), we addressed a new photophysical model, i.e., a high-lying 31Ag dark-state-mediated ultrafast SF process in the benzodipyrrolidone (BDPP) skeleton. Such a 31Ag dark state with distinctive double excitation character, described as the ME state, could be populated from the initial 11Bu bright state on an ultrafast time scale given the quasi-degeneracy and intersection of the two electronic states. Furthermore, the suitable optical band gap and triplet energy, high triplet yield, and excellent photostability render BDPP a promising SF candidate for photovoltaic devices. These results not only enrich the arsenal of SF materials but also shed new insights into the understanding of dark-state-related photophysics, which could promote the development of new SF-active materials.
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Affiliation(s)
- Long Wang
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Teng-Shuo Zhang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Liyuan Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, China
| | - Shaohua Xie
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, China
| | - Yishi Wu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Jiannian Yao
- Beijing National Laboratory for Molecules Science (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, China
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26
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Budden PJ, Weiss LR, Müller M, Panjwani NA, Dowland S, Allardice JR, Ganschow M, Freudenberg J, Behrends J, Bunz UHF, Friend RH. Singlet exciton fission in a modified acene with improved stability and high photoluminescence yield. Nat Commun 2021; 12:1527. [PMID: 33750774 PMCID: PMC7943798 DOI: 10.1038/s41467-021-21719-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 01/26/2021] [Indexed: 12/14/2022] Open
Abstract
We report a fully efficient singlet exciton fission material with high ambient chemical stability. 10,21-Bis(triisopropylsilylethynyl)tetrabenzo[a,c,l,n]pentacene (TTBP) combines an acene core with triphenylene wings that protect the formal pentacene from chemical degradation. The electronic energy levels position singlet exciton fission to be endothermic, similar to tetracene despite the triphenylenes. TTBP exhibits rapid early time singlet fission with quantitative yield of triplet pairs within 100 ps followed by thermally activated separation to free triplet excitons over 65 ns. TTBP exhibits high photoluminescence quantum efficiency, close to 100% when dilute and 20% for solid films, arising from triplet-triplet annihilation. In using such a system for exciton multiplication in a solar cell, maximum thermodynamic performance requires radiative decay of the triplet population, observed here as emission from the singlet formed by recombination of triplet pairs. Combining chemical stabilisation with efficient endothermic fission provides a promising avenue towards singlet fission materials for use in photovoltaics. Designing optimised molecules for singlet fission is crucial to improve the efficiency of solar cells beyond its theoretical limit. Here, the authors investigate pentacene derivative TTBP, which exhibits high stability and luminescence yield, and find it highly suitable for exciton multiplication purposes.
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Affiliation(s)
- Peter J Budden
- Cavendish Laboratory, University of Cambridge, JJ Thompson Avenue, Cambridge, UK
| | - Leah R Weiss
- Cavendish Laboratory, University of Cambridge, JJ Thompson Avenue, Cambridge, UK.,Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Matthias Müller
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, Heidelberg, Germany
| | - Naitik A Panjwani
- Berlin Joint EPR Lab, Fachbereich Physik, Freie Universität Berlin, Berlin, Germany
| | - Simon Dowland
- Cavendish Laboratory, University of Cambridge, JJ Thompson Avenue, Cambridge, UK
| | - Jesse R Allardice
- Cavendish Laboratory, University of Cambridge, JJ Thompson Avenue, Cambridge, UK
| | - Michael Ganschow
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, Heidelberg, Germany
| | - Jan Freudenberg
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, Heidelberg, Germany
| | - Jan Behrends
- Berlin Joint EPR Lab, Fachbereich Physik, Freie Universität Berlin, Berlin, Germany.
| | - Uwe H F Bunz
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, Heidelberg, Germany.
| | - Richard H Friend
- Cavendish Laboratory, University of Cambridge, JJ Thompson Avenue, Cambridge, UK.
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27
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Kundu A, Dasgupta J. Photogeneration of Long-Lived Triplet States through Singlet Fission in Lycopene H-Aggregates. J Phys Chem Lett 2021; 12:1468-1474. [PMID: 33528257 DOI: 10.1021/acs.jpclett.0c03301] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Molecular triplet excitons produced through singlet fission (SF) usually have shorter triplet lifetimes due to exciton-exciton recombination and relaxation pathways, thereby resulting in complex device architectures for SF-boosted solar cells. Using broadband transient absorption spectroscopy, we here show that the photoexcitation of nanostructured lycopene H-aggregates at room temperature produces free triplets with an unprecedented 35-fold enhancement in the lifetime compared to those localized on the monomer backbone. The observed rise of a spectrally blue-shifted correlated T-T pair state in ∼19 ps with distinct vibronic features provides the basis for SF-induced triplet generation.
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Affiliation(s)
- Arup Kundu
- Department of Chemical Sciences, Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400005, India
| | - Jyotishman Dasgupta
- Department of Chemical Sciences, Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400005, India
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28
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Aster A, Zinna F, Rumble C, Lacour J, Vauthey E. Singlet Fission in a Flexible Bichromophore with Structural and Dynamic Control. J Am Chem Soc 2021; 143:2361-2371. [PMID: 33512153 DOI: 10.1021/jacs.0c12384] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Singlet fission (SF), i.e., the splitting of a high-energy exciton into two lower-energy triplet excitons, has the potential to increase the efficiency for harvesting spectrally broad light. The path from the photopopulated singlet state to free triplets is complicated by competing processes that decrease the overall SF efficiency. A detailed understanding of the whole cascade and the nature of the photoexcited singlet state is still a major challenge. Here, we introduce a pentacene dimer with a flexible crown ether spacer enabling a control of the interchromophore coupling upon solvent-induced self-aggregation as well as cation binding. The systematic change of solvent polarity and viscosity and excitation wavelength, as well as the available conformational phase space, allows us to draw a coherent picture of the whole SF cascade from the femtosecond to microsecond time scales. High coupling leads to ultrafast SF (<2 ps), independent of the solvent polarity, and to highly coupled correlated triplet pairs. The absence of a polarity effect indicates that the solvent coordinate does not play a significant role and that SF is driven by intramolecular modes. Low coupling results in much slower SF (∼500 ps), which depends on viscosity, and leads to weakly coupled correlated triplet pairs. These two triplet pairs could be spectrally distinguished and their contribution to the overall SF efficiency, i.e., to the population of free triplets, could be determined. Our results reveal how the overall SF efficiency can be increased by conformational restrictions and control of the structural fluctuation dynamics.
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Affiliation(s)
- Alexander Aster
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Francesco Zinna
- Department of Organic Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Christopher Rumble
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Jérôme Lacour
- Department of Organic Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, CH-1211 Geneva, Switzerland
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Zhao X, Bae YJ, Chen M, Harvey SM, Lin C, Zhou J, Schaller RD, Young RM, Wasielewski MR. Singlet fission in core-linked terrylenediimide dimers. J Chem Phys 2020; 153:244306. [PMID: 33380082 DOI: 10.1063/5.0026254] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Xingang Zhao
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Youn Jue Bae
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Michelle Chen
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Samantha M. Harvey
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Chenjian Lin
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Jiawang Zhou
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Richard D. Schaller
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Ryan M. Young
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Michael R. Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
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30
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He G, Busby E, Appavoo K, Wu Q, Xia J, Campos LM, Sfeir MY. Charge transfer states impact the triplet pair dynamics of singlet fission polymers. J Chem Phys 2020; 153:244902. [PMID: 33380093 DOI: 10.1063/5.0029858] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Polymers are desirable optoelectronic materials, stemming from their solution processability, tunable electronic properties, and large absorption coefficients. An exciting development is the recent discovery that singlet fission (SF), the conversion of a singlet exciton to a pair of triplet states, can occur along the backbone of an individual conjugated polymer chain. Compared to other intramolecular SF compounds, the nature of the triplet pair state in SF polymers remains poorly understood, hampering the development of new materials with optimized excited state dynamics. Here, we investigate the effect of solvent polarity on the triplet pair dynamics in the SF polymer polybenzodithiophene-thiophene-1,1-dioxide. We use transient emission measurements to study isolated polymer chains in solution and use the change in the solvent polarity to investigate the role of charge transfer character in both the singlet exciton and the triplet pair multiexciton. We identify both singlet fluorescence and direct triplet pair emission, indicating significant symmetry breaking. Surprisingly, the singlet emission peak is relatively insensitive to solvent polarity despite its nominal "charge-transfer" nature. In contrast, the redshift of the triplet pair energy with increasing solvent polarity indicates significant charge transfer character. While the energy separation between singlet and triplet pair states increases with solvent polarity, the overall SF rate constant depends on both the energetic driving force and additional environmental factors. The triplet pair lifetime is directly determined by the solvent effect on its overall energy. The dominant recombination channel is a concerted, radiationless decay process that scales as predicted by a simple energy gap law.
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Affiliation(s)
- Guiying He
- Department of Physics, Graduate Center, City University of New York, New York, New York 10016, USA
| | - Erik Busby
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Kannatassen Appavoo
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Qin Wu
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Jianlong Xia
- School of Chemistry, Chemical Engineering and Life Science; State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
| | - Luis M Campos
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Matthew Y Sfeir
- Department of Physics, Graduate Center, City University of New York, New York, New York 10016, USA
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31
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Wang L, Liu X, Shi X, Anderson CL, Klivansky LM, Liu Y, Wu Y, Chen J, Yao J, Fu H. Singlet Fission in a para-Azaquinodimethane-Based Quinoidal Conjugated Polymer. J Am Chem Soc 2020; 142:17892-17896. [DOI: 10.1021/jacs.0c06604] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Long Wang
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Xuncheng Liu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley 94720, United States
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Xiaomei Shi
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan 030001, China
| | - Christopher L. Anderson
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley 94720, United States
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Liana M. Klivansky
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley 94720, United States
| | - Yi Liu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley 94720, United States
| | - Yishi Wu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, China
| | - Junwu Chen
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Jiannian Yao
- Beijing National Laboratory for Molecules Science (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, China
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32
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Optical Projection and Spatial Separation of Spin-Entangled Triplet Pairs from the S1 (21 Ag–) State of Pi-Conjugated Systems. Chem 2020. [DOI: 10.1016/j.chempr.2020.09.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Ullrich T, Pinter P, Messelberger J, Haines P, Kaur R, Hansmann MM, Munz D, Guldi DM. Singlet Fission in Carbene-Derived Diradicaloids. Angew Chem Int Ed Engl 2020; 59:7906-7914. [PMID: 32129920 PMCID: PMC7317569 DOI: 10.1002/anie.202001286] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/21/2020] [Indexed: 01/12/2023]
Abstract
Herein, we present a new class of singlet fission (SF) materials based on diradicaloids of carbene scaffolds, namely cyclic (alkyl)(amino)carbenes (CAACs). Our modular approach allows the tuning of two key SF criteria: the steric factor and the diradical character. In turn, we modified the energy landscapes of excited states in a systematic manner to accommodate the needs for SF. We report the first example of intermolecular SF in solution by dimer self-assembly at cryogenic temperatures.
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Affiliation(s)
- Tobias Ullrich
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM)Friedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 391058ErlangenGermany
| | - Piermaria Pinter
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM), Allgemeine und Anorganische ChemieFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 191058ErlangenGermany
| | - Julian Messelberger
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM), Allgemeine und Anorganische ChemieFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 191058ErlangenGermany
| | - Philipp Haines
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM)Friedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 391058ErlangenGermany
| | - Ramandeep Kaur
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM)Friedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 391058ErlangenGermany
| | - Max M. Hansmann
- Fakultät für Chemie und Chemische BiologieTechnische Universität DortmundOtto-Hahn Straße 644227DortmundGermany
| | - Dominik Munz
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM), Allgemeine und Anorganische ChemieFriedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 191058ErlangenGermany
| | - Dirk M. Guldi
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM)Friedrich-Alexander-Universität Erlangen-NürnbergEgerlandstraße 391058ErlangenGermany
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34
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Ullrich T, Pinter P, Messelberger J, Haines P, Kaur R, Hansmann MM, Munz D, Guldi DM. Singlet Fission in Carbene‐Derived Diradicaloids. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202001286] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Tobias Ullrich
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 3 91058 Erlangen Germany
| | - Piermaria Pinter
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM), Allgemeine und Anorganische Chemie Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Julian Messelberger
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM), Allgemeine und Anorganische Chemie Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Philipp Haines
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 3 91058 Erlangen Germany
| | - Ramandeep Kaur
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 3 91058 Erlangen Germany
| | - Max M. Hansmann
- Fakultät für Chemie und Chemische Biologie Technische Universität Dortmund Otto-Hahn Straße 6 44227 Dortmund Germany
| | - Dominik Munz
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM), Allgemeine und Anorganische Chemie Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Dirk M. Guldi
- Department of Chemistry and Pharmacy Interdisciplinary Center for Molecular Materials (ICMM) Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 3 91058 Erlangen Germany
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35
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Korovina NV, Pompetti NF, Johnson JC. Lessons from intramolecular singlet fission with covalently bound chromophores. J Chem Phys 2020; 152:040904. [PMID: 32007061 DOI: 10.1063/1.5135307] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Molecular dimers, oligomers, and polymers are versatile components in photophysical and optoelectronic architectures that could impact a variety of applications. We present a perspective on such systems in the field of singlet fission, which effectively multiplies excitons and produces a unique excited state species, the triplet pair. The choice of chromophore and the nature of the attachment between units, both geometrical and chemical, play a defining role in the dynamical scheme that evolves upon photoexcitation. Specific final outcomes (e.g., separated and uncorrelated triplet pairs) are being sought through rational design of covalently bound chromophore architectures built with guidance from recent fundamental studies that correlate structure with excited state population flow kinetics.
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Affiliation(s)
- Nadezhda V Korovina
- National Renewable Energy Laboratory, 15013 Denver West Pkwy, Golden, Colorado 80401, USA
| | - Nicholas F Pompetti
- National Renewable Energy Laboratory, 15013 Denver West Pkwy, Golden, Colorado 80401, USA
| | - Justin C Johnson
- National Renewable Energy Laboratory, 15013 Denver West Pkwy, Golden, Colorado 80401, USA
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36
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Wang L, Bai S, Wu Y, Liu Y, Yao J, Fu H. Revealing the Nature of Singlet Fission under the Veil of Internal Conversion. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201912202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Long Wang
- Beijing Key Laboratory for Optical Materials and Photonic DevicesDepartment of ChemistryCapital Normal University Beijing 100048 P. R. China
- Key Laboratory of Interface Science and Engineering in Advanced MaterialsMinistry of EducationTaiyuan University of Technology Taiyuan 030024 P. R. China
| | - Shuming Bai
- Department of ChemistryDuke University Durham NC 27708 USA
| | - Yishi Wu
- Beijing Key Laboratory for Optical Materials and Photonic DevicesDepartment of ChemistryCapital Normal University Beijing 100048 P. R. China
| | - Yanping Liu
- Beijing Key Laboratory for Optical Materials and Photonic DevicesDepartment of ChemistryCapital Normal University Beijing 100048 P. R. China
| | - Jiannian Yao
- Beijing Key Laboratory for Optical Materials and Photonic DevicesDepartment of ChemistryCapital Normal University Beijing 100048 P. R. China
- Institute of Molecular PlusSchool of Chemical Engineering and TechnologyTianjin UniversityCollaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300072 P. R. China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic DevicesDepartment of ChemistryCapital Normal University Beijing 100048 P. R. China
- Institute of Molecular PlusSchool of Chemical Engineering and TechnologyTianjin UniversityCollaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300072 P. R. China
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37
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Wang L, Bai S, Wu Y, Liu Y, Yao J, Fu H. Revealing the Nature of Singlet Fission under the Veil of Internal Conversion. Angew Chem Int Ed Engl 2019; 59:2003-2007. [PMID: 31729139 DOI: 10.1002/anie.201912202] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/02/2019] [Indexed: 11/07/2022]
Abstract
Singlet fission (SF) holds the potential to boost the maximum power conversion efficiency of photovoltaic devices. Internal conversion (IC) has been considered as one of the major competitive deactivation pathways to transform excitation energy into heat. Now, using time-resolved spectroscopy and theoretical calculation, it is demonstrated that, instead of a conventional IC pathway, an unexpected intramolecular singlet fission (iSF) process is responsible for excited state deactivation in isoindigo derivatives. The 1 TT state could form at ultrafast rate and nearly quantitatively in solution. In solid films, the slipped stacked intermolecular packing of a thiophene-functionalized derivative leads to efficient triplet pair separation, giving rise to an overall triplet yield of 181 %. This work not only enriches the pool of iSF-capable materials, but also contributes to a better understanding of the iSF mechanism, which could be relevant for designing new SF sensitizers.
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Affiliation(s)
- Long Wang
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, P. R. China
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan, 030024, P. R. China
| | - Shuming Bai
- Department of Chemistry, Duke University, Durham, NC, 27708, USA
| | - Yishi Wu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, P. R. China
| | - Yanping Liu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, P. R. China
| | - Jiannian Yao
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, P. R. China
- Institute of Molecular Plus, School of Chemical Engineering and Technology, Tianjin University, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, P. R. China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, P. R. China
- Institute of Molecular Plus, School of Chemical Engineering and Technology, Tianjin University, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, P. R. China
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38
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Alvertis AM, Lukman S, Hele TJH, Fuemmeler EG, Feng J, Wu J, Greenham NC, Chin AW, Musser AJ. Switching between Coherent and Incoherent Singlet Fission via Solvent-Induced Symmetry Breaking. J Am Chem Soc 2019; 141:17558-17570. [DOI: 10.1021/jacs.9b05561] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Antonios M. Alvertis
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Steven Lukman
- Institute of Materials Research and Engineering, Agency for Science Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Timothy J. H. Hele
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Eric G. Fuemmeler
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Jiaqi Feng
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543 Singapore
| | - Jishan Wu
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543 Singapore
| | - Neil C. Greenham
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Alex W. Chin
- CNRS & Institut des NanoSciences de Paris, Sorbonne Université, 4 place Jussieu boite courrier 840, 75252 Paris Cedex 05, France
| | - Andrew J. Musser
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
- Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield S3 7RH, U.K
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39
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Wang Z, Zhang C, Wang R, Wang G, Wang X, Xiao M. Weakly coupled triplet pair states probed by quantum beating in delayed fluorescence in tetracene crystals. J Chem Phys 2019; 151:134309. [DOI: 10.1063/1.5110188] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Zhiwei Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Chunfeng Zhang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Rui Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Guodong Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Xiaoyong Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Min Xiao
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA
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40
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Wang L, Wu Y, Liu Y, Wang L, Yao J, Fu H. Morphology independent triplet formation in pentalene films: Singlet fission as the triplet formation mechanism. J Chem Phys 2019; 151:124701. [PMID: 31575178 DOI: 10.1063/1.5097192] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Singlet fission (SF), a spin-allowed multiexciton generation process, experienced renewed interest in the last decade due to its potential to increase the efficiency of photovoltaic devices. The hurdles now lie in the limited range of SF-capable materials and demanding morphology requirement for an efficient fission process. Although primary fission to yield triplet pair (1TT) can occur independently of film morphology in intramolecular singlet fission (iSF) materials, the separation of the 1TT state has been shown to be highly dependent on the packing motif and morphologies. In this work, we have demonstrated that both iSF and triplet pair separation processes took place irrelevant of molecular order and/or film morphology in a series of pentalene compounds. With the >180% fission efficiency, the suitable triplet energy levels, and the long lifetime of the triplet excitons, these iSF systems can be integrated into practical photovoltaic application.
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Affiliation(s)
- Long Wang
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Yishi Wu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, China
| | - Yanping Liu
- Beijing National Laboratory for Molecules Science (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species and Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Lanfen Wang
- Beijing National Laboratory for Molecules Science (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species and Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jiannian Yao
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, China
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41
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Alvertis AM, Schröder FAYN, Chin AW. Non-equilibrium relaxation of hot states in organic semiconductors: Impact of mode-selective excitation on charge transfer. J Chem Phys 2019; 151:084104. [PMID: 31470711 DOI: 10.1063/1.5115239] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The theoretical study of open quantum systems strongly coupled to a vibrational environment remains computationally challenging due to the strongly non-Markovian characteristics of the dynamics. We study this problem in the case of a molecular dimer of the organic semiconductor tetracene, the exciton states of which are strongly coupled to a few hundreds of molecular vibrations. To do so, we employ a previously developed tensor network approach, based on the formalism of matrix product states. By analyzing the entanglement structure of the system wavefunction, we can expand it in a tree tensor network state, which allows us to perform a fully quantum mechanical time evolution of the exciton-vibrational system, including the effect of 156 molecular vibrations. We simulate the dynamics of hot states, i.e., states resulting from excess energy photoexcitation, by constructing various initial bath states, and show that the exciton system indeed has a memory of those initial configurations. In particular, the specific pathway of vibrational relaxation is shown to strongly affect the quantum coherence between exciton states in time scales relevant for the ultrafast dynamics of application-relevant processes such as charge transfer. The preferential excitation of low-frequency modes leads to a limited number of relaxation pathways, thus "protecting" quantum coherence and leading to a significant increase in the charge transfer yield in the dimer structure.
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Affiliation(s)
- Antonios M Alvertis
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Florian A Y N Schröder
- Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Alex W Chin
- CNRS, Institut des NanoSciences de Paris, Sorbonne Université, 4 place Jussieu boite courrier 840, 75252 Paris Cedex 05, France
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42
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Fallon KJ, Budden P, Salvadori E, Ganose AM, Savory CN, Eyre L, Dowland S, Ai Q, Goodlett S, Risko C, Scanlon DO, Kay CWM, Rao A, Friend RH, Musser AJ, Bronstein H. Exploiting Excited-State Aromaticity To Design Highly Stable Singlet Fission Materials. J Am Chem Soc 2019; 141:13867-13876. [PMID: 31381323 DOI: 10.1021/jacs.9b06346] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Singlet fission, the process of forming two triplet excitons from one singlet exciton, is a characteristic reserved for only a handful of organic molecules due to the atypical energetic requirement for low energy excited triplet states. The predominant strategy for achieving such a trait is by increasing ground state diradical character; however, this greatly reduces ambient stability. Herein, we exploit Baird's rule of excited state aromaticity to manipulate the singlet-triplet energy gap and create novel singlet fission candidates. We achieve this through the inclusion of a [4n] 5-membered heterocycle, whose electronic resonance promotes aromaticity in the triplet state, stabilizing its energy relative to the singlet excited state. Using this theory, we design a family of derivatives of indolonaphthyridine thiophene (INDT) with highly tunable excited state energies. Not only do we access novel singlet fission materials, they also exhibit excellent ambient stability, imparted due to the delocalized nature of the triplet excited state. Spin-coated films retained up to 85% activity after several weeks of exposure to oxygen and light, while analogous films of TIPS-pentacene showed full degradation after 4 days, showcasing the excellent stability of this class of singlet fission scaffold. Extension of our theoretical analysis to almost ten thousand candidates reveals an unprecedented degree of tunability and several thousand potential fission-capable candidates, while clearly demonstrating the relationship between triplet aromaticity and singlet-triplet energy gap, confirming this novel strategy for manipulating the exchange energy in organic materials.
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Affiliation(s)
- Kealan J Fallon
- Department of Chemistry , University of Cambridge , Cambridge CB2 1EW , U.K
| | - Peter Budden
- Cavendish Laboratory , University of Cambridge , Cambridge CB3 0HE , U.K
| | - Enrico Salvadori
- Department of Chemistry , University of Turin , Via Pietro Giuria 7 , 10125 Torino , Italy.,London Centre for Nanotechnology , University College London , 17-19 Gordon Street , London WC1H 0AH , U.K
| | - Alex M Ganose
- Kathleen Lonsdale Materials Chemistry, Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , U.K.,Thomas Young Centre , University College London , Gower Street , London WC1E 6BT , U.K.,Diamond Light Source Ltd., Diamond House , Harwell Science and Innovation Campus , Oxfordshire OX11 0DE , U.K
| | - Christopher N Savory
- Kathleen Lonsdale Materials Chemistry, Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , U.K.,Thomas Young Centre , University College London , Gower Street , London WC1E 6BT , U.K
| | - Lissa Eyre
- Cavendish Laboratory , University of Cambridge , Cambridge CB3 0HE , U.K
| | - Simon Dowland
- Cavendish Laboratory , University of Cambridge , Cambridge CB3 0HE , U.K
| | - Qianxiang Ai
- Department of Chemistry and Center for Applied Energy Research , University of Kentucky , Lexington , Kentucky 40506 , United States
| | - Stephen Goodlett
- Department of Chemistry and Center for Applied Energy Research , University of Kentucky , Lexington , Kentucky 40506 , United States
| | - Chad Risko
- Department of Chemistry and Center for Applied Energy Research , University of Kentucky , Lexington , Kentucky 40506 , United States
| | - David O Scanlon
- Kathleen Lonsdale Materials Chemistry, Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , U.K.,Thomas Young Centre , University College London , Gower Street , London WC1E 6BT , U.K.,Diamond Light Source Ltd., Diamond House , Harwell Science and Innovation Campus , Oxfordshire OX11 0DE , U.K
| | - Christopher W M Kay
- London Centre for Nanotechnology , University College London , 17-19 Gordon Street , London WC1H 0AH , U.K.,Department of Chemistry , University of Saarland , 66123 Saarbrücken , Germany
| | - Akshay Rao
- Cavendish Laboratory , University of Cambridge , Cambridge CB3 0HE , U.K
| | - Richard H Friend
- Cavendish Laboratory , University of Cambridge , Cambridge CB3 0HE , U.K
| | - Andrew J Musser
- Department of Physics and Astronomy , University of Sheffield , Hicks Building, Hounsfield Road , Sheffield S3 7RH , U.K
| | - Hugo Bronstein
- Department of Chemistry , University of Cambridge , Cambridge CB2 1EW , U.K.,Cavendish Laboratory , University of Cambridge , Cambridge CB3 0HE , U.K
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43
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Grey JK. Resonance Raman Spectroscopy and Imaging of Franck-Condon Vibrational Activity and Morphology in Conjugated Polymers for Solar Cells. Acc Chem Res 2019; 52:2221-2231. [PMID: 31369235 DOI: 10.1021/acs.accounts.9b00088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Vibrational reorganization influences photophysical outcomes in conjugated polymers used as active materials for optoelectronic devices. Excited state geometric rearrangements typically involve many displaced vibrations, yet most materials design schemes rely solely on pure electronic models with limited predictive capability. Although the coupling of vibrational motions to electronic processes occurs over a broad range of time scales, resolving structural displacements immediately following photon absorption can be particularly insightful for understanding the intrinsic stabilities of excited states. These Franck-Condon vibrational relaxation processes occur on time scales of <1 ps in polymers and mainly involve high-frequency skeletal motions. Establishing correlations between Franck-Condon vibrational reorganization and steady-state material properties could generate new avenues for informing materials design, which is especially important in the fast-paced field of organic photovoltaics (OPV) where seemingly elegant strategies often fail but molecular-level insights are usually lacking. The goal of this Account is to highlight relationships between molecular structure, packing, and vibrational reorganization in OPV systems, such as blends of conjugated polymers with fullerenes. Resonance Raman spectroscopy (RRS) is a sensitive probe of Franck-Condon activity in OPV materials, and signals are bolstered by large resonance enhancements and low backgrounds from quantitative fluorescence quenching. Our group has undertaken extensive RRS investigations of heterogeneous OPV materials in functioning device environments to uncover new insights of the multidimensional excited state potential energy landscape and fluctuations with local morphology. Time-dependent quantum mechanical approaches facilitate this effort by providing an intuitive theoretical framework to access dynamical perspectives of Raman transitions. Moreover, dynamics regimes of Franck-Condon excited state structural evolution can be selected simply by tuning excitation energies. This excitation detuning approach also reveals structurally and electronically distinct conformers with unique Franck-Condon signatures typically concealed under inhomogeneously broadened absorption line shapes. Interestingly, long and rich progressions of overtone and combination transitions-rare for large molecules with multiple displaced modes-are frequently resolved that exhibit strong sensitivity to the local chromophore environment. These harmonic features encode useful dynamics information by serving as internal "clocks" of Franck-Condon vibrational activity in addition to enabling quantitative estimates of mode-specific displacements. RRS attributes may be further exploited to perform noninvasive imaging of functioning OPV devices in concert with variable frequency electrical imaging probes. This approach generates direct spatial correlations between morphology-dependent Franck-Condon vibrational activity and material performance metrics (e.g., photocurrent generation) on submicrometer size scales.
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Affiliation(s)
- John K. Grey
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
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44
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Deng GH, Wei Q, Han J, Qian Y, Luo J, Harutyunyan AR, Chen G, Bian H, Chen H, Rao Y. Vibronic fingerprint of singlet fission in hexacene. J Chem Phys 2019. [DOI: 10.1063/1.5110263] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Affiliation(s)
- Gang-Hua Deng
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, USA
| | - Qianshun Wei
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, China
| | - Jian Han
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, USA
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Yuqin Qian
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, USA
| | - Jun Luo
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | | | - Gugang Chen
- Honda Research Institute USA, Inc., San Jose, California 95134, USA
| | - Hongtao Bian
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710119, China
| | - Hanning Chen
- Department of Chemistry, George Washington University, Washington, DC 20052, USA
| | - Yi Rao
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah 84322, USA
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45
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Musser AJ, Al-Hashimi M, Heeney M, Clark J. Heavy-atom effects on intramolecular singlet fission in a conjugated polymer. J Chem Phys 2019; 151:044902. [DOI: 10.1063/1.5110269] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Affiliation(s)
- Andrew J. Musser
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA
| | - Mohammed Al-Hashimi
- Department of Chemistry, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar
| | - Martin Heeney
- Department of Chemistry and Centre for Plastic Electronics, Imperial College London, Exhibition Rd., London SW7 2AZ, United Kingdom
| | - Jenny Clark
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom
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46
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Abstract
Entanglement of states is one of the most surprising and counterintuitive consequences of quantum mechanics, with potent applications in cryptography and computing. In organic semiconductor materials, one particularly significant manifestation is the spin-entangled triplet-pair state, which consists of a pair of localized triplet excitons coupled into an overall spin-0, -1, or -2 configuration. The most widely analyzed of these is the spin-0 pair, denoted 1(TT), which was initially invoked in the 1960s to explain delayed fluorescence in acene films. It is considered an essential gateway state for triplet-triplet annihilation and the reverse process, singlet fission, enabling interconversion between one singlet and two triplet excitons without any change in overall spin. This state has returned to the forefront of organic materials research in recent years, thanks both to its central role in the resurgent field of singlet fission and to its implication in a host of exotic new photophysical behaviors. Here we review the properties of triplet-pair states, from first principles to recent experimental results.
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Affiliation(s)
- Andrew J Musser
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom; ,
| | - Jenny Clark
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, United Kingdom; ,
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47
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Ni W, Gurzadyan GG, Zhao J, Che Y, Li X, Sun L. Singlet Fission from Upper Excited Electronic States of Cofacial Perylene Dimer. J Phys Chem Lett 2019; 10:2428-2433. [PMID: 31025867 DOI: 10.1021/acs.jpclett.9b00717] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Singlet fission directly from the upper excited vibrational and electronic states of cofacial perylene dimers, bypassing the relaxed state S1, was detected within 50 fs. This process competes well with vibrational cooling in S1 (4.7-7.0 ps) and S2 → S1 internal conversion (380 fs). The singlet fission has the energy threshold E = 3.06 eV. Other competitive relaxation processes are excimer and dimer cation formation on an ultrafast time scale. Excitation to higher energy levels (4.96 eV) leads to a higher efficiency of singlet fission.
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Affiliation(s)
- Wenjun Ni
- State Key Laboratory of Fine Chemicals, Institute of Artificial Photosynthesis , Dalian University of Technology , 116024 Dalian , China
| | - Gagik G Gurzadyan
- State Key Laboratory of Fine Chemicals, Institute of Artificial Photosynthesis , Dalian University of Technology , 116024 Dalian , China
| | - Jianzhang Zhao
- State Key Laboratory of Fine Chemicals , Dalian University of Technology , 116024 Dalian , China
| | - Yuanyuan Che
- State Key Laboratory of Fine Chemicals , Dalian University of Technology , 116024 Dalian , China
| | - Xiaoxin Li
- State Key Laboratory of Fine Chemicals, Institute of Artificial Photosynthesis , Dalian University of Technology , 116024 Dalian , China
| | - Licheng Sun
- State Key Laboratory of Fine Chemicals, Institute of Artificial Photosynthesis , Dalian University of Technology , 116024 Dalian , China
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health , KTH Royal Institute of Technology , 10044 Stockholm , Sweden
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48
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Xie X, Santana-Bonilla A, Fang W, Liu C, Troisi A, Ma H. Exciton–Phonon Interaction Model for Singlet Fission in Prototypical Molecular Crystals. J Chem Theory Comput 2019; 15:3721-3729. [DOI: 10.1021/acs.jctc.9b00122] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiaoyu Xie
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | | | - Weihai Fang
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
- Department of Chemistry, Beijing Normal University, Beijing, 100875, China
| | - Chungen Liu
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Alessandro Troisi
- Department of Chemistry, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - Haibo Ma
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
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49
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Datko BD, Livshits M, Zhang Z, Qin Y, Jakubikova E, Rack JJ, Grey JK. Large Excited-State Conformational Displacements Expedite Triplet Formation in a Small Conjugated Oligomer. J Phys Chem Lett 2019; 10:1259-1263. [PMID: 30811200 DOI: 10.1021/acs.jpclett.9b00495] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Intersystem crossing in conjugated organic molecules is most conveniently viewed from pure electronic perspectives; yet, vibrational displacements may often drive these transitions. We investigate an alkyl-substituted thienylene-vinylene dimer (dTV) displaying efficient triplet formation. Steady-state electronic and Raman spectra display large Stokes shifts (∼4000 cm-1) involving high-frequency skeletal symmetric stretching modes (∼900-1600 cm-1) in addition to large displacements of low-frequency torsional motions (∼300-340 cm-1). Transient absorption spectroscopy reveals the emergence of distorted singlet (S1) and triplet signatures following initial vibrational relaxation dynamics that dominate spectral dynamics on time scales > 100 ps, with the latter persisting on time scales up to ca. 7 μs. Potential energy surfaces calculated along the dominant displaced out-of-plane torsional mode reveal shallow energy barriers for entering the triplet manifold from S1. We propose that dTV is a good model system for understanding vibrational contributions to intersystem crossing events in related polymer systems.
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Affiliation(s)
- Benjamin D Datko
- Department of Chemistry and Chemical Biology , University of New Mexico , Albuquerque , New Mexico 87131 , United States
| | - Maksim Livshits
- Department of Chemistry and Chemical Biology , University of New Mexico , Albuquerque , New Mexico 87131 , United States
| | - Zhen Zhang
- Department of Chemistry and Chemical Biology , University of New Mexico , Albuquerque , New Mexico 87131 , United States
| | - Yang Qin
- Department of Chemistry and Chemical Biology , University of New Mexico , Albuquerque , New Mexico 87131 , United States
| | - Elena Jakubikova
- Department of Chemistry , North Carolina State University , Raleigh , North Carolina 27695 , United States
| | - Jeffrey J Rack
- Department of Chemistry and Chemical Biology , University of New Mexico , Albuquerque , New Mexico 87131 , United States
| | - John K Grey
- Department of Chemistry and Chemical Biology , University of New Mexico , Albuquerque , New Mexico 87131 , United States
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50
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Krishnapriya KC, Roy P, Puttaraju B, Salzner U, Musser AJ, Jain M, Dasgupta J, Patil S. Spin density encodes intramolecular singlet exciton fission in pentacene dimers. Nat Commun 2019; 10:33. [PMID: 30604740 PMCID: PMC6318326 DOI: 10.1038/s41467-018-07736-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 11/25/2018] [Indexed: 11/09/2022] Open
Abstract
The formation of two triplet excitons at the cost of one photon via singlet exciton fission in organic semiconductors can potentially enhance the photocurrent in photovoltaic devices. However, the role of spin density distribution in driving this photophysical process has been unclear until now. Here we present the significance of electronic spin density distribution in facilitating efficient intramolecular singlet exciton fission (iSEF) in π-bridged pentacene dimers. We synthetically modulate the spin density distribution in a series of pentacene dimers using phenyl-, thienyl- and selenyl- flanked diketopyrrolopyrrole (DPP) derivatives as π-bridges. Using femtosecond transient absorption spectroscopy, we find that efficient iSEF is only observed for the phenyl-derivative in ~2.4 ps while absent in the other two dimers. Electronic structure calculations reveal that phenyl-DPP bridge localizes α- and β-spin densities on distinct terminal pentacenes. Upon photoexcitation, a spin exchange mechanism enables iSEF from a singlet state which has an innate triplet pair character.
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Affiliation(s)
- K C Krishnapriya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Palas Roy
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India
- Department of Chemistry, Northwestern University, Evanston, IL, USA
| | - Boregowda Puttaraju
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Ulrike Salzner
- Department of Chemistry, Bilkent University, Ankara, 06800, Turkey
| | - Andrew J Musser
- Department of Physics and Astronomy, University of Sheffield, Sheffield, S37RH, UK
| | - Manish Jain
- Department of Physics, Indian Institute of Science, Bangalore, 560012, India
| | - Jyotishman Dasgupta
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India.
| | - Satish Patil
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, 560012, India.
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