1
|
Wang X, Gao S, Luo Y, Liu X, Tom R, Zhao K, Chang V, Marom N. Computational Discovery of Intermolecular Singlet Fission Materials Using Many-Body Perturbation Theory. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2024; 128:7841-7864. [PMID: 38774154 PMCID: PMC11103713 DOI: 10.1021/acs.jpcc.4c01340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/16/2024] [Accepted: 04/17/2024] [Indexed: 05/24/2024]
Abstract
Intermolecular singlet fission (SF) is the conversion of a photogenerated singlet exciton into two triplet excitons residing on different molecules. SF has the potential to enhance the conversion efficiency of solar cells by harvesting two charge carriers from one high-energy photon, whose surplus energy would otherwise be lost to heat. The development of commercial SF-augmented modules is hindered by the limited selection of molecular crystals that exhibit intermolecular SF in the solid state. Computational exploration may accelerate the discovery of new SF materials. The GW approximation and Bethe-Salpeter equation (GW+BSE) within the framework of many-body perturbation theory is the current state-of-the-art method for calculating the excited-state properties of molecular crystals with periodic boundary conditions. In this Review, we discuss the usage of GW+BSE to assess candidate SF materials as well as its combination with low-cost physical or machine learned models in materials discovery workflows. We demonstrate three successful strategies for the discovery of new SF materials: (i) functionalization of known materials to tune their properties, (ii) finding potential polymorphs with improved crystal packing, and (iii) exploring new classes of materials. In addition, three new candidate SF materials are proposed here, which have not been published previously.
Collapse
Affiliation(s)
- Xiaopeng Wang
- School
of Foundational Education, University of
Health and Rehabilitation Sciences, Qingdao 266113, China
- Qingdao
Institute for Theoretical and Computational Sciences, Institute of
Frontier and Interdisciplinary Science, Shandong University, Qingdao, Shandong 266237, P. R. China
| | - Siyu Gao
- Department
of Materials Science and Engineering, Carnegie
Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Yiqun Luo
- Department
of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Xingyu Liu
- Department
of Materials Science and Engineering, Carnegie
Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Rithwik Tom
- Department
of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Kaiji Zhao
- Department
of Materials Science and Engineering, Carnegie
Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Vincent Chang
- Department
of Materials Science and Engineering, Carnegie
Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Noa Marom
- Department
of Materials Science and Engineering, Carnegie
Mellon University, Pittsburgh, Pennsylvania 15213, United States
- Department
of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- Department
of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| |
Collapse
|
2
|
de Clercq DM, Collins MI, Sloane NP, Feng J, McCamey DR, Tayebjee MJY, Nielsen MP, Schmidt TW. Singlet fission in TIPS-anthracene thin films. Chem Sci 2024; 15:6402-6409. [PMID: 38699250 PMCID: PMC11062091 DOI: 10.1039/d3sc06774b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 03/24/2024] [Indexed: 05/05/2024] Open
Abstract
Singlet fission is an exciton multiplication process that allows for the conversion of one singlet exciton into two triplet excitons. Organic semiconductors, such as acenes and their soluble bis(triisopropylsilylethynyl) (TIPS) substituted counterparts, have played a major role in elucidating the understanding of the underlying mechanisms of singlet fission. Despite this, one prominent member of the acene family that has received little experimental attention to date is TIPS-anthracene, even with computational studies suggesting potential high singlet fission yields in the solid state. Here, time-resolved spectroscopic and magneto-photoluminescence measurements were performed on spin-cast films of TIPS-anthracene, showing evidence for singlet fission. A singlet fission yield of 19% (out of 200%) is estimated from transient absorption spectroscopy. Kinetic modeling of the magnetic field effect on photoluminescence suggests that fast rates of triplet dissociation lead to a low magnetic photoluminescence effect and that non-radiative decay of both the S1 and 1(TT) states is the cause for the low triplet yield.
Collapse
Affiliation(s)
- Damon M de Clercq
- School of Chemistry, ARC Centre of Excellence in Exciton Science, UNSW Sydney NSW 2052 Australia
| | - Miles I Collins
- School of Physics, ARC Centre of Excellence in Exciton Science, UNSW Sydney NSW 2052 Australia
| | - Nicholas P Sloane
- School of Physics, ARC Centre of Excellence in Exciton Science, UNSW Sydney NSW 2052 Australia
| | - Jiale Feng
- School of Chemistry, ARC Centre of Excellence in Exciton Science, UNSW Sydney NSW 2052 Australia
| | - Dane R McCamey
- School of Physics, ARC Centre of Excellence in Exciton Science, UNSW Sydney NSW 2052 Australia
| | - Murad J Y Tayebjee
- School of Photovoltaic and Renewable Energy Engineering, UNSW Sydney NSW 2052 Australia
| | - Michael P Nielsen
- School of Photovoltaic and Renewable Energy Engineering, UNSW Sydney NSW 2052 Australia
| | - Timothy W Schmidt
- School of Chemistry, ARC Centre of Excellence in Exciton Science, UNSW Sydney NSW 2052 Australia
| |
Collapse
|
3
|
Cohen G, Haber JB, Neaton JB, Qiu DY, Refaely-Abramson S. Phonon-Driven Femtosecond Dynamics of Excitons in Crystalline Pentacene from First Principles. PHYSICAL REVIEW LETTERS 2024; 132:126902. [PMID: 38579218 DOI: 10.1103/physrevlett.132.126902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 08/24/2023] [Accepted: 02/11/2024] [Indexed: 04/07/2024]
Abstract
Nonradiative exciton relaxation processes are critical for energy transduction and transport in optoelectronic materials, but how these processes are connected to the underlying crystal structure and the associated electron, exciton, and phonon band structures, as well as the interactions of all these particles, is challenging to understand. Here, we present a first-principles study of exciton-phonon relaxation pathways in pentacene, a paradigmatic molecular crystal and optoelectronic semiconductor. We compute the momentum- and band-resolved exciton-phonon interactions, and use them to analyze key scattering channels. We find that both exciton intraband scattering and interband scattering to parity-forbidden dark states occur on the same ∼100 fs timescale as a direct consequence of the longitudinal-transverse splitting of the bright exciton band. Consequently, exciton-phonon scattering exists as a dominant nonradiative relaxation channel in pentacene. We further show how the propagation of an exciton wave packet is connected with crystal anisotropy, which gives rise to the longitudinal-transverse exciton splitting and concomitant anisotropic exciton and phonon dispersions. Our results provide a framework for understanding the role of exciton-phonon interactions in exciton nonradiative lifetimes in molecular crystals and beyond.
Collapse
Affiliation(s)
- Galit Cohen
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Jonah B Haber
- Department of Physics, University of California Berkeley, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Jeffrey B Neaton
- Department of Physics, University of California Berkeley, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Kavli Energy Nanosciences Institute at Berkeley, Berkeley, California 94720, USA
| | - Diana Y Qiu
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06520, USA
| | - Sivan Refaely-Abramson
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
| |
Collapse
|
4
|
Bhuyan R, Mony J, Kotov O, Castellanos GW, Gómez Rivas J, Shegai TO, Börjesson K. The Rise and Current Status of Polaritonic Photochemistry and Photophysics. Chem Rev 2023; 123:10877-10919. [PMID: 37683254 PMCID: PMC10540218 DOI: 10.1021/acs.chemrev.2c00895] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Indexed: 09/10/2023]
Abstract
The interaction between molecular electronic transitions and electromagnetic fields can be enlarged to the point where distinct hybrid light-matter states, polaritons, emerge. The photonic contribution to these states results in increased complexity as well as an opening to modify the photophysics and photochemistry beyond what normally can be seen in organic molecules. It is today evident that polaritons offer opportunities for molecular photochemistry and photophysics, which has caused an ever-rising interest in the field. Focusing on the experimental landmarks, this review takes its reader from the advent of the field of polaritonic chemistry, over the split into polariton chemistry and photochemistry, to present day status within polaritonic photochemistry and photophysics. To introduce the field, the review starts with a general description of light-matter interactions, how to enhance these, and what characterizes the coupling strength. Then the photochemistry and photophysics of strongly coupled systems using Fabry-Perot and plasmonic cavities are described. This is followed by a description of room-temperature Bose-Einstein condensation/polariton lasing in polaritonic systems. The review ends with a discussion on the benefits, limitations, and future developments of strong exciton-photon coupling using organic molecules.
Collapse
Affiliation(s)
- Rahul Bhuyan
- Department
of Chemistry and Molecular Biology, University
of Gothenburg, 412 96 Göteborg, Sweden
| | - Jürgen Mony
- Department
of Chemistry and Molecular Biology, University
of Gothenburg, 412 96 Göteborg, Sweden
| | - Oleg Kotov
- Department
of Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden
| | - Gabriel W. Castellanos
- Department
of Applied Physics and Science Education, Eindhoven Hendrik Casimir
Institute and Institute for Complex Molecular Systems, Eindhoven University of Technology, 5612 AE Eindhoven, The Netherlands
| | - Jaime Gómez Rivas
- Department
of Applied Physics and Science Education, Eindhoven Hendrik Casimir
Institute and Institute for Complex Molecular Systems, Eindhoven University of Technology, 5612 AE Eindhoven, The Netherlands
| | - Timur O. Shegai
- Department
of Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden
| | - Karl Börjesson
- Department
of Chemistry and Molecular Biology, University
of Gothenburg, 412 96 Göteborg, Sweden
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Wu Y, Lu L, Yu B, Zhang S, Luo P, Chen M, He J, Li Y, Zhang C, Zhu J, Yao J, Fu H. Dynamic Evolving Exothermicity Steers Ultrafast Formation of a Correlated Triplet Pair State. J Phys Chem Lett 2023; 14:4233-4240. [PMID: 37126526 DOI: 10.1021/acs.jpclett.3c00193] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Singlet fission (SF) presents an attractive solution to overcome the Shockley-Queisser limit of single-junction solar cells. The conversion from an initial singlet state to final triplet is mediated by the correlated triplet pair state 1(T1T1). Despite significant advancement on 1(T1T1) properties and its role in SF, a comprehensive understanding of the energetic landscape during SF is still unclear. Here, we study an unconventional SF system with excited-state aromaticity, i.e., cyano-substituted dipyrrolonaphtheridinedione derivative (DPND-CN), using time-resolved spectroscopy as a function of the temperature. We demonstrate that the population transfer from S1 to 1(T1T1) is driven by a time-dependent exothermicity resulting from the coherent coupling between electronic and spin degrees of freedom. This is followed by thermal-activated dissociation of 1(T1T1) to yield free triplets. Our results provide some new insight into the SF mechanism, which may guide the development of new efficient and stable SF materials for practical applications.
Collapse
Affiliation(s)
- Yishi Wu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, People's Republic of China
| | - Lina Lu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, People's Republic of China
| | - Buyang Yu
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing, Jiangsu 210093, People's Republic of China
| | - San Zhang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing, Jiangsu 210093, People's Republic of China
| | - Pengdong Luo
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, People's Republic of China
| | - Mingxing Chen
- Analytical Instrumentation Center, Peking University, Beijing 100871, People's Republic of China
| | - Jingping He
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, People's Republic of China
| | - Yongyao Li
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, People's Republic of China
| | - Chunfeng Zhang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing, Jiangsu 210093, People's Republic of China
| | - Jun Zhu
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, People's Republic of China
| | - Jiannian Yao
- Beijing National Laboratory for Molecules Science (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, People's Republic of China
| |
Collapse
|
7
|
de la Perrelle JM, Tapping PC, Schrefl E, Stuart AN, Huang DM, Kee TW. Singlet fission preserves polarisation correlation of excitons. Phys Chem Chem Phys 2023; 25:6817-6829. [PMID: 36790866 DOI: 10.1039/d2cp01943d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Singlet fission (SF) holds the promise to circumvent the photovoltaic efficiency limit to reach a power-conversion efficiency above 34%. SF of TIPS-pentacene (TIPS-Pn) has been investigated but its mechanism is yet to be well elucidated. Recently, we developed a nanoparticle (NP) system, in which doping of TIPS-Pn in a host matrix yields a range of average intermolecular distances, d, to study the dependence of SF in TIPS-Pn on d. At large d values, where the bimolecular SF process should be unfavourable, a relatively high SF quantum yield (ΦSF) is still observed, which implies a deviation from a random distribution of TIPS-Pn throughout the NP. Here, using polarisation-sensitive femtosecond time-resolved spectroscopy and Monte Carlo simulations of exciton migration and SF, we quantify the level of clustering of TIPS-Pn in the host matrix, which is responsible for the higher than expected ΦSF. The experimental data indicate a preservation of polarisation correlation by SF, which is uncommon because energy transfer in amorphous materials tends to result in depolarisation. We show that the preservation of polarisation correlation is due to SF upon exciton migration. Although exciton migration decorrelates polarisation, SF acts to remove decorrelated excitons to give an overall preservation of polarisation correlation.
Collapse
Affiliation(s)
| | - Patrick C Tapping
- Department of Chemistry, The University of Adelaide, South Australia 5005, Australia.
| | - Elisabeth Schrefl
- Department of Chemistry, The University of Adelaide, South Australia 5005, Australia.
| | - Alexandra N Stuart
- Department of Chemistry, The University of Adelaide, South Australia 5005, Australia.
| | - David M Huang
- Department of Chemistry, The University of Adelaide, South Australia 5005, Australia.
| | - Tak W Kee
- Department of Chemistry, The University of Adelaide, South Australia 5005, Australia.
| |
Collapse
|
8
|
Unger F, Moretti L, Hausch J, Bredehoeft J, Zeiser C, Haug S, Tempelaar R, Hestand NJ, Cerullo G, Broch K. Modulating Singlet Fission by Scanning through Vibronic Resonances in Pentacene-Based Blends. J Am Chem Soc 2022; 144:20610-20619. [DOI: 10.1021/jacs.2c07237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Frederik Unger
- Institute for Applied Physics, University of Tuebingen, Auf der Morgenstelle 10, Tuebingen, 72076, Germany
| | - Luca Moretti
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milan 20133, Italy
| | - Julian Hausch
- Institute for Applied Physics, University of Tuebingen, Auf der Morgenstelle 10, Tuebingen, 72076, Germany
| | - Jona Bredehoeft
- Institute for Applied Physics, University of Tuebingen, Auf der Morgenstelle 10, Tuebingen, 72076, Germany
| | - Clemens Zeiser
- Institute for Applied Physics, University of Tuebingen, Auf der Morgenstelle 10, Tuebingen, 72076, Germany
| | - Sara Haug
- Institute for Applied Physics, University of Tuebingen, Auf der Morgenstelle 10, Tuebingen, 72076, Germany
| | - Roel Tempelaar
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Nicholas J. Hestand
- Department of Natural and Applied Sciences, Evangel University, 1111 North Glenstone Avenue, Springfield, Missouri 65802, United States
| | - Giulio Cerullo
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milan 20133, Italy
| | - Katharina Broch
- Institute for Applied Physics, University of Tuebingen, Auf der Morgenstelle 10, Tuebingen, 72076, Germany
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Abraham V, Mayhall NJ. Revealing the Contest between Triplet-Triplet Exchange and Triplet-Triplet Energy Transfer Coupling in Correlated Triplet Pair States in Singlet Fission. J Phys Chem Lett 2021; 12:10505-10514. [PMID: 34677988 DOI: 10.1021/acs.jpclett.1c03217] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Understanding the separation of the correlated triplet pair state 1(TT) intermediate is critical for leveraging singlet fission to improve solar cell efficiency. This separation mechanism is dominated by two key interactions: (i) the exchange interaction (K) between the triplets which leads to the spin splitting of the biexciton state into 1(TT),3(TT) and 5(TT) states, and (ii) the triplet-triplet energy transfer integral (t) which enables the formation of the spatially separated (but still spin entangled) state 1(T···T). We develop a simple ab initio technique to compute both the biexciton exchange (K) and biexciton transfer coupling. Our key findings reveal new conditions for successful correlated triplet pair state dissociation. The biexciton exchange interaction needs to be ferromagnetic or negligible to the triplet energy transfer for favorable dissociation. We also explore the effect of chromophore packing to reveal geometries where these conditions are achieved for tetracene.
Collapse
Affiliation(s)
- Vibin Abraham
- Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24060, United States
| | - Nicholas J Mayhall
- Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24060, United States
| |
Collapse
|
11
|
Zeiser C, Moretti L, Geiger T, Kalix L, Valencia AM, Maiuri M, Cocchi C, Bettinger HF, Cerullo G, Broch K. Permanent Dipole Moments Enhance Electronic Coupling and Singlet Fission in Pentacene. J Phys Chem Lett 2021; 12:7453-7458. [PMID: 34339199 DOI: 10.1021/acs.jpclett.1c01805] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Singlet fission (SF), the photophysical process in which one singlet exciton is transformed into two triplets, depends inter alia on the coupling of electronic states. Here, we use fluorination and the resulting changes in partial charge distribution across the chromophore backbone as a particularly powerful tool to control this parameter in pentacene. We find that the introduction of a permanent dipole moment leads to an enhanced coupling of Frenkel exciton and charge transfer states and to an increased SF rate which we probed using ultrafast transient absorption spectroscopy. These findings are contrasted with H-aggregate formation and a significantly reduced triplet-pair state lifetime in a fluorinated pentacene for which the different partial charge distribution leads to a negligible dipole moment.
Collapse
Affiliation(s)
- Clemens Zeiser
- Institute for Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| | - Luca Moretti
- Dipartimento di Fisica, IFN-CNR, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Thomas Geiger
- Institute for Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Lukas Kalix
- Institute for Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Ana M Valencia
- Institute of Physics, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Straße 9, 26129 Oldenburg, Germany
- Physics Department and IRIS Adlershof, Humboldt-Universität zu Berlin, Zum Großen Windkanal 6, 12489 Berlin, Germany
| | - Margherita Maiuri
- Dipartimento di Fisica, IFN-CNR, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Caterina Cocchi
- Institute of Physics, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Straße 9, 26129 Oldenburg, Germany
- Physics Department and IRIS Adlershof, Humboldt-Universität zu Berlin, Zum Großen Windkanal 6, 12489 Berlin, Germany
| | - Holger F Bettinger
- Institute for Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Giulio Cerullo
- Dipartimento di Fisica, IFN-CNR, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Katharina Broch
- Institute for Applied Physics, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
| |
Collapse
|
12
|
Sun K, Liu X, Hu W, Zhang M, Long G, Zhao Y. Singlet fission dynamics and optical spectra of pentacene and its derivatives. Phys Chem Chem Phys 2021; 23:12654-12667. [PMID: 34036985 DOI: 10.1039/d1cp00563d] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A multimode Brownian oscillator model is employed to investigate the absorption spectra of pentacene and its derivatives in solution and thin films. Excellent agreement has been obtained between simulated and measured absorption spectra. Furthermore, using parameters obtained from fitting the absorption spectra of these pentacene derivatives, the singlet fission dynamics and two-dimensional electronic spectra of an ab initio Hamiltonian are investigated by Dirac-Frenkel time-dependent variation with multiple Davydov trial states. It is found that the periodic wave packet motion induced in the displaced excited state, and the accompanying vibrational relaxation, can be visualized by two-dimensional electronic spectra at short times.
Collapse
Affiliation(s)
- Kewei Sun
- School of Science, Hangzhou Dianzi University, Hangzhou 310018, China
| | | | | | | | | | | |
Collapse
|
13
|
Kato K, Teki Y. Photogenerated carrier dynamics of TIPS-pentacene films as studied by photocurrent and electrically detected magnetic resonance. Phys Chem Chem Phys 2021; 23:6361-6369. [PMID: 33439177 DOI: 10.1039/d0cp05125j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The carrier generation process and spin dynamics through photoexcitation in the vacuum vapour deposition film of 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-Pn) were investigated by temperature dependence measurements of photocurrent and electrically detected magnetic resonance (EDMR). The EDMR signal was constructed from two components and showed a maximum at approximately 200 K. The temperature dependence was analysed using quantum mechanical simulation, assuming the carrier dynamics of the weakly coupled electron-hole pair (e-h pair). In addition, the analytical formula of photocurrent generation and EDMR signal intensity were also derived based on classical rate equations and used to understand the carrier dynamics. Through phase-shift analysis in quadrature detection of the EDMR signals, one of the two components was well analysed by using a narrow Lorentzian shape, and the other was by using a broad Gaussian.
Collapse
Affiliation(s)
- Ken Kato
- Division of Molecular Materials Science, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
| | | |
Collapse
|
14
|
Karlsson JKG, Atahan A, Harriman A, Tkachenko NV, Ward AD, Schaberle FA, Serpa C, Arnaut LG. Singlet Exciton Fission and Associated Enthalpy Changes with a Covalently Linked Bichromophore Comprising TIPS-Pentacenes Held in an Open Conformation. J Phys Chem A 2021; 125:1184-1197. [DOI: 10.1021/acs.jpca.0c09961] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joshua K. G. Karlsson
- Molecular Photonics Laboratory, School of Natural and Environmental Sciences, Newcastle University, Bedson Building, Newcastle upon Tyne NE1 7RU, U.K
| | - Alparslan Atahan
- Molecular Photonics Laboratory, School of Natural and Environmental Sciences, Newcastle University, Bedson Building, Newcastle upon Tyne NE1 7RU, U.K
| | - Anthony Harriman
- Molecular Photonics Laboratory, School of Natural and Environmental Sciences, Newcastle University, Bedson Building, Newcastle upon Tyne NE1 7RU, U.K
| | - Nikolai V. Tkachenko
- Faculty of Engineering and Natural Sciences, Tampere University, Koereakoulunkatu 7, FIN-33720 Tampere, Finland
| | - Andrew D. Ward
- Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Didcot OX11 0FA, U.K
| | - Fabio A. Schaberle
- CQC, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Carlos Serpa
- CQC, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| | - Luis G. Arnaut
- CQC, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal
| |
Collapse
|
15
|
Abstract
Singlet fission (SF) is a photophysical downconversion pathway, in which a singlet excitation transforms into two triplet excited states. As such, it constitutes an exciton multiplication generation process, which is currently at the focal point for future integration into solar energy conversion devices. Beyond this, various other exciting applications were proposed, including quantum cryptography or organic light emitting diodes. Also, the mechanistic understanding evolved rapidly during the last year. Unfortunately, the number of suitable SF-chromophores is still limited. This is per se problematic, considering the wide range of envisaged applicability. With that in mind, we emphasize uncommon SF-scaffolds and outline requirements as well as strategies to expand the chromophore pool of SF-materials.
Collapse
Affiliation(s)
- Tobias Ullrich
- Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Department für Chemie und Pharmazie, Egerlandstr. 1-3, 91058 Erlangen, Germany.
| | | | | |
Collapse
|
16
|
Chesler R, Khan S, Mazumdar S. Wave Function Based Analysis of Dynamics versus Yield of Free Triplets in Intramolecular Singlet Fission. J Phys Chem A 2020; 124:10091-10099. [PMID: 33258585 DOI: 10.1021/acs.jpca.0c07938] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Experiments in several intramolecular singlet fission materials have indicated that the triplet-triplet spin biexciton has a much longer lifetime than believed until recently, opening up loss mechanisms that can annihilate the biexciton prior to its dissociation to free triplets. We have performed many-body calculations of excited state wave functions of hypothetical phenylene-linked anthracene molecules to better understand linker-dependent behavior of dimers of larger acenes being investigated as potential singlet fission candidates. The calculations reveal unanticipated features that we show carry over to the real covalently linked pentacene dimers. Dissociation of the correlated triplet-triplet spin biexciton and free triplet generation may be difficult in acene dimers where the formation of the triplet-triplet spin biexciton is truly ultrafast. Conversely, relatively slower biexciton formation may indicate smaller spin biexciton binding energy and greater yield of free triplets. Currently available experimental results appear to support this conclusion. Whether or not the two distinct behaviors are consequences of distinct mechanisms of triplet-triplet generation from the optical singlet is an interesting theoretical question.
Collapse
Affiliation(s)
- Rafi Chesler
- Department of Physics, University of Arizona, Tucson, Arizona 85721, United States
| | - Souratosh Khan
- School of Information, University of Arizona, Tucson, Arizona 85721, United States
| | - Sumit Mazumdar
- Department of Physics, University of Arizona, Tucson, Arizona 85721, United States.,Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States.,College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, United States
| |
Collapse
|
17
|
Parenti KR, He G, Sanders SN, Pun AB, Kumarasamy E, Sfeir MY, Campos LM. Bridge Resonance Effects in Singlet Fission. J Phys Chem A 2020; 124:9392-9399. [PMID: 33138366 DOI: 10.1021/acs.jpca.0c08427] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A major benefit of intramolecular singlet fission (iSF) materials, in which through-bond interactions mediate triplet pair formation, is the ability to control the triplet formation dynamics through molecular engineering. One common design strategy is the use of molecular bridges to mediate interchromophore interactions, decreasing electronic coupling by increasing chromophore-chromophore separation. Here, we report how the judicious choice of aromatic bridges can enhance chromophore-chromophore electronic coupling. This molecular engineering strategy takes advantage of "bridge resonance", in which the frontier orbital energies are nearly degenerate with those of the covalently linked singlet fission chromophores, resulting in fast iSF even at large interchromophore separations. Using transient absorption spectroscopy, we investigate this bridge resonance effect in a series of pentacene and tetracene-bridged dimers, and we find that the rate of triplet formation is enhanced as the bridge orbitals approach resonance. This work highlights the important role of molecular connectivity in controlling the rate of iSF through chemical bonds and establishes critical design principles for future use of iSF materials in optoelectronic devices.
Collapse
Affiliation(s)
- Kaia R Parenti
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - 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
| | - Samuel N Sanders
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Andrew B Pun
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Elango Kumarasamy
- 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
| | - Luis M Campos
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| |
Collapse
|
18
|
Duan HG, Jha A, Li X, Tiwari V, Ye H, Nayak PK, Zhu XL, Li Z, Martinez TJ, Thorwart M, Miller RJD. Intermolecular vibrations mediate ultrafast singlet fission. SCIENCE ADVANCES 2020; 6:eabb0052. [PMID: 32948583 PMCID: PMC7500928 DOI: 10.1126/sciadv.abb0052] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 07/31/2020] [Indexed: 05/20/2023]
Abstract
Singlet fission is a spin-allowed exciton multiplication process in organic semiconductors that converts one spin-singlet exciton to two triplet excitons. It offers the potential to enhance solar energy conversion by circumventing the Shockley-Queisser limit on efficiency. We study the primary steps of singlet fission in a pentacene film by using a combination of TG and 2D electronic spectroscopy complemented by quantum chemical and nonadiabatic dynamics calculations. We show that the coherent vibrational dynamics induces the ultrafast transition from the singlet excited electronic state to the triplet-pair state via a degeneracy of potential energy surfaces, i.e., a multidimensional conical intersection. Significant vibronic coupling of the electronic wave packet to a few key intermolecular rocking modes in the low-frequency region connect the excited singlet and triplet-pair states. Along with high-frequency local vibrations acting as tuning modes, they open a new channel for the ultrafast exciton transfer through the resulting conical intersection.
Collapse
Affiliation(s)
- Hong-Guang Duan
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany
- I. Institut für Theoretische Physik, Universität Hamburg, Jungiusstraße 9, 20355 Hamburg, Germany
- The Hamburg Center for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Ajay Jha
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Xin Li
- Department of Chemistry and PULSE Institute, Stanford University, Stanford, CA 94305, USA
| | - Vandana Tiwari
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany
- Department of Chemistry, University of Hamburg, Martin-Luther-King Platz 6, 20146 Hamburg, Germany
| | - Hanyang Ye
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| | - Pabitra K Nayak
- TIFR Centre for Interdisciplinary Sciences, 36/P, Gopanpally Village, Ranga Reddy District, Hyderabad 500107, India
| | - Xiao-Lei Zhu
- Department of Chemistry and PULSE Institute, Stanford University, Stanford, CA 94305, USA
| | - Zheng Li
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany.
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Todd J Martinez
- Department of Chemistry and PULSE Institute, Stanford University, Stanford, CA 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Michael Thorwart
- I. Institut für Theoretische Physik, Universität Hamburg, Jungiusstraße 9, 20355 Hamburg, Germany.
- The Hamburg Center for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - R J Dwayne Miller
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany.
- The Hamburg Center for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
- Departments of Chemistry and Physics, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada
| |
Collapse
|
19
|
Schlesinger I, Powers-Riggs NE, Logsdon JL, Qi Y, Miller SA, Tempelaar R, Young RM, Wasielewski MR. Charge-transfer biexciton annihilation in a donor-acceptor co-crystal yields high-energy long-lived charge carriers. Chem Sci 2020; 11:9532-9541. [PMID: 34094218 PMCID: PMC8162030 DOI: 10.1039/d0sc03301d] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Organic donor-acceptor (D-A) co-crystals have attracted much interest due to their important optical and electronic properties. Co-crystals having ⋯DADA⋯ π-stacked morphologies are especially interesting because photoexcitation produces a charge-transfer (CT) exciton, D˙+-A˙-, between adjacent D-A molecules. Although several studies have reported on the steady-state optical properties of this type of CT exciton, very few have measured the dynamics of its formation and decay in a single D-A co-crystal. We have co-crystallized a peri-xanthenoxanthene (PXX) donor with a N,N-bis(3-pentyl)-2,5,8,11-tetraphenylperylene-3,4:9,10-bis(dicarboximide) (Ph4PDI) acceptor to give an orthorhombic PXX-Ph4PDI ⋯DADA⋯ π-stacked co-crystal with a CT transition dipole moment that is perpendicular to the transition moments for S n ← S0 excitation of PXX and Ph4PDI. Using polarized, broadband, femtosecond pump-probe microscopy, we have determined that selective photoexcitation of Ph4PDI in the single co-crystal results in CT exciton formation within the 300 fs instrument response time. At early times (0.3 ≤ t ≤ 500 ps), the CT excitons decay with a t -1/2 dependence, which is attributed to CT biexciton annihilation within the one-dimensional ⋯DADA⋯ π-stacks producing high-energy, long-lived (>8 ns) electron-hole pairs in the crystal. These energetic charge carriers may prove useful in applications ranging from photovoltaics and opto-electronics to photocatalysis.
Collapse
Affiliation(s)
- Itai Schlesinger
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA
| | - Natalia E Powers-Riggs
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA
| | - Jenna L Logsdon
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA
| | - Yue Qi
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA
| | - Stephen A Miller
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA
| | - Roel Tempelaar
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA
| | - Ryan M Young
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA
| | - Michael R Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University 2145 Sheridan Road Evanston Illinois 60208-3113 USA
| |
Collapse
|
20
|
Tao G, Tan Y. Modular Tensor Diagram Approach for the Construction of Spin Eigenfunctions: The Case Study of Exciton Pair States. J Phys Chem A 2020; 124:5435-5443. [PMID: 32551608 DOI: 10.1021/acs.jpca.0c00263] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Mapping out the high-dimensional state space would be valuable for better understanding the multistate quantum systems. Here, we demonstrate that high-dimensional spin state space can be mapped onto a tensor diagram in full dimension or self-similarly onto the reduced base state space. Based on the tensor diagram, a modular approach is proposed to construct spin eigenfunctions taking the basis of the lower-dimensional space as modules. The implementation of the approach on exciton pair states results in 16 spin eigenstates including 2 singlet states, 3 triplet states, and 1 quintet state with proper symmetry, in contrast to the ones generated using the conventional branching diagram method. The corresponding state energies obtained show the order of spin eigenstates reverses with respect to spin multiplicity. Interestingly, the state space can be decomposed into three subspaces corresponding to the singlet-singlet pair, singlet-triplet pair, and triplet-triplet pair, resulting in a modular structure that is invariant as intermolecular interactions diminish. The proposed approach offers a new perspective on the state space structure of multiple spin states, featuring a hierarchical symmetry, which could be extended to general high-dimensional quantum multistate systems.
Collapse
Affiliation(s)
- Guohua Tao
- School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, China.,Shenzhen Key Laboratory of New Energy Materials by Design, Peking University, Shenzhen 518055, China
| | - Yunshu Tan
- School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, China.,Shenzhen Key Laboratory of New Energy Materials by Design, Peking University, Shenzhen 518055, China
| |
Collapse
|
21
|
Sardar S. Effects of site-specific substitution to hexacene and its effect towards singlet fission. J Mol Graph Model 2020; 98:107608. [DOI: 10.1016/j.jmgm.2020.107608] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 03/25/2020] [Accepted: 03/25/2020] [Indexed: 01/08/2023]
|
22
|
Kwang SY, Frontiera RR. Spatially Offset Femtosecond Stimulated Raman Spectroscopy: Observing Exciton Transport through a Vibrational Lens. J Phys Chem Lett 2020; 11:4337-4344. [PMID: 32427490 DOI: 10.1021/acs.jpclett.0c01114] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
To design better molecular electronic devices, we need a strong understanding of how charges or excitons propagate, as many efficiency losses arise during transport. Exciton transport has been difficult to study because excitons tend to be short-lived, have short diffusion lengths, and can easily recombine. Here, we debut spatially offset femtosecond stimulated Raman spectroscopy (SO-FSRS), a three-pulse ultrafast microscopy technique. By offsetting the photoexcitation beam, we can monitor Raman spectral changes as a function of both time and position. We used SO-FSRS on 6,13-bis(triisopropylsilylethynyl) pentacene, a well-studied organic semiconductor used in photovoltaics and field-effect transistors. We demonstrated that the fast exciton and free charge carrier transport axes are identical and observed that exciton transport is less anisotropic by a factor of ∼3. SO-FSRS is the first technique that directly tracks molecular structural evolution during exciton transport, which can provide roadmaps for tailor-making molecules for specific electronic devices.
Collapse
Affiliation(s)
- Siu Yi Kwang
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Renee R Frontiera
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
23
|
Lewis AM, Berkelbach TC. Ab Initio Linear and Pump-Probe Spectroscopy of Excitons in Molecular Crystals. J Phys Chem Lett 2020; 11:2241-2246. [PMID: 32109074 DOI: 10.1021/acs.jpclett.0c00031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Linear and nonlinear spectroscopies are powerful tools used to investigate the energetics and dynamics of electronic excited states of both molecules and crystals. While highly accurate ab initio calculations of molecular spectra can be performed relatively routinely, extending these calculations to periodic systems is challenging. Here, we present calculations of the linear absorption spectrum and pump-probe two-photon photoemission spectra of the naphthalene crystal using equation-of-motion coupled-cluster theory with single and double excitations (EOM-CCSD). Molecular acene crystals are of interest due to the low-energy multiexciton singlet states they exhibit, which have been studied extensively as intermediates involved in singlet fission. Our linear absorption spectrum is in good agreement with experiment, predicting a first exciton absorption peak at 4.4 eV, and our two-photon photoemission spectra capture the qualitative behavior of multiexciton states, whose double-excitation character cannot be captured by current methods. The simulated pump-probe spectra provide support for existing interpretations of two-photon photoemission experiments in closely related acene crystals such as tetracene and pentacene.
Collapse
Affiliation(s)
- Alan M Lewis
- Department of Chemistry and James Franck Institute, University of Chicago, Chicago, Illinois 60637, United States
| | - Timothy C Berkelbach
- Department of Chemistry, Columbia University, New York, New York 10027, United States
- Center for Computational Quantum Physics, Flatiron Institute, New York, New York 10010, United States
| |
Collapse
|
24
|
Folie BD, Tan JA, Huang J, Sercel PC, Delor M, Lai M, Lyons JL, Bernstein N, Efros AL, Yang P, Ginsberg NS. Effect of Anisotropic Confinement on Electronic Structure and Dynamics of Band Edge Excitons in Inorganic Perovskite Nanowires. J Phys Chem A 2020; 124:1867-1876. [DOI: 10.1021/acs.jpca.9b11981] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
| | | | | | - Peter C. Sercel
- Department of Applied Physics and Materials Science, California Institute of Technology, Pasadena California 91125, United States
| | | | | | - John L. Lyons
- Center for Computational Material Science, Naval Research Laboratory, Washington D.C. 20375, United States
| | - Noam Bernstein
- Center for Computational Material Science, Naval Research Laboratory, Washington D.C. 20375, United States
| | - Alexander L. Efros
- Center for Computational Material Science, Naval Research Laboratory, Washington D.C. 20375, United States
| | - Peidong Yang
- Kavli Energy NanoSciences Institute, Berkeley, California 94720, United States
| | - Naomi S. Ginsberg
- Kavli Energy NanoSciences Institute, Berkeley, California 94720, United States
| |
Collapse
|
25
|
Han J, Xie Q, Luo J, Deng GH, Qian Y, Sun D, Harutyunyan AR, Chen G, Rao Y. Anisotropic Geminate and Non-Geminate Recombination of Triplet Excitons in Singlet Fission of Single Crystalline Hexacene. J Phys Chem Lett 2020; 11:1261-1267. [PMID: 31971388 DOI: 10.1021/acs.jpclett.9b03800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Singlet fission is believed to improve the efficiency of solar energy conversion by breaking up the Shockley-Queisser thermodynamic limit. Understanding of triplet excitons generated by singlet fission is essential for solar energy exploitation. Here we employed transient absorption microscopy to examine dynamical behaviors of triplet excitons. We observed anisotropic recombination of triplet excitons in hexacene single crystals. The triplet exciton relaxations from singlet fission proceed in both geminate and non-geminate recombination. For the geminate recombination, the different rates were attributed to the significant difference in their related energy change based on the Redfield quantum dissipation theory. The process is mainly governed by the electron-phonon interaction in hexacene. On the other hand, the non-geminate recombination is of bimolecular origin through energy transfer. In the triplet-triplet bimolecular process, the rates along the two different optical axes in the a-b crystalline plane differ by a factor of 4. This anisotropy in the triplet-triplet recombination rates was attributed to the interference in the coupling probability of dipole-dipole interactions in the different geometric configurations of hexacene single crystals. Our experimental findings provide new insight into future design of singlet fission materials with desirable triplet exciton exploitations.
Collapse
Affiliation(s)
- Jian Han
- School of Chemical Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
- Department of Chemistry and Biochemistry , Utah State University , Logan , Utah 84322 , United States
| | - Qing Xie
- Department of Chemistry and Biochemistry , Utah State University , Logan , Utah 84322 , United States
| | - Jun Luo
- School of Chemical Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
| | - Gang-Hua Deng
- Department of Chemistry and Biochemistry , Utah State University , Logan , Utah 84322 , United States
| | - Yuqin Qian
- Department of Chemistry and Biochemistry , Utah State University , Logan , Utah 84322 , United States
| | - Dezheng Sun
- Department of Physics , Columbia University , New York , New York 10027 , United States
| | - Avetik R Harutyunyan
- Honda Research Institute, USA, Inc. , San Jose , California 95134 , United States
| | - Gugang Chen
- Honda Research Institute, USA, Inc. , San Jose , California 95134 , United States
| | - Yi Rao
- Department of Chemistry and Biochemistry , Utah State University , Logan , Utah 84322 , United States
| |
Collapse
|
26
|
Hudson RJ, de la Perrelle JM, Pensack RD, Kudisch B, Scholes GD, Huang DM, Kee TW. Organizing Crystalline Functionalized Pentacene Using Periodicity of Poly(Vinyl Alcohol). J Phys Chem Lett 2020; 11:516-523. [PMID: 31884794 DOI: 10.1021/acs.jpclett.9b03373] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Nanoparticles of acenes exhibit highly efficient intermolecular singlet fission (SF). Recent reports indicate that altering the morphology of 6,13-bis-(triisopropylsilylethynyl)pentacene (TIPS-Pn) nanoparticles has a profound influence on their SF dynamics. Here, we show that poly(vinyl alcohol) (PVA) induces a phase transition in preformed TIPS-Pn nanoparticles. These nanoparticles are amorphous when initially formed but crystalline after addition of PVA. Surface characterization indicates that a diffuse PVA layer surrounds the nanoparticles. We propose that a periodic interaction between the hydroxyl groups of PVA and TIPS groups of TIPS-Pn on the nanoparticle surface induces a large-scale structural rearrangement to yield crystalline TIPS-Pn. Such reorganization in preformed organic nanoparticles is unprecedented, and we believe that this is the first report of such an effect induced by polymer adsorption. Transient absorption spectroscopic results reveal that SF within these nanoparticles is accelerated by an order of magnitude upon structural rearrangement.
Collapse
Affiliation(s)
- Rohan J Hudson
- Department of Chemistry , The University of Adelaide , Adelaide , South Australia 5005 , Australia
| | - Jessica M de la Perrelle
- Department of Chemistry , The University of Adelaide , Adelaide , South Australia 5005 , Australia
| | - Ryan D Pensack
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
| | - Bryan Kudisch
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
| | - Gregory D Scholes
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , United States
| | - David M Huang
- Department of Chemistry , The University of Adelaide , Adelaide , South Australia 5005 , Australia
| | - Tak W Kee
- Department of Chemistry , The University of Adelaide , Adelaide , South Australia 5005 , Australia
| |
Collapse
|
27
|
Zhu Y, Cheng JX. Transient absorption microscopy: Technological innovations and applications in materials science and life science. J Chem Phys 2020; 152:020901. [PMID: 31941290 PMCID: PMC7195865 DOI: 10.1063/1.5129123] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 12/15/2019] [Indexed: 01/08/2023] Open
Abstract
Transient absorption (TA) spectroscopy has been extensively used in the study of excited state dynamics of various materials and molecules. The transition from TA spectroscopy to TA microscopy, which enables the space-resolved measurement of TA, is opening new investigations toward a more complete picture of excited state dynamics in functional materials, as well as the mapping of crucial biopigments for precision diagnosis. Here, we review the recent instrumental advancement that is pushing the limit of spatial resolution, detection sensitivity, and imaging speed. We further highlight the emerging application in materials science and life science.
Collapse
Affiliation(s)
- Yifan Zhu
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, USA
| | - Ji-Xin Cheng
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, USA
| |
Collapse
|
28
|
Sanders SN, Kumarasamy E, Fallon KJ, Sfeir MY, Campos LM. Singlet fission in a hexacene dimer: energetics dictate dynamics. Chem Sci 2019; 11:1079-1084. [PMID: 34084363 PMCID: PMC8146228 DOI: 10.1039/c9sc05066c] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Singlet fission (SF) is an exciton multiplication process with the potential to raise the efficiency limit of single junction solar cells from 33% to up to 45%. Most chromophores generally undergo SF as solid-state crystals. However, when such molecules are covalently coupled, the dimers can be used as model systems to study fundamental photophysical dynamics where a singlet exciton splits into two triplet excitons within individual molecules. Here we report the synthesis and photophysical characterization of singlet fission of a hexacene dimer. Comparing the hexacene dimer to analogous tetracene and pentacene dimers reveals that excess exoergicity slows down singlet fission, similar to what is observed in molecular crystals. Conversely, the lower triplet energy of hexacene results in an increase in the rate of triplet pair recombination, following the energy gap law for radiationless transitions. These results point to design rules for singlet fission chromophores: the energy gap between singlet and triplet pair should be minimal, and the gap between triplet pair and ground state should be large. We report the synthesis and photophysical characterization of highly exoergic singlet fission in a hexacene dimer revealing exciton dynamics that follow the energy gap law.![]()
Collapse
Affiliation(s)
- Samuel N Sanders
- Department of Chemistry, Columbia University New York NY 10027 USA
| | | | - Kealan J Fallon
- Department of Chemistry, Columbia University New York NY 10027 USA
| | - Matthew Y Sfeir
- Photonics Initiative, Advanced Science Research Center, City University of New York New York NY 10031 USA .,Department of Physics, Graduate Center, City University of New York New York NY 10016 USA
| | - Luis M Campos
- Department of Chemistry, Columbia University New York NY 10027 USA
| |
Collapse
|
29
|
Jones AC, Kearns NM, Ho JJ, Flach JT, Zanni MT. Impact of non-equilibrium molecular packings on singlet fission in microcrystals observed using 2D white-light microscopy. Nat Chem 2019; 12:40-47. [PMID: 31792384 DOI: 10.1038/s41557-019-0368-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 10/08/2019] [Indexed: 11/09/2022]
Abstract
Singlet fission, the process of splitting a singlet exciton into two triplet excitons, has been proposed as a mechanism for improving the efficiency of future photovoltaic devices. In organic semiconductors exhibiting singlet fission, the geometric relationship between molecules plays an important role by setting the intermolecular couplings that determine the system energetics. Here, we spatially image TIPS-pentacene microcrystals using ultrafast two-dimensional white-light microscopy and discover a low-energy singlet state sparsely distributed throughout the microcrystals, with higher concentrations at edges and morphological defects. The spectra of these singlet states are consistent with slip-stacked molecular geometries and increased charge-transfer couplings. The picosecond-timescale kinetics of these low-energy singlet states matches that of the correlated triplet-pair state, which we attribute to singlet/triplet-pair interconversion at these sites. Our observations support the conclusion that small populations of geometries with favourable energetics can play outsized roles in singlet fission processes.
Collapse
Affiliation(s)
- Andrew C Jones
- Department of Chemistry, University of Wisconsin, Madison, WI, USA
| | | | - Jia-Jung Ho
- Department of Chemistry, University of Wisconsin, Madison, WI, USA
| | - Jessica T Flach
- Department of Chemistry, University of Wisconsin, Madison, WI, USA
| | - Martin T Zanni
- Department of Chemistry, University of Wisconsin, Madison, WI, USA.
| |
Collapse
|
30
|
Ginsberg NS, Tisdale WA. Spatially Resolved Photogenerated Exciton and Charge Transport in Emerging Semiconductors. Annu Rev Phys Chem 2019; 71:1-30. [PMID: 31756129 DOI: 10.1146/annurev-physchem-052516-050703] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We review recent advances in the characterization of electronic forms of energy transport in emerging semiconductors. The approaches described all temporally and spatially resolve the evolution of initially localized populations of photogenerated excitons or charge carriers. We first provide a comprehensive background for describing the physical origin and nature of electronic energy transport both microscopically and from the perspective of the observer. We introduce the new family of far-field, time-resolved optical microscopies developed to directly resolve not only the extent of this transport but also its potentially temporally and spatially dependent rate. We review a representation of examples from the recent literature, including investigation of energy flow in colloidal quantum dot solids, organic semiconductors, organic-inorganic metal halide perovskites, and 2D transition metal dichalcogenides. These examples illustrate how traditional parameters like diffusivity are applicable only within limited spatiotemporal ranges and how the techniques at the core of this review,especially when taken together, are revealing a more complete picture of the spatiotemporal evolution of energy transport in complex semiconductors, even as a function of their structural heterogeneities.
Collapse
Affiliation(s)
- Naomi S Ginsberg
- Department of Chemistry and Department of Physics, University of California, Berkeley, California 94720, USA; .,Material Sciences Division and Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.,Kavli Energy NanoSciences Institute, Berkeley, California 94720, USA
| | - William A Tisdale
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA;
| |
Collapse
|
31
|
Jones AC, Kearns NM, Bohlmann Kunz M, Flach JT, Zanni MT. Multidimensional Spectroscopy on the Microscale: Development of a Multimodal Imaging System Incorporating 2D White-Light Spectroscopy, Broadband Transient Absorption, and Atomic Force Microscopy. J Phys Chem A 2019; 123:10824-10836. [DOI: 10.1021/acs.jpca.9b09099] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Andrew C. Jones
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Nicholas M. Kearns
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Miriam Bohlmann Kunz
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Jessica T. Flach
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Martin T. Zanni
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| |
Collapse
|
32
|
Schnedermann C, Sung J, Pandya R, Verma SD, Chen RYS, Gauriot N, Bretscher HM, Kukura P, Rao A. Ultrafast Tracking of Exciton and Charge Carrier Transport in Optoelectronic Materials on the Nanometer Scale. J Phys Chem Lett 2019; 10:6727-6733. [PMID: 31592672 PMCID: PMC6844127 DOI: 10.1021/acs.jpclett.9b02437] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We present a novel optical transient absorption and reflection microscope based on a diffraction-limited pump pulse in combination with a wide-field probe pulse, for the spatiotemporal investigation of ultrafast population transport in thin films. The microscope achieves a temporal resolution down to 12 fs and simultaneously provides sub-10 nm spatial accuracy. We demonstrate the capabilities of the microscope by revealing an ultrafast excited-state exciton population transport of up to 32 nm in a thin film of pentacene and by tracking the carrier motion in p-doped silicon. The use of few-cycle optical excitation pulses enables impulsive stimulated Raman microspectroscopy, which is used for in situ verification of the chemical identity in the 100-2000 cm-1 spectral window. Our methodology bridges the gap between optical microscopy and spectroscopy, allowing for the study of ultrafast transport properties down to the nanometer length scale.
Collapse
Affiliation(s)
- Christoph Schnedermann
- Department
of Physics, Cavendish Laboratory, University
of Cambridge, JJ Thompson Avenue, Cambridge CB3 0HE, United Kingdom
- E-mail: (C.S.)
| | - Jooyoung Sung
- Department
of Physics, Cavendish Laboratory, University
of Cambridge, JJ Thompson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Raj Pandya
- Department
of Physics, Cavendish Laboratory, University
of Cambridge, JJ Thompson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Sachin Dev Verma
- Department
of Physics, Cavendish Laboratory, University
of Cambridge, JJ Thompson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Richard Y. S. Chen
- Department
of Physics, Cavendish Laboratory, University
of Cambridge, JJ Thompson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Nicolas Gauriot
- Department
of Physics, Cavendish Laboratory, University
of Cambridge, JJ Thompson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Hope M. Bretscher
- Department
of Physics, Cavendish Laboratory, University
of Cambridge, JJ Thompson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Philipp Kukura
- Physical
and Theoretical Chemistry Laboratory, University
of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Akshay Rao
- Department
of Physics, Cavendish Laboratory, University
of Cambridge, JJ Thompson Avenue, Cambridge CB3 0HE, United Kingdom
- E-mail: (A.R.)
| |
Collapse
|
33
|
Bardeen CJ. Time dependent correlations of entangled states with nondegenerate branches and possible experimental realization using singlet fission. J Chem Phys 2019; 151:124503. [DOI: 10.1063/1.5117155] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
|
34
|
Sun D, Deng GH, Xu B, Xu E, Li X, Wu Y, Qian Y, Zhong Y, Nuckolls C, Harutyunyan AR, Dai HL, Chen G, Chen H, Rao Y. Anisotropic Singlet Fission in Single Crystalline Hexacene. iScience 2019; 19:1079-1089. [PMID: 31522118 PMCID: PMC6745488 DOI: 10.1016/j.isci.2019.08.053] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 07/01/2019] [Accepted: 08/26/2019] [Indexed: 11/25/2022] Open
Abstract
Singlet fission is known to improve solar energy utilization by circumventing the Shockley-Queisser limit. The two essential steps of singlet fission are the formation of a correlated triplet pair and its subsequent quantum decoherence. However, the mechanisms of the triplet pair formation and decoherence still remain elusive. Here we examined both essential steps in single crystalline hexacene and discovered remarkable anisotropy of the overall singlet fission rate along different crystal axes. Since the triplet pair formation emerges on the same timescale along both crystal axes, the quantum decoherence is likely responsible for the directional anisotropy. The distinct quantum decoherence rates are ascribed to the notable difference on their associated energy loss according to the Redfield quantum dissipation theory. Our hybrid experimental/theoretical framework will not only further our understanding of singlet fission, but also shed light on the systematic design of new materials for the third-generation solar cells.
Collapse
Affiliation(s)
- Dezheng Sun
- Department of Physics, Columbia University, New York, NY 10027, USA
| | - Gang-Hua Deng
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322, USA
| | - Bolei Xu
- Department of Chemistry, Temple University, Philadelphia, PA 19122, USA
| | - Enshi Xu
- Department of Chemistry, George Washington University, Washington, DC 20052, USA
| | - Xia Li
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322, USA
| | - Yajing Wu
- Department of Chemistry, Temple University, Philadelphia, PA 19122, USA
| | - Yuqin Qian
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322, USA
| | - Yu Zhong
- Department of Chemistry, Columbia University, New York, NY 10027, USA
| | - Colin Nuckolls
- Department of Chemistry, Columbia University, New York, NY 10027, USA
| | | | - Hai-Lung Dai
- Department of Chemistry, Temple University, Philadelphia, PA 19122, USA
| | - Gugang Chen
- Honda Research Institute USA, Inc., San Jose, CA 95134, USA.
| | - Hanning Chen
- Department of Chemistry, George Washington University, Washington, DC 20052, USA.
| | - Yi Rao
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322, USA.
| |
Collapse
|
35
|
Huang H, He G, Xu K, Wu Q, Wu D, Sfeir MY, Xia J. Achieving Long-Lived Triplet States in Intramolecular SF Films through Molecular Engineering. Chem 2019. [DOI: 10.1016/j.chempr.2019.06.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
36
|
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.
Collapse
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
| |
Collapse
|
37
|
Pun AB, Asadpoordarvish A, Kumarasamy E, Tayebjee MJY, Niesner D, McCamey DR, Sanders SN, Campos LM, Sfeir MY. Ultra-fast intramolecular singlet fission to persistent multiexcitons by molecular design. Nat Chem 2019; 11:821-828. [PMID: 31406323 DOI: 10.1038/s41557-019-0297-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 06/14/2019] [Indexed: 11/10/2022]
Abstract
Singlet fission-that is, the generation of two triplets from a lone singlet state-has recently resurfaced as a promising process for the generation of multiexcitons in organic systems. Although advances in this area have led to the discovery of modular classes of chromophores, controlling the fate of the multiexciton states has been a major challenge; for example, promoting fast multiexciton generation while maintaining long triplet lifetimes. Unravelling the dynamical evolution of the spin- and energy conversion processes from the transition of singlet excitons to correlated triplet pairs and individual triplet excitons is necessary to design materials that are optimized for translational technologies. Here, we engineer molecules featuring a discrete energy gradient that promotes the migration of strongly coupled triplet pairs to a spatially separated, weakly coupled state that readily dissociates into free triplets. This 'energy cleft' concept allows us to combine the amplification and migration processes within a single molecule, with rapid dissociation of tightly bound triplet pairs into individual triplets that exhibit lifetimes of ~20 µs.
Collapse
Affiliation(s)
- Andrew B Pun
- Department of Chemistry, Columbia University, NewYork, NY, USA
| | - Amir Asadpoordarvish
- ARC Centre of Excellence in Exciton Science, School of Physics, University of New South Wales, Sydney, New South Wales, Australia
| | | | - Murad J Y Tayebjee
- Cavendish Laboratory, University of Cambridge, Cambridge, UK.,School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney, New South Wales, Australia
| | - Daniel Niesner
- Department of Chemistry, Columbia University, NewYork, NY, USA.,Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, MA, USA
| | - Dane R McCamey
- ARC Centre of Excellence in Exciton Science, School of Physics, University of New South Wales, Sydney, New South Wales, Australia
| | - Samuel N Sanders
- Department of Chemistry, Columbia University, NewYork, NY, USA. .,Rowland Institute at Harvard, Cambridge, MA, USA.
| | - Luis M Campos
- Department of Chemistry, Columbia University, NewYork, NY, USA.
| | - Matthew Y Sfeir
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, MA, USA. .,Photonics Initiative, Advanced Science Research Center, City University of New York, New York, NY, USA. .,Department of Physics, Graduate Center, City University of New York, New York, NY, USA.
| |
Collapse
|
38
|
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
| |
Collapse
|
39
|
Sanders SN, Pun AB, Parenti KR, Kumarasamy E, Yablon LM, Sfeir MY, Campos LM. Understanding the Bound Triplet-Pair State in Singlet Fission. Chem 2019. [DOI: 10.1016/j.chempr.2019.05.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
40
|
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
| |
Collapse
|
41
|
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.
Collapse
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; ,
| |
Collapse
|
42
|
Abstract
This account aims at providing an understanding of singlet fission, i.e., the photophysical process of a singlet state ( S1) splitting into two triplet states (2 × T1) in molecular chromophores. Since its discovery 50 years ago, the field of singlet fission has enjoyed rapid expansion in the past 8 years. However, there have been lingering confusion and debates on the nature of the all-important triplet pair intermediate states and the definition of singlet fission rates. Here we clarify the confusion from both theoretical and experimental perspectives. We distinguish the triplet pair state that maintains electronic coherence between the two constituent triplets, 1(TT), from one which does not, 1(T···T). Only the rate of formation of 1(T···T) is defined as that of singlet fission. We present distinct experimental evidence for 1(TT), whose formation may occur via incoherent and/or vibronic coherent mechanisms. We discuss the challenges in treating singlet fission beyond the dimer approximation, in understanding the often neglected roles of delocalization on singlet fission rates, and in realizing the much lauded goal of increasing solar energy conversion efficiencies with singlet fission chromophores.
Collapse
Affiliation(s)
- Kiyoshi Miyata
- Department of Chemistry , Columbia University , New York , New York 10027 , United States.,Department of Chemistry , Kyushu University , Fukuoka 819-0395 , Japan
| | - Felisa S Conrad-Burton
- Department of Chemistry , Columbia University , New York , New York 10027 , United States
| | - Florian L Geyer
- Department of Chemistry , Columbia University , New York , New York 10027 , United States
| | - X-Y Zhu
- Department of Chemistry , Columbia University , New York , New York 10027 , United States
| |
Collapse
|
43
|
Wang C, Kodaimati MS, Lian S, Weiss EA. Systematic control of the rate of singlet fission within 6,13-diphenylpentacene aggregates with PbS quantum dot templates. Faraday Discuss 2019; 216:162-173. [DOI: 10.1039/c8fd00157j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Perturbation of molecular packing and dielectric environment at a quantum dot surface can promote singlet fission in diphenylpentacene aggregates.
Collapse
Affiliation(s)
- Chen Wang
- Department of Chemistry and Biochemistry
- City University of New York
- Queens College
- Flushing
- USA
| | | | - Shichen Lian
- Department of Chemistry
- Northwestern University
- Evanston
- USA
| | - Emily A. Weiss
- Department of Chemistry
- Northwestern University
- Evanston
- USA
| |
Collapse
|
44
|
Abstract
The highly unusual state, 1(TT), is a coupled, double triplet state that has recently garnered significant attention. This multiexcitonic state can be formed by a quantum transition from a single-photon bright state in a variety of organic semiconducting materials. 1(TT)'s transient nature and similarity to independent triplets, however, has led to significant difficulties in characterization and prediction of its properties. Recent progress describing 1(TT) from theory and experiment are breaking through these difficulties, and have greatly advanced our comprehension of this state. Starting from the early description of 1(TT) in polyenes, this perspective discusses formation mechanisms, spectroscopic signatures, and the scope of intertriplet interactions. When employing singlet fission to generate charge carriers in a solar cell, 1(TT) has a central role. Due to the variety of coupling strengths between triplet states in 1(TT) amongst different chromophores, two different strategies are discussed to enable efficient charge carrier extraction. Continued growth in our understanding of 1(TT) may lead to control over complex quantum states for intriguing applications beyond high-efficiency, organic solar cells.
Collapse
Affiliation(s)
- Hyungjun Kim
- Department of Chemistry, Incheon National University, Incheon 22012, Republic of Korea.
| | | |
Collapse
|
45
|
Wan Y, Wiederrecht GP, Schaller RD, Johnson JC, Huang L. Transport of Spin-Entangled Triplet Excitons Generated by Singlet Fission. J Phys Chem Lett 2018; 9:6731-6738. [PMID: 30403874 DOI: 10.1021/acs.jpclett.8b02944] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Singlet fission provides a promising route for overcoming the Shockley-Queisser limit in solar cells using organic materials. Despite singlet fission dynamics having been extensively investigated, the transport of the various intermediates in relation to the singlet and triplet states is largely unknown. Here we employ temperature-dependent ultrafast transient absorption microscopy to image the transport of singlet fission intermediates in single crystals of tetracene. These measurements suggest a mobile singlet fission intermediate state at low temperatures, with a diffusion constant of 36 cm2s-1 at 5 K, approaching that for the free singlet excitons, which we attribute to the spin-entangled correlated triplet pair state 1[TT]. These results indicate that 1[TT] could transport with a similar mechanism as the bright singlet excitons, which has important implications in designing materials for singlet fission and spintronic applications.
Collapse
Affiliation(s)
- Yan Wan
- College of Chemistry , Beijing Normal University , Beijing 100875 , China
- Department of Chemistry , Purdue University , West Lafayette , Indiana 47907 , United States
| | - Gary P Wiederrecht
- Center for Nanoscale Materials , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - Richard D Schaller
- Center for Nanoscale Materials , Argonne National Laboratory , Argonne , Illinois 60439 , United States
- Department of Chemistry , Northwestern University , Evanston , Illinois 60208 , United States
| | - Justin C Johnson
- National Renewable Energy Laboratory , 15013 Denver West Pkwy , Golden , Colorado 80401 , United States
| | - Libai Huang
- Department of Chemistry , Purdue University , West Lafayette , Indiana 47907 , United States
| |
Collapse
|
46
|
Zhu T, Huang L. Exciton Transport in Singlet Fission Materials: A New Hare and Tortoise Story. J Phys Chem Lett 2018; 9:6502-6510. [PMID: 30358404 DOI: 10.1021/acs.jpclett.8b02181] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Singlet fission is promising for redistributing the solar spectrum to overcome the Shockley-Queisser limit for single-junction solar cells using molecular materials. Despite recent experimental and theoretical advances in understanding the underlying mechanisms, how exciton transport is coupled to singlet fission dynamics is much less explored. In this Perspective, we examine exciton transport in singlet fission materials, highlighting the use of transient absorption microscopy (TAM) to track the population of different states in both spatial and temporal domains. In contrast to the conventional picture where singlet and triplet excitons migrate independently, TAM measurements of acene single crystals reveal cooperative transport between fast-moving singlet and slow-moving triplet excitons. Such cooperative transport is unique to singlet fission materials and allows hundreds of nanometers triplet migration on the nanosecond time scale, beneficial for solar cell applications. The transport of triplet pair intermediates and general criteria for achieving cooperative singlet-triplet transport are also discussed.
Collapse
Affiliation(s)
- Tong Zhu
- Department of Chemistry , Purdue University , West Lafayette , Indiana 47907 , United States
| | - Libai Huang
- Department of Chemistry , Purdue University , West Lafayette , Indiana 47907 , United States
| |
Collapse
|
47
|
Pensack RD, Tilley AJ, Grieco C, Purdum GE, Ostroumov EE, Granger DB, Oblinsky DG, Dean JC, Doucette GS, Asbury JB, Loo YL, Seferos DS, Anthony JE, Scholes GD. Striking the right balance of intermolecular coupling for high-efficiency singlet fission. Chem Sci 2018; 9:6240-6259. [PMID: 30090312 PMCID: PMC6062843 DOI: 10.1039/c8sc00293b] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 05/31/2018] [Indexed: 12/02/2022] Open
Abstract
Singlet fission is a process that splits collective excitations, or excitons, into two with unity efficiency. This exciton splitting process, unique to molecular photophysics, has the potential to considerably improve the efficiency of optoelectronic devices through more efficient light harvesting. While the first step of singlet fission has been characterized in great detail, subsequent steps critical to achieving overall highly-efficient singlet-to-triplet conversion are only just beginning to become well understood. One of the most elementary suggestions, which has yet to be tested, is that an appropriately balanced coupling is necessary to ensure overall highly efficient singlet fission; that is, the coupling needs to be strong enough so that the first step is fast and efficient, yet weak enough to ensure the independent behavior of the resultant triplets. In this work, we show how high overall singlet-to-triplet conversion efficiencies can be achieved in singlet fission by ensuring that the triplets comprising the triplet pair behave as independently as possible. We show that side chain sterics govern local packing in amorphous pentacene derivative nanoparticles, and that this in turn controls both the rate at which triplet pairs form and the rate at which they decay. We show how compact side chains and stronger couplings promote a triplet pair that effectively couples to the ground state, whereas bulkier side chains promote a triplet pair that appears more like two independent and long-lived triplet excitations. Our results show that the triplet pair is not emissive, that its decay is best viewed as internal conversion rather than triplet-triplet annihilation, and perhaps most critically that, in contrast to a number of recent suggestions, the triplets comprising the initially formed triplet pair cannot be considered independently. This work represents a significant step toward better understanding intermediates in singlet fission, and how molecular packing and couplings govern overall triplet yields.
Collapse
Affiliation(s)
- Ryan D Pensack
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , USA .
| | - Andrew J Tilley
- Department of Chemistry , University of Toronto , Toronto , Ontario M5S 3H6 , Canada
| | - Christopher Grieco
- Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , USA
| | - Geoffrey E Purdum
- Department of Chemical and Biological Engineering , Princeton University , Princeton , New Jersey 08544 , USA
| | - Evgeny E Ostroumov
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , USA .
| | - Devin B Granger
- Department of Chemistry , University of Kentucky , Lexington , Kentucky 40506 , USA .
| | - Daniel G Oblinsky
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , USA .
| | - Jacob C Dean
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , USA .
| | - Grayson S Doucette
- Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , USA
| | - John B Asbury
- Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , USA
| | - Yueh-Lin Loo
- Department of Chemical and Biological Engineering , Princeton University , Princeton , New Jersey 08544 , USA
- Andlinger Center for Energy and the Environment , Princeton University , Princeton , New Jersey 08544 , USA
| | - Dwight S Seferos
- Department of Chemistry , University of Toronto , Toronto , Ontario M5S 3H6 , Canada
- Department of Chemical Engineering and Applied Chemistry , University of Toronto , Toronto , Ontario M5S 3E5 , Canada
| | - John E Anthony
- Department of Chemistry , University of Kentucky , Lexington , Kentucky 40506 , USA .
| | - Gregory D Scholes
- Department of Chemistry , Princeton University , Princeton , New Jersey 08544 , USA .
| |
Collapse
|
48
|
Korovina NV, Joy J, Feng X, Feltenberger C, Krylov AI, Bradforth SE, Thompson ME. Linker-Dependent Singlet Fission in Tetracene Dimers. J Am Chem Soc 2018; 140:10179-10190. [PMID: 30016102 DOI: 10.1021/jacs.8b04401] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Separation of triplet excitons produced by singlet fission is crucial for efficient application of singlet fission materials. While earlier works explored the first step of singlet fission, the formation of the correlated triplet pair state, the focus of recent studies has been on understanding the second step of singlet fission, the formation of independent triplets from the correlated pair state. We present the synthesis and excited-state dynamics of meta- and para-bis(ethynyltetracenyl)benzene dimers that are analogues to the ortho-bis(ethynyltetracenyl)benzene dimer reported by our groups previously. A comparison of the excited-state properties of these dimers allows us to investigate the effects of electronic conjugation and coupling on singlet fission between the ethynyltetracene units within a dimer. In the para isomer, in which the two chromophores are conjugated, the singlet exciton yields the correlated triplet pair state, from which the triplet excitons can decouple via molecular rotations. In contrast, the meta isomer in which the two chromophores are cross-coupled predominantly relaxes via radiative decay. We also report the synthesis and excited-state dynamics of two para dimers with different bridging units joining the ethynyltetracenes. The rate of singlet fission is found to be faster in the dimer with the bridging unit that has orbitals closer in energy to that of the ethynyltetracene chromophores.
Collapse
Affiliation(s)
- Nadezhda V Korovina
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Jimmy Joy
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Xintian Feng
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Cassidy Feltenberger
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Anna I Krylov
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Stephen E Bradforth
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Mark E Thompson
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| |
Collapse
|
49
|
Hu J, Xu K, Shen L, Wu Q, He G, Wang JY, Pei J, Xia J, Sfeir MY. New insights into the design of conjugated polymers for intramolecular singlet fission. Nat Commun 2018; 9:2999. [PMID: 30065295 PMCID: PMC6068183 DOI: 10.1038/s41467-018-05389-w] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 06/28/2018] [Indexed: 11/09/2022] Open
Abstract
Singlet fission (SF), a multiple exciton generation process that generates two triplet excitons after the absorption of one photon, can potentially enable more efficient solar cell designs by harvesting energy normally lost as heat. While low-bandgap conjugated polymers are highly promising candidates for efficient SF-based solar cells, few polymer materials capable of SF have been reported because the SF process in polymer chains is poorly understood. Using transient spectroscopy, we demonstrate a new, highly efficient (triplet yield of 160-200%) isoindigo-based donor-acceptor polymer and show that the triplet pairs are directly emissive and exhibit a time-dependent energy evolution. Importantly, aggregation in poor solvents and in films significantly lowers the singlet energy, suppressing triplet formation because the energy conservation criterion is no longer met. These results suggest a new design rule for developing intramolecular SF capable low-bandgap conjugated polymers, whereby inter-chain interactions must be carefully engineered.
Collapse
Affiliation(s)
- Jiahua Hu
- School of Chemistry, Chemical Engineering and Life Science, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 430070, Wuhan, China
| | - Ke Xu
- School of Chemistry, Chemical Engineering and Life Science, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 430070, Wuhan, China
| | - Lei Shen
- School of Chemistry, Chemical Engineering and Life Science, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 430070, Wuhan, China
| | - Qin Wu
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Guiying He
- School of Chemistry, Chemical Engineering and Life Science, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 430070, Wuhan, China
| | - Jie-Yu Wang
- Beijing National Laboratory for Molecular Sciences (BNLMS), The Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education; Key Laboratory of Polymer Chemistry and Physics of Ministry of Education; Center of Soft Matter Science and Engineering; College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Jian Pei
- Beijing National Laboratory for Molecular Sciences (BNLMS), The Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education; Key Laboratory of Polymer Chemistry and Physics of Ministry of Education; Center of Soft Matter Science and Engineering; College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - 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, 430070, Wuhan, China.
| | - Matthew Y Sfeir
- School of Chemistry, Chemical Engineering and Life Science, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 430070, Wuhan, China.
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA.
| |
Collapse
|
50
|
Tokoro Y, Ohtsuka N, Fukuzawa SI, Oyama T. Intra- and intermolecular interaction of anthracene moieties in 7,8-disilabicyclo[3.3.0]octadienyl-bridged bisanthracenes. RSC Adv 2018; 8:25177-25180. [PMID: 35542129 PMCID: PMC9082342 DOI: 10.1039/c8ra05293j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 07/06/2018] [Indexed: 11/21/2022] Open
Abstract
V-shaped 9-anthrylarylsilane dimers prepared through ruthenium-catalyzed C–H cleavage showed excimer emission and bathochromic shifts by promoted contact of π-orbitals.
Collapse
Affiliation(s)
- Yuichiro Tokoro
- Department of Advanced Materials Chemistry
- Faculty of Engineering
- Yokohama National University
- Hodogaya-ku, Yokohama
- 240-8501 Japan
| | - Nobuhiko Ohtsuka
- Department of Applied Chemistry
- Institute of Science and Engineering
- Chuo University
- Tokyo
- Japan
| | - Shin-ichi Fukuzawa
- Department of Applied Chemistry
- Institute of Science and Engineering
- Chuo University
- Tokyo
- Japan
| | - Toshiyuki Oyama
- Department of Advanced Materials Chemistry
- Faculty of Engineering
- Yokohama National University
- Hodogaya-ku, Yokohama
- 240-8501 Japan
| |
Collapse
|