1
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Panthi YR, Thottappali MA, Horáková P, Kubáč L, Pfleger J, Menšík M, Khan T. Photophysics of Benzoxazole and Dicyano Functionalised Diketopyrrolopyrrole Derivatives: Insights into Ultrafast Processes and the Triplet State. Chemphyschem 2024; 25:e202300872. [PMID: 38572936 DOI: 10.1002/cphc.202300872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 04/04/2024] [Accepted: 04/04/2024] [Indexed: 04/05/2024]
Abstract
Diketopyrrolopyrrole (DPP) functionalised with an electron donating unit acts as a donor-acceptor molecules that have shown potential for application in dyes and photovoltaics. These molecules offer broad absorption/emission properties and structure-dependent dynamics. In this study, we used femtosecond pump-probe spectroscopy to investigate the photo-initiated dynamics of thiophene linked DPP derivatives. The thio-DPPs are further functionalised by different electrons withdrawing terminal groups, namely benzoxazole and thiophene dicyanide. The benzoxazole derivative is strongly emissive and directly relaxes directly to the ground state chloroform solution. Thiophene dicyanide derivative exhibits distinct spectral evolution in the first 10 ps, associated with structural and vibronic process. Later, it crosses over to the triplet state with a yield of 20 %. In the solid-state (thin film), we observed a signal that resembles singlet fission. However, upon careful analysis of temperature-dependent steady state absorbance spectra, we conclude that these features are due to laser-induced thermal artifacts. We describe a simplified excited state evolution in the thin film that does not include any additional excited states. These findings have significant implications for the analysis of triplet formation, which plays a major role in the photophysics of many organic materials.
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Affiliation(s)
- Yadu Ram Panthi
- Department of Polymer for Electronics and Photonics, Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague 2, Czech Republic
| | - Muhammed Arshad Thottappali
- Department of Polymer for Electronics and Photonics, Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague 2, Czech Republic
| | - Petra Horáková
- Centre for Organic Chemistry, Rybitvi 296, 533 54, Rybitvi, Czech Republic
| | - Lubomír Kubáč
- Centre for Organic Chemistry, Rybitvi 296, 533 54, Rybitvi, Czech Republic
| | - Jiří Pfleger
- Department of Polymer for Electronics and Photonics, Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic
| | - Miroslav Menšík
- Department of Polymer for Electronics and Photonics, Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic
| | - Tuhin Khan
- Department of Polymer for Electronics and Photonics, Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic
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2
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Jiang LH, Miao X, Zhang MY, Li JY, Zeng L, Hu W, Huang L, Pang DW. Near Infrared-II Excited Triplet Fusion Upconversion with Anti-Stokes Shift Approaching the Theoretical Limit. J Am Chem Soc 2024; 146:10785-10797. [PMID: 38573588 DOI: 10.1021/jacs.4c00936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
The anti-Stokes shift represents the capacity of photon upconversion to convert low-energy photons to high-energy photons. Although triplet exciton-mediated photon upconversion presents outstanding performance in solar energy harvesting, photoredox catalysis, stereoscopic 3D printing, and disease therapeutics, the interfacial multistep triplet exciton transfer leads to exciton energy loss to suppress the anti-Stokes shift. Here, we report near infrared-II (NIR-II) excitable triplet exciton-mediated photon upconversion using a hybrid photosensitizer consisting of lead sulfide quantum dots (PbS QDs) and new surface ligands of thiophene-substituted diketopyrrolopyrrole (Th-DPP). Under 1064 nm excitation, this photon upconversion revealed a record-corrected upconversion efficiency of 0.37% (normalized to 100%), with the anti-Stokes shift (1.07 eV) approaching the theoretical limit (1.17 eV). The observation of this unexpected result is due to our discovery of the presence of a weak interaction between the sulfur atom on Th-DPP and Pb2+ on the PbS QDs surface, facilitating electronic coupling between PbS QDs and Th-DPP, such that the realization of triplet exciton transfer efficiency is close to 100% even when the energy gap is as small as 0.04 eV. With this premise, this photon upconversion as a photocatalyst enables the production of standing organic gel via photopolymerization under 1064 nm illumination, displaying NIR-II photon-driven photoredox catalysis. This research not only establishes the foundation for enhancing the performance of NIR-II excitable photonic upconversion but also promotes its development in photonics and photoredox catalysis.
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Affiliation(s)
- Lin-Han Jiang
- Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Sciences, Frontiers Science Center for New Organic Matter, Haihe Laboratory of Sustainable Chemical Transformations, College of Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Xiaofei Miao
- Frontiers Science Center for Flexible Electronics and Xi'an Institute of Flexible Electronics (IFE), Northwestern Polytechnical University, Xi'an 710072, P. R. China
| | - Ming-Yu Zhang
- Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Sciences, Frontiers Science Center for New Organic Matter, Haihe Laboratory of Sustainable Chemical Transformations, College of Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Jia-Yao Li
- Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Sciences, Frontiers Science Center for New Organic Matter, Haihe Laboratory of Sustainable Chemical Transformations, College of Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Le Zeng
- School of Materials Science and Engineering, TKL of Metal and Molecule-Based Material Chemistry, Nankai University, Tianjin 300350, P. R. China
| | - Wenbo Hu
- Frontiers Science Center for Flexible Electronics and Xi'an Institute of Flexible Electronics (IFE), Northwestern Polytechnical University, Xi'an 710072, P. R. China
| | - Ling Huang
- Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Sciences, Frontiers Science Center for New Organic Matter, Haihe Laboratory of Sustainable Chemical Transformations, College of Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Dai-Wen Pang
- Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Sciences, Frontiers Science Center for New Organic Matter, Haihe Laboratory of Sustainable Chemical Transformations, College of Chemistry, Nankai University, Tianjin 300071, P. R. China
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3
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Wang K, Chen X, Xu J, Peng S, Wu D, Xia J. Recent Advance in the Development of Singlet-Fission-Capable Polymeric Materials. Macromol Rapid Commun 2024; 45:e2300241. [PMID: 37548255 DOI: 10.1002/marc.202300241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/24/2023] [Indexed: 08/08/2023]
Abstract
Singlet fission (SF) is a spin-allowed process in which a higher-energy singlet exciton is converted into two lower-energy triplet excitons via a triplet pair intermediate state. Implementing SF in photovoltaic devices holds the potential to exceed the Shockley-Queisser limit of conventional single-junction solar cells. Although great progress has been made in exploiting the underlying mechanism of SF over the past decades, the scope of materials capable of SF, particularly polymeric materials, remains poor. SF-capable polymer is one of the most potential candidates in the implementation of SF into devices due to their distinct superiorities in flexibility, solution processability and self-assembly behavior. Notably, recent advancements have demonstrated high-performance SF in isolated donor-acceptor (D-A) copolymer chains. This review provides an overview of recent progress in the development of SF-capable polymeric materials, with a significant focus on elucidating the mechanisms of SF in polymers and optimizing the design strategies for SF-capable polymers. Additionally, the paper discusses the challenges encountered in this field and presents future perspectives. It is expected that this comprehensive review will offer valuable insights into the design of novel SF-capable polymeric materials, further advancing the potential for SF implementation in photovoltaic devices.
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Affiliation(s)
- Kangwei Wang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan, 430070, China
| | - Xingyu Chen
- International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, China
| | - Jingwen Xu
- International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, China
| | - Shaoqian Peng
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan, 430070, China
| | - Di Wu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan, 430070, China
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan, 430070, China
| | - Jianlong Xia
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Center of Smart Materials and Devices, Wuhan University of Technology, Wuhan, 430070, China
- International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, China
- School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan, 430070, China
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4
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Fynbo C, Huss-Hansen MK, Bikondoa O, Gangadharappa C, da Silva Filho DA, Patil S, Knaapila M, Kjelstrup-Hansen J. Structural Study of Diketopyrrolopyrrole Derivative Thin Films: Influence of Deposition Method, Substrate Surface, and Aging. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:12099-12109. [PMID: 37587409 DOI: 10.1021/acs.langmuir.3c01378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
Abstract
We report the morphology and microstructure of n-dialkyl side-chain-substituted thiophene DPP end-capped with phenyl groups (Ph-TDPP-Ph) thin films and compare the influence of deposition method and substrate surface using thermally oxidized Si and graphene substrates as well as monolayer graphene surfaces with an underlying self-assembled octadecyltrichlorosilane monolayer, complemented by an aging study of spin-coated films over a 2 weeks aging period. A distinct difference in morphology was observed between spin-coated and vacuum-deposited thin films, which formed a fiber-like morphology and a continuous layer of terraced grains, respectively. After an initial film evolution, all combinations of deposition method and substrate type result in well-ordered thin films with almost identical crystalline phases with slight variations in crystallinity and mosaicity. These findings point toward strong intermolecular forces dominating during growth, and the templating effect observed for other oligomer films formed on graphene is consequently ineffective for this material type. Upon aging of spin-coated films, a noticeable evolution involving two different morphologies and crystalline phases were observed. After several days, the thin film evolved into a more stable crystal phase and a fiber-like morphology. Moreover, slight variation in optical spectra were elucidated on the basis on density functional theory calculations. These results demonstrate that thin-film properties of DPP derivatives can be tailored by manipulating the film formation process.
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Affiliation(s)
- Cecilie Fynbo
- NanoSYD, Mads Clausen Institute, University of Southern Denmark, 6400 Sønderborg, Denmark
| | - Mathias K Huss-Hansen
- NanoSYD, Mads Clausen Institute, University of Southern Denmark, 6400 Sønderborg, Denmark
| | - Oier Bikondoa
- XMaS UK CRG Beamline, European Synchrotron Radiation Facility, 38043 Grenoble Cedex 09, France
- Department of Physics, University of Warwick, CV4 7AL Coventry, U.K
| | | | - Demetrio Antonio da Silva Filho
- Grupo de Semicondutores Orgânicos, Instituto de Física, Campus Darcy Ribeiro, Universidade de Brasília, CP 4478, Brasília 70919-970, DF, Brazil
| | - Satish Patil
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Matti Knaapila
- Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Jakob Kjelstrup-Hansen
- NanoSYD, Mads Clausen Institute, University of Southern Denmark, 6400 Sønderborg, Denmark
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5
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Pauk K, Luňák S, Machalický O, Perdih F, Vyňuchal J, Eliáš Z, Imramovský A. Four Slip-Stacked Arrangements, Three Types of Photophysics: Crystal Structure and Solid-State Fluorescence of 3,6-Diaryl Substituted Furo[3,4-c]furanone Polymorphs and Regioisomers. Chempluschem 2023; 88:e202300310. [PMID: 37477623 DOI: 10.1002/cplu.202300310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 07/11/2023] [Accepted: 07/13/2023] [Indexed: 07/22/2023]
Abstract
Six symmetrical 3,6-diaryl (aryl=phenyl, 2-, 3- and 4-tolyl, 2,4- and 3,5-xylyl) substituted furo[3,4-c]furanones (DFF) were synthesized. The computational analysis, based on density functional theory, found eight possible centrosymmetrical slipped π-stack arrangements, formed according to electron repulsion minimization principle, as for previously reported for π-isoelectronic diketopyrrolopyrroles (DPP). One of these slipped stack arrangements was found to form infinite columns in the crystals of a new polymorph of parent phenyl derivative (with centre-to-centre distance CC=6.975 Å), other three types of stacks were found for 3-tolyl (CC=6.153 Å), 4-tolyl (CC=3.849 Å) and 2,4-xylyl (CC=4.856 Å) derivatives by single crystal X-ray diffractometry. All six derivatives show intense solution fluorescence in blue/green region, with a maximum driven entirely by a number and position of methyl substituents on phenyl rings. On the other hand, the solid-state fluorescence from yellow over orange to red is observed only for four derivatives and its presence/absence, spectral position and vibronic structure is driven exclusively by the slips in π-stacks (with interplanar distance always less than 3.5 Å) of almost planar DFF molecules, resulting in J-type emission, H-type excimer-like emission and H-type quenching.
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Affiliation(s)
- Karel Pauk
- Department of Organic Technology Institute of Organic Chemistry and Technology Faculty of Chemical Technology, University of Pardubice, Studentská 95, 532 10, Pardubice, Czech Republic
| | - Stanislav Luňák
- Materials Research Centre Faculty of Chemistry, Brno University of Technology, Purkyňova 464/118, 612 00, Brno, Czech Republic
| | - Oldřich Machalický
- Department of Organic Technology Institute of Organic Chemistry and Technology Faculty of Chemical Technology, University of Pardubice, Studentská 95, 532 10, Pardubice, Czech Republic
| | - Franc Perdih
- Chair of Inorganic Chemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000, Ljubljana, Slovenia
| | - Jan Vyňuchal
- Department of Organic Technology Institute of Organic Chemistry and Technology Faculty of Chemical Technology, University of Pardubice, Studentská 95, 532 10, Pardubice, Czech Republic
- Synthesia a.s., Semtín 103, 532 17, Pardubice, Czech Republic
| | - Zdeněk Eliáš
- Department of Organic Technology Institute of Organic Chemistry and Technology Faculty of Chemical Technology, University of Pardubice, Studentská 95, 532 10, Pardubice, Czech Republic
- Farmak, a.s., Na vlčinci 16/3 Klašterní Hradisko, 77900, Olomouc, Czech Republic
| | - Aleš Imramovský
- Department of Organic Technology Institute of Organic Chemistry and Technology Faculty of Chemical Technology, University of Pardubice, Studentská 95, 532 10, Pardubice, Czech Republic
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6
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Popli C, Jang Y, Misra R, D'Souza F. Charge Resonance and Photoinduced Charge Transfer in Bis( N, N-dimethylaminophenyl-tetracyanobutadiene)-diketopyrrolopyrrole Multimodular System. J Phys Chem B 2023; 127:4286-4299. [PMID: 37133351 DOI: 10.1021/acs.jpcb.3c01528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Intervalence charge transfer (IVCT) or charge resonance is often observed in redox-active systems encompassed of two identical electroactive groups, where one of the groups is either oxidized or reduced and serves as a model system to improve our fundamental understanding of charge transfer. This property has been explored in the present study in a multimodular push-pull system carrying two N,N-dimethylaminophenyl-tetracyanobutadiene (DMA-TCBD) entities covalently linked to the opposite ends of bis(thiophenyl)diketopyrrolopyrrole (TDPP). Electrochemical or chemical reduction of one of the TCBDs promoted electron resonance between them, exhibiting an IVCT absorption peak in the near-infrared area. The comproportionation energy, -ΔGcom, and equilibrium constant, Kcom, evaluated from the split reduction peak were, respectively, 1.06 × 104 J/mol and 72.3 M-1. Excitation of the TDPP entity in the system promoted the thermodynamically feasible sequential charge transfer and separation of charges in benzonitrile, wherein the IVCT peak formed upon charge separation served as a signature peak in characterizing the product. Further, transient data analyzed using Global Target Analysis revealed the charge separation to take place in a ps time scale (k ∼ 1010 s-1) as a result of close positioning and strong electronic interaction between the entities. The significance of IVCT in probing excited-state processes is evidenced by the present study.
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Affiliation(s)
- Charu Popli
- Department of Chemistry, Indian Institute of Technology, Indore 453552, India
| | - Youngwoo Jang
- Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States
| | - Rajneesh Misra
- Department of Chemistry, Indian Institute of Technology, Indore 453552, India
| | - Francis D'Souza
- Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States
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7
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Lowrie W, Westbrook RJE, Guo J, Gonev HI, Marin-Beloqui J, Clarke TM. Organic photovoltaics: The current challenges. J Chem Phys 2023; 158:110901. [PMID: 36948814 DOI: 10.1063/5.0139457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023] Open
Abstract
Organic photovoltaics are remarkably close to reaching a landmark power conversion efficiency of 20%. Given the current urgent concerns regarding climate change, research into renewable energy solutions is crucially important. In this perspective article, we highlight several key aspects of organic photovoltaics, ranging from fundamental understanding to implementation, that need to be addressed to ensure the success of this promising technology. We cover the intriguing ability of some acceptors to undergo efficient charge photogeneration in the absence of an energetic driving force and the effects of the resulting state hybridization. We explore one of the primary loss mechanisms of organic photovoltaics-non-radiative voltage losses-and the influence of the energy gap law. Triplet states are becoming increasingly relevant owing to their presence in even the most efficient non-fullerene blends, and we assess their role as both a loss mechanism and a potential strategy to enhance efficiency. Finally, two ways in which the implementation of organic photovoltaics can be simplified are addressed. The standard bulk heterojunction architecture could be superseded by either single material photovoltaics or sequentially deposited heterojunctions, and the attributes of both are considered. While several important challenges still lie ahead for organic photovoltaics, their future is, indeed, bright.
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Affiliation(s)
- William Lowrie
- Department of Chemistry, University College London, Christopher Ingold Building, London WC1H 0AJ, United Kingdom
| | - Robert J E Westbrook
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Junjun Guo
- Department of Chemistry, University College London, Christopher Ingold Building, London WC1H 0AJ, United Kingdom
| | - Hristo Ivov Gonev
- Department of Chemistry, University College London, Christopher Ingold Building, London WC1H 0AJ, United Kingdom
| | - Jose Marin-Beloqui
- Departamento de Química Física, Universidad de Malaga, Campus Teatinos s/n, 29071 Málaga, Spain
| | - Tracey M Clarke
- Department of Chemistry, University College London, Christopher Ingold Building, London WC1H 0AJ, United Kingdom
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8
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Lin C, Qi Y, Brown PJ, Williams ML, Palmer JR, Myong M, Zhao X, Young RM, Wasielewski MR. Singlet Fission in Perylene Monoimide Single Crystals and Polycrystalline Films. J Phys Chem Lett 2023; 14:2573-2579. [PMID: 36880847 DOI: 10.1021/acs.jpclett.2c03621] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Singlet fission (SF) is a spin-allowed process in which a photogenerated singlet exciton down-converts into two triplet excitons. Perylene-3,4-dicarboximide (PMI) has singlet and triplet state energies of 2.4 and 1.1 eV, respectively; thus making SF slightly exoergic and providing triplet excitons that have sufficient energy to raise the efficiency of single-junction solar cells by reducing thermalization losses from hot excitons formed when absorbed photons have energies higher than the semiconductor bandgap. However, PMI SF in the solid state has not been studied previously. Here, we show that 2,5-diphenyl-N-(2-ethylhexyl)perylene-3,4-dicarboximide (dp-PMI) crystallizes into a slip-stacked intermolecular morphology favorable for SF. Transient absorption microscopy and spectroscopy show that dp-PMI SF occurs in ≤50 ps in both single crystals and polycrystalline thin films with a triplet yield of 150 ± 20%. Ultrafast SF in the solid state, the high triplet yield, and its photostability make dp-PMI an attractive candidate for SF-enhanced solar cells.
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Affiliation(s)
- Chenjian Lin
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113 United States
| | - Yue Qi
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Paige J Brown
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113 United States
| | - Malik L Williams
- Department of Chemistry, Center for Molecular Quantum Transduction, and Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Jonathan R Palmer
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113 United States
| | - Michele Myong
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113 United States
| | - Xingang Zhao
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113 United States
| | - Ryan M Young
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113 United States
| | - Michael R Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113 United States
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9
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Fukaya N, Ogi S, Sotome H, Fujimoto KJ, Yanai T, Bäumer N, Fernández G, Miyasaka H, Yamaguchi S. Impact of Hydrophobic/Hydrophilic Balance on Aggregation Pathways, Morphologies, and Excited-State Dynamics of Amphiphilic Diketopyrrolopyrrole Dyes in Aqueous Media. J Am Chem Soc 2022; 144:22479-22492. [PMID: 36459436 DOI: 10.1021/jacs.2c07299] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
We report the thermodynamic and kinetic aqueous self-assembly of a series of amide-functionalized dithienyldiketopyrrolopyrroles (TDPPs) that bear various hydrophilic oligoethylene glycol (OEG) and hydrophobic alkyl chains. Spectroscopic and microscopic studies showed that the TDPP-based amphiphiles with an octyl group form sheet-like aggregates with J-type exciton coupling. The effect of the alkyl chains on the aggregated structure and the internal molecular orientation was examined via computational studies combining MD simulations and TD-DFT calculations. Furthermore, solvent and thermal denaturation experiments provided a state diagram that indicates the formation of unexpected nanoparticles during the self-assembly into nanosheets when longer OEG side chains are introduced. A kinetic analysis revealed that the nanoparticles were obtained selectively as an on-pathway intermediate state toward the formation of thermodynamically controlled nanosheets. The metastable aggregates were used for seed-initiated supramolecular assembly, which allowed establishing control over the assembly kinetics and the aggregate size. The sheet-like aggregates prepared using the seeding method exhibited coherent vibration in the excited state, indicating a well-ordered orientation of the TDPP units. These results underline the significance of fine tuning of the hydrophobic/hydrophilic balance in the molecular design to kinetically control the assembly of amphiphilic π-conjugated molecules into two-dimensional nanostructures in aqueous media.
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Affiliation(s)
- Natsumi Fukaya
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya464-8602, Japan
| | - Soichiro Ogi
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya464-8602, Japan.,Integrated Research Consortium on Chemical Science (IRCCS), Nagoya University, Furo, Chikusa, Nagoya464-8602, Japan
| | - Hikaru Sotome
- Division of Frontier Materials Science and Center for Advanced Interdisciplinary Research, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka560-8531, Japan
| | - Kazuhiro J Fujimoto
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya464-8602, Japan.,Integrated Research Consortium on Chemical Science (IRCCS), Nagoya University, Furo, Chikusa, Nagoya464-8602, Japan.,Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo, Chikusa, Nagoya464-8602, Japan
| | - Takeshi Yanai
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya464-8602, Japan.,Integrated Research Consortium on Chemical Science (IRCCS), Nagoya University, Furo, Chikusa, Nagoya464-8602, Japan.,Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo, Chikusa, Nagoya464-8602, Japan
| | - Nils Bäumer
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149Münster, Germany
| | - Gustavo Fernández
- Organisch-Chemisches Institut Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149Münster, Germany
| | - Hiroshi Miyasaka
- Division of Frontier Materials Science and Center for Advanced Interdisciplinary Research, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka560-8531, Japan
| | - Shigehiro Yamaguchi
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya464-8602, Japan.,Integrated Research Consortium on Chemical Science (IRCCS), Nagoya University, Furo, Chikusa, Nagoya464-8602, Japan.,Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo, Chikusa, Nagoya464-8602, Japan
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10
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Wang L, Jiang W, Guo S, Wang S, Zhang M, Liu Z, Wang G, Miao Y, Yan L, Shao JY, Zhong YW, Liu Z, Zhang D, Fu H, Yao J. Robust singlet fission process in strong absorption π-expanded diketopyrrolopyrroles. Chem Sci 2022; 13:13907-13913. [PMID: 36544745 PMCID: PMC9710207 DOI: 10.1039/d2sc05580e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 10/25/2022] [Indexed: 11/17/2022] Open
Abstract
Singlet fission (SF) has drawn tremendous attention as a multiexciton generation process that could mitigate the thermal loss and boost the efficiency of solar energy conversion. Although a SF-based solar cell with an EQE above 100% has already been fabricated successfully, the practical efficiency of the corresponding devices is plagued by the limited scope of SF materials. Therefore, it is of great importance to design and develop new SF-capable compounds aiming at practical device application. In the current contribution, via a π-expanded strategy, we presented a new series of robust SF chromophores based on polycyclic DPP derivatives, Ex-DPPs. Compared to conventional DPP molecules, Ex-DPPs feature strong absorption with a fivefold extinction coefficient, good molecular rigidity to effectively restrain non-radiative deactivation, and an expanded π-skeleton which endow them with well-suited intermolecular packing geometries for achieving efficient SF process. These results not only provide a new type of high-efficiency SF chromophore but also address some basic guidelines for the design of potential SF materials targeting practical light harvesting applications.
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Affiliation(s)
- Long Wang
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, College of Chemistry, Taiyuan University of TechnologyTaiyuan 030024China
| | - Wenlin Jiang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory for Organic Solids, Institute of Chemistry, Chinese Academy of SciencesBeijing100190China
| | - Shaoting Guo
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, College of Chemistry, Taiyuan University of TechnologyTaiyuan 030024China
| | - Senhao Wang
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, College of Chemistry, Taiyuan University of TechnologyTaiyuan 030024China
| | - Mengfan Zhang
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, College of Chemistry, Taiyuan University of TechnologyTaiyuan 030024China
| | - Zuyuan Liu
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, College of Chemistry, Taiyuan University of TechnologyTaiyuan 030024China
| | - Guoliang Wang
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, College of Chemistry, Taiyuan University of TechnologyTaiyuan 030024China
| | - Yanqin Miao
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, College of Chemistry, Taiyuan University of TechnologyTaiyuan 030024China
| | - Lingpeng Yan
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, College of Chemistry, Taiyuan University of TechnologyTaiyuan 030024China
| | - Jiang-Yang Shao
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of SciencesBeijing 100190China
| | - Yu-Wu Zhong
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of SciencesBeijing 100190China
| | - Zitong Liu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory for Organic Solids, Institute of Chemistry, Chinese Academy of SciencesBeijing100190China,State Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Special Function Materials and Structure Design, College of Chemistry and Chemical Engineering, Lanzhou UniversityLanzhou 730000China
| | - Deqing Zhang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory for Organic Solids, Institute of Chemistry, Chinese Academy of SciencesBeijing100190China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal UniversityBeijing 100048China
| | - Jiannian Yao
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of SciencesBeijing 100190China
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11
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Nagaoka T, Matsui Y, Fuki M, Ogaki T, Ohta E, Kobori Y, Ikeda H. Diphenyldihydropentalenediones: Wide Singlet-Triplet Energy Gap Compounds Possessing the Planarly Fixed Diene Subunit. ACS OMEGA 2022; 7:40364-40373. [PMID: 36385848 PMCID: PMC9648098 DOI: 10.1021/acsomega.2c05341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
2,2,5,5-Tetramethyl-3,6-diphenyl-2,5-dihydropentalene-1,4-dione (PD-H) and its dimethoxy (PD-OCH3) and bis(trifluoromethyl) derivatives (PD-CF3) were developed as a new class of compounds possessing a wide excited singlet-triplet energy gap. The PD derivatives would also have a high energy level of the triplet-excited state (E T) due to the planarity of the fused-diene subunit. The results of photophysical studies revealed that the energy level of the singlet-excited state (E S) and E T of PD-H are 2.88 and 1.43 eV, respectively. These values indicate that PD-H has the energy relationship, E S > 2E T, required for it to be a singlet fission (SF) material. Moreover, the introduction of electron-donating or -withdrawing groups on the benzene rings in PD-H enables fine-tuning of E S and E T. The results of transient absorption spectroscopic studies show that PD-H, PD-OCH3, and PD-CF3 in CH2Cl2 have respective T1 lifetimes of 71, 118, and 107 μs, which are long enough to utilize its triplet exciton in other optoelectronic systems. These findings suggest that the PDs are potential candidates for SF materials with high E T levels.
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Affiliation(s)
- Tomoki Nagaoka
- Department
of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka599-8531, Japan
| | - Yasunori Matsui
- Department
of Applied Chemistry, Graduate School of Engineering, Osaka Metropolitan University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka599-8531, Japan
- The
Research Institute for Molecular Electronic Devices (RIMED), Osaka Metropolitan University, 1-1 Gakuen-cho,
Nakaku, Sakai, Osaka599-8531, Japan
| | - Masaaki Fuki
- Molecular
Photoscience Research Center, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo657-8501, Japan
| | - Takuya Ogaki
- Department
of Applied Chemistry, Graduate School of Engineering, Osaka Metropolitan University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka599-8531, Japan
- The
Research Institute for Molecular Electronic Devices (RIMED), Osaka Metropolitan University, 1-1 Gakuen-cho,
Nakaku, Sakai, Osaka599-8531, Japan
| | - Eisuke Ohta
- Department
of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka599-8531, Japan
| | - Yasuhiro Kobori
- Molecular
Photoscience Research Center, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo657-8501, Japan
- Graduate
School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo657-8501, Japan
| | - Hiroshi Ikeda
- Department
of Applied Chemistry, Graduate School of Engineering, Osaka Metropolitan University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka599-8531, Japan
- The
Research Institute for Molecular Electronic Devices (RIMED), Osaka Metropolitan University, 1-1 Gakuen-cho,
Nakaku, Sakai, Osaka599-8531, Japan
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12
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do Casal MT, Toldo JM, Plasser F, Barbatti M. Using diketopyrrolopyrroles to stabilize double excitation and control internal conversion. Phys Chem Chem Phys 2022; 24:23279-23288. [PMID: 36164816 DOI: 10.1039/d2cp03533b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Diketopyrrolopyrrole (DPP) is a pivotal functional group to tune the physicochemical properties of novel organic photoelectronic materials. Among multiple uses, DPP-thiophene derivatives forming a dimer through a vinyl linker were recently shown to quench the fluorescence observed in their isolated monomers. Here, we explain this fluorescence quenching using computational chemistry. The DPP-thiophene dimer has a low-lying doubly excited state that is not energetically accessible for the monomer. This state delays the fluorescence allowing internal conversion to occur first. We characterize the doubly excited state wavefunction by systematically changing the derivatives to tune the π-scaffold size and the acceptor and donor characters. The origin of this state's stabilization is related to the increase in the π-system and not to the charge-transfer features. This analysis delivers core conceptual information on the electronic properties of organic chromophores arranged symmetrically around a vinyl linker, opening new ways to control the balance between luminescence and internal conversion.
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Affiliation(s)
| | | | | | - Mario Barbatti
- Aix Marseille University, CNRS, ICR, Marseille, France. .,Institut Universitaire de France, 75231, Paris, France
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13
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Parallel triplet formation pathways in a singlet fission material. Nat Commun 2022; 13:5244. [PMID: 36068233 PMCID: PMC9448805 DOI: 10.1038/s41467-022-32844-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 08/18/2022] [Indexed: 11/08/2022] Open
Abstract
Harvesting long-lived free triplets in high yields by utilizing organic singlet fission materials can be the cornerstone for increasing photovoltaic efficiencies potentially. However, except for polyacenes, which are the most studied systems in the singlet fission field, spin-entangled correlated triplet pairs and free triplets born through singlet fission are relatively poorly characterized. By utilizing transient absorption and photoluminescence spectroscopy in supramolecular aggregate thin films consisting of Hamilton-receptor-substituted diketopyrrolopyrrole derivatives, we show that photoexcitation gives rise to the formation of spin-0 correlated triplet pair 1(TT) from the lower Frenkel exciton state. The existence of 1(TT) is proved through faint Herzberg-Teller emission that is enabled by vibronic coupling and correlated with an artifact-free triplet-state photoinduced absorption in the near-infrared. Surprisingly, transient electron paramagnetic resonance reveals that long-lived triplets are produced through classical intersystem crossing instead of 1(TT) dissociation, with the two pathways in competition. Moreover, comparison of the triplet-formation dynamics in J-like and H-like thin films with the same energetics reveals that spin-orbit coupling mediated intersystem crossing persists in both. However, 1(TT) only forms in the J-like film, pinpointing the huge impact of intermolecular coupling geometry on singlet fission dynamics.
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14
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Polak DW, do Casal MT, Toldo JM, Hu X, Amoruso G, Pomeranc O, Heeney M, Barbatti M, Ashfold MNR, Oliver TAA. Probing the electronic structure and photophysics of thiophene-diketopyrrolopyrrole derivatives in solution. Phys Chem Chem Phys 2022; 24:20138-20151. [PMID: 35993400 PMCID: PMC9429679 DOI: 10.1039/d2cp03238d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Diketopyrrolopyrroles are a popular class of electron-withdrawing unit in optoelectronic materials. When combined with electron donating side-chain functional groups such as thiophenes, they form a very broad class of donor–acceptor molecules: thiophene–diketopyrrolopyrroles (TDPPs). Despite their widescale use in biosensors and photovoltaic materials, studies have yet to establish the important link between the electronic structure of the specific TDPP and the critical optical properties. To bridge this gap, ultrafast transient absorption with 22 fs time resolution has been used to explore the photophysics of three prototypical TDPP molecules: a monomer, dimer and polymer in solution. Interpretation of experimental data was assisted by a recent high-level theoretical study, and additional density functional theory calculations. These studies show that the photophysics of these molecular prototypes under visible photoexcitation are determined by just two excited electronic states, having very different electronic characters (one is optically bright, the other dark), their relative energetic ordering and the timescales for internal conversion from one to the other and/or to the ground state. The underlying difference in electronic structure alters the branching between these excited states and their associated dynamics. In turn, these factors dictate the fluorescence quantum yields, which are shown to vary by ∼1–2 orders of magnitude across the TDPP prototypes investigated here. The fast non-radiative transfer of molecules from the bright to dark states is mediated by conical intersections. Remarkably, wavepacket signals in the measured transient absorption data carry signatures of the nuclear motions that enable mixing of the electronic-nuclear wavefunction and facilitate non-adiabatic coupling between the bright and dark states. The interplay of two excited electronic states dictates the ultrafast dynamics and functionality of thiophene-diketopyrrolopyrrole derivatives.![]()
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Affiliation(s)
- Daniel W Polak
- School of Chemistry, Cantock's Close, University of Bristol, Bristol, BS8 1TS, UK.
| | | | | | - Xiantao Hu
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, White City Campus, London, W12 0BZ, UK
| | - Giordano Amoruso
- School of Chemistry, Cantock's Close, University of Bristol, Bristol, BS8 1TS, UK.
| | - Olivia Pomeranc
- School of Chemistry, Cantock's Close, University of Bristol, Bristol, BS8 1TS, UK.
| | - Martin Heeney
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, White City Campus, London, W12 0BZ, UK
| | - Mario Barbatti
- Aix Marseille Université, CNRS, ICR, Marseille, France.,Institut Universitaire de France, 75231, Paris, France
| | - Michael N R Ashfold
- School of Chemistry, Cantock's Close, University of Bristol, Bristol, BS8 1TS, UK.
| | - Thomas A A Oliver
- School of Chemistry, Cantock's Close, University of Bristol, Bristol, BS8 1TS, UK.
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15
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Zhou J, Liu H, Liu S, Su P, Wang W, Li Z, Liu Z, Chen Y, Dong Y, Li X. Singlet Fission in Colloidal Nanoparticles of Amphipathic Diketopyrrolopyrrole Derivatives: Probing the Role of the Charge Transfer State. J Phys Chem B 2022; 126:6483-6492. [PMID: 35979942 DOI: 10.1021/acs.jpcb.2c03163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To evaluate the role of the charge transfer (CT) state in the singlet fission (SF) process, we prepared three 3,6-bis(thiophen-2-yl)diketopyrrolopyrrole (TDPP) derivatives with zero (Ph2TDPP), one (Ph2TDPP-COOH), and two (Ph2TDPP-(COOH)2) carboxylic groups, respectively. Their colloidal nanoparticles were also prepared by a simple precipitation method. The SF dynamics and mechanism in these colloid nanoparticles were investigated by using steady-state/transient absorption and fluorescence spectroscopy. Steady-state absorption spectra reveal that the strength of the CT resonance interactions between the adjacent DPP units is increased gradually from Ph2TDPP to Ph2TDPP-COOH and then to Ph2TDPP-(COOH)2. Fluorescence and transient absorption spectra demonstrate that SF is proceeded via a CT-assisted superexchange mechanism in these three nanoparticles. Furthermore, SF rate and yield are enhanced gradually with the increase of the number of the carboxylic group, which may be attributed to the enhancement of the CT coupling strength. The result of this work not only provides a better understanding of the SF mechanism especially for the role of the CT state but also gives some new insights for the design of efficient SF materials based on DPP derivatives.
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Affiliation(s)
- Jun Zhou
- College of Chemical Engineering, School of Materials Science and Engineering, College of New Energy, China University of Petroleum (East China), Qingdao, Shandong 266580, China
| | - Heyuan Liu
- College of Chemical Engineering, School of Materials Science and Engineering, College of New Energy, China University of Petroleum (East China), Qingdao, Shandong 266580, China.,National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China
| | - Shanshan Liu
- College of Chemical Engineering, School of Materials Science and Engineering, College of New Energy, China University of Petroleum (East China), Qingdao, Shandong 266580, China
| | - Pengkun Su
- College of Chemical Engineering, School of Materials Science and Engineering, College of New Energy, China University of Petroleum (East China), Qingdao, Shandong 266580, China
| | - Weijie Wang
- College of Chemical Engineering, School of Materials Science and Engineering, College of New Energy, China University of Petroleum (East China), Qingdao, Shandong 266580, China
| | - Zhi Li
- Shandong Energy Group Co., Ltd., Jinan, Shandong 250014, China
| | - Zhaobin Liu
- Shandong Energy Group Co., Ltd., Jinan, Shandong 250014, China
| | - Yanli Chen
- College of Chemical Engineering, School of Materials Science and Engineering, College of New Energy, China University of Petroleum (East China), Qingdao, Shandong 266580, China
| | - Yunqin Dong
- College of Chemical Engineering and Materials Science, Zaozhuang University, Zaozhuang 277160, China
| | - Xiyou Li
- College of Chemical Engineering, School of Materials Science and Engineering, College of New Energy, China University of Petroleum (East China), Qingdao, Shandong 266580, China
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16
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Maity N, Majumder K, Patel AK, Swain D, Suryaprakash N, Patil S. Synthesis and Emergent Photophysical Properties of Diketopyrrolopyrrole-Based Supramolecular Self-Assembly. ACS OMEGA 2022; 7:23179-23188. [PMID: 35847286 PMCID: PMC9280760 DOI: 10.1021/acsomega.2c01091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Diketopyrrolopyrrole (DPP)-based molecular semiconductors exhibit intriguing optical and charge transport properties. Herein, we rationally design a series of electronically identical but structurally distinct Hamilton receptor (HR)-based supramolecular assembly of DPP. The HR endows supramolecular assemblies via hydrogen bonding with enhanced structural ordering and excitonic couplings. The mechanism of supramolecular self-assembly was probed by diffusion ordered spectroscopy (DOSY) nuclear magnetic resonance (NMR) and solid-state IR spectroscopy studies. We investigated the morphology of self-assembly, photophysical and electrochemical properties and compared them with the identical DPP molecular structures without HRs. The microstructure of self-assembly was probed with atomic force microscopy in thin films. Subsequently, the influence of solid-state packing was studied by single-crystal X-ray diffraction. The single-crystal structure of HR-TDPP-C20 reveals slipped stack arrangements between the two neighboring chromophores with π-π stacking distance and slip angle of 3.55 Å and 35.4°, respectively. Notably, the slight torsional angle of 1° between thiophene and lactam rings and small π-π stacking distance suggest a significant intermolecular coupling between thiophene (D) and lactam (A) rings. This intramolecular coupling between two π-π chromophore stacks manifests in their optical properties. In this manuscript, we report rational design and synthesis of supramolecular self-assembly of DPP with a collection of compelling structural and optical properties.
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Affiliation(s)
- Nilabja Maity
- Solid
State and Structural Chemistry Unit, Indian
Institute of Science, Bangalore 560012, India
| | - Kanad Majumder
- Solid
State and Structural Chemistry Unit, Indian
Institute of Science, Bangalore 560012, India
| | - Arun Kumar Patel
- NMR
Research Centre, Indian Institute of Science, Bangalore 560012, India
| | - Diptikanta Swain
- Solid
State and Structural Chemistry Unit, Indian
Institute of Science, Bangalore 560012, India
| | | | - Satish Patil
- Solid
State and Structural Chemistry Unit, Indian
Institute of Science, Bangalore 560012, India
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17
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Luňák S, Weiter M, Vala M. Complete Set of Diketopyrrolopyrrole Centrosymmetrical Cofacial Stacked Pairs. Chemphyschem 2022; 23:e202200252. [PMID: 35770507 DOI: 10.1002/cphc.202200252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/29/2022] [Indexed: 11/12/2022]
Abstract
Stacked centrosymmetrical dimers and simultaneously H-bonded and stacked hexamers of thiophene-substituted diketopyrrolopyrrole (ThDPP) were studied using DFT as models for crystals with slipped-stacked molecules in 1D columns. Eight stacked dimer arrangements were found, six of which are driven by the minimisation of electron repulsion and realised by placing the partially negatively charged atoms of the diketopyrrolopyrrole rings below the centre of an adjancent thiophene ring. Four of these stacks are related to N,N'-diacylated derivative. An analogous set of eight stacks was discovered computationally for phenyl-substituted DPP (PhDPP), four of which are known among H-bonded DPP pigments, and one more among N,N'-dialkylated PhDPP derivatives. The results shed more light on the mechanisms that drive the formation of stacks between nonaromatic (DPP) and aromatic (Th, Ph) rings. The excitation energies of the lowest four singlet states computed by TD DFT enabled excitonic coupling and energy separation between Frenkel-resonsnce-type and charge-transfer states to be established, depending on the equilibrium stack geometry.
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Affiliation(s)
- Stanislav Luňák
- Brno University of Technology: Vysoke uceni technicke v Brne, Faculty of Chemistry, Purkyňova 464/118, 61200, Brno, CZECH REPUBLIC
| | - Martin Weiter
- Brno University of Technology: Vysoke uceni technicke v Brne, Faculty of Chemistry, Purkyňova 464/118, 61200, Brno, CZECH REPUBLIC
| | - Martin Vala
- Brno University of Technology: Vysoke uceni technicke v Brne, Faculty of Chemistry, Purkyňova 464/118, 61200, Brno, CZECH REPUBLIC
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18
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Pensack RD, Purdum GE, Mazza SM, Grieco C, Asbury JB, Anthony JE, Loo YL, Scholes GD. Excited-State Dynamics of 5,14- vs 6,13-Bis(trialkylsilylethynyl)-Substituted Pentacenes: Implications for Singlet Fission. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2022; 126:9784-9793. [PMID: 35756579 PMCID: PMC9210346 DOI: 10.1021/acs.jpcc.2c00897] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 05/20/2022] [Indexed: 05/16/2023]
Abstract
Singlet fission is a process in conjugated organic materials that has the potential to considerably improve the performance of devices in many applications, including solar energy conversion. In any application involving singlet fission, efficient triplet harvesting is essential. At present, not much is known about molecular packing arrangements detrimental to singlet fission. In this work, we report a molecular packing arrangement in crystalline films of 5,14-bis(triisopropylsilylethynyl)-substituted pentacene, specifically a local (pairwise) packing arrangement, responsible for complete quenching of triplet pairs generated via singlet fission. We first demonstrate that the energetic condition necessary for singlet fission is satisfied in amorphous films of the 5,14-substituted pentacene derivative. However, while triplet pairs form highly efficiently in the amorphous films, only a modest yield of independent triplets is observed. In crystalline films, triplet pairs also form highly efficiently, although independent triplets are not observed because triplet pairs decay rapidly and are quenched completely. We assign the quenching to a rapid nonadiabatic transition directly to the ground state. Detrimental quenching is observed in crystalline films of two additional 5,14-bis(trialkylsilylethynyl)-substituted pentacenes with either ethyl or isobutyl substituents. Developing a better understanding of the losses identified in this work, and associated molecular packing, may benefit overcoming losses in solids of other singlet fission materials.
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Affiliation(s)
- Ryan D. Pensack
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Geoffrey E. Purdum
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Samuel M. Mazza
- Department
of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Christopher Grieco
- Department
of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - John B. Asbury
- Department
of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - John E. Anthony
- Department
of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Yueh-Lin Loo
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
- Andlinger
Center for Energy and the Environment, Princeton
University, Princeton, New Jersey 08544, United States
| | - Gregory D. Scholes
- Department
of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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19
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Gauci V, Seddon A, Adams DJ. Synthesis and characterisation of diketopyrrolopyrrole-based hydrogels. SOFT MATTER 2022; 18:3756-3761. [PMID: 35506734 DOI: 10.1039/d2sm00277a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Diketopyrrolopyrrole (DPP) based materials can be easily tuned by functionalising with groups that extend the conjugation and thus alter the electronic properties. When attaching thiophenes to give dithiophene-diketopyrrolopyrroles (DTDPPs), a donor-acceptor-donor system is created that is suitable for charge-transfer applications. This core also promotes π-stacking and hydrophobic interactions. Here, we describe a number of DTDPPs functionalised with amino acids that undergo pH-trigerred gelation. We show that the optical properties of our DTDPPs are affected by whether the amino acids have aromatic or aliphatic side chains. We also describe the effect of solvent polarity. We have successfully produced hydrogels via a pH trigger with examples containing phenylalanine (F), valine (V), leucine (L) and alanine (A) amino acids. Viscosity and small angle X-ray scattering measurements show the presence of micellar structures in solution in water at pH 10.5, with gelation starting at a pH less than 7 due to the formation of a fibrous network.
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Affiliation(s)
- Valentina Gauci
- School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Annela Seddon
- School of Physics, HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, UK
| | - Dave J Adams
- School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
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20
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Papadopoulos I, Gutiérrez-Moreno D, Bo Y, Casillas R, Greißel PM, Clark T, Fernández-Lázaro F, Guldi DM. Altering singlet fission pathways in perylene-dimers; perylene-diimide versus perylene-monoimide. NANOSCALE 2022; 14:5194-5203. [PMID: 35315470 DOI: 10.1039/d1nr08523a] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We used a systematic approach to shed light on the inherent differences in perylenes, namely monoimides versus diimides, including coplanarity and dipole moment, and their impact on singlet fission (SF) by designing, synthesizing, and probing a full fledged series of phenylene- and naphthalene-linked dimers. Next to changing the functionality of the perylene core, we probed the effect of the spacers and their varying degrees of rotational freedom, molecular electrostatic potentials, and intramolecular interactions on the SF-mechanism and -efficiencies. An arsenal of spectroscopic techniques revealed that for perylene-monoimides, a strong charge-transfer mixing with the singlet and triplet excited states restricts SF and yields low triplet quantum yields. This is accompanied by an up-conversion channel that includes geminate triplet-triplet recombination. Using perylene-diimides alters the SF-mechanism by populating a charge-separated-state intermediate, which either favors or shuts-down SF. Napthylene-spacers bring about higher triplet quantum yields and overall better SF-performance for all perylene-monoimides and perylene-diimides. The key to better SF-performance is rotational freedom because it facilitates the overall excited-state polarization and amplifies intramolecular interactions between chromophores.
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Affiliation(s)
- Ilias Papadopoulos
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany.
| | - David Gutiérrez-Moreno
- Área de Química Orgánica, Instituto de Bioingeniería, Universidad Miguel Hernández, Avda. de la Universidad s/n, 03203 Elche, Spain.
| | - Yifan Bo
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany.
- Computer-Chemistry-Center, Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nuremberg, Nägelsbachstr. 25, 91052 Erlangen, Germany
| | - Rubén Casillas
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany.
- Computer-Chemistry-Center, Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nuremberg, Nägelsbachstr. 25, 91052 Erlangen, Germany
| | - Phillip M Greißel
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany.
| | - Timothy Clark
- Computer-Chemistry-Center, Department of Chemistry and Pharmacy, Friedrich-Alexander-University Erlangen-Nuremberg, Nägelsbachstr. 25, 91052 Erlangen, Germany
| | - Fernando Fernández-Lázaro
- Área de Química Orgánica, Instituto de Bioingeniería, Universidad Miguel Hernández, Avda. de la Universidad s/n, 03203 Elche, Spain.
| | - Dirk M Guldi
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany.
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21
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Ross AM, Osella S, Policht VR, Zheng M, Maggini M, Marangi F, Cerullo G, Gatti T, Scotognella F. Deciphering Photoinduced Charge Transfer Dynamics in a Cross-Linked Graphene-Dye Nanohybrid. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2022; 126:3569-3581. [PMID: 35242271 PMCID: PMC8883522 DOI: 10.1021/acs.jpcc.1c10570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/04/2022] [Indexed: 06/14/2023]
Abstract
The search for synthetic materials that mimic natural photosynthesis by converting solar energy into other more useful forms of energy is an ever-growing research endeavor. Graphene-based materials, with their exceptional electronic and optical properties, are exemplary candidates for high-efficiency solar energy harvesting devices. High photoactivity can be conveniently achieved by functionalizing graphene with small molecule organic semiconductors whose band-gaps can be tuned by structural modification, leading to interactions between the π-conjugated electronic systems in both the semiconductor and graphene. Here we investigate the ultrafast transient optical properties of a cross-linked graphene-dye (diphenyl-dithiophenediketopyrrolopyrrole) nanohybrid material, in which oligomers of the organic semiconductor dye are covalently bound to a random network of few-layer graphene flakes, and compare the results to those obtained for the reference dye monomer. Using a combination of ultrafast transient absorption and two-dimensional electronic spectroscopy, we provide substantial evidence for photoinduced charge transfer that occurs within 18 ps in the nanohybrid system. Notably, subpicosecond photoinduced torsional relaxation observed in the constituent dye monomer is absent in the cross-linked nanohybrid system. Through density functional theory calculations, we compare the competing effects of covalent bonding, increasing conjugation length, and the presence of multiple graphene flakes. We find evidence that the observed ultrafast charge transfer process occurs through a superexchange mechanism in which the oligomeric dye bridge provides virtual states enabling charge transfer between graphene-dye covalent bond sites.
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Affiliation(s)
- Aaron M. Ross
- Department
of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Silvio Osella
- Chemical
and Biological Systems Simulation Lab, Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097 Warsaw, Poland
| | - Veronica R. Policht
- Department
of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Meng Zheng
- Chemical
Sciences Department, Università degli
Studi di Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Michele Maggini
- Chemical
Sciences Department, Università degli
Studi di Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Fabio Marangi
- Department
of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
- Center
for Nano Science and Technology, Istituto
Italiano di Tecnologia, Via Pascolo, 70/3 Milano 20133, Italy
| | - Giulio Cerullo
- Department
of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Teresa Gatti
- Center
for Materials Research, Justus Liebig University, Heinrich-Buff-Ring 17, 35392, Giessen, Germany
| | - Francesco Scotognella
- Department
of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
- Center
for Nano Science and Technology, Istituto
Italiano di Tecnologia, Via Pascolo, 70/3 Milano 20133, Italy
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22
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Manian A, Shaw RA, Lyskov I, Russo SP. Exciton Dynamics of a Diketo-Pyrrolopyrrole Core for All Low-Lying Electronic Excited States Using Density Functional Theory-Based Methods. J Chem Theory Comput 2022; 18:1838-1848. [PMID: 35196857 DOI: 10.1021/acs.jctc.2c00070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ab initio treatments of interexcited state internal conversion (IC) are more often than not missing from exciton dynamic descriptions, because of their inherent complexity. Here, we define "interexcited state IC" as a same-spin nonradiative transition between states i and j, where i ≠ j ≠ 0. Competing directly with multiexciton processes such as singlet fission or triplet photoupconversion, inclusion of this mechanism in the narrative of molecular photophysics would allow for strategic synthesis of chromophores for more efficient photon-harvesting applications. Herein, we present a robust formalism which can model these rates using density functional theory (DFT)-based methods within the Franck-Condon and Herzberg-Teller regime. Using an unsubstituted diketo-pyrrolopyrrole (DPP) core as a case study, we illustrate the exciton dynamics along the first four excited states for both singlet and triplet manifolds, showing ultrafast same-spin transfer mechanisms due to all excited states, excluding the first triplet level, being in close energetic proximity (within 0.8 eV of each other). The resulting electron same-spin rates outcompete the electron spin-flipping intersystem crossing (ISC) rates, with excitons firmly obeying Kasha's rule as they cascade down from the high-lying excited states toward the lower states. Furthermore, we calculated that only the first singlet excited state displayed a reasonable probability of triplet exciton generation, of ∼40%, with a near-zero chance of the exciton reverting to the singlet manifold once the electron-hole pair are of parallel spin.
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Affiliation(s)
- Anjay Manian
- ARC Centre of Excellence in Exciton Science, School of Science, RMIT University, Melbourne, 3000, Australia
| | - Robert A Shaw
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - Igor Lyskov
- ARC Centre of Excellence in Exciton Science, School of Science, RMIT University, Melbourne, 3000, Australia
| | - Salvy P Russo
- ARC Centre of Excellence in Exciton Science, School of Science, RMIT University, Melbourne, 3000, Australia
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23
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Wang L, Cai W, Sun J, Wu Y, Zhang B, Tian X, Guo S, Liang W, Fu H, Yao J. H-Type-like Aggregation-Accelerated Singlet Fission Process in Dipyrrolonaphthyridinedione Thin Film: The Role of Charge Transfer/Excimer Mixed Intermediate State. J Phys Chem Lett 2021; 12:12276-12282. [PMID: 34931841 DOI: 10.1021/acs.jpclett.1c03265] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Through the combination of transient spectroscopy and theoretical simulations, an accelerated singlet fission (SF) process was evidently observed in the strongly coupled H-type-like aggregation thin films of a dipyrrolonaphthyridinedione skeleton. Results elucidate that in this H-type-like aggregation, the substantially stabilized charge transfer (CT) state is close in energy with singlet and excimer states, resulting in a CT/excimer mixed state, which could drive excited-state population escaping from excimer trap and promote an ultrafast and highly efficient SF process. Our results not only enrich the limited capacity of SF materials but also contribute to an in-depth understanding of SF dynamics in H-type aggregation, which is of fundamental importance for designing new SF sensitizers and implementing practical SF applications.
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Affiliation(s)
- Long Wang
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Wanlin Cai
- Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Jing Sun
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Yuling Wu
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Bin Zhang
- Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Xiangbin Tian
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Shaoting Guo
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - WanZhen Liang
- Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, China
| | - Jiannian Yao
- Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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24
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Khan F, Jang Y, Patil Y, Misra R, D'Souza F. Photoinduced Charge Separation Prompted Intervalence Charge Transfer in a Bis(thienyl)diketopyrrolopyrrole Bridged Donor‐TCBD Push‐Pull System. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202108293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Faizal Khan
- Department of Chemistry Indian Institute of Technology Indore 453552 India
| | - Youngwoo Jang
- Department of Chemistry University of North Texas 1155 Union Circle, #305070 Denton TX 76203-5017 USA
| | - Yuvraj Patil
- Department of Chemistry Indian Institute of Technology Indore 453552 India
| | - Rajneesh Misra
- Department of Chemistry Indian Institute of Technology Indore 453552 India
| | - Francis D'Souza
- Department of Chemistry University of North Texas 1155 Union Circle, #305070 Denton TX 76203-5017 USA
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25
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Manian A, Shaw RA, Lyskov I, Wong W, Russo SP. Modeling radiative and non-radiative pathways at both the Franck-Condon and Herzberg-Teller approximation level. J Chem Phys 2021; 155:054108. [PMID: 34364347 DOI: 10.1063/5.0058643] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Here, we present a concise model that can predict the photoluminescent properties of a given compound from first principles, both within and beyond the Franck-Condon approximation. The formalism required to compute fluorescence, Internal Conversion (IC), and Inter-System Crossing (ISC) is discussed. The IC mechanism, in particular, is a difficult pathway to compute due to difficulties associated with the computation of required bosonic configurations and non-adiabatic coupling elements. Here, we offer a discussion and breakdown on how to model these pathways at the Density Functional Theory (DFT) level with respect to its computational implementation, strengths, and current limitations. The model is then used to compute the photoluminescent quantum yield (PLQY) of a number of small but important compounds: anthracene, tetracene, pentacene, diketo-pyrrolo-pyrrole (DPP), and Perylene Diimide (PDI) within a polarizable continuum model. Rate constants for fluorescence, IC, and ISC compare well for the most part with respect to experiment, despite triplet energies being overestimated to a degree. The resulting PLQYs are promising with respect to the level of theory being DFT. While we obtained a positive result for PDI within the Franck-Condon limit, the other systems require a second order correction. Recomputing quantum yields with Herzberg-Teller terms yields PLQYs of 0.19, 0.08, 0.04, 0.70, and 0.99 for anthracene, tetracene, pentacene, DPP, and PDI, respectively. Based on these results, we are confident that the presented methodology is sound with respect to the level of quantum chemistry and presents an important stepping stone in the search for a tool to predict the properties of larger coupled systems.
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Affiliation(s)
- A Manian
- ARC Centre of Excellence in Exciton Science, School of Science, RMIT Univeristy, Melbourne 3000, Australia
| | - R A Shaw
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - I Lyskov
- ARC Centre of Excellence in Exciton Science, School of Science, RMIT Univeristy, Melbourne 3000, Australia
| | - W Wong
- ARC Centre of Excellence in Exciton Science, School of Chemistry, The University of Melbourne, Parkville VIC 3052, Australia
| | - S P Russo
- ARC Centre of Excellence in Exciton Science, School of Science, RMIT Univeristy, Melbourne 3000, Australia
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26
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Khan F, Jang Y, Patil Y, Misra R, D'Souza F. Photoinduced Charge Separation Prompted Intervalence Charge Transfer in a Bis(thienyl)diketopyrrolopyrrole Bridged Donor-TCBD Push-Pull System. Angew Chem Int Ed Engl 2021; 60:20518-20527. [PMID: 34258866 DOI: 10.1002/anie.202108293] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/10/2021] [Indexed: 11/10/2022]
Abstract
Intervalence charge transfer (IVCT), a phenomenon observed in molecular systems comprised of two redox centers differing in oxidation states by one unit, is reported in a novel, newly synthesized, multi-modular donor-acceptor system comprised of central bis(thienyl)diketopyrrolopyrrole (TDPP) hosting two phenothiazine-tetracyanobutadiene (PTZ-TCBD) entities on the opposite sides. One-electron reduction of TCBD promoted electron exchange between the two TCBD resulting in IVCT transition in the near-infrared region. The stabilization energy, -ΔGcom and comproportionation equilibrium constant, Kcom calculated from peak potentials of the split reduction waves were found to be 1.06×104 J mol-1 , and 72.3 M-1 , respectively. Further, the IVCT transition was also witnessed during the process of thermodynamically feasible electron transfer upon excitation of the TDPP entity in the system, and served as a diagnostic marker to characterize the electron transfer product. Subsequent transient absorption spectral studies and data analysis by Global and Target analyses revealed occurrence of ultrafast charge separation (kcs ≈1010 s-1 ) owing to the close proximity and good communication between the entities of the multi-modular donor-acceptor system. The role of central TDPP in promoting IVCT is borne out from the present investigation.
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Affiliation(s)
- Faizal Khan
- Department of Chemistry, Indian Institute of Technology, Indore, 453552, India
| | - Youngwoo Jang
- Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, TX, 76203-5017, USA
| | - Yuvraj Patil
- Department of Chemistry, Indian Institute of Technology, Indore, 453552, India
| | - Rajneesh Misra
- Department of Chemistry, Indian Institute of Technology, Indore, 453552, India
| | - Francis D'Souza
- Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, TX, 76203-5017, USA
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27
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Fumanal M, Corminboeuf C. Pushing the Limits of the Donor-Acceptor Copolymer Strategy for Intramolecular Singlet Fission. J Phys Chem Lett 2021; 12:7270-7277. [PMID: 34318679 DOI: 10.1021/acs.jpclett.1c01986] [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
Donor-acceptor (D-A) copolymers have shown great potential for intramolecular singlet fission (iSF). Nonetheless, very few design principles exist for optimizing these systems for iSF, with very little knowledge about how to engineer them for this purpose. In recent work, a fundamental trade-off between the main electronic ingredients required for iSF capable D-A coplanar copolymers was revealed. Still, further investigations are needed to understand these limitations and learn how to bypass them. In this work, we propose to induce torsion as an effective way to circumvent the limits of the coplanar approach. We disclose the potential of noncoplanar copolymers with inherently low triplet energies that encompass all the characteristics required for iSF beyond the limiting values associated with fully coplanar systems. Our findings shed some light on the electronic structure aspects of D-A copolymers for iSF and offer a new avenue for the rational design of novel promising candidates.
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Affiliation(s)
- Maria Fumanal
- Laboratory for Computational Molecular Design, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Clémence Corminboeuf
- Laboratory for Computational Molecular Design, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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28
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Papadopoulos I, Menon A, Plass F, Molina D, Harreiß C, Kahnt A, Spiecker E, Sastre-Santos Á, Guldi DM. Efficient charge-transfer from diketopyrrolopyrroles to single-walled carbon nanotubes. NANOSCALE 2021; 13:11544-11551. [PMID: 34184025 DOI: 10.1039/d1nr03105h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In this contribution, the excited state charge-transfer interactions between single-walled carbon nanotubes (SWCNTs) and a variety of phenyl, 4-bromophenyl, and thiophene substituted diketopyrrolopyrroles (DPPs), is described. Atomic force microscopy (AFM) and aberration corrected high resolution transmission electron microscopy (AC-HRTEM) corroborated the successful formation of DPP/SWCNTs. Steady-state absorption, fluorescence, and Raman spectroscopies all gave insights into the impact on their ground and excited states as well as on the nature of their electronic communication/interaction. Of great value was time-resolved transient absorption spectroscopy on the femto- and nanosecond time-scales; it assisted in deciphering the charge-transfer mechanism from the DPPs to the SWCNT and in analyzing the dynamics thereof with transfer efficiencies of up to 81%. Important confirmation for the one-electron oxidized DPPs came from pulse radiolysis assays with focus on establishing their spectral fingerprints. Our full-fledged work demonstrates that the successful preparation of stable DPP/SWCNTs represents an important step towards establishing them as a viable alternative to porphyrin-based systems in emerging applications such as solar energy conversion.
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Affiliation(s)
- Ilias Papadopoulos
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany.
| | - Arjun Menon
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany.
| | - Fabian Plass
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany. and Leibniz Institute of Surface Engineering (IOM), Permoserstraße 15, 04318 Leipzig, Germany
| | - Desiré Molina
- Área de Química Orgánica, Instituto de Bioingeniería, Universidad Miguel Hernández, Avda. de la Universidad s/n, 03203 Elche, Spain.
| | - Christina Harreiß
- Institute of Micro- and Nanostructure Research (IMN) & Center for Nanoanalysis and Electron Microscopy (CENEM) and Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander University Erlangen-Nuremberg, Cauerstraße 3, 91058 Erlangen, Germany
| | - Axel Kahnt
- Leibniz Institute of Surface Engineering (IOM), Permoserstraße 15, 04318 Leipzig, Germany
| | - Erdmann Spiecker
- Institute of Micro- and Nanostructure Research (IMN) & Center for Nanoanalysis and Electron Microscopy (CENEM) and Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander University Erlangen-Nuremberg, Cauerstraße 3, 91058 Erlangen, Germany
| | - Ángela Sastre-Santos
- Área de Química Orgánica, Instituto de Bioingeniería, Universidad Miguel Hernández, Avda. de la Universidad s/n, 03203 Elche, Spain.
| | - Dirk M Guldi
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-University Erlangen-Nuremberg, Egerlandstraße 3, 91058 Erlangen, Germany.
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29
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Rais D, Toman P, Pfleger J, Acharya U, Panthi YR, Menšík M, Zhigunov A, Thottappali MA, Vala M, Marková A, Stříteský S, Weiter M, Cigánek M, Krajčovič J, Pauk K, Imramovský A, Zaykov A, Michl J. Singlet Fission in Thin Solid Films of Bis(thienyl)diketopyrrolopyrroles. Chempluschem 2021; 85:2689-2703. [PMID: 33332757 DOI: 10.1002/cplu.202000623] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 11/30/2020] [Indexed: 11/07/2022]
Abstract
The singlet fission (SF) process discovered in bis(thienyl)diketopyrrolopyrroles (TDPPs) can boost their potential for photovoltaics (PV). The crystal structures of TDPP analogs carrying n-hexyl, n-butyl, or 2-(adamant-1-yl)ethyl substituents are similar, but contain increasingly slipped stacked neighbor molecules. The observed SF rate constants, kSF , (7±4), (9±3) and (5.6±1.9) ns-1 for thin films of the three compounds, respectively, are roughly equal, but the triplet quantum yields vary strongly: (120±40), (160±40) and (70±16), respectively. The recent molecular pair model reproduces the near equality of all three kSF at the crystal geometries and identifies all possible pair arrangements in which SF is predicted to be faster, by up to two orders of magnitude. However, it is also clear that the presently non-existent ability to predict the rates of processes competing with SF is pivotal for providing a guide for efforts to optimize the materials for PV.
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Affiliation(s)
- David Rais
- Department of Polymers for Electronics and Photonics, Institute of Macromolecular Chemistry Czech Academy of Sciences, Heyrovského nám. 2, 16206, Prague 6, Czech Republic
| | - Petr Toman
- Department of Polymers for Electronics and Photonics, Institute of Macromolecular Chemistry Czech Academy of Sciences, Heyrovského nám. 2, 16206, Prague 6, Czech Republic
| | - Jiří Pfleger
- Department of Polymers for Electronics and Photonics, Institute of Macromolecular Chemistry Czech Academy of Sciences, Heyrovského nám. 2, 16206, Prague 6, Czech Republic
| | - Udit Acharya
- Department of Polymers for Electronics and Photonics, Institute of Macromolecular Chemistry Czech Academy of Sciences, Heyrovského nám. 2, 16206, Prague 6, Czech Republic
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague 2, Czech Republic
| | - Yadu R Panthi
- Department of Polymers for Electronics and Photonics, Institute of Macromolecular Chemistry Czech Academy of Sciences, Heyrovského nám. 2, 16206, Prague 6, Czech Republic
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague 2, Czech Republic
| | - Miroslav Menšík
- Department of Polymers for Electronics and Photonics, Institute of Macromolecular Chemistry Czech Academy of Sciences, Heyrovského nám. 2, 16206, Prague 6, Czech Republic
| | - Alexander Zhigunov
- Department of X-ray and Neutron Structural Analysis, Institute of Macromolecular Chemistry Czech Academy of Sciences, Heyrovského nám. 2, 16206, Prague 6, Czech Republic
| | - Muhammed A Thottappali
- Department of Polymers for Electronics and Photonics, Institute of Macromolecular Chemistry Czech Academy of Sciences, Heyrovského nám. 2, 16206, Prague 6, Czech Republic
- Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague 2, Czech Republic
| | - Martin Vala
- Materials Research Centre Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 612 00, Brno, Czech Republic
| | - Aneta Marková
- Materials Research Centre Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 612 00, Brno, Czech Republic
| | - Stanislav Stříteský
- Materials Research Centre Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 612 00, Brno, Czech Republic
| | - Martin Weiter
- Materials Research Centre Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 612 00, Brno, Czech Republic
| | - Martin Cigánek
- Materials Research Centre Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 612 00, Brno, Czech Republic
| | - Jozef Krajčovič
- Materials Research Centre Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 612 00, Brno, Czech Republic
| | - Karel Pauk
- Department of Organic Technology, Institute of Organic Chemistry and Technology at the University of Pardubice, Studentská 573, 532 10, Pardubice, Czech Republic
| | - Aleš Imramovský
- Department of Organic Technology, Institute of Organic Chemistry and Technology at the University of Pardubice, Studentská 573, 532 10, Pardubice, Czech Republic
| | - Alexandr Zaykov
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague, Czech Republic
- University of Chemistry and Technology, Technická 5, 16628, Prague 6, Czech Republic
| | - Josef Michl
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague, Czech Republic
- Department of Chemistry, University of Colorado, Boulder, Colorado, 80309-0215, USA
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30
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Shaikh J, Congrave DG, Forster A, Minotto A, Cacialli F, Hele TJH, Penfold TJ, Bronstein H, Clarke TM. Intrinsic photogeneration of long-lived charges in a donor-orthogonal acceptor conjugated polymer. Chem Sci 2021; 12:8165-8177. [PMID: 34194707 PMCID: PMC8208312 DOI: 10.1039/d1sc00919b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 05/08/2021] [Indexed: 11/21/2022] Open
Abstract
Efficient charge photogeneration in conjugated polymers typically requires the presence of a second component to act as electron acceptor. Here, we report a novel low band-gap conjugated polymer with a donor/orthogonal acceptor motif: poly-2,6-(4,4-dihexadecyl-4H-cyclopenta [2,1-b:3,4-b']dithiophene)-alt-2,6-spiro [cyclopenta[2,1-b:3,4-b']dithiophene-4,9'-fluorene]-2',7'-dicarbonitrile, referred to as PCPDT-sFCN. The role of the orthogonal acceptor is to spatially isolate the LUMO from the HOMO, allowing for negligible exchange energy between electrons in these orbitals and minimising the energy gap between singlet and triplet charge transfer states. We employ ultrafast and microsecond transient absorption spectroscopy to demonstrate that, even in the absence of a separate electron acceptor, PCPDT-sFCN shows efficient charge photogeneration in both pristine solution and film. This efficient charge generation is a result of an isoenergetic singlet/triplet charge transfer state equilibrium acting as a reservoir for charge carrier formation. Furthermore, clear evidence of enhanced triplet populations, which form in less than 1 ps, is observed. Using group theory, we show that this ultrafast triplet formation is due to highly efficient, quantum mechanically allowed intersystem crossing between the bright, initially photoexcited local singlet state and the triplet charge transfer state. Remarkably, the free charges that form via the charge transfer state are extraordinarily long-lived with millisecond lifetimes, possibly due to the stabilisation imparted by the spatial separation of PCPDT-sFCN's donor and orthogonal acceptor motifs. The efficient generation of long-lived charge carriers in a pristine polymer paves the way for single-material applications such as organic photovoltaics and photodetectors.
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Affiliation(s)
- Jordan Shaikh
- Department of Chemistry, University College London Christopher Ingold Building London WC1H 0AJ UK
| | - Daniel G Congrave
- Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
| | - Alex Forster
- Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
| | - Alessandro Minotto
- Department of Physics, University College London Gower Street London WC1E 6BT UK
| | - Franco Cacialli
- Department of Physics, University College London Gower Street London WC1E 6BT UK
| | - Timothy J H Hele
- Department of Chemistry, University College London Christopher Ingold Building London WC1H 0AJ UK
| | - Thomas J Penfold
- Chemistry - School of Natural and Environmental Sciences, Newcastle University Newcastle upon Tyne NE1 7RU UK
| | - Hugo Bronstein
- Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
| | - Tracey M Clarke
- Department of Chemistry, University College London Christopher Ingold Building London WC1H 0AJ UK
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31
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Bradley SJ, Chi M, White JM, Hall CR, Goerigk L, Smith TA, Ghiggino KP. The role of conformational heterogeneity in the excited state dynamics of linked diketopyrrolopyrrole dimers. Phys Chem Chem Phys 2021; 23:9357-9364. [PMID: 33885111 DOI: 10.1039/d1cp00541c] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Diketopyrrolopyrrole (DPP) derivatives have been proposed for both singlet fission and energy upconversion as they meet the energetic requirements and exhibit superior photostability compared to many other chromophores. In this study, both time-resolved electronic and IR spectroscopy have been applied to investigate excited state relaxation processes competing with fission in dimers of DPP derivatives with varying linker structures. A charge-separated (CS) state is shown to be an important intermediate with dynamics that are both solvent and linker dependent. The CS state is found for a subset of the total population of excited molecules and it is proposed that CS state formation requires suitably aligned dimers within a broader distribution of conformations available in solution. No long-lived triplet signatures indicative of singlet fission were detected, with the CS state likely acting as an alternative relaxation pathway for the excitation energy. This study provides insight into the role of molecular conformation in determining excited state relaxation pathways in DPP dimer systems.
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32
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Budden PJ, Weiss LR, Müller M, Panjwani NA, Dowland S, Allardice JR, Ganschow M, Freudenberg J, Behrends J, Bunz UHF, Friend RH. Singlet exciton fission in a modified acene with improved stability and high photoluminescence yield. Nat Commun 2021; 12:1527. [PMID: 33750774 PMCID: PMC7943798 DOI: 10.1038/s41467-021-21719-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 01/26/2021] [Indexed: 12/14/2022] Open
Abstract
We report a fully efficient singlet exciton fission material with high ambient chemical stability. 10,21-Bis(triisopropylsilylethynyl)tetrabenzo[a,c,l,n]pentacene (TTBP) combines an acene core with triphenylene wings that protect the formal pentacene from chemical degradation. The electronic energy levels position singlet exciton fission to be endothermic, similar to tetracene despite the triphenylenes. TTBP exhibits rapid early time singlet fission with quantitative yield of triplet pairs within 100 ps followed by thermally activated separation to free triplet excitons over 65 ns. TTBP exhibits high photoluminescence quantum efficiency, close to 100% when dilute and 20% for solid films, arising from triplet-triplet annihilation. In using such a system for exciton multiplication in a solar cell, maximum thermodynamic performance requires radiative decay of the triplet population, observed here as emission from the singlet formed by recombination of triplet pairs. Combining chemical stabilisation with efficient endothermic fission provides a promising avenue towards singlet fission materials for use in photovoltaics. Designing optimised molecules for singlet fission is crucial to improve the efficiency of solar cells beyond its theoretical limit. Here, the authors investigate pentacene derivative TTBP, which exhibits high stability and luminescence yield, and find it highly suitable for exciton multiplication purposes.
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Affiliation(s)
- Peter J Budden
- Cavendish Laboratory, University of Cambridge, JJ Thompson Avenue, Cambridge, UK
| | - Leah R Weiss
- Cavendish Laboratory, University of Cambridge, JJ Thompson Avenue, Cambridge, UK.,Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Matthias Müller
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, Heidelberg, Germany
| | - Naitik A Panjwani
- Berlin Joint EPR Lab, Fachbereich Physik, Freie Universität Berlin, Berlin, Germany
| | - Simon Dowland
- Cavendish Laboratory, University of Cambridge, JJ Thompson Avenue, Cambridge, UK
| | - Jesse R Allardice
- Cavendish Laboratory, University of Cambridge, JJ Thompson Avenue, Cambridge, UK
| | - Michael Ganschow
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, Heidelberg, Germany
| | - Jan Freudenberg
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, Heidelberg, Germany
| | - Jan Behrends
- Berlin Joint EPR Lab, Fachbereich Physik, Freie Universität Berlin, Berlin, Germany.
| | - Uwe H F Bunz
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, Heidelberg, Germany.
| | - Richard H Friend
- Cavendish Laboratory, University of Cambridge, JJ Thompson Avenue, Cambridge, UK.
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33
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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.
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Affiliation(s)
- Tobias Ullrich
- Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg, Department für Chemie und Pharmazie, Egerlandstr. 1-3, 91058 Erlangen, Germany.
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34
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Humphreys J, Pop F, Hume PA, Murphy AS, Lewis W, Davies ES, Argent SP, Amabilino DB. Solid state structure and properties of phenyl diketopyrrolopyrrole derivatives. CrystEngComm 2021. [DOI: 10.1039/d1ce00039j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Crystal structures of the title compounds show diverse packing by interactions of auxochromes giving materials with varied optoelectronic properties.
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Affiliation(s)
- Joshua Humphreys
- The GSK Carbon Neutral Laboratories for Sustainable Chemistry
- The University of Nottingham Jubilee Campus
- Nottingham NG7 2TU
- UK
- School of Chemistry
| | - Flavia Pop
- The GSK Carbon Neutral Laboratories for Sustainable Chemistry
- The University of Nottingham Jubilee Campus
- Nottingham NG7 2TU
- UK
- School of Chemistry
| | - Paul A. Hume
- MacDiarmid Institute for Advanced Materials and Nanotechnology and School of Chemical and Physical Sciences
- Victoria University of Wellington
- Wellington 6010
- New Zealand
| | - Alanna S. Murphy
- The GSK Carbon Neutral Laboratories for Sustainable Chemistry
- The University of Nottingham Jubilee Campus
- Nottingham NG7 2TU
- UK
- School of Chemistry
| | - William Lewis
- School of Chemistry
- University of Nottingham
- Nottingham NG7 2RD
- UK
| | | | | | - David B. Amabilino
- The GSK Carbon Neutral Laboratories for Sustainable Chemistry
- The University of Nottingham Jubilee Campus
- Nottingham NG7 2TU
- UK
- School of Chemistry
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35
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Saes BW, Lutz M, Wienk MM, Meskers SCJ, Janssen RAJ. Tuning the Optical Characteristics of Diketopyrrolopyrrole Molecules in the Solid State by Alkyl Side Chains. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2020; 124:25229-25238. [PMID: 33244323 PMCID: PMC7682139 DOI: 10.1021/acs.jpcc.0c07334] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/25/2020] [Indexed: 06/11/2023]
Abstract
The optical properties of two sets of donor-acceptor-donor molecules with terminal bithiophene donor units and a central diketopyrrolopyrrole (DPP) acceptor unit are studied. The two sets differ in the alkyl chains on the DPP, which are either branched at the α-carbon (3-pentyl) (1-4) or linear (n-hexyl) (5-8). Within each set, the molecules differ by the absence or presence of n-hexyl chains on the terminal thiophene rings in the 3', 4', or 5' positions. While in solution, the optical spectra differ only subtly; they differ dramatically in the solid state. In contrast to 5-8, 1-4 are nonplanar as a consequence of the sterically demanding 3-pentyl groups, which inhibit π-stacking of the DPP units. Using the crystal structures of 2 (brick layer stacking) and 6 (slipped stacking), we quantitatively explain the solid state absorption spectra. By computing the molecular transition charge density and solving the dispersion relation, the optical absorption of the molecules in the crystal is predicted and in agreement with experiments. For 2, a single resonance frequency is obtained, while for 6 two transitions are seen, with the lower-energy transition being less intense. The results demonstrate how subtle changes in substitution exert large effects in optical properties.
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Affiliation(s)
- Bart W.
H. Saes
- Molecular
Materials and Nanosystems & Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Martin Lutz
- Utrecht
University, Crystal and Structural
Chemistry, Bijvoet Centre for Biomolecular Research, Faculty of Science, 3584 CH Utrecht, The Netherlands
| | - Martijn M. Wienk
- Molecular
Materials and Nanosystems & Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Stefan C. J. Meskers
- Molecular
Materials and Nanosystems & Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - René A. J. Janssen
- Molecular
Materials and Nanosystems & Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
- Dutch
Institute for Fundamental Energy Research, 5612 AJ Eindhoven, The Netherlands
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36
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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.
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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
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37
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Fallon KJ, Churchill EM, Sanders SN, Shee J, Weber JL, Meir R, Jockusch S, Reichman DR, Sfeir MY, Congreve DN, Campos LM. Molecular Engineering of Chromophores to Enable Triplet-Triplet Annihilation Upconversion. J Am Chem Soc 2020; 142:19917-19925. [PMID: 33174728 DOI: 10.1021/jacs.0c06386] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Triplet-triplet annihilation upconversion (TTA-UC) is an unconventional photophysical process that yields high-energy photons from low-energy incident light and offers pathways for innovation across many technologies, including solar energy harvesting, photochemistry, and optogenetics. Within aromatic organic chromophores, TTA-UC is achieved through several consecutive energy conversion events that ultimately fuse two triplet excitons into a singlet exciton. In chromophores where the singlet exciton is roughly isoergic with two triplet excitons, the limiting step is the triplet-triplet annihilation pathway, where the kinetics and yield depend sensitively on the energies of the lowest singlet and triplet excited states. Herein we report up to 40-fold improvements in upconversion quantum yields using molecular engineering to selectively tailor the relative energies of the lowest singlet and triplet excited states, enhancing the yield of triplet-triplet annihilation and promoting radiative decay of the resulting singlet exciton. Using this general and effective strategy, we obtain upconversion yields with red emission that are among the highest reported, with remarkable chemical stability under ambient conditions.
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Affiliation(s)
- Kealan J Fallon
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Emily M Churchill
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Samuel N Sanders
- Rowland Institute at Harvard University, Cambridge, Massachusetts 02142, United States
| | - James Shee
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - John L Weber
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Rinat Meir
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Steffen Jockusch
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - David R Reichman
- 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
| | - Daniel N Congreve
- Rowland Institute at Harvard University, Cambridge, Massachusetts 02142, United States
| | - Luis M Campos
- Department of Chemistry, Columbia University, New York, New York 10027, United States
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38
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Wang L, Liu X, Shi X, Anderson CL, Klivansky LM, Liu Y, Wu Y, Chen J, Yao J, Fu H. Singlet Fission in a para-Azaquinodimethane-Based Quinoidal Conjugated Polymer. J Am Chem Soc 2020; 142:17892-17896. [DOI: 10.1021/jacs.0c06604] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Long Wang
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Xuncheng Liu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley 94720, United States
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Xiaomei Shi
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan 030001, China
| | - Christopher L. Anderson
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley 94720, United States
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Liana M. Klivansky
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley 94720, United States
| | - Yi Liu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley 94720, United States
| | - Yishi Wu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, China
| | - Junwu Chen
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Jiannian Yao
- Beijing National Laboratory for Molecules Science (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, China
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39
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Ramirez CE, Chen S, Powers-Riggs NE, Schlesinger I, Young RM, Wasielewski MR. Symmetry-Breaking Charge Separation in the Solid State: Tetra(phenoxy)perylenediimide Polycrystalline Films. J Am Chem Soc 2020; 142:18243-18250. [DOI: 10.1021/jacs.0c09185] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Carolyn E. Ramirez
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208-3113, United States
- Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Su Chen
- Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Natalia E. Powers-Riggs
- Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Itai Schlesinger
- Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Ryan M. Young
- Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Michael R. Wasielewski
- Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
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40
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Gish MK, Thorley KJ, Parkin SR, Anthony JE, Johnson JC. Hydrogen Bonding Optimizes Singlet Fission in Carboxylic Acid Functionalized Anthradithiophene Films. CHEMPHOTOCHEM 2020. [DOI: 10.1002/cptc.202000168] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Melissa K. Gish
- Chemistry and Nanoscience Center National Renewable Energy Laboratory 15013 Denver West Parkway Golden CO 80401 USA
| | - Karl J. Thorley
- Department of Chemistry University of Kentucky Lexington, Kentucky 40506 USA
| | - Sean R. Parkin
- Department of Chemistry University of Kentucky Lexington, Kentucky 40506 USA
| | - John E. Anthony
- Department of Chemistry University of Kentucky Lexington, Kentucky 40506 USA
| | - Justin C. Johnson
- Chemistry and Nanoscience Center National Renewable Energy Laboratory 15013 Denver West Parkway Golden CO 80401 USA
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41
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Bae YJ, Shimizu D, Schultz JD, Kang G, Zhou J, Schatz GC, Osuka A, Wasielewski MR. Balancing Charge Transfer and Frenkel Exciton Coupling Leads to Excimer Formation in Molecular Dimers: Implications for Singlet Fission. J Phys Chem A 2020; 124:8478-8487. [DOI: 10.1021/acs.jpca.0c07646] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Youn Jue Bae
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Daiki Shimizu
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Jonathan D. Schultz
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Gyeongwon Kang
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Jiawang Zhou
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - George C. Schatz
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Atsuhiro Osuka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Michael R. Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
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42
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Menon A, Papadopoulos I, Harreiß C, Mora-Fuentes JP, Cortizo-Lacalle D, Mateo-Alonso A, Spiecker E, Guldi DM. Collecting up to 115% of Singlet-Fission Products by Single-Walled Carbon Nanotubes. ACS NANO 2020; 14:8875-8886. [PMID: 32543172 DOI: 10.1021/acsnano.0c03668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In this contribution, we focused on integrating a phenylene-bridged dibenzodiazahexacene dimer (o-DAD), which is singlet fission (SF) active, onto single-walled carbon nanotubes (SWCNTs) as a low-energy sink for energetically low lying excited states that stem from SF. Spectroscopic and microscopic assays assisted in documenting that SWCNT/o-DAD feature high stability in THF as a result of electronic interactions between the individual constituents. For example, statistical Raman analysis underlined n-doping of SWCNTs in the presence of o-DAD. Fluorescence spectroscopy prompted an energy transfer between the individual constituents, a conclusion that was exclusively derived from the quenching of the o-DAD-centered fluorescence. Excitation spectroscopy with a focus on the SWCNT fluorescence confirmed independently this conclusion by showing o-DAD-centered features. Our work was rounded off by time-resolved transient absorption measurements with SWCNT/o-DAD, in which evidence was gathered for the sequential o-DAD-centered SF with an efficiency of 112% followed by a unidirectional energy transfer from o-DAD to SWCNT and a rapid deactivation. The energy transfer efficiency from SF products such as (S1S0)CT and 1(T1T1) exceeded the 100% threshold with values of 115%, which is conventionally found in energy transfer schemes.
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Affiliation(s)
- Arjun Menon
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials, Friedrich-Alexander-University Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Ilias Papadopoulos
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials, Friedrich-Alexander-University Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen, Germany
| | - Christina Harreiß
- Institute of Micro- and Nanostructure Research (IMN) & Center for Nanoanalysis and Electron Microscopy (CENEM) and Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander University Erlangen-Nürnberg, Cauerstrasse 3, 91058 Erlangen, Germany
| | - Juan P Mora-Fuentes
- POLYMAT, University of the Basque Country UPV/EHU, Avenida de Tolosa 72, 20018 Donostia-San Sebastian, Spain
| | - Diego Cortizo-Lacalle
- POLYMAT, University of the Basque Country UPV/EHU, Avenida de Tolosa 72, 20018 Donostia-San Sebastian, Spain
| | - Aurelio Mateo-Alonso
- POLYMAT, University of the Basque Country UPV/EHU, Avenida de Tolosa 72, 20018 Donostia-San Sebastian, Spain
- Ikerbasque, Basque Foundation for Science, Maria Diaz de Haro 3, 6 Solairua, 48013 Bilbao, Spain
| | - Erdmann Spiecker
- Institute of Micro- and Nanostructure Research (IMN) & Center for Nanoanalysis and Electron Microscopy (CENEM) and Interdisciplinary Center for Nanostructured Films (IZNF), Friedrich-Alexander University Erlangen-Nürnberg, Cauerstrasse 3, 91058 Erlangen, Germany
| | - Dirk M Guldi
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials, Friedrich-Alexander-University Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen, Germany
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43
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Shen L, Lu J, Liu H, Meng Q, Li X. Evaluation of Fused Aromatic-Substituted Diketopyrrolopyrrole Derivatives for Singlet Fission Sensitizers. J Phys Chem A 2020; 124:5331-5340. [PMID: 32498515 DOI: 10.1021/acs.jpca.0c02248] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Singlet fission (SF) is a spin-allowed carrier multiplication process that has potential to overcome the Shockley-Queisser limit of solar energy conversion efficiency for single-junction solar cells. It is of importance to prescreen appropriate SF candidates for both basic research and practical applications of SF. Besides common polycyclic aromatic hydrocarbons (PAHs), diketopyrrolopyrrole (DPP) derivatives also undergo efficient SF. A series of DPP derivatives with fused aromatic substituents were investigated considering their conjugation length, constitution, and the introduction of terminal substituents. A comparison of SF properties between nonfused and fused aromatic-substituted DPP derivatives was carried out. Detailed analysis focused on elucidating the relationship between the frontier molecular orbital energies, multiple diradical characters, and SF-relevant excited-state energy levels. Compared to nonfused aromatic-substituted DPP derivatives, fused aromatic-substituted DPP derivatives which contain three aromatic units (thiophene or furan) still share more appropriate energy levels for SF sensitizers. Changing the five-membered aromatic units with benzene ring and introducing -F, -OMe, and -COOH as terminal substituents are both effective ways to improve their performance as SF sensitizers. The results of this research help us to understand the SF properties of DPP derivatives deeply and are beneficial for the design of new DPP-based SF sensitizers.
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Affiliation(s)
- Li Shen
- College of Chemical Engineering and Environmental Chemistry, Weifang University, Weifang 261061, China
| | - Jitao Lu
- College of Chemical Engineering and Environmental Chemistry, Weifang University, Weifang 261061, China
| | - Heyuan Liu
- Institute of New Energy, China University of Petroleum (East China), Qingdao 266580, China
| | - Qingguo Meng
- College of Chemical Engineering and Environmental Chemistry, Weifang University, Weifang 261061, China
| | - Xiyou Li
- School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao 266580, China.,Institute of New Energy, China University of Petroleum (East China), Qingdao 266580, China
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44
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Abstract
AbstractPhotoinduced charge generation forms the physical basis for energy conversion in organic photovoltaic (OPV) technology. The fundamental initial steps involved are absorption of light by organic semiconductors (generally π-conjugated polymers) to generate photoexcited states (Frenkel excitons) followed by charge transfer and charge separation processes in presence of suitable acceptor. The absorbed photon energy must be utilized completely for achieving maximum device efficiency. However progressive relaxation losses of instantaneously generated high-energy or hot-excited states form major bottleneck for maximum derivable voltage. This efficiency limiting factor has been challenged recently by the role of hot-carriers in efficient generation of charges. Therefore tailoring the dissociation of hot-exciton to be temporally faster than all relaxation processes could minimize the energy loss pathways. Implementation of this concept of hot-carrier photovoltaics demands critical understanding of molecular parameters that circumvent all energy relaxation processes and favor hot-carrier generation. In my dissertation work, I have examined the fate of photo-generated excitons in the context of polymer backbone and morphology, and therefore obtain a fundamental structure-function correlation in organic semiconductors.
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Affiliation(s)
- Palas Roy
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai-400005, India
- School of Chemistry, University of East Anglia, Norwich NR4 7TJ, UK
| | - Jyotishman Dasgupta
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai-400005, India
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45
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Ross AM, Zheng M, Maggini M, Marangi F, Cerullo G, Gatti T, Scotognella F. Revealing excited states dynamics in cross-linked covalent hybrids of graphene and diketopyrrolopyrrole oligomers via ultrafast transient absorption spectroscopy. EPJ WEB OF CONFERENCES 2020. [DOI: 10.1051/epjconf/202023807007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report on ultrafast dynamics in cross-linked covalent hybrids of graphene and diketopyrrolopyrrole (TDPP) oligomers. Comparisons between non-polymerizing (EXG-TDPP) and polymerizing (c-EXG-TDPP) hybrids show that charge/energy transfer occurs faster than 50 ps in EXGTDPP, while the c-EXG-TDPP system shows quenching within 18 ps. The transient response of c-EXGTDPP is completely quenched (>99%), while in EXG-TDPP full quenching occurs after 1.39 ns. Photocurrent studies of c-EXG-TDPP films show IPCE > 2%, indicating ultrafast charge transfer between TDPP and graphene.
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46
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Medina DP, Papadopoulos I, Lavarda G, Gotfredsen H, Rami PR, Tykwinski RR, Rodríguez-Morgade MS, Guldi DM, Torres T. Light-harvesting porphyrazines to enable intramolecular singlet fission. NANOSCALE 2019; 11:22286-22292. [PMID: 31730142 DOI: 10.1039/c9nr08161e] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A porphyrazine featuring complementary absorption to a pentacene dimer was chosen to fill the absorption gap of the latter in the range of 450 to 600 nm to realize panchromatic absorption through the visible region out to ca. 700 nm. Of even greater relevance is the quantitative intramolecular Förster resonance energy transfer (i-FRET) to funnel energy to the pentacene moieties, where efficient intramolecular singlet fission (i-SF) converts the singlet excited state into the corresponding triplet excited states. Remarkably, the triplet quantum yield either via direct excitation or via indirect i-FRET is up to 200% ± 20% in polar solvents.
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Affiliation(s)
- Diana-Paola Medina
- Departamento de Química Orgánica, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
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47
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Zaykov A, Felkel P, Buchanan EA, Jovanovic M, Havenith RWA, Kathir RK, Broer R, Havlas Z, Michl J. Singlet Fission Rate: Optimized Packing of a Molecular Pair. Ethylene as a Model. J Am Chem Soc 2019; 141:17729-17743. [PMID: 31509712 DOI: 10.1021/jacs.9b08173] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A procedure is described for unbiased identification of all π-electron chromophore pair geometry choices that locally maximize the rate of conversion of a singlet exciton into a singlet biexciton (triplet pair), using a simplified version of the diabatic frontier orbital model of singlet fission (SF). The resulting approximate optimal geometries provide insight and are expected to represent useful starting points for searches by more advanced methods. The general procedure is illustrated on a pair of ethylenes as the simplest model of a π-electron system, but it is applicable to pairs of much larger molecules, with dozens of non-hydrogen atoms, and not necessarily planar. We first examine the value of |TA|2, the square of the electronic matrix element for SF with initial excitation fully localized on partner A, on a grid of several billion geometries within the six-dimensional space of physically realizable possibilities. Several of the optimized pair geometries are somewhat unexpected, but all are found to follow the qualitative guidance proposed earlier. In the neighborhood of each local maximum of |TA|2, consideration of mixing with charge-transfer configurations and of excitonic interaction between partners A and B determines the SF energy balance and yields squared matrix elements |T*|2 and |T**|2 for the lower and upper excitonic states S* and S**, respectively. Assuming Boltzmann populations of these states, the geometry is further optimized to maximize k, the sum of the SF rates obtained from Marcus theory, and this reorders the suitable geometries substantially. At 87 pair geometries, the |T*|2 and |T**|2 values are compared with those obtained from high-level ab initio nonorthogonal configuration interaction calculations and found to follow the same trend. Finally, the biexciton binding energy at the optimized geometries is calculated. Altogether, 13 significant local maxima of SF rate for a pair of ethylenes are identified in the physically relevant part of space that avoids molecular interpenetration in the hard-sphere approximation. The three best geometries are twist-stacked, slip-stacked, and L-shaped. The maxima occur at the (five-dimensional) surfaces of seven six-dimensional "parent" regions of space centered at physically inaccessible geometries at which the calculated SF rate is very large but the two ethylenes interpenetrate. The results are displayed in interactive graphics. The computer code ("Simple") written for these calculations is flexible in that it permits a choice of performing the search for local maxima in six dimensions on |TA|2, |T*|2, or k. It is available as freeware at https://cloud.uochb.cas.cz/simple .
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Affiliation(s)
- Alexandr Zaykov
- Institute of Organic Chemistry and Biochemistry , Czech Academy of Sciences , 16610 Prague 6, Czech Republic.,Department of Physical Chemistry , University of Chemistry and Technology , 16628 Prague 6, Czech Republic
| | - Petr Felkel
- Faculty of Electrical Engineering , Czech Technical University in Prague , 16627 Prague 6, Czech Republic
| | - Eric A Buchanan
- Department of Chemistry , University of Colorado , Boulder , Colorado 80309-0215 , United States
| | - Milena Jovanovic
- Department of Chemistry , University of Colorado , Boulder , Colorado 80309-0215 , United States
| | - Remco W A Havenith
- Zernike Institute for Advanced Materials , University of Groningen , Nijenborgh 4, 9747 AG Groningen , The Netherlands.,Stratingh Institute for Chemistry , University of Groningen , Nijenborgh 4, 9747 AG Groningen , The Netherlands.,Department of Inorganic and Physical Chemistry , Ghent University , Krijgslaan 281 (S3) , B-9000 Gent , Belgium
| | - R K Kathir
- Zernike Institute for Advanced Materials , University of Groningen , Nijenborgh 4, 9747 AG Groningen , The Netherlands
| | - Ria Broer
- Zernike Institute for Advanced Materials , University of Groningen , Nijenborgh 4, 9747 AG Groningen , The Netherlands
| | - Zdeněk Havlas
- Institute of Organic Chemistry and Biochemistry , Czech Academy of Sciences , 16610 Prague 6, Czech Republic
| | - Josef Michl
- Institute of Organic Chemistry and Biochemistry , Czech Academy of Sciences , 16610 Prague 6, Czech Republic.,Department of Chemistry , University of Colorado , Boulder , Colorado 80309-0215 , United States
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48
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Basel BS, Young RM, Krzyaniak MD, Papadopoulos I, Hetzer C, Gao Y, La Porte NT, Phelan BT, Clark T, Tykwinski RR, Wasielewski MR, Guldi DM. Influence of the heavy-atom effect on singlet fission: a study of platinum-bridged pentacene dimers. Chem Sci 2019; 10:11130-11140. [PMID: 32206262 PMCID: PMC7069226 DOI: 10.1039/c9sc04410h] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 10/20/2019] [Indexed: 12/11/2022] Open
Abstract
Two platinum-bridged pentacene dimers undergo efficient singlet fission to form a correlated triplet pair (T1T1). The internal heavy-atom effect of the platinum allows for 1(T1T1)–3(T1T1) mixing leading to the formation of mainly (T1S0).
The process of singlet fission (SF) produces two triplet excited states (T1 + T1) from one singlet excited exciton (S1) and a molecule in its ground state (S0). It, thus, possesses the potential to boost the solar cell efficiency above the thermodynamic Shockley–Queisser limit of 33%. A key intermediate in the SF mechanism is the singlet correlated triplet pair state 1(T1T1). This state is of great relevance, as its formation is spin-allowed and, therefore, very fast and efficient. Three fundamentally different pathways to formation of 1(T1T1) have been documented so far. The factors that influence which mechanism is associated with which chromophore, however, remain largely unknown. In order to harvest both triplet excitons independently, a decorrelation of the correlated triplet pair state to two individual triplets is required. This second step of the SF process implies a change in the total spin quantum number. In the case of a dimer, this is usually only possible if the coupling between the two pentacenes is sufficiently weak. In this study, we present two platinum-bridged pentacene dimers in which the pentacenes are coupled strongly, so that spin-decorrelation yielding (T1 + T1) was initially expected to be outcompeted by triplet–triplet annihilation (TTA) to the ground state. Both platinum-bridged pentacene dimers undergo quantitative formation of the (T1T1) state on a picosecond timescale that is unaffected by the internal heavy-atom effect of the platinum. Instead of TTA of (T1T1) to the ground state, the internal heavy-atom effect allows for 1(T1T1)–3(T1T1) and 1(T1T1)–5(T1T1) mixing and, thus, triggers subsequent TTA to the (T1S0) state and minor formation of (T1 + T1). A combination of transient absorption and transient IR spectroscopy is applied to investigate the mechanism of the (T1T1) formation in both dimers. Using a combination of experiment and quantum chemical calculations, we are able to observe a transition from the CT-mediated to the direct SF mechanism and identify relevant factors that influence the mechanism that dominates SF in pentacene. Moreover, a combination of time-resolved optical and electron paramagnetic resonance spectroscopic data allows us to develop a kinetic model that describes the effect of enhanced spin–orbit couplings on the correlated triplet pair state.
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Affiliation(s)
- Bettina S Basel
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Egerlandstrasse 3 , 91058 Erlangen , Germany .
| | - Ryan M Young
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern (ISEN) , Northwestern University , Evanston , IL 60208-3113 , USA .
| | - Matthew D Krzyaniak
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern (ISEN) , Northwestern University , Evanston , IL 60208-3113 , USA .
| | - Ilias Papadopoulos
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Egerlandstrasse 3 , 91058 Erlangen , Germany .
| | - Constantin Hetzer
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Nikolaus-Fiebiger-Strasse 10 , 91058 Erlangen , Germany
| | - Yueze Gao
- Department of Chemistry , University of Alberta , Edmonton , Alberta T6G 2G2 , Canada .
| | - Nathan T La Porte
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern (ISEN) , Northwestern University , Evanston , IL 60208-3113 , USA .
| | - Brian T Phelan
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern (ISEN) , Northwestern University , Evanston , IL 60208-3113 , USA .
| | - Timothy Clark
- Department of Chemistry and Pharmacy & Computer-Chemistry-Center (CCC) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Nägelsbachstrasse 25 , 91052 Erlangen , Germany .
| | - Rik R Tykwinski
- Department of Chemistry , University of Alberta , Edmonton , Alberta T6G 2G2 , Canada .
| | - Michael R Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern (ISEN) , Northwestern University , Evanston , IL 60208-3113 , USA .
| | - Dirk M Guldi
- Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Egerlandstrasse 3 , 91058 Erlangen , Germany .
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49
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Bae YJ, Christensen JA, Kang G, Zhou J, Young RM, Wu YL, Van Duyne RP, Schatz GC, Wasielewski MR. Substituent effects on energetics and crystal morphology modulate singlet fission in 9,10-bis(phenylethynyl)anthracenes. J Chem Phys 2019; 151:044501. [PMID: 31370542 DOI: 10.1063/1.5110411] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Singlet fission (SF) converts a singlet exciton into two triplet excitons in two or more electronically coupled organic chromophores, which may then be used to increase solar cell efficiency. Many known SF chromophores are unsuitable for device applications due to chemical instability or low triplet state energies. The results described here show that efficient SF occurs in derivatives of 9,10-bis(phenylethynyl)anthracene (BPEA), which is a highly robust and tunable chromophore. Fluoro and methoxy substituents at the 4- and 4'-positions of the BPEA phenyl groups control the intermolecular packing in the crystal structure, which alters the interchromophore electronic coupling, while also changing the SF energetics. The lowest excited singlet state (S1) energy of 4,4'-difluoro-BPEA is higher than that of BPEA so that the increased thermodynamic favorability of SF results in a (16 ± 2 ps)-1 SF rate and a 180% ± 16% triplet yield, which is about an order of magnitude faster than BPEA with a comparable triplet yield. By contrast, 4-fluoro-4'-methoxy-BPEA and 4,4'-dimethoxy-BPEA have slower SF rates, (90 ± 20 ps)-1 and (120 ± 10 ps)-1, and lower triplet yields, (110 ± 4)% and (168 ± 7)%, respectively, than 4,4'-difluoro-BPEA. These differences are attributed to changes in the crystal structure controlling interchromophore electronic coupling as well as SF energetics in these polycrystalline solids.
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Affiliation(s)
- Youn Jue Bae
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Joseph A Christensen
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Gyeongwon Kang
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Jiawang Zhou
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Ryan M Young
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Yi-Lin Wu
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Richard P Van Duyne
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - George C Schatz
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
| | - Michael R Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, USA
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50
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Willems RM, Meskers SCJ, Wienk MM, Janssen RAJ. Effect of Charge-Transfer State Energy on Charge Generation Efficiency via Singlet Fission in Pentacene-Fullerene Solar Cells. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2019; 123:10253-10261. [PMID: 31049121 PMCID: PMC6488139 DOI: 10.1021/acs.jpcc.9b00568] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 03/24/2019] [Indexed: 06/01/2023]
Abstract
Singlet fission in pentacene creates two triplet excitons per absorbed photon. In a solar cell, each triplet can generate an electron-hole pair, and hence, external quantum efficiencies exceeding 100% have been reported for pentacene-fullerene solar cells. The energetics of this process are intriguing because the minimum photon energy loss, defined as the energy difference between the (triplet) exciton state and the open-circuit voltage, is less than 0.5 eV and distinctively smaller than that in most organic donor-acceptor solar cells. To investigate the energetics of this process, we analyze the effect of the energy of the lowest unoccupied molecular orbital (LUMO) for different fullerene derivatives. With the LUMO energy becoming less negative, the open-circuit voltage increases and charge generation decreases. For all but one of the fullerenes tested, the charge-transfer state energy is distinctively higher than the pentacene triplet energy, revealing that charge generation via singlet fission is actually endergonic. An elementary Marcus model for the rate of electron transfer provides a qualitative description of the experimental trends, in accordance with an endergonic charge transfer. Considering that charge generation from triplet states is endergonic, involvement of pentacene singlet states, either from direct photoexcitation or via triplet-triplet annihilation, cannot be excluded.
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Affiliation(s)
- Robin
E. M. Willems
- Molecular
Materials and Nanosystems and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Stefan C. J. Meskers
- Molecular
Materials and Nanosystems and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Martijn M. Wienk
- Molecular
Materials and Nanosystems and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - René A. J. Janssen
- Molecular
Materials and Nanosystems and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Dutch
Institute for Fundamental Energy Research, De Zaale 20, 5612
AJ Eindhoven, The Netherlands
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