1
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Hubenko K, Kusber A, Naumann M, Büchner B, Knupfer M. Evolution of the pentacene exciton band width in pentacene-tetracene blends. J Chem Phys 2024; 160:144708. [PMID: 38597316 DOI: 10.1063/5.0188846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 03/25/2024] [Indexed: 04/11/2024] Open
Abstract
Pentacene is one of the most investigated organic semiconductors. It is well known that the motion of excitons in pentacene and other organic semiconductors is determined by inter-molecular exciton coupling based on charge-transfer processes. In the present study, we demonstrate the impact of the admixture of tetracene, which has a larger band gap and interrupts the pentacene-pentacene interaction, on the exciton behavior in pentacene. Using a combination of optical absorption and electron energy-loss spectroscopy, we show that both the Davydov splitting and the exciton band width in pentacene strongly decrease with increasing tetracene concentration, while the decrease of the exciton band width is substantially larger.
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Affiliation(s)
- Kateryna Hubenko
- Leibniz Institute for Solid State and Materials Research, Helmholtz Str. 20, D-01069 Dresden, Germany
- Institute for Scintillation Materials National Academy of Sciences of Ukraine, 60 Nauky ave., 61072 Kharkiv, Ukraine
| | - Anncharlott Kusber
- Leibniz Institute for Solid State and Materials Research, Helmholtz Str. 20, D-01069 Dresden, Germany
| | - Marco Naumann
- Leibniz Institute for Solid State and Materials Research, Helmholtz Str. 20, D-01069 Dresden, Germany
| | - Bernd Büchner
- Leibniz Institute for Solid State and Materials Research, Helmholtz Str. 20, D-01069 Dresden, Germany
| | - Martin Knupfer
- Leibniz Institute for Solid State and Materials Research, Helmholtz Str. 20, D-01069 Dresden, Germany
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2
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Kang S, Choi W, Ahn J, Kim T, Oh JH, Kim D. Impact of Packing Geometry on Excimer Characteristics and Mobility in Perylene Bisimide Polycrystalline Films. ACS APPLIED MATERIALS & INTERFACES 2024; 16:18134-18143. [PMID: 38554079 DOI: 10.1021/acsami.3c19140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/01/2024]
Abstract
Efficient exciton transport is essential for high-performance optoelectronics. Considerable efforts have been focused on improving the exciton mobility in organic materials. While it is feasible to improve mobility in organic systems by forming well-ordered stacks, the formation of trap states, particularly the lower-lying states referred to as excimers, remains a significant challenge to enhancing mobility. The mobility of excimer excitons intricately depends on the strength of excitonic coupling in terms of Förster-type diffusive exciton transfer processes. Given that the formation and mobility of excimer excitons are highly sensitive to molecular arrangements (packing geometries), conducting comprehensive investigations into the structure-property relationship in organic systems is crucial. In this study, we prepared three types of polycrystalline films of perylene bisimide (PBI) by varying substituents at the imide and bay positions, which allowed us to tailor the properties of excimer excitons and their mobility based on packing geometries and excitonic coupling strengths. By utilizing femtosecond transient absorption spectroscopy, we observed ultrafast excimer formation in the higher coupling regime, while in the lower coupling regime, the transition from Frenkel to excimer excitons occurs with a time constant of 500 fs. Under high pump-fluence, exciton-exciton annihilation processes occur, indicating the diffusion of excimer excitons. Intriguingly, employing a three-dimensional diffusion model, we derived a diffusion constant that is 3000 times greater in the high coupling regime than in the low coupling regime. To investigate the optoelectronic properties in the form of a bulk system, we fabricated n-type organic field effect transistors and obtained 8000 times higher mobility in the high coupling regime. Furthermore, photocurrent measurements enable us to investigate the charge carrier transport by mobile excimer excitons, suggesting a 230-fold improvement in external quantum efficiency with tightly packing PBI molecules compared to the low coupling regime. These findings not only offer valuable insights into optimizing organic materials for optoelectronic devices but also unveil the intriguing potential of exciton migration within excimers.
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Affiliation(s)
- Seongsoo Kang
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
| | - Wonbin Choi
- School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Jaeyong Ahn
- School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Taeyeon Kim
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Joon Hak Oh
- School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea
| | - Dongho Kim
- Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 03722, Republic of Korea
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3
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Nguyen H, Lima RLS, Neto NMB, Araujo PT. What is the significance of the chloroform stabilizer C 5H 10 and its association with MeOH in concentration-dependent polymeric solutions? SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 310:123886. [PMID: 38245968 DOI: 10.1016/j.saa.2024.123886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 12/10/2023] [Accepted: 01/10/2024] [Indexed: 01/23/2024]
Abstract
The understanding of excitonic transitions associated with polymeric aggregates is fundamental, as such transitions have implications on coherence lengths, coherence numbers and inter- and intra-chain binding parameters. In this context, the investigation of efficient solvents and other ways to control polymer aggregate formation is key for their consolidation as materials for new technologies. In this manuscript, we use Poly(3-hexothiophene) (P3HT) as a probe to investigate the significance of amylene (C5H10) and its association with methanol (MeOH) in both pure and C5H10-stabilized chloroform (CHCl3)-based polymeric solutions. Using the intensity ratio between the first and second vibronic transitions of the P3HT H-aggregates formed, values for their exciton bandwidths and interchain interactions are obtained and correlated with the presence of C5H10 and MeOH as agents determining the CHCl3 quality.
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Affiliation(s)
- Huan Nguyen
- Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL, USA
| | - Ruan L S Lima
- Institute of Natural Sciences, Federal University of Para, Belem, PA, Brazil
| | | | - Paulo T Araujo
- Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL, USA.
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4
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Fabre N, Trojanowicz R, Moreaud L, Fiorini-Debuisschert C, Vassant S, Charra F. Structure and Photonic Properties of a Perylenediimide Monolayer Assembled by the Langmuir-Blodgett Technique. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:18252-18262. [PMID: 38051255 DOI: 10.1021/acs.langmuir.3c02038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
The photonic responses of densely packed dye molecule assemblies are strongly dependent on their organization and environment. The precise control of molecular orientations and distances relative to the substrate and to each other is thus a key point in the design of photonic molecular materials. Herein, we report the preparation of a homogeneous and well-organized single monolayer of the perylenediimide (PDI) derivative by means of the Langmuir-Blodgett technique. Its optical properties disclose an intense charge-transfer excitonic absorption band related to important intermolecular coupling. Furthermore, an important immunity to photobleaching is observed for such a molecular assembly. The dipolar orientations of the molecules along the substrate have been unambiguously determined by angle-of-incidence-resolved polarized absorption and back-focal-plane fluorescence mapping. In addition, time-resolved spectroscopy reveals a fast two-dimensional diffusion of excitons consistent with strong π-stacking of adjacent PDI molecules.
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Affiliation(s)
- Nicolas Fabre
- Université Paris-Saclay, CEA-CNRS, Service de Physique de l'État condensé (SPEC), Gif-sur-Yvette F-91191, France
| | - Remigiusz Trojanowicz
- Université Paris-Saclay, CEA-CNRS, Service de Physique de l'État condensé (SPEC), Gif-sur-Yvette F-91191, France
| | - Laureen Moreaud
- Université Paris-Saclay, CEA-CNRS, Service de Physique de l'État condensé (SPEC), Gif-sur-Yvette F-91191, France
| | - Céline Fiorini-Debuisschert
- Université Paris-Saclay, CEA-CNRS, Service de Physique de l'État condensé (SPEC), Gif-sur-Yvette F-91191, France
| | - Simon Vassant
- Université Paris-Saclay, CEA-CNRS, Service de Physique de l'État condensé (SPEC), Gif-sur-Yvette F-91191, France
| | - Fabrice Charra
- Université Paris-Saclay, CEA-CNRS, Service de Physique de l'État condensé (SPEC), Gif-sur-Yvette F-91191, France
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5
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Zheng Y, Venkatesh R, Callaway CP, Viersen C, Fagbohungbe KH, Liu AL, Risko C, Reichmanis E, Silva-Acuña C. Chain Conformation and Exciton Delocalization in a Push-Pull Conjugated Polymer. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2023; 35:10258-10267. [PMID: 38107193 PMCID: PMC10720347 DOI: 10.1021/acs.chemmater.3c02665] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 10/24/2023] [Indexed: 12/19/2023]
Abstract
Linear and nonlinear optical line shapes reveal details of excitonic structure in polymer semiconductors. We implement absorption, photoluminescence, and transient absorption spectroscopies in DPP-DTT, an electron push-pull copolymer, to explore the relationship between their spectral line shapes and chain conformation, deduced from resonance Raman spectroscopy and from ab initio calculations. The viscosity of precursor polymer solutions before film casting displays a transition that suggests gel formation above a critical concentration. Upon crossing this viscosity deflection concentration, the line shape analysis of the absorption spectra within a photophysical aggregate model reveals a gradual increase in interchain excitonic coupling. We also observe a red-shifted and line-narrowed steady-state photoluminescence spectrum along with increasing resonance Raman intensity in the stretching and torsional modes of the dithienothiophene unit, which suggests a longer exciton coherence length along the polymer-chain backbone. Furthermore, we observe a change of line shape in the photoinduced absorption component of the transient absorption spectrum. The derivative-like line shape may originate from two possibilities: a new excited-state absorption or Stark effect, both of which are consistent with the emergence of a high-energy shoulder as seen in both photoluminescence and absorption spectra. Therefore, we conclude that the exciton is more dispersed along the polymer chain backbone with increasing concentrations, leading to the hypothesis that polymer chain order is enhanced when the push-pull polymers are processed at higher concentrations. Thus, tuning the microscopic chain conformation by concentration would be another factor of interest when considering the polymer assembly pathways for pursuing large-area and high-performance organic optoelectronic devices.
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Affiliation(s)
- Yulong Zheng
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, 901 Atlantic Drive, Atlanta, Georgia 30332, United States
| | - Rahul Venkatesh
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332, United States
| | - Connor P. Callaway
- Department
of Chemistry and Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Campbell Viersen
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, 901 Atlantic Drive, Atlanta, Georgia 30332, United States
| | - Kehinde H. Fagbohungbe
- Department
of Chemistry and Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Aaron L. Liu
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332, United States
| | - Chad Risko
- Department
of Chemistry and Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Elsa Reichmanis
- Department
of Chemical & Biomolecular Engineering, Lehigh University, 124 East Morton Street, Bethlehem, Pennsylvania 18015, United States
| | - Carlos Silva-Acuña
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, 901 Atlantic Drive, Atlanta, Georgia 30332, United States
- School
of Physics, Georgia Institute of Technology, 837 State Street, Atlanta, Georgia 30332, United States
- School
of Materials Science and Engineering, Georgia
Institute of Technology, North Avenue, Atlanta, Georgia 30332, United States
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6
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Meskers SCJ. The Exciton Model for Molecular Materials: Past, Present and Future? Chemphyschem 2023:e202300666. [PMID: 38010974 DOI: 10.1002/cphc.202300666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 10/09/2023] [Indexed: 11/29/2023]
Abstract
In assemblies of identical molecules or chromophores, electronic excitations can be described as excitons, bound electron-hole pairs that can move from site to site as a pair in a coherent manner. The understanding of excitons is crucial when trying to engineer favorable photophysical properties through structuring organic molecular matter. In recent decades, limitations of the concept of an exciton have become clear. The exciton can hybridize with phonon and photons. To clarify these issues, the exciton is discussed within the broader context of the gauge properties of the electromagnetic force.
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Affiliation(s)
- Stefan C J Meskers
- Molecular Materials and Nanosystems Institute for Complex Molecular Systems, Department of Chemical Engineering and Chemistry, Eindhoven university of Technology, 5600 MB, Eindhoven, The Netherlands
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7
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Nellissen AC, Fron E, Vandenwijngaerden JBF, De Feyter S, Mertens SFL, Van der Auweraer M. Spectroscopic Characterization of Thiacarbocyanine Dye Molecules Adsorbed on Hexagonal Boron Nitride: a Time-Resolved Study. ACS OMEGA 2023; 8:35638-35652. [PMID: 37810698 PMCID: PMC10552479 DOI: 10.1021/acsomega.3c02020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 09/06/2023] [Indexed: 10/10/2023]
Abstract
Physisorption on hexagonal boron nitride (hBN) gained interest over the years thanks to its properties (chemically and thermally stable, insulating properties, etc.) and similarities to the well-known graphene. A recent study showed flat-on adsorption of several cationic thiacarbocyanine dyes on hBN with a tendency to form weakly coupled H- or I-type aggregates, while a zwitterionic thiacarbocyanine dye rather led to a tilted adsorption. With this in-depth time-resolved study using the TC-SPC technique, we confirm the results proven by adsorption isotherms, atomic force microscopy, and stationary state spectroscopy combined with molecular mechanics simulations and estimation of the corresponding exciton interaction. The absence of a systematic trend for the dependence of the decay times, normalized amplitudes of the decay components, and contribution of different components to the stationary emission spectra upon the emission wavelength observed for all studied dyes and coverages suggests the occurrence of a single emitting species. At low coverage levels, the non-mono-exponential character of the decays was attributed to adsorption on different sites characterized by different intramolecular rotational freedom or energy transfer to nonfluorescent traps or a combination of both. The difference between the decay rates of the four dyes reflects a different density of the nonfluorescent traps. Although the decay time of the unquenched dyes was in the order of magnitude of that of dye monomers in a rigid environment, it is also compatible with weakly coupled aggregates such as proposed earlier based on the stationary spectra. Hence, the adsorption leads to a rigid environment of the dyes, blocking internal conversion. Increasing the concentration of the dye solution from which the adsorption on hBN occurs increases not only the coverage of the hBN surface but also the extent of energy transfer to nonfluorescent traps. For TDC (5,5-dichloro-3-3'-diethyl-9-ethyl-thiacarbocyanine) and TD2 (3-3'-diethyl-9-ethyl-thiacarbocyanine), besides direct energy transfer to traps, exciton hopping between dye dimers followed by energy transfer to these traps occurs, which resulted in a decreasing decay time of the longest decaying component. For all dyes, it was also possible to analyze the fluorescence decays as a stretched exponential as would be expected for energy transfer to randomly distributed traps in a two-dimensional (2D) geometry. This analysis yielded a fluorescence decay time of the unquenched dyes similar to the longest decay time obtained by analysis of the fluorescence decays as a sum of three of four exponentials.
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Affiliation(s)
- Anne-Charlotte Nellissen
- Laboratory
for Photochemistry and Spectroscopy, KU
Leuven, Chem & Tech,
Celestijnenlaan 200F, 3001 Leuven, Belgium
| | - Eduard Fron
- Laboratory
for Photochemistry and Spectroscopy, KU
Leuven, Chem & Tech,
Celestijnenlaan 200F, 3001 Leuven, Belgium
| | | | - Steven De Feyter
- Laboratory
for Photochemistry and Spectroscopy, KU
Leuven, Chem & Tech,
Celestijnenlaan 200F, 3001 Leuven, Belgium
| | - Stijn F. L. Mertens
- Department
of Chemistry, Energy Lancaster and Materials Science Institute, Lancaster University, Bailrigg, LA1 4YB Lancaster, United Kingdom
| | - Mark Van der Auweraer
- Laboratory
for Photochemistry and Spectroscopy, KU
Leuven, Chem & Tech,
Celestijnenlaan 200F, 3001 Leuven, Belgium
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8
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Gelin MF, Borrelli R. Thermo-Field Dynamics Approach to Photo-induced Electronic Transitions Driven by Incoherent Thermal Radiation. J Chem Theory Comput 2023; 19:6402-6413. [PMID: 37656914 DOI: 10.1021/acs.jctc.3c00590] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/03/2023]
Abstract
The effects of thermal light-matter interaction on the dynamics of photo-induced electronic transitions in molecules are investigated using a novel first principles approach based on the thermo-field dynamics description of both the molecular vibrational modes and of the radiation field. The developed approach permits numerically accurate simulations of quantum dynamics of electronic/excitonic systems coupled to nuclear and photonic baths kept at different temperatures. The baths can be described by arbitrary spectral densities and can have any system-bath coupling strengths. In agreement with the results obtained previously by less rigorous methods, we show that the excitation process obtained by the continuous interaction with the suddenly turned-on thermal radiation field creates a mixed ensemble having a nonnegligible component consisting of a superposition of vibronic eigenstates which can sustain coherent oscillations for relatively long times. The results become especially relevant for the dynamics of electronic transitions upon sunlight excitation. Analytical results based on time-dependent perturbation theory support the numerical simulations and provide a simple interpretation of the time evolution of quantum observables.
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Affiliation(s)
- Maxim F Gelin
- School of Sciences, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Raffaele Borrelli
- DISAFA, University of Torino, Largo Paolo Braccini 2, Grugliasco I-10095, Italy
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9
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Turelli M, Ciofini I, Wang Q, Ottochian A, Labat F, Adamo C. Organic compounds for solid state luminescence enhancement/aggregation induced emission: a theoretical perspective. Phys Chem Chem Phys 2023; 25:17769-17786. [PMID: 37377211 DOI: 10.1039/d3cp02364h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
Organic luminophores displaying one or more forms of luminescence enhancement in solid state are extremely promising for the development and performance optimization of functional materials essential to many modern key technologies. Yet, the effort to harness their huge potential is riddled with hurdles that ultimately come down to a limited understanding of the interactions that result in the diverse molecular environments responsible for the macroscopic response. In this context, the benefits of a theoretical framework able to provide mechanistic explanations to observations, supported by quantitative predictions of the phenomenon, are rather apparent. In this perspective, we review some of the established facts and recent developments about the current theoretical understanding of solid-state luminescence enhancement (SLE) with an accent on aggregation-induced emission (AIE). A description of the macroscopic phenomenon and the questions it raises is accompanied by a discussion of the approaches and quantum chemistry methods that are more apt to model these molecular systems with the inclusion of an accurate yet efficient simulation of the local environment. A sketch of a general framework, building from the current available knowledge, is then attempted via the analysis of a few varied SLE/AIE molecular systems from literature. A number of fundamental elements are identified offering the basis for outlining design rules for molecular architectures exhibiting SLE that involve specific structural features with the double role of modulating the optical response of the luminophores and defining the environment they experience in solid state.
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Affiliation(s)
- Michele Turelli
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, Theoretical Chemistry and Modeling Team, 75005 Paris, France.
| | - Ilaria Ciofini
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, Theoretical Chemistry and Modeling Team, 75005 Paris, France.
| | - Qinfan Wang
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, Theoretical Chemistry and Modeling Team, 75005 Paris, France.
| | - Alistar Ottochian
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, Theoretical Chemistry and Modeling Team, 75005 Paris, France.
| | - Frédéric Labat
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, Theoretical Chemistry and Modeling Team, 75005 Paris, France.
| | - Carlo Adamo
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, Theoretical Chemistry and Modeling Team, 75005 Paris, France.
- Institut Universitaire de France, 103 Boulevard Saint Michel, F-75005 Paris, France
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10
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Richardson BJ, Zhang C, Rauthe P, Unterreiner AN, Golberg DV, Poad BLJ, Frisch H. Peptide Self-Assembly Controlled Photoligation of Polymers. J Am Chem Soc 2023. [PMID: 37433011 DOI: 10.1021/jacs.3c03961] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2023]
Abstract
Highly efficient chemical ligations that operate in water under mild conditions are the foundation of bioorthogonal chemistry. However, the toolbox of suitable reactions is limited. Conventional approaches to expand this toolbox aim at altering the inherent reactivity of functional groups to design new reactions that meet the required benchmarks. Inspired by controlled reaction environments that enzymes provide, we report a fundamentally different approach that makes inefficient reactions highly efficient within defined local environments. Contrasting enzymatically catalyzed reactions, the reactivity controlling self-assembled environment is brought about by the ligation targets themselves─avoiding the use of a catalyst. Targeting [2 + 2] photocycloadditions, which are inefficient at low concentrations and readily quenched by oxygen, short β-sheet encoded peptide sequences are inserted between a hydrophobic photoreactive styrylpyrene unit and a hydrophilic polymer. In water, electrostatic repulsion of deprotonated amino acid residues governs the formation of small self-assembled structures, which enable a highly efficient photoligation of the polymer, reaching ∼90% ligation within 2 min (0.034 mM). Upon protonation at low pH, the self-assembly changes into 1D fibers, altering photophysical properties and shutting down the photocycloaddition reaction. Using the reversible morphology change, it is possible to switch the photoligation "ON" or "OFF" under constant irradiation simply by varying the pH. Importantly, in dimethylformamide, the photoligation reaction did not occur even at 10-fold higher concentrations (0.34 mM). The self-assembly into a specific architecture, encoded into the polymer ligation target, enables a highly efficient ligation that overcomes the concentration limitations and high oxygen sensitivity of [2 + 2] photocycloadditions.
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Affiliation(s)
- Bailey J Richardson
- School of Chemistry and Physics, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
- Centre for Materials Science, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
| | - Chao Zhang
- School of Chemistry and Physics, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
- Centre for Materials Science, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
- Central Analytical Research Facility, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
| | - Pascal Rauthe
- Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 2, Karlsruhe 76131, Germany
| | - Andreas-Neil Unterreiner
- Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 2, Karlsruhe 76131, Germany
| | - Dmitri V Golberg
- School of Chemistry and Physics, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
- Centre for Materials Science, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
| | - Berwyck L J Poad
- School of Chemistry and Physics, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
- Centre for Materials Science, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
- Central Analytical Research Facility, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
| | - Hendrik Frisch
- School of Chemistry and Physics, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
- Centre for Materials Science, Queensland University of Technology, 2 George Street, Brisbane, Queensland 4000, Australia
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11
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Bhat V, Callaway CP, Risko C. Computational Approaches for Organic Semiconductors: From Chemical and Physical Understanding to Predicting New Materials. Chem Rev 2023. [PMID: 37141497 DOI: 10.1021/acs.chemrev.2c00704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
While a complete understanding of organic semiconductor (OSC) design principles remains elusive, computational methods─ranging from techniques based in classical and quantum mechanics to more recent data-enabled models─can complement experimental observations and provide deep physicochemical insights into OSC structure-processing-property relationships, offering new capabilities for in silico OSC discovery and design. In this Review, we trace the evolution of these computational methods and their application to OSCs, beginning with early quantum-chemical methods to investigate resonance in benzene and building to recent machine-learning (ML) techniques and their application to ever more sophisticated OSC scientific and engineering challenges. Along the way, we highlight the limitations of the methods and how sophisticated physical and mathematical frameworks have been created to overcome those limitations. We illustrate applications of these methods to a range of specific challenges in OSCs derived from π-conjugated polymers and molecules, including predicting charge-carrier transport, modeling chain conformations and bulk morphology, estimating thermomechanical properties, and describing phonons and thermal transport, to name a few. Through these examples, we demonstrate how advances in computational methods accelerate the deployment of OSCsin wide-ranging technologies, such as organic photovoltaics (OPVs), organic light-emitting diodes (OLEDs), organic thermoelectrics, organic batteries, and organic (bio)sensors. We conclude by providing an outlook for the future development of computational techniques to discover and assess the properties of high-performing OSCs with greater accuracy.
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Affiliation(s)
- Vinayak Bhat
- Department of Chemistry & Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506-0055, United States
| | - Connor P Callaway
- Department of Chemistry & Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506-0055, United States
| | - Chad Risko
- Department of Chemistry & Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506-0055, United States
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12
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Jiang Y, Zhang J, Jung SR, Chen H, Xu S, Chiu DT. High-Precision Mapping of Membrane Proteins on Synaptic Vesicles using Spectrally Encoded Super-Resolution Imaging. Angew Chem Int Ed Engl 2023; 62:e202217889. [PMID: 36581589 PMCID: PMC9908834 DOI: 10.1002/anie.202217889] [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: 12/07/2022] [Revised: 12/27/2022] [Accepted: 12/29/2022] [Indexed: 12/31/2022]
Abstract
The spatial resolution of single-molecule localization microscopy is limited by the photon number of a single switching event because of the difficulty of correlating switching events dispersed in time. Here we overcome this limitation by developing a new class of photoswitching semiconducting polymer dots (Pdots) with structured and highly dispersed single-particle spectra. We imaged the Pdots at the first and the second vibronic emission peaks and used the ratio of peak intensities as a spectral coding. By correlating switching events using the spectral coding and performing 4-9 frame binning, we achieved a 2-3 fold experimental resolution improvement versus conventional superresolution imaging. We applied this method to count and map SV2 and proton ATPase proteins on synaptic vesicles (SVs). The results reveal that these proteins are trafficked and organized with high precision, showing unprecedented level of detail about the composition and structure of SVs.
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Affiliation(s)
- Yifei Jiang
- Departments of Chemistry and Bioengineering, University of Washington, Seattle, Washington 98195, USA
- Institute of Basic Medicine and Cancer, Chinese Academy of Science, Hangzhou, Zhejiang 310016, China
| | - Jicheng Zhang
- Departments of Chemistry and Bioengineering, University of Washington, Seattle, Washington 98195, USA
| | - Seung-Ryoung Jung
- Departments of Chemistry and Bioengineering, University of Washington, Seattle, Washington 98195, USA
| | - Haobin Chen
- Departments of Chemistry and Bioengineering, University of Washington, Seattle, Washington 98195, USA
| | - Shihan Xu
- Departments of Chemistry and Bioengineering, University of Washington, Seattle, Washington 98195, USA
| | - Daniel T. Chiu
- Departments of Chemistry and Bioengineering, University of Washington, Seattle, Washington 98195, USA
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13
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Majumder R, Dey S, Jana D, Ghorai BK. Donor-acceptor cyanostilbene based nano-AIEgens: Synthesis and properties. RESULTS IN CHEMISTRY 2023. [DOI: 10.1016/j.rechem.2023.100856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
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14
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Ghosh R, Paesani F. Connecting the dots for fundamental understanding of structure-photophysics-property relationships of COFs, MOFs, and perovskites using a Multiparticle Holstein Formalism. Chem Sci 2023; 14:1040-1064. [PMID: 36756323 PMCID: PMC9891456 DOI: 10.1039/d2sc03793a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 11/09/2022] [Indexed: 11/17/2022] Open
Abstract
Photoactive organic and hybrid organic-inorganic materials such as conjugated polymers, covalent organic frameworks (COFs), metal-organic frameworks (MOFs), and layered perovskites, display intriguing photophysical signatures upon interaction with light. Elucidating structure-photophysics-property relationships across a broad range of functional materials is nontrivial and requires our fundamental understanding of the intricate interplay among excitons (electron-hole pair), polarons (charges), bipolarons, phonons (vibrations), inter-layer stacking interactions, and different forms of structural and conformational defects. In parallel with electronic structure modeling and data-driven science that are actively pursued to successfully accelerate materials discovery, an accurate, computationally inexpensive, and physically-motivated theoretical model, which consistently makes quantitative connections with conceptually complicated experimental observations, is equally important. Within this context, the first part of this perspective highlights a unified theoretical framework in which the electronic coupling as well as the local coupling between the electronic and nuclear degrees of freedom can be efficiently described for a broad range of quasiparticles with similarly structured Holstein-style vibronic Hamiltonians. The second part of this perspective discusses excitonic and polaronic photophysical signatures in polymers, COFs, MOFs, and perovskites, and attempts to bridge the gap between different research fields using a common theoretical construct - the Multiparticle Holstein Formalism. We envision that the synergistic integration of state-of-the-art computational approaches with the Multiparticle Holstein Formalism will help identify and establish new, transformative design strategies that will guide the synthesis and characterization of next-generation energy materials optimized for a broad range of optoelectronic, spintronic, and photonic applications.
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Affiliation(s)
- Raja Ghosh
- Department of Chemistry and Biochemistry, University of California La Jolla San Diego California 92093 USA
| | - Francesco Paesani
- Department of Chemistry and Biochemistry, University of California La Jolla San Diego California 92093 USA
- San Diego Supercomputer Center, University of California La Jolla San Diego California 92093 USA
- Materials Science and Engineering, University of California La Jolla San Diego California 92093 USA
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15
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Zakutauskaitė K, Mačernis M, Nguyen HH, Ogilvie JP, Abramavičius D. Extracting the excitonic Hamiltonian of a chlorophyll dimer from broadband two-dimensional electronic spectroscopy. J Chem Phys 2023; 158:015103. [PMID: 36610982 DOI: 10.1063/5.0108166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We apply Frenkel exciton theory to model the entire Q-band of a tightly bound chlorophyll dimer inspired by the photosynthetic reaction center of photosystem II. The potential of broadband two-dimensional electronic spectroscopy experiment spanning the Qx and Qy regions to extract the parameters of the model dimer Hamiltonian is examined through theoretical simulations of the experiment. We find that the local nature of Qx excitation enables identification of molecular properties of the delocalized Qy excitons. Specifically, we demonstrate that the cross-peak region, where excitation energy is resonant with Qy while detection is at Qx, contains specific spectral signatures that can reveal the full real-space molecular Hamiltonian, a task that is impossible by considering the Qy transitions alone. System-bath coupling and site energy disorder in realistic systems may limit the resolution of these spectral signatures due to spectral congestion.
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Affiliation(s)
- Kristina Zakutauskaitė
- Institute of Chemical Physics, Vilnius University, Sauletekio al. 9-III, Vilnius, Lithuania
| | - Mindaugas Mačernis
- Institute of Chemical Physics, Vilnius University, Sauletekio al. 9-III, Vilnius, Lithuania
| | - Hoang H Nguyen
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Jennifer P Ogilvie
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Darius Abramavičius
- Institute of Chemical Physics, Vilnius University, Sauletekio al. 9-III, Vilnius, Lithuania
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16
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Boeije Y, Olivucci M. From a one-mode to a multi-mode understanding of conical intersection mediated ultrafast organic photochemical reactions. Chem Soc Rev 2023; 52:2643-2687. [PMID: 36970950 DOI: 10.1039/d2cs00719c] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
This review discusses how ultrafast organic photochemical reactions are controlled by conical intersections, highlighting that decay to the ground-state at multiple points of the intersection space results in their multi-mode character.
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Affiliation(s)
- Yorrick Boeije
- Van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Massimo Olivucci
- Chemistry Department, University of Siena, Via Aldo Moro n. 2, 53100 Siena, Italy
- Chemistry Department, Bowling Green State University, Overman Hall, Bowling Green, Ohio 43403, USA
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17
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Yin F, De J, Liu M, Huang H, Geng H, Yao J, Liao Q, Fu H. High-Performance Organic Laser Semiconductor Enabling Efficient Light-Emitting Transistors and Low-Threshold Microcavity Lasers. NANO LETTERS 2022; 22:5803-5809. [PMID: 35848711 DOI: 10.1021/acs.nanolett.2c01345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
An organic light-emitting transistor (OLET) is a candidate device architecture for developing electrically pumped organic solid-state lasers, but it remains a critical challenge because of the lack of organic semiconductors that simultaneously possess a high solid-state emission efficiency (Φs), a high and balanced ambipolar mobility (μh,e), and a large stimulated emission cross-section. Here, we designed a molecule of 4,4'-bis(2-dibenzothiophenyl-vinyl)-biphenyl (DBTVB) and prepared its ultrathin single-crystal microplates with herringbone packing arrangements, which achieve balanced mobilities of μh = 3.55 ± 0.5 and μe = 2.37 ± 0.5 cm2 V-1 s-1, a high Φs of 85 ± 3%, and striking low-threshold laser characteristics. Theoretical and experimental investigations reveal that a strong electronic coupling and a small reorganization energy ensure efficient charge transport; meanwhile, the exciton-vibration effect and negligible π-π orbital overlap give rise to highly emissive H-aggregates and facilitate laser emission. Furthermore, OLET-based DBTVB crystals offer an internal quantum efficiency approaching 100% and a record-high electroluminescence external quantum efficiency of 4.03%.
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Affiliation(s)
- Fan Yin
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China
| | - Jianbo De
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China
| | - Meihui Liu
- Beijing Key Laboratory for Optical Materials and Photonic Devices Department of Chemistry, Capital Normal University & Beijing Advanced Innovation Center for Imaging Theory and Technology, Beijing 100048, P. R. China
| | - Han Huang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China
| | - Hua Geng
- Beijing Key Laboratory for Optical Materials and Photonic Devices Department of Chemistry, Capital Normal University & Beijing Advanced Innovation Center for Imaging Theory and Technology, Beijing 100048, P. R. China
| | - Jiannian Yao
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, P.R. China
| | - Qing Liao
- Beijing Key Laboratory for Optical Materials and Photonic Devices Department of Chemistry, Capital Normal University & Beijing Advanced Innovation Center for Imaging Theory and Technology, Beijing 100048, P. R. China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices Department of Chemistry, Capital Normal University & Beijing Advanced Innovation Center for Imaging Theory and Technology, Beijing 100048, P. R. China
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18
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Cainelli M, Borrelli R, Tanimura Y. Effect of mixed Frenkel and charge transfer states in time-gated fluorescence spectra of perylene bisimides H-aggregates: Hierarchical equations of motion approach. J Chem Phys 2022; 157:084103. [DOI: 10.1063/5.0102000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We theoretically investigated the effect of mixed Frenkel (F) and charge transfer (CT) states on the spectral properties of perylene bisimide (PBI) derivatives, focusing on the role of strong electron-phonon interactions. The model consists of a four-level system described by the Holstein Hamiltonian coupled to independent local heat-baths on each site, described by Brownian spectral distribution functions. We employ the reduced hierarchical equations of motion (HEOM) approach to calculate the time evolution of the system and compare it to the pure F exciton cases. We compute the absorption and time-gated fluorescence (TGF) spectra for different exciton transfer integrals and F-CT band gap conditions. The coherence length of excitons ($N_{coh}$) is evaluated employing two different definitions. We observe the presence of an excited hot state peak whose intensity is associated with the delocalization of the excited species and ultrafast dynamics that are solely dependent on the frequency of the local bath. The results indicate that the inclusion of CT states promotes localization of the excitons which is manifested in a decrease in the intensity of the hot state peak and the 0--1 peak, and an increase in the intensity of the 0--0 emission peak in TGF spectrum, leading to a decrease of $N_{coh}$.
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Affiliation(s)
| | - Raffaele Borrelli
- Department of Agricoltural Science, Università degli Studi di Torino, Italy
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19
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Bauer B, Sharma R, Chergui M, Oppermann M. Exciton decay mechanism in DNA single strands: back-electron transfer and ultrafast base motions. Chem Sci 2022; 13:5230-5242. [PMID: 35655577 PMCID: PMC9093102 DOI: 10.1039/d1sc06450a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 04/09/2022] [Indexed: 12/03/2022] Open
Abstract
The photochemistry of DNA systems is characterized by the ultraviolet (UV) absorption of π-stacked nucleobases, resulting in exciton states delocalized over several bases. As their relaxation sensitively depends on local stacking conformations, disentangling the ensuing electronic and structural dynamics has remained an experimental challenge, despite their fundamental role in protecting the genome from potentially harmful UV radiation. Here we use transient absorption and transient absorption anisotropy spectroscopy with broadband femtosecond deep-UV pulses (250–360 nm) to resolve the exciton dynamics of UV-excited adenosine single strands under physiological conditions. Due to the exceptional deep-UV bandwidth and polarization sensitivity of our experimental approach, we simultaneously resolve the population dynamics, charge-transfer (CT) character and conformational changes encoded in the UV transition dipoles of the π-stacked nucleotides. Whilst UV excitation forms fully charge-separated CT excitons in less than 0.3 ps, we find that most decay back to the ground state via a back-electron transfer. Based on the anisotropy measurements, we propose that this mechanism is accompanied by a structural relaxation of the photoexcited base-stack, involving an inter-base rotation of the nucleotides. Our results finally complete the exciton relaxation mechanism for adenosine single strands and offer a direct view into the coupling of electronic and structural dynamics in aggregated photochemical systems. Despite its key role in DNA photochemistry, the decay mechanism of excitons in stacked bases has remained difficult to resolve. Ultrafast polarization spectroscopy now reveals a back-electron transfer and ultrafast base motions in adenosine strands.![]()
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Affiliation(s)
- Benjamin Bauer
- Laboratory of Ultrafast Spectroscopy (LSU), Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne, ISIC-FSB CH-1015 Lausanne Switzerland
| | - Rahul Sharma
- Laboratory for Computation and Visualization in Mathematics and Mechanics, École Polytechnique Fédérale de Lausanne, MATH-FSB CH-1015 Lausanne Switzerland
| | - Majed Chergui
- Laboratory of Ultrafast Spectroscopy (LSU), Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne, ISIC-FSB CH-1015 Lausanne Switzerland
| | - Malte Oppermann
- Laboratory of Ultrafast Spectroscopy (LSU), Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne, ISIC-FSB CH-1015 Lausanne Switzerland
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20
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Biswas S, Kim J, Zhang X, Scholes GD. Coherent Two-Dimensional and Broadband Electronic Spectroscopies. Chem Rev 2022; 122:4257-4321. [PMID: 35037757 DOI: 10.1021/acs.chemrev.1c00623] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Over the past few decades, coherent broadband spectroscopy has been widely used to improve our understanding of ultrafast processes (e.g., photoinduced electron transfer, proton transfer, and proton-coupled electron transfer reactions) at femtosecond resolution. The advances in femtosecond laser technology along with the development of nonlinear multidimensional spectroscopy enabled further insights into ultrafast energy transfer and carrier relaxation processes in complex biological and material systems. New discoveries and interpretations have led to improved design principles for optimizing the photophysical properties of various artificial systems. In this review, we first provide a detailed theoretical framework of both coherent broadband and two-dimensional electronic spectroscopy (2DES). We then discuss a selection of experimental approaches and considerations of 2DES along with best practices for data processing and analysis. Finally, we review several examples where coherent broadband and 2DES were employed to reveal mechanisms of photoinitiated ultrafast processes in molecular, biological, and material systems. We end the review with a brief perspective on the future of the experimental techniques themselves and their potential to answer an even greater range of scientific questions.
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Affiliation(s)
- Somnath Biswas
- Department of Chemistry, Princeton University, Princeton, New Jersey 08 544, United States
| | - JunWoo Kim
- Department of Chemistry, Princeton University, Princeton, New Jersey 08 544, United States
| | - Xinzi Zhang
- Department of Chemistry, Princeton University, Princeton, New Jersey 08 544, United States
| | - Gregory D Scholes
- Department of Chemistry, Princeton University, Princeton, New Jersey 08 544, United States
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21
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Borrelli R, Dolgov S. Expanding the Range of Hierarchical Equations of Motion by Tensor-Train Implementation. J Phys Chem B 2021; 125:5397-5407. [DOI: 10.1021/acs.jpcb.1c02724] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Raffaele Borrelli
- DISAFA, University of Torino, Largo Paolo Braccini 2, Grugliasco 10095, Italy
| | - Sergey Dolgov
- University of Bath, Claverton Down, BA2 7AY Bath, United Kingdom
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22
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Ghosh R, Paesani F. Unraveling the effect of defects, domain size, and chemical doping on photophysics and charge transport in covalent organic frameworks. Chem Sci 2021; 12:8373-8384. [PMID: 34221318 PMCID: PMC8221171 DOI: 10.1039/d1sc01262b] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/12/2021] [Indexed: 11/21/2022] Open
Abstract
Understanding the underlying physical mechanisms that govern charge transport in two-dimensional (2D) covalent organic frameworks (COFs) will facilitate the development of novel COF-based devices for optoelectronic and thermoelectric applications. In this context, the low-energy mid-infrared absorption contains valuable information about the structure-property relationships and the extent of intra- and inter-framework "hole" polaron delocalization in doped and undoped polymeric materials. In this study, we provide a quantitative characterization of the intricate interplay between electronic defects, domain sizes, pore volumes, chemical dopants, and three dimensional anisotropic charge migration in 2D COFs. We compare our simulations with recent experiments on doped COF films and establish the correlations between polaron coherence, conductivity, and transport signatures. By obtaining the first quantitative agreement with the measured absorption spectra of iodine doped (aza)triangulene-based COF, we highlight the fundamental differences between the underlying microstructure, spectral signatures, and transport physics of polymers and COFs. Our findings provide conclusive evidence of why iodine doped COFs exhibit lower conductivity compared to doped polythiophenes. Finally, we propose new research directions to address existing limitations and improve charge transport in COFs for applications in functional molecular electronic devices.
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Affiliation(s)
- Raja Ghosh
- Department of Chemistry and Biochemistry, University of California San Diego La Jolla California 92093 USA
| | - Francesco Paesani
- Department of Chemistry and Biochemistry, University of California San Diego La Jolla California 92093 USA
- San Diego Supercomputer Center, University of California San Diego La Jolla California 92093 USA
- Materials Science and Engineering, University of California San Diego La Jolla California 92093 USA
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23
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Nematiaram T, Padula D, Troisi A. Bright Frenkel Excitons in Molecular Crystals: A Survey. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2021; 33:3368-3378. [PMID: 34526736 PMCID: PMC8432684 DOI: 10.1021/acs.chemmater.1c00645] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/14/2021] [Indexed: 05/12/2023]
Abstract
We computed the optical properties of a large set of molecular crystals (∼2200 structures) composed of molecules whose lowest excited states are strongly coupled and generate wide excitonic bands. Such bands are classified in terms of their dimensionality (1-, 2-, and 3-dimensional), the position of the optically allowed state in relation with the excitonic density of states, and the presence of Davydov splitting. The survey confirms that one-dimensional aggregates are rare in molecular crystals highlighting the need to go beyond the simple low-dimensional models. Furthermore, this large set of data is used to search for technologically interesting and less common properties. For instance, we considered the largest excitonic bandwidth that is achievable within known molecular crystals and identified materials with strong super-radiant states. Finally, we explored the possibility that strong excitonic coupling can be used to generate emissive states in the near-infrared region in materials formed by molecules with bright visible absorption and we could identify the maximum allowable red shift in this material class. These insights with the associated searchable database provide practical guidelines for designing materials with interesting optical properties.
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Affiliation(s)
- Tahereh Nematiaram
- Department
of Chemistry and Materials Innovation Factory, University of Liverpool, Liverpool L69 7ZD, U.K.
| | - Daniele Padula
- Dipartimento
di Biotecnologie, Chimica e Farmacia, Università
di Siena, via A. Moro 2, Siena 53100, Italy
| | - Alessandro Troisi
- Department
of Chemistry and Materials Innovation Factory, University of Liverpool, Liverpool L69 7ZD, U.K.
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24
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Li Y, Wang K, Liao Q, Fu L, Gu C, Yu Z, Fu H. Tunable Triplet-Mediated Multicolor Lasing from Nondoped Organic TADF Microcrystals. NANO LETTERS 2021; 21:3287-3294. [PMID: 33724847 DOI: 10.1021/acs.nanolett.1c00632] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Thermally activated delayed fluorescent (TADF) emitters have received great attention in organic light-emitting diodes and laser diodes because of high exciton utilization efficiency and low optical loss caused by triplets. However, the direct observation of lasing emission from nondoped TADF microcrystals has yet to be reported. Here, we demonstrated a three-color (green, yellow, and red) microlaser from three nondoped TADF microcrystals with well-controlled geometries. The temperature-dependent dynamic analyses testify that the regenerated singlets which originated from the reverse intersystem crossing process at room temperature are beneficial for population inversion and reduce triplet-absorption/annihilation optical loses, together resulting in thermally activated lasing actions. Thanks to single-crystalline structures of TADF emitters, the relationship between triplet-harvesting capability and the molecular structure was systematically investigated. The results not only offer rational design of pure TADF gain materials but also provide guidance for the high-performance electrically driven organic solid-state lasers and multicolor laser integration.
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Affiliation(s)
- Yuan Li
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, P. R. China
| | - Kai Wang
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, P. R. China
| | - Qing Liao
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, P. R. China
| | - Liyuan Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, P. R. China
| | - Chunling Gu
- Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhenyi Yu
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, P. R. China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, P. R. China
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25
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Liu M, Wei Y, Ou Q, Yu P, Wang G, Duan Y, Geng H, Peng Q, Shuai Z, Liao Y. Molecular Design Strategy for Simultaneously Strong Luminescence and High Mobility: Multichannel CH-π Interaction. J Phys Chem Lett 2021; 12:938-946. [PMID: 33439658 DOI: 10.1021/acs.jpclett.0c03453] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
It is a big challenge to achieve high-performance organic semiconductor materials integrating both high luminescence efficiency and carrier mobility, because they are commonly regarded as a pair of contradiction. Here, combining a tight-binding model and density functional theory/time-dependent density functional theory, we propose a theoretical protocol to characterize the luminescence efficiency via an excitonic effective mass and charge transport ability via charge effective mass at the same level. Applying this protocol to a series of organic semiconductor materials, we find that the multichannel CH-π interaction can induce a heavy excitonic effective mass and light charge effective mass, which effectively balance the light-emitting efficiency and carrier mobility. Thus, a practical molecular design strategy is figured out to exploit novel organic semiconductor materials with strong luminescence and fast carrier transport simultaneously.
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Affiliation(s)
- Meihui Liu
- Department of Chemistry, Beijing Advanced Innovation Center for Imaging Theory and Technology Capital Normal University, Beijing 100048, China
| | - Yuling Wei
- Department of Chemistry, Beijing Advanced Innovation Center for Imaging Theory and Technology Capital Normal University, Beijing 100048, China
| | - Qi Ou
- Department of Chemistry, Tsinghua University, Beijing 100083, China
| | - Peiyi Yu
- Department of Chemistry, Beijing Advanced Innovation Center for Imaging Theory and Technology Capital Normal University, Beijing 100048, China
| | - Guo Wang
- Department of Chemistry, Beijing Advanced Innovation Center for Imaging Theory and Technology Capital Normal University, Beijing 100048, China
| | - Yuai Duan
- Department of Chemistry, Beijing Advanced Innovation Center for Imaging Theory and Technology Capital Normal University, Beijing 100048, China
| | - Hua Geng
- Department of Chemistry, Beijing Advanced Innovation Center for Imaging Theory and Technology Capital Normal University, Beijing 100048, China
| | - Qian Peng
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhigang Shuai
- Department of Chemistry, Tsinghua University, Beijing 100083, China
| | - Yi Liao
- Department of Chemistry, Beijing Advanced Innovation Center for Imaging Theory and Technology Capital Normal University, Beijing 100048, China
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26
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Zhang D, Yokomori S, Kameyama R, Zhao C, Ueda A, Zhang L, Kumai R, Murakami Y, Meng H, Mori H. Effect of Alkyl Chain Length on Charge Transport Property of Anthracene-Based Organic Semiconductors. ACS APPLIED MATERIALS & INTERFACES 2021; 13:989-998. [PMID: 33332081 DOI: 10.1021/acsami.0c16144] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Anthracene, a simple planar building block for organic semiconductors, shows strong intermolecular interactions and exhibits strong blue fluorescence. Thus, its derivatives have a great potential to integrate considerable charge carrier mobility and strong emission within a molecule. Here, we systematically studied the influence of alkyl chain length on the crystal structures, thermal properties, photophysical characteristics, electrochemical behaviors, and mobilities for a series of 2,6-di(4-alkyl-phenyl)anthracenes (Cn-Ph-Ants, where n represents the alkyl chain length). Among them, Cn-Ph-Ants (n = 0, 1, 2, and 3) display similar layered herringbone (LHB) packing motifs, which facilitate two-dimensional charge transport and thereby enables high-performance organic field-effect transistors (OFETs). All Cn-Ph-Ants exhibit similar work functions and show strong blue fluorescence with photoluminescence quantum yields (PLQY) of approximately 40% in toluene. In addition, the absolute powder PLQYs of C0-, C2-, C3-, C4-, and C6-Ph-Ants are 24.6, 8.2, 5.7, 10.9, and 8.6%, respectively. Note that the alkyl chain length shows a significant effect on the charge mobilities of Cn-Ph-Ants. Our newly synthesized C1-, C3-, and C4-Ph-Ants show hole mobilities of up to 2.40, 1.34, and 1.00 cm2 V-1 s-1, respectively, with mobilities of 3.40, 1.57, and 0.82 cm2 V-1 s-1 for C0-, C2-, and C6-Ph-Ants, indicating an increasing tendency of mobility with shorter alkyl chain length. This feature is related to the microstructures of the thin films, which reveal the enhanced film order, crystallinity, and grain size with a decrease in the alkyl chain length. Moreover, we theoretically analyze the intermolecular transfer integrals of HOMOs, which increase at T-shaped contacts as the alkyl chain length decreases, which improves the intermolecular charge transport properties, leading to the increases in mobility. Interestingly, the anisotropy of the transfer integral tends to decrease upon substitution with longer alkyl chains, suggesting that alkyl chain adjustments may facilitate isotropic charge transport property in 2,6-alkylated anthracenes.
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Affiliation(s)
- Dongwei Zhang
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - So Yokomori
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Ryohei Kameyama
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Changbin Zhao
- School of Advanced Materials, Peking University Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Akira Ueda
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
- Department of Chemistry, Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan
| | - Lei Zhang
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
| | - Reiji Kumai
- Condensed Matter Research Center (CMRC) and Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 3050801, Japan
| | - Youichi Murakami
- Condensed Matter Research Center (CMRC) and Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 3050801, Japan
| | - Hong Meng
- School of Advanced Materials, Peking University Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Hatsumi Mori
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan
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27
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Green JA, Asha H, Santoro F, Improta R. Excitonic Model for Strongly Coupled Multichromophoric Systems: The Electronic Circular Dichroism Spectra of Guanine Quadruplexes as Test Cases. J Chem Theory Comput 2021; 17:405-415. [PMID: 33378185 DOI: 10.1021/acs.jctc.0c01100] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We here propose a general and flexible approach, based on fragment diabatization, which incorporates charge transfer states and significantly increases the reliability of excitonic Hamiltonians for systems where the chromophores are very close. This model (FrDEx) is used to compute the electronic circular dichroism and absorption spectra of two prototype guanine-rich DNA sequences folded in quadruple helices (GQs), i.e., a fragment of the human telomeric sequence (Tel21, antiparallel), and (TGGGGT)4 (TG4T, parallel). Calculations on different subsets of Tel21 and TG4T, from dimers to tetramers, show that FrDEx provides spectra close to the reference full quantum mechanical (QM) ones (obtained with time-dependent density functional theory), with significant improvements with respect to "standard" excitonic Hamiltonians. Furthermore, these tests enable the most cost-effective procedure for the whole GQ to be determined. FrDEx spectra of Tel21 and TG4T are also in good agreement with the QM and experimental ones and give access to interesting insights into the chemical-physical effects modulating the spectral signals. FrDEx could be profitably used to investigate many other biological and nanotechnological materials, from DNA to (opto)electronic polymers.
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Affiliation(s)
- James A Green
- Consiglio Nazionale delle Ricerche, Istituto di Biostrutture e Bioimmagini (IBB-CNR), via Mezzocannone 16, I-80136 Napoli, Italy
| | - Haritha Asha
- Consiglio Nazionale delle Ricerche, Istituto di Biostrutture e Bioimmagini (IBB-CNR), via Mezzocannone 16, I-80136 Napoli, Italy
| | - Fabrizio Santoro
- Consiglio Nazionale delle Ricerche, Istituto di Chimica dei Composti Organo Metallici (ICCOM-CNR), SS di Pisa, Area della Ricerca, via G. Moruzzi 1, I-56124 Pisa, Italy
| | - Roberto Improta
- Consiglio Nazionale delle Ricerche, Istituto di Biostrutture e Bioimmagini (IBB-CNR), via Mezzocannone 16, I-80136 Napoli, Italy
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28
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Abdulkarim A, Nathusius M, Bäuerle R, Strunk KP, Beck S, Räder HJ, Pucci A, Melzer C, Jänsch D, Freudenberg J, Bunz UHF, Müllen K. Beyond p-Hexaphenylenes: Synthesis of Unsubstituted p-Nonaphenylene by a Precursor Protocol. Chemistry 2021; 27:281-288. [PMID: 32786130 PMCID: PMC7839583 DOI: 10.1002/chem.202001531] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 08/11/2020] [Indexed: 11/12/2022]
Abstract
The synthesis of unsubstituted oligo‐para‐phenylenes (OPP) exceeding para‐hexaphenylene—in the literature often referred to as p‐sexiphenyl—has long remained elusive due to their insolubility. We report the first preparation of unsubstituted para‐nonaphenylenes (9PPs) by extending our precursor route to poly‐para‐phenylenes (PPP) to a discrete oligomer. Two geometric isomers of methoxylated syn‐ and anti‐cyclohexadienylenes were synthesized, from which 9PP was obtained via thermal aromatization in thin films. 9PP was characterized via optical, infrared and solid‐state 13C NMR spectroscopy as well as atomic force microscopy and mass spectrometry, and compared to polymeric analogues. Due to the lack of substitution, para‐nonaphenylene, irrespective of the precursor isomer employed, displays pronounced aggregation in the solid state. Intermolecular excitonic coupling leads to formation of H‐type aggregates, red‐shifting emission of the films to greenish. 9PP allows to study the structure–property relationship of para‐phenylene oligomers and polymers, especially since the optical properties of PPP depend on the molecular shape of the precursor.
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Affiliation(s)
- Ali Abdulkarim
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.,InnovationLab, Speyerer Str. 4, 69115, Heidelberg, Germany
| | - Marvin Nathusius
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.,InnovationLab, Speyerer Str. 4, 69115, Heidelberg, Germany.,Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Rainer Bäuerle
- InnovationLab, Speyerer Str. 4, 69115, Heidelberg, Germany.,Kirchhoff-Institut für Physik, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany
| | - Karl-Philipp Strunk
- Kirchhoff-Institut für Physik, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany.,Centre for Advanced Materials, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
| | - Sebastian Beck
- InnovationLab, Speyerer Str. 4, 69115, Heidelberg, Germany.,Kirchhoff-Institut für Physik, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany
| | - Hans Joachim Räder
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Annemarie Pucci
- InnovationLab, Speyerer Str. 4, 69115, Heidelberg, Germany.,Kirchhoff-Institut für Physik, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany.,Centre for Advanced Materials, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
| | - Christian Melzer
- InnovationLab, Speyerer Str. 4, 69115, Heidelberg, Germany.,Kirchhoff-Institut für Physik, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 227, 69120, Heidelberg, Germany.,Centre for Advanced Materials, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
| | - Daniel Jänsch
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.,InnovationLab, Speyerer Str. 4, 69115, Heidelberg, Germany
| | - Jan Freudenberg
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.,InnovationLab, Speyerer Str. 4, 69115, Heidelberg, Germany
| | - Uwe H F Bunz
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.,InnovationLab, Speyerer Str. 4, 69115, Heidelberg, Germany.,Centre for Advanced Materials, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
| | - Klaus Müllen
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
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29
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Hu W, Sun K, Xu Q, Chen L, Zhao Y. Ultrafast dynamics in rubrene and its spectroscopic manifestation. J Chem Phys 2020; 153:174105. [DOI: 10.1063/5.0023887] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Wangjun Hu
- School of Science, Hangzhou Dianzi University, Hangzhou 310018, China
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Kewei Sun
- School of Science, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Quan Xu
- School of Science, Hangzhou Dianzi University, Hangzhou 310018, China
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Lipeng Chen
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Strasse 38, D-01187 Dresden, Germany
| | - Yang Zhao
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
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30
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Abstract
ConspectusExcitons and polarons play a central role in the electronic and optical properties of organic semiconducting polymers and molecular aggregates and are of fundamental importance in understanding the operation of organic optoelectronic devices such as solar cells and light-emitting diodes. For many conjugated organic molecules and polymers, the creation of neutral electronic excitations or ionic radicals is associated with significant nuclear relaxation, the bulk of which occurs along the vinyl-stretching mode or the aromatic-quinoidal stretching mode when conjugated rings are present. Within a polymer chain or molecular aggregate, nuclear relaxation competes with energy- and charge-transfer, mediated by electronic interactions between the constituent units (repeat units for polymers and individual chromophores for a molecular aggregate); for neutral electronic excitations, such inter-unit interactions lead to extended excited states or excitons, while for positive (or negative) charges, interactions lead to delocalized hole (or electron) polarons. The electronic coupling as well as the local coupling between electronic and nuclear degrees of freedom in both excitons and polarons can be described with a Holstein Hamiltonian. However, although excitons and polarons derive from similarly structured Hamiltonians, their optical signatures are quite distinct, largely due to differing ground states and optical selection rules.In this Account, we explore the similarities and differences in the spectral response of excitons and polarons in organic polymers and molecular aggregates. We limit our analysis to the subspace of excitons and hole polarons containing at most one excitation; hence we omit the influence of bipolarons, biexcitons, and higher multiparticle excitations. Using a generic linear array of coupled units as a model host for both excitons and polarons, we compare and contrast the optical responses of both quasiparticles, with a particular emphasis on the spatial coherence length, the length over which an exciton or polaron possesses wave-like properties important for more efficient transport. For excitons, the UV-vis absorption spectrum is generally represented by a distorted vibronic progression with H-like or J-like signatures depending on the sign of the electronic coupling, Jex. The spectrum broadens with increasing site disorder, with the spectral area preserved due to an oscillator strength sum rule. For (hole) polarons, the generally stronger electronic coupling results in a mid-IR spectrum consisting of a narrow, low-energy peak (A) with energy near a vibrational quantum of the vinyl stretching mode, and a broader, higher-energy feature (B). In contrast to the UV-vis spectrum, the mid-IR spectrum is invariant to the sign of the electronic coupling, th, and completely resistant to long-range disorder, where it remains entirely homogeneously broadened. Even in the presence of short-range disorder, the width of peak A remains surprisingly narrow as long as |th| remains sufficiently large, a property that can be understood in terms of Herzberg-Teller coupling. Unlike for excitons, for polarons, the absorption spectral area decreases with increasing short-range disorder σ (i.e., there is no oscillator sum rule) reflective of a decreasing polaron coherence length. The intensity of the low-energy peak A in relation to B is an important signature of polaron coherence. By contrast, for excitons, the absorption spectrum contains no unambiguous signs of exciton coherence. One must instead resort to the shape of the steady-state photoluminescence spectrum. The Holstein-based model has been highly successful in accounting for the spectral properties of molecular aggregates as well as conjugated polymers like poly(3-hexylthiophene) (P3HT) in the mid-IR and UV-vis spectral regions.
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Affiliation(s)
- Raja Ghosh
- Department of Chemistry Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Frank C. Spano
- Department of Chemistry Temple University, Philadelphia, Pennsylvania 19122, United States
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31
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Albano G, Pescitelli G, Di Bari L. Chiroptical Properties in Thin Films of π-Conjugated Systems. Chem Rev 2020; 120:10145-10243. [PMID: 32892619 DOI: 10.1021/acs.chemrev.0c00195] [Citation(s) in RCA: 235] [Impact Index Per Article: 58.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chiral π-conjugated molecules provide new materials with outstanding features for current and perspective applications, especially in the field of optoelectronic devices. In thin films, processes such as charge conduction, light absorption, and emission are governed not only by the structure of the individual molecules but also by their supramolecular structures and intermolecular interactions to a large extent. Electronic circular dichroism, ECD, and its emission counterpart, circularly polarized luminescence, CPL, provide tools for studying aggregated states and the key properties to be sought for designing innovative devices. In this review, we shall present a comprehensive coverage of chiroptical properties measured on thin films of organic π-conjugated molecules. In the first part, we shall discuss some general concepts of ECD, CPL, and other chiroptical spectroscopies, with a focus on their applications to thin film samples. In the following, we will overview the existing literature on chiral π-conjugated systems whose thin films have been characterized by ECD and/or CPL, as well other chiroptical spectroscopies. Special emphasis will be put on systems with large dissymmetry factors (gabs and glum) and on the application of ECD and CPL to derive structural information on aggregated states.
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Affiliation(s)
- Gianluigi Albano
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi 13, 56124 Pisa, Italy
| | - Gennaro Pescitelli
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi 13, 56124 Pisa, Italy
| | - Lorenzo Di Bari
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi 13, 56124 Pisa, Italy
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32
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Farahvash A, Lee CK, Sun Q, Shi L, Willard AP. Machine learning Frenkel Hamiltonian parameters to accelerate simulations of exciton dynamics. J Chem Phys 2020; 153:074111. [DOI: 10.1063/5.0016009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Affiliation(s)
- Ardavan Farahvash
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | | | - Qiming Sun
- Tencent America, Palo Alto, California 94306, USA
| | - Liang Shi
- Department of Chemistry and Chemical Biology, University of California, Merced, California 95343, USA
| | - Adam P. Willard
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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33
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34
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Allard C, Schué L, Fossard F, Recher G, Nascimento R, Flahaut E, Loiseau A, Desjardins P, Martel R, Gaufrès E. Confinement of Dyes inside Boron Nitride Nanotubes: Photostable and Shifted Fluorescence down to the Near Infrared. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2001429. [PMID: 32483892 DOI: 10.1002/adma.202001429] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/20/2020] [Accepted: 04/27/2020] [Indexed: 05/28/2023]
Abstract
Fluorescence is ubiquitous in life science and used in many fields of research ranging from ecology to medicine. Among the most common fluorogenic compounds, dyes are being exploited in bioimaging for their outstanding optical properties from UV down to the near IR (NIR). However, dye molecules are often toxic to living organisms and photodegradable, which limits the time window for in vivo experiments. Here, it is demonstrated that organic dye molecules are passivated and photostable when they are encapsulated inside a boron nitride nanotube (dyes@BNNT). The results show that the BNNTs drive an aggregation of the encapsulated dyes, which induces a redshifted fluorescence from visible to NIR-II. The fluorescence remains strong and stable, exempt of bleaching and blinking, over a time scale longer than that of free dyes by more than 104 . This passivation also reduces the toxicity of the dyes and induces exceptional chemical robustness, even in harsh conditions. These properties are highlighted in bioimaging where the dyes@BNNT nanohybrids are used as fluorescent nanoprobes for in vivo monitoring of Daphnia Pulex microorganisms and for diffusion tracking on human hepatoblastoma cells with two-photon imaging.
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Affiliation(s)
- Charlotte Allard
- Département de génie physique, Polytechnique Montréal, Montréal, Québec, H3C 3A7, Canada
| | - Léonard Schué
- Département de chimie, Université de Montréal, Montréal, Québec, H3C 3J7, Canada
| | - Frédéric Fossard
- Laboratoire d'Etude des Microstructures, ONERA-CNRS, UMR104, Université Paris-Saclay, BP 72, Châtillon, 92322, France
| | - Gaëlle Recher
- CNRS & Institut d'Optique, UMR 5298, Talence, F-33400, France
- LP2N, Laboratoire Photonique Numerique et Nanosciences, University of Bordeaux, Talence, F-33400, France
| | - Rafaella Nascimento
- Département de chimie, Université de Montréal, Montréal, Québec, H3C 3J7, Canada
| | - Emmanuel Flahaut
- CIRIMAT, Université de Toulouse, CNRS, INPT, UPS, UMR CNRS-UPS-INP N°5085, Université Toulouse 3 Paul Sabatier, Bât. CIRIMAT, 118, route de Narbonne, Toulouse, 31062, France
| | - Annick Loiseau
- Laboratoire d'Etude des Microstructures, ONERA-CNRS, UMR104, Université Paris-Saclay, BP 72, Châtillon, 92322, France
| | - Patrick Desjardins
- Département de génie physique, Polytechnique Montréal, Montréal, Québec, H3C 3A7, Canada
| | - Richard Martel
- Département de chimie, Université de Montréal, Montréal, Québec, H3C 3J7, Canada
| | - Etienne Gaufrès
- Laboratoire d'Etude des Microstructures, ONERA-CNRS, UMR104, Université Paris-Saclay, BP 72, Châtillon, 92322, France
- CNRS & Institut d'Optique, UMR 5298, Talence, F-33400, France
- LP2N, Laboratoire Photonique Numerique et Nanosciences, University of Bordeaux, Talence, F-33400, France
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35
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Lee CK, Willard AP. Representing the Molecular Signatures of Disordered Molecular Semiconductors in Size-Extendable Models of Exciton Dynamics. J Phys Chem B 2020; 124:5238-5245. [PMID: 32422051 DOI: 10.1021/acs.jpcb.0c02898] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This manuscript presents an approach to developing size-extendable phenomenological site-based models for simulating exciton dynamics in disordered organic molecular semiconducting materials. This approach extends an existing methodology that assigns the parameters of the time-dependent Frenkel exciton model by applying fragmentation-based electronic structure calculations to the output of classical molecular dynamics simulations. This methodology is inherently limited by the system size of the all-atom simulation, which is well below the performance capability of site-based models. Here, we demonstrate that this system size limitation can be effectively overcome by defining a size-extendable surrogate model based on the correlated parameter statistics derived from existing fragmentation-based methods. We demonstrate our approach on a monolayer film of sexithiophene molecules, first validating the accuracy of the surrogate system in reproducing exciton dynamical properties of a 150 molecule system, then extending it to systems of 2500 molecules. With this extended system, we explore the sensitivity of exciton dynamics to variations in the temperature as well as the amplitude and spatial correlations of energetic disorder. We conclude that exciton dynamics can be significantly enhanced in morphologies with spatially correlated molecular configurations but only if the overall distribution of site energies is sufficiently broad.
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Affiliation(s)
- Chee Kong Lee
- Tencent America, Palo Alto, California 94306, United States
| | - Adam P Willard
- Department of Chemistry, MIT, Cambridge, Massachusetts 02139, United States
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36
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Spano FC. Exciton-phonon polaritons in organic microcavities: Testing a simple ansatz for treating a large number of chromophores. J Chem Phys 2020; 152:204113. [PMID: 32486687 DOI: 10.1063/5.0002164] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Polaritons in an ensemble of permutationally symmetric chromophores confined to an optical microcavity are investigated numerically. The analysis is based on the Holstein-Tavis-Cummings Hamiltonian which accounts for the coupling between an electronic excitation on each chromophore and a single cavity mode, as well as the coupling between the electronic and nuclear degrees of freedom on each chromophore. A straightforward ensemble partitioning scheme is introduced, which, along with an intuitive ansatz, allows one to obtain accurate evaluations of the lowest-energy polaritons using a subset of collective states. The polaritons include all three degrees of freedom-electronic, vibronic, and photonic-and can therefore be described as exciton-phonon polaritons. Applications focus on the limiting regimes where the Rabi frequency is small or large compared to the nuclear relaxation energy subsequent to optical excitation, with relaxation occurring mainly along the vinyl stretching coordinate in conjugated organic chromophores. Comparisons are also made to the more conventional vibronic polariton approach, which does not take into account two-particle excitations and vibration-photon states.
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Affiliation(s)
- Frank C Spano
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
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37
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Sun Y, Geng H, Peng Q, Shuai Z. Computational Study on the Charge Transport and Optical Spectra of Anthracene Derivatives in Aggregates. Chemphyschem 2020; 21:952-957. [PMID: 32182404 DOI: 10.1002/cphc.202000187] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 03/16/2020] [Indexed: 11/09/2022]
Abstract
A recent experiment [Angew. Chem. Int. Ed. 2017, 56, 722-727] found that a (1 : 9) blend film of two anthracene derivatives, 2-fluorenyl-2-anthracene (FlAnt) and 2-anthryl-2-anthracence (2 A), exhibit both efficient white light emission and high hole mobility, thus promising for organic light-emitting transistors (OLETs). Employing quantum chemistry at the polarizable continuum model (PCM) and the quantum mechanics/molecular mechanics (QM/MM) levels, we investigated the excited-state structures, optical spectra, band structure and the carrier mobility for FlAnt and 2 A from solution to aggregate phases. We suggest using the ratio of intermolecular excitonic coupling J and intramolecular excited state relaxation energy E to judge the bathochromic shift in optical emission in aggregates. For FlAnt, ρ=J/E is calculated to be less than 0.17, a critical value we identified earlier, and the spectra in solution and aggregate phases present quite similar features (blue emission). However, ρ is ∼0.5 for 2 A systems, and the calculated emission in the aggregate phase exhibits a remarkable bathochromic shift. In addition, the 0-0 emission is strongly suppressed in the herringbone stacking. These observations justify the experimental findings that (i) 2 A is blue emissive in solution but yellow-green in the aggregate phase, whereas FlAnt is always blue, and (ii) the blend of them show white emission. By using the "quantum nuclear tunneling" model we proposed earlier, we found the hole mobility for FlAnt and 2 A are 0.5 and 4.2 cm2 V-1 s-1 , respectively, indicating both are good hole transport materials.
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Affiliation(s)
- Yajing Sun
- Department of Chemistry, Tianjin University, Tianjin, 300072, PR China
| | - Hua Geng
- Department of Chemistry, Capital Normal University, Beijing, 100048, PR China
| | - Qian Peng
- Key Laboratory of Organic Solids and, Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Zhigang Shuai
- MOE Key Laboratory of Organic Optoelectronics and, Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing, 100084, PR China
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38
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Janke SM, Qarai MB, Blum V, Spano FC. Frenkel-Holstein Hamiltonian applied to absorption spectra of quaterthiophene-based 2D hybrid organic-inorganic perovskites. J Chem Phys 2020; 152:144702. [PMID: 32295353 DOI: 10.1063/1.5139044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
For the prototypical two-dimensional hybrid organic-inorganic perovskites (2D HOIPs) (AE4T)PbX4 (X = Cl, Br, and I), we demonstrate that the Frenkel-Holstein Hamiltonian (FHH) can be applied to describe the absorption spectrum arising from the organic component. We first model the spectra using only the four nearest neighbor couplings between translationally inequivalent molecules in the organic herringbone lattice as fitting parameters in the FHH. We next use linear-response time-dependent density functional theory (LR-TDDFT) to calculate molecular transition densities, from which extended excitonic couplings are evaluated based on the atomic positions within the 2D HOIPs. We find that both approaches reproduce the experimentally observed spectra, including changes in their shape and peak positions. The spectral changes are correlated with a decrease in excitonic coupling from X = Cl to X = I. Importantly, the LR-TDDFT-based approach with extended excitonic couplings not only gives better agreement with the experimental absorption line shape than the approach using a restricted set of fitted parameters but also allows us to relate the changes in excitonic coupling to the underlying geometry. We accordingly find that the decrease in excitonic coupling from X = Cl to Br to I is due to an increase in molecular separation, which in turn can be related to the increasing Pb-X bond length from Cl to I. Our research opens up a potential pathway to predicting optoelectronic properties of new 2D HOIPs from ab initio calculations and to gain insight into structural relations from 2D HOIP absorption spectra.
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Affiliation(s)
- Svenja M Janke
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA
| | - Mohammad B Qarai
- Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - Volker Blum
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, USA
| | - Frank C Spano
- Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
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39
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Hagara J, Mrkyvkova N, NádaŽdy P, Hodas M, Bodík M, Jergel M, Majková E, Tokár K, Hutár P, Sojková M, Chumakov A, Konovalov O, Pandit P, Roth S, Hinderhofer A, Hulman M, Siffalovic P, Schreiber F. Reorientation of π-conjugated molecules on few-layer MoS 2 films. Phys Chem Chem Phys 2020; 22:3097-3104. [PMID: 31967129 DOI: 10.1039/c9cp05728e] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Small π-conjugated organic molecules have attracted substantial attention in the past decade as they are considered as candidates for future organic-based (opto-)electronic applications. The molecular arrangement in the organic layer is one of the crucial parameters that determine the efficiency of a given device. The desired orientation of the molecules is achieved by a proper choice of the underlying substrate and growth conditions. Typically, one underlying material supports only one inherent molecular orientation at its interface. Here, we report on two different orientations of diindenoperylene (DIP) molecules on the same underlayer, i.e. on a few-layer MoS2 substrate. We show that DIP molecules adopt a lying-down orientation when deposited on few-layer MoS2 with horizontally oriented layers. In contrast, for vertically aligned MoS2 layers, DIP molecules are arranged in a standing-up manner. Employing in situ and real-time grazing-incidence wide-angle X-ray scattering (GIWAXS), we monitored the stress evolution within the thin DIP layer from the early stages of the growth, revealing different substrate-induced phases for the two molecular orientations. Our study opens up new possibilities for the next-generation of flexible electronics, which might benefit from the combination of MoS2 layers with unique optical and electronic properties and an extensive reservoir of small organic molecules.
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Affiliation(s)
- Jakub Hagara
- Institute of Physics, Slovak Academy of Sciences, Dúbravská Cesta 9, 845 11 Bratislava, Slovakia.
| | - Nada Mrkyvkova
- Institute of Physics, Slovak Academy of Sciences, Dúbravská Cesta 9, 845 11 Bratislava, Slovakia. and Center for Advanced Materials Application, Slovak Academy of Sciences, Dúbravská Cesta 9, Bratislava 84511, Slovakia
| | - Peter NádaŽdy
- Institute of Physics, Slovak Academy of Sciences, Dúbravská Cesta 9, 845 11 Bratislava, Slovakia.
| | - Martin Hodas
- Institute of Applied Physics, University of Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen, Germany
| | - Michal Bodík
- Institute of Physics, Slovak Academy of Sciences, Dúbravská Cesta 9, 845 11 Bratislava, Slovakia.
| | - Matej Jergel
- Institute of Physics, Slovak Academy of Sciences, Dúbravská Cesta 9, 845 11 Bratislava, Slovakia. and Center for Advanced Materials Application, Slovak Academy of Sciences, Dúbravská Cesta 9, Bratislava 84511, Slovakia
| | - Eva Majková
- Institute of Physics, Slovak Academy of Sciences, Dúbravská Cesta 9, 845 11 Bratislava, Slovakia. and Center for Advanced Materials Application, Slovak Academy of Sciences, Dúbravská Cesta 9, Bratislava 84511, Slovakia
| | - Kamil Tokár
- Institute of Physics, Slovak Academy of Sciences, Dúbravská Cesta 9, 845 11 Bratislava, Slovakia. and Advanced Technologies Research Institute, Faculty of Materials Science and Technology in Trnava, Slovak University of Technology in Bratislava, 917 24 Trnava, Slovakia
| | - Peter Hutár
- Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská Cesta 9, 845 11 Bratislava, Slovakia
| | - Michaela Sojková
- Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská Cesta 9, 845 11 Bratislava, Slovakia
| | - Andrei Chumakov
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble 38000, France
| | - Oleg Konovalov
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble 38000, France
| | - Pallavi Pandit
- Photon Science, Deutsches Elektronen-Synchrotron (DESY), Hamburg 22607, Germany
| | - Stephan Roth
- Photon Science, Deutsches Elektronen-Synchrotron (DESY), Hamburg 22607, Germany
| | - Alexander Hinderhofer
- Institute of Applied Physics, University of Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen, Germany
| | - Martin Hulman
- Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská Cesta 9, 845 11 Bratislava, Slovakia
| | - Peter Siffalovic
- Institute of Physics, Slovak Academy of Sciences, Dúbravská Cesta 9, 845 11 Bratislava, Slovakia. and Center for Advanced Materials Application, Slovak Academy of Sciences, Dúbravská Cesta 9, Bratislava 84511, Slovakia
| | - Frank Schreiber
- Institute of Applied Physics, University of Tübingen, Auf der Morgenstelle 10, D-72076 Tübingen, Germany
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40
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Castellanos MA, Dodin A, Willard AP. On the design of molecular excitonic circuits for quantum computing: the universal quantum gates. Phys Chem Chem Phys 2020; 22:3048-3057. [DOI: 10.1039/c9cp05625d] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
This manuscript presents a strategy for controlling the transformation of excitonic states through the design of circuits made up of coupled organic dye molecules.
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Affiliation(s)
| | - Amro Dodin
- Department of Chemistry
- Massachusetts Institute of Technology
- Cambridge
- USA
| | - Adam P. Willard
- Department of Chemistry
- Massachusetts Institute of Technology
- Cambridge
- USA
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41
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Zheng J, Peng J, Xie Y, Long Y, Ning X, Lan Z. Study of the exciton dynamics in perylene bisimide (PBI) aggregates with symmetrical quasiclassical dynamics based on the Meyer–Miller mapping Hamiltonian. Phys Chem Chem Phys 2020; 22:18192-18204. [DOI: 10.1039/d0cp00648c] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The exciton dynamics in one-dimensional stacked PBI (Perylene Bisimide) aggregates was studied with SQC-MM dynamics (Symmetrical Quasiclassical Dynamics based on the Meyer–Miller mapping Hamiltonian).
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Affiliation(s)
- Jie Zheng
- Industrial Research Institute of Nonwovens & Technical Textiles
- Shandong Center for Engineered Nonwovens (SCEN)
- College of Textiles Clothing
- Qingdao University
- Qingdao 266071
| | - Jiawei Peng
- SCNU Environmental Research Institute
- Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment
- South China Normal University
- Guangzhou 510006
- China
| | - Yu Xie
- SCNU Environmental Research Institute
- Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment
- South China Normal University
- Guangzhou 510006
- China
| | - Yunze Long
- Industrial Research Institute of Nonwovens & Technical Textiles
- Shandong Center for Engineered Nonwovens (SCEN)
- College of Textiles Clothing
- Qingdao University
- Qingdao 266071
| | - Xin Ning
- Industrial Research Institute of Nonwovens & Technical Textiles
- Shandong Center for Engineered Nonwovens (SCEN)
- College of Textiles Clothing
- Qingdao University
- Qingdao 266071
| | - Zhenggang Lan
- SCNU Environmental Research Institute
- Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment
- South China Normal University
- Guangzhou 510006
- China
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42
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Zubiria-Ulacia M, Matxain JM, Casanova D. The role of CT excitations in PDI aggregates. Phys Chem Chem Phys 2020; 22:15908-15918. [DOI: 10.1039/d0cp02344b] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Energies and couplings of local excitations and charge transfer states control the nature of singlets and triplets in PDI aggregates.
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Affiliation(s)
- Maria Zubiria-Ulacia
- Donostia International Physics Center (DIPC)
- 20018 Donostia
- Spain
- Universidad del País Vasco/Euskal Herriko Unibertsitatea
- Euskadi
| | - Jon M. Matxain
- Universidad del País Vasco/Euskal Herriko Unibertsitatea
- Euskadi
- Spain
| | - David Casanova
- Donostia International Physics Center (DIPC)
- 20018 Donostia
- Spain
- IKERBASQUE
- Basque Foundation for Science
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43
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Jang SJ. Fourth order expressions for the electronic absorption lineshape of molecular excitons. J Chem Phys 2019; 151:044110. [DOI: 10.1063/1.5100986] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Seogjoo J. Jang
- Department of Chemistry and Biochemistry, Queens College, City University of New York, 65-30 Kissena Boulevard, Queens, New York 11367, USA and Ph.D. Programs in Chemistry and Physics, and Initiative for Theoretical Sciences, Graduate Center, City University of New York, 365 Fifth Avenue, New York, New York 10016, USA
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44
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Popp W, Polkehn M, Hughes KH, Martinazzo R, Burghardt I. Vibronic coupling models for donor-acceptor aggregates using an effective-mode scheme: Application to mixed Frenkel and charge-transfer excitons in oligothiophene aggregates. J Chem Phys 2019; 150:244114. [DOI: 10.1063/1.5100529] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Wjatscheslaw Popp
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt, Germany
| | - Matthias Polkehn
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt, Germany
| | - Keith H. Hughes
- School of Natural Sciences, Bangor University, Bangor, Gwynedd LL572UW, United Kingdom
| | - Rocco Martinazzo
- Department of Chemistry, Università degli Studi di Milano, v. Golgi 19, 20133 Milano, Italy
| | - Irene Burghardt
- Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt, Germany
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45
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Cruz CD, Yuan J, Climent C, Tierce NT, Christensen PR, Chronister EL, Casanova D, Wolf MO, Bardeen CJ. Using sulfur bridge oxidation to control electronic coupling and photochemistry in covalent anthracene dimers. Chem Sci 2019; 10:7561-7573. [PMID: 31489171 PMCID: PMC6713866 DOI: 10.1039/c8sc05598j] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 06/15/2019] [Indexed: 12/02/2022] Open
Abstract
For anthracene dimers bridged by a sulfur atom, modulating the sulfur oxidation state profoundly affects excited state behavior. The SO2-bridge supports long-lived states and photodimerization, while the S-bridge undergoes intersystem crossing.
Covalently tethered bichromophores provide an ideal proving ground to develop strategies for controlling excited state behavior in chromophore assemblies. In this work, optical spectroscopy and electronic structure theory are combined to demonstrate that the oxidation state of a sulfur linker between anthracene chromophores gives control over not only the photophysics but also the photochemistry of the molecules. Altering the oxidation state of the sulfur linker does not change the geometry between chromophores, allowing electronic effects between chromophores to be isolated. Previously, we showed that excitonic states in sulfur-bridged terthiophene dimers were modulated by electronic screening of the sulfur lone pairs, but that the sulfur orbitals were not directly involved in these states. In the bridged anthracene dimers that are the subject of the current paper, the atomic orbitals of the unoxidized S linker can actively mix with the anthracene molecular orbitals to form new electronic states with enhanced charge transfer character, different excitonic coupling, and rapid (sub-nanosecond) intersystem crossing that depends on solvent polarity. However, the fully oxidized SO2 bridge restores purely through-space electronic coupling between anthracene chromophores and inhibits intersystem crossing. Photoexcitation leads to either internal conversion on a sub-20 picosecond timescale, or to the creation of a long-lived emissive state that is the likely precursor of the intramolecular [4 + 4] photodimerization. These results illustrate how chemical modification of a single atom in the covalent bridge can dramatically alter not only the photophysics but also the photochemistry of molecules.
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Affiliation(s)
- Chad D Cruz
- Department of Chemistry , University of California Riverside , 501 Big Springs Road, Riverside , California 92521 , USA .
| | - Jennifer Yuan
- Department of Chemistry , University of British Columbia , 2036 Main Mall , Vancouver , BC , Canada V6T 1Z1
| | - Clàudia Climent
- Departamento de Física Teórica de la Materia Condensada , Universidad Autónoma de Madrid , E-28049 Madrid , Spain
| | - Nathan T Tierce
- Department of Chemistry , University of California Riverside , 501 Big Springs Road, Riverside , California 92521 , USA .
| | - Peter R Christensen
- Department of Chemistry , University of British Columbia , 2036 Main Mall , Vancouver , BC , Canada V6T 1Z1
| | - Eric L Chronister
- Department of Chemistry , University of California Riverside , 501 Big Springs Road, Riverside , California 92521 , USA .
| | - David Casanova
- Donostia International Physics Center (DIPC) , Paseo Manuel de Lardizabal 4 , 20018 Donostia , Euskadi , Spain.,IKERBASQUE , Basque Foundation for Science , 48013 Bilbao , Euskadi , Spain
| | - Michael O Wolf
- Department of Chemistry , University of British Columbia , 2036 Main Mall , Vancouver , BC , Canada V6T 1Z1
| | - Christopher J Bardeen
- Department of Chemistry , University of California Riverside , 501 Big Springs Road, Riverside , California 92521 , USA .
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46
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Basel BS, Hetzer C, Zirzlmeier J, Thiel D, Guldi R, Hampel F, Kahnt A, Clark T, Guldi DM, Tykwinski RR. Davydov splitting and singlet fission in excitonically coupled pentacene dimers. Chem Sci 2019; 10:3854-3863. [PMID: 31015927 PMCID: PMC6461118 DOI: 10.1039/c9sc00384c] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 02/21/2019] [Indexed: 11/21/2022] Open
Abstract
Singlet fission (SF) allows two charges to be generated from the absorption of a single photon and is, therefore, potentially transformative toward improving solar energy conversion. Key to the present study of SF is the design of pentacene dimers featuring a xanthene linker that strictly places two pentacene chromophores in a rigid arrangement and, in turn, enforces efficient, intramolecular π-overlap that mimics interactions typically found in condensed state (e.g., solids, films, etc.). Inter-chromophore communication ensures Davydov splitting, which plays an unprecedented role toward achieving SF in pentacene dimers. Transient absorption measurements document that intramolecular SF evolves upon excitation into the lower Davydov bands to form a correlated triplet pair at cryogenic temperature. At room temperature, the two spin-correlated triplets, one per pentacene moiety within the dimers, are electronically coupled to an excimer state. The presented results are transferable to a broad range of acene morphologies including aggregates, crystals, and films.
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Affiliation(s)
- Bettina Sabine Basel
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität (FAU) , Egerlandstrasse 3 , 91058 Erlangen , Germany .
| | - Constantin Hetzer
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität (FAU) , Nikolaus-Fiebiger-Strasse 10 , 91058 Erlangen , Germany
| | - Johannes Zirzlmeier
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität (FAU) , Egerlandstrasse 3 , 91058 Erlangen , Germany .
| | - Dominik Thiel
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität (FAU) , Egerlandstrasse 3 , 91058 Erlangen , Germany .
| | - Rebecca Guldi
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität (FAU) , Nikolaus-Fiebiger-Strasse 10 , 91058 Erlangen , Germany
| | - Frank Hampel
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität (FAU) , Nikolaus-Fiebiger-Strasse 10 , 91058 Erlangen , Germany
| | - Axel Kahnt
- Leibniz Institute of Surface Engineering (IOM) , Permoserstr. 15 , D-04318 Leipzig , Germany
| | - Timothy Clark
- Department of Chemistry and Pharmacy , Computer-Chemistry-Center (CCC) , Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , Nägelsbachstrasse 25 , 91052 Erlangen , Germany .
| | - Dirk Michael Guldi
- Department of Chemistry and Pharmacy , Interdisciplinary Center for Molecular Materials (ICMM) , Friedrich-Alexander-Universität (FAU) , Egerlandstrasse 3 , 91058 Erlangen , Germany .
| | - Rik R Tykwinski
- Department of Chemistry , University of Alberta , Edmonton , Alberta, T6G 2G2 , Canada .
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47
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Kowalczyk M, Chen N, Jang SJ. Comparative Computational Study of Electronic Excitations of Neutral and Charged Small Oligothiophenes and Their Extrapolations Based on Simple Models. ACS OMEGA 2019; 4:5758-5767. [PMID: 31459728 PMCID: PMC6648384 DOI: 10.1021/acsomega.8b02972] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 02/25/2019] [Indexed: 06/10/2023]
Abstract
This work reports electronic excitation energies of neutral and charged oligothiophenes (OT n ) with repeat unit n = 2-6 computed by routinely used semiempirical and time-dependent density functional theory (TD-DFT) methods. More specifically, for OT n , OTn +, and OTn -, we calculated vertical transition energies for electronic absorption spectroscopy employing the Zerner's version of intermediate neglect differential overlap method for structures optimized by the PM6 semiempirical method and the TD-DFT method with three different functionals, B3LYP, BVP86, and M06-2X, for structures optimized by the ground-state DFT method employing the same functionals. We also calculated vertical transition energies for the emission spectroscopy from the lowest singlet excited states by employing the TD-DFT method for the structures optimized for the lowest singlet excited states. In addition to computational results in vacuum, solution phase data calculated at the level of polarizable continuum model are reported and compared with available experimental data. Most of the data are fitted reasonably well by two simple model functions, one based on a Frenkel exciton theory and the other based on the model of independent electrons in a box with sinusoidal modulation of potential. Despite similar levels of fitting performance, the two models produce distinctively different asymptotic values of excitation energies. Comparison of these with available experimental and computational data suggests that the values based on the exciton model, while seemingly overestimating, are closer to true values than those based on the other model. This assessment is confirmed by additional calculations for a larger oligomer. The fitting parameters offer new means to understand the relationship between electronic excitations of OTs and their sizes and suggest the feasibility of constructing simple coarse-grained exciton-bath models applicable for aggregates of OTs.
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Affiliation(s)
- Marta Kowalczyk
- Department
of Chemistry and Biochemistry, Queens College, City University
of New York, 65-30 Kissena Boulevard, Queens, New York 11367, United
States
| | - Ning Chen
- Department
of Chemistry and Biochemistry, Queens College, City University
of New York, 65-30 Kissena Boulevard, Queens, New York 11367, United
States
- Ph.D.
Programs in Chemistry and Physics, and Initiative for the Theoretical
Sciences, Graduate Center, City University
of New York, 365 Fifth
Avenue, New York, New York 10016, United States
| | - Seogjoo J. Jang
- Department
of Chemistry and Biochemistry, Queens College, City University
of New York, 65-30 Kissena Boulevard, Queens, New York 11367, United
States
- Ph.D.
Programs in Chemistry and Physics, and Initiative for the Theoretical
Sciences, Graduate Center, City University
of New York, 365 Fifth
Avenue, New York, New York 10016, United States
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48
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Abstract
This account aims at providing an understanding of singlet fission, i.e., the photophysical process of a singlet state ( S1) splitting into two triplet states (2 × T1) in molecular chromophores. Since its discovery 50 years ago, the field of singlet fission has enjoyed rapid expansion in the past 8 years. However, there have been lingering confusion and debates on the nature of the all-important triplet pair intermediate states and the definition of singlet fission rates. Here we clarify the confusion from both theoretical and experimental perspectives. We distinguish the triplet pair state that maintains electronic coherence between the two constituent triplets, 1(TT), from one which does not, 1(T···T). Only the rate of formation of 1(T···T) is defined as that of singlet fission. We present distinct experimental evidence for 1(TT), whose formation may occur via incoherent and/or vibronic coherent mechanisms. We discuss the challenges in treating singlet fission beyond the dimer approximation, in understanding the often neglected roles of delocalization on singlet fission rates, and in realizing the much lauded goal of increasing solar energy conversion efficiencies with singlet fission chromophores.
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Affiliation(s)
- Kiyoshi Miyata
- Department of Chemistry , Columbia University , New York , New York 10027 , United States.,Department of Chemistry , Kyushu University , Fukuoka 819-0395 , Japan
| | - Felisa S Conrad-Burton
- Department of Chemistry , Columbia University , New York , New York 10027 , United States
| | - Florian L Geyer
- Department of Chemistry , Columbia University , New York , New York 10027 , United States
| | - X-Y Zhu
- Department of Chemistry , Columbia University , New York , New York 10027 , United States
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49
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Ding R, Wang XP, Feng J, Li XB, Dong FX, Tian WQ, Du JR, Fang HH, Wang HY, Yamao T, Hotta S, Sun HB. Clarification of the Molecular Doping Mechanism in Organic Single-Crystalline Semiconductors and their Application in Color-Tunable Light-Emitting Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1801078. [PMID: 30260510 DOI: 10.1002/adma.201801078] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 07/27/2018] [Indexed: 06/08/2023]
Abstract
Organic single-crystalline semiconductors with long-range periodic order have attracted much attention for potential applications in electronic and optoelectronic devices due to their high carrier mobility, highly thermal stability, and low impurity content. Molecular doping has been proposed as a valuable strategy for improving the performance of organic semiconductors and semiconductor-based devices. However, a fundamental understanding of the inherent doping mechanism is still a key challenge impeding its practical application. In this study, solid evidence for the "perfect" substitutional doping mechanism of the stacking mode between the guest and host molecules in organic single-crystalline semiconductors using polarized photoluminescence spectrum measurements and first-principles calculations is provided. The molecular host-guest doping is further exploited for efficient color-tunable and even white organic single-crystal-based light-emitting devices by controlling the doping concentration. The clarification of the molecular doping mechanism in organic single-crystalline semiconductor host-guest system paves the way for their practical application in high-performance electronic and optoelectronic devices.
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Affiliation(s)
- Ran Ding
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, China
- International Research Centre for Nano Handing and Manufacturing of China (CNM), Changchun University of Science and Technology, Changchun, 130022, China
| | - Xue-Peng Wang
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, China
| | - Jing Feng
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, China
| | - Xian-Bin Li
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, China
| | - Feng-Xi Dong
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, China
| | - Wei-Quan Tian
- College of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400044, China
| | - Jia-Ren Du
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, China
| | - Hong-Hua Fang
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, China
| | - Hai-Yu Wang
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, China
| | - Takeshi Yamao
- Department of Macromolecular Science and Engineering, Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki Sakyo-ku, Kyoto, 606-8585, Japan
| | - Shu Hotta
- Department of Macromolecular Science and Engineering, Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki Sakyo-ku, Kyoto, 606-8585, Japan
| | - Hong-Bo Sun
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, China
- State Key Lab of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Haidian, Beijing, 100084, China
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50
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Shi L, Willard AP. Modeling the effects of molecular disorder on the properties of Frenkel excitons in organic molecular semiconductors. J Chem Phys 2018; 149:094110. [DOI: 10.1063/1.5044553] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Affiliation(s)
- Liang Shi
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Adam P. Willard
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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