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Rijal K, Fuller N, Rudayni F, Zhang N, Zuo X, Berrie CL, Yip HL, Chan WL. Endothermic Charge Separation Occurs Spontaneously in Non-Fullerene Acceptor/Polymer Bulk Heterojunction. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2400578. [PMID: 38762779 DOI: 10.1002/adma.202400578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 04/22/2024] [Indexed: 05/20/2024]
Abstract
Organic photovoltaics (OPVs) based on non-fullerene acceptors (NFAs) have achieved a power conversion efficiency close to 20%. These NFA OPVs can generate free carriers efficiently despite a very small energy level offset at the donor/acceptor interface. Why these NFAs can enable efficient charge separation (CS) with low energy losses remains an open question. Here, the CS process in the PM6:Y6 bulk heterojunction is probed by time-resolved two-photon photoemission spectroscopy. It is found that the CS, the conversion from bound charge transfer (CT) excitons to free carriers, is an endothermic process with an enthalpy barrier of 0.15 eV. The CS can occur spontaneously despite being an endothermic process, which implies that it is driven by entropy. It is further argued that the morphology of the PM6:Y6 film and the anisotropic electron delocalization restrict the electron and hole wavefunctions within the CT exciton such that they can primarily contact each other through point-like junctions. This configuration can maximize the entropic driving force.
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Affiliation(s)
- Kushal Rijal
- Department of Physics and Astronomy, University of Kansas, Lawrence, KS, 66045, USA
| | - Neno Fuller
- Department of Physics and Astronomy, University of Kansas, Lawrence, KS, 66045, USA
| | - Fatimah Rudayni
- Department of Physics and Astronomy, University of Kansas, Lawrence, KS, 66045, USA
- Department of Physics, Jazan University, Jazan, 45142, Saudi Arabia
| | - Nan Zhang
- Department of Materials Science and Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, 999077, Hong Kong
| | - Xiaobing Zuo
- X-ray Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Cindy L Berrie
- Department of Chemistry, University of Kansas, Lawrence, KS, 66045, USA
| | - Hin-Lap Yip
- Department of Materials Science and Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, 999077, Hong Kong
- School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, 999077, Hong Kong
- Hong Kong Institute for Clean Energy, City University of Hong Kong, Tat Chee Avenue, Kowloon, 999077, Hong Kong
- Center of Super-Diamond and Advanced Films, City University of Hong Kong, Tat Chee Avenue, Kowloon, 999077, Hong Kong
| | - Wai-Lun Chan
- Department of Physics and Astronomy, University of Kansas, Lawrence, KS, 66045, USA
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2
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Lama B, Sarma M. Ultrafast Hot Exciton Nonadiabatic Excited-State Dynamics in Green Fluorescent Protein Chromophore Analogue. J Phys Chem B 2024; 128:6786-6796. [PMID: 38959128 DOI: 10.1021/acs.jpcb.4c02733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
The ultrafast high-energy nonadiabatic excited-state dynamics of the benzylidenedimethylimidazolinone chromophore dimer has been investigated using an electronic structure method coupled with on-the-fly quantitative wave function analysis to gain insight into the photophysics of hot excitons in biological systems. The dynamical simulation provides a rationalization of the behavior of the exciton in a dimer after the photoabsorption of light to higher-energy states. The results suggest that hot exciton localization within the manifold of excited states is caused by the hindrance of torsional rotation due to imidazolinone (I) or phenolate (P) bonds i.e., ΦI- or ΦP-dihedral rotation, in the monomeric units of a dimer. This hindrance arises due to weak π-π stacking interaction in the dimer, resulting in an energetically uphill excited-state barrier for ΦI- and ΦP-twisted rotation, impeding the isomerization process in the chromophore. Thus, this study highlights the potential impact of the weak π-π interaction in regulating the photodynamics of the green fluorescent protein chromophore derivatives.
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Affiliation(s)
- Bittu Lama
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam 781039, India
| | - Manabendra Sarma
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam 781039, India
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3
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Shimazaki T, Tachikawa M. Theoretical study of short-range exchange interaction based on semiconductor dielectric function model toward time-dependent dielectric density functional theory. J Chem Phys 2024; 161:014107. [PMID: 38949277 DOI: 10.1063/5.0207751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 06/12/2024] [Indexed: 07/02/2024] Open
Abstract
This study explores various models of semiconductor dielectric functions, with a specific emphasis on the large wavenumber spectrum and the derivation of the screened exchange interaction. Particularly, we discuss the short-range effect of the screened exchange potential. Our investigation reveals that the short-range effect originating from the high wavenumber spectrum is contingent upon the dielectric constant of the targeted system. To incorporate dielectric-dependent behaviors concerning the short-range aspect into the dielectric density functional theory (DFT) framework, we utilize the local Slater term and the Yukawa-type term, adjusting the ratio between these terms based on the dielectric constant. Additionally, we demonstrate the efficacy of the time-dependent dielectric DFT method in accurately characterizing the electronic structure of excited states in dyes and functional molecules. Several theoretical approaches have incorporated parameters dependent on the system to elucidate short-range exchange interactions. Our theoretical analysis and discussions will be useful for those studies.
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Affiliation(s)
- Tomomi Shimazaki
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-Ku, Yokohama 236-0026, Japan
| | - Masanori Tachikawa
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-Ku, Yokohama 236-0026, Japan
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Gierster L, Turkina O, Deinert JC, Vempati S, Baeta E, Garmshausen Y, Hecht S, Draxl C, Stähler J. Right On Time: Ultrafast Charge Separation Before Hybrid Exciton Formation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2403765. [PMID: 38874072 DOI: 10.1002/advs.202403765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Indexed: 06/15/2024]
Abstract
Organic/inorganic hybrid systems offer great potential for novel solar cell design combining the tunability of organic chromophore absorption properties with high charge carrier mobilities of inorganic semiconductors. However, often such material combinations do not show the expected performance: while ZnO, for example, basically exhibits all necessary properties for a successful application in light-harvesting, it was clearly outpaced by TiO2 in terms of charge separation efficiency. The origin of this deficiency has long been debated. This study employs femtosecond time-resolved photoelectron spectroscopy and many-body ab initio calculations to identify and quantify all elementary steps leading to the suppression of charge separation at an exemplary organic/ZnO interface. It is demonstrated that charge separation indeed occurs efficiently on ultrafast (350 fs) timescales, but that electrons are recaptured at the interface on a 100 ps timescale and subsequently trapped in a strongly bound (0.7 eV) hybrid exciton state with a lifetime exceeding 5 µs. Thus, initially successful charge separation is followed by delayed electron capture at the interface, leading to apparently low charge separation efficiencies. This finding provides a sufficiently large time frame for counter-measures in device design to successfully implement specifically ZnO and, moreover, invites material scientists to revisit charge separation in various kinds of previously discarded hybrid systems.
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Affiliation(s)
- Lukas Gierster
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany
- Department of Physical Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Olga Turkina
- Department of Physics, Humboldt-Universität zu Berlin, Newtonstr. 15, 12489, Berlin, Germany
| | - Jan-Christoph Deinert
- Department of Physical Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Sesha Vempati
- Department of Physical Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Elsie Baeta
- Department of Physical Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
| | - Yves Garmshausen
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany
| | - Stefan Hecht
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany
- Center for the Science of Materials Berlin, Humboldt-Universität zu Berlin, Zum Großen Windkanal 2, 12489, Berlin, Germany
| | - Claudia Draxl
- Department of Physics, Humboldt-Universität zu Berlin, Newtonstr. 15, 12489, Berlin, Germany
- Center for the Science of Materials Berlin, Humboldt-Universität zu Berlin, Zum Großen Windkanal 2, 12489, Berlin, Germany
| | - Julia Stähler
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489, Berlin, Germany
- Department of Physical Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195, Berlin, Germany
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5
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Citty B, Lynd JK, Gera T, Varvelo L, Raccah DIGB. MesoHOPS: Size-invariant scaling calculations of multi-excitation open quantum systems. J Chem Phys 2024; 160:144118. [PMID: 38619062 DOI: 10.1063/5.0197825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 03/11/2024] [Indexed: 04/16/2024] Open
Abstract
The photoexcitation dynamics of molecular materials on the 10-100 nm length scale depend on complex interactions between electronic and vibrational degrees of freedom, rendering exact calculations difficult or intractable. The adaptive Hierarchy of Pure States (adHOPS) is a formally exact method that leverages the locality imposed by interactions between thermal environments and electronic excitations to achieve size-invariant scaling calculations for single-excitation processes in systems described by a Frenkel-Holstein Hamiltonian. Here, we extend adHOPS to account for arbitrary couplings between thermal environments and vertical excitation energies, enabling formally exact, size-invariant calculations that involve multiple excitations or states with shared thermal environments. In addition, we introduce a low-temperature correction and an effective integration of the noise to reduce the computational expense of including ultrafast vibrational relaxation in Hierarchy of Pure States (HOPS) simulations. We present these advances in the latest version of the open-source MesoHOPS library and use MesoHOPS to characterize charge separation at a one-dimensional organic heterojunction when both the electron and hole are mobile.
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Affiliation(s)
- Brian Citty
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA
| | - Jacob K Lynd
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA
| | - Tarun Gera
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA
| | - Leonel Varvelo
- Department of Chemistry, Southern Methodist University, PO Box 750314 Dallas, Texas 75205, USA
| | - Doran I G B Raccah
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA
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6
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Sivanesan V, Broch K, Tegeder P. Excited States Dynamics at Pentacene/Perfluoropentacene Interfaces: A Femtosecond Time-Resolved Second Harmonic Generation Study. Chemphyschem 2024; 25:e202300904. [PMID: 38305504 DOI: 10.1002/cphc.202300904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/31/2024] [Accepted: 01/31/2024] [Indexed: 02/03/2024]
Abstract
Understanding the dynamics of excited states after optical excitation at donor-acceptor (D/A) interfaces is of paramount importance for improving the efficiency and performance of optoelectronic devices. Here, we studied the ultrafast excited state dynamics after optical excitation at interfaces between the electron donor (D) pentacene (PEN) and the electron acceptor (A) perfuoropentacene (PFP) as well as within the single compounds (PEN and PFP) using femtosecond (fs) time-resolved second harmonic generation (SHG). In the single compounds singlet fission is observed on a time scale of around 200 fs. In the bilayer systems a huge SHG intensity rise is observed due to the creation of charge transfer states at the interface and accordingly to formation of a local electric field within tens of picoseconds. The local electric field and therefore the SHG signal intensity from the interface of PEN/PFP bilayer is much more intense compared to the PFP/PEN system because the PFP and PEN intermixing at the PEN/PFP interface is higher. Accordingly a population of defect states on a time scale of 55±12 ps has been proposed for PEN/PFP. Our study provides important insights into D/A charge transfer properties, which is needed for the understanding of the interfacial photophysics of pentacene-based organic compounds.
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Affiliation(s)
- Vipilan Sivanesan
- Physikalisch-Chemisches Institut, Universität Heidelberg, 69120, Heidelberg, Germany
| | - Katharina Broch
- Institut für Angewandte Physik, Universität Tübingen, 72076, Tübingen, Germany
| | - Petra Tegeder
- Physikalisch-Chemisches Institut, Universität Heidelberg, 69120, Heidelberg, Germany
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7
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Rudayni F, Rijal K, Fuller N, Chan WL. Enthalpy-uphill exciton dissociation in organic/2D heterostructures promotes free carrier generation. MATERIALS HORIZONS 2024; 11:813-821. [PMID: 38018228 DOI: 10.1039/d3mh01522j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
Despite the large binding energy of charge transfer (CT) excitons in type-II organic/2D heterostructures, it has been demonstrated that free carriers can be generated from CT excitons with a long lifetime. Using a model fluorinated zine phthalocyanine (F8ZnPc)/monolayer-WS2 interface, we find that CT excitons can dissociate spontaneously into free carriers despite it being an enthalpy-uphill process. Specifically, it is observed that CT excitons can gain an energy of 250 meV in 50 ps and dissociate into free carriers without any applied electric field. This observation is surprising because excited electrons typically lose energy to the environment and relax to lower energy states. We hypothesize that this abnormal enthalpy-uphill CT exciton dissociation process is driven by entropy gain. Kinetically, the entropic driving force can also reduce the rate for the reverse process - the conversion of free electron-hole pairs back to CT excitons. Hence, this mechanism can potentially explain the very long carrier lifetime observed in organic/2D heterostructures.
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Affiliation(s)
- Fatimah Rudayni
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, US.
- Department of Physics, Jazan University, Jazan 45142, Saudi Arabia
| | - Kushal Rijal
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, US.
| | - Neno Fuller
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, US.
| | - Wai-Lun Chan
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, US.
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8
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Hassan AU, Sumrra SH. Structure-based screening of sp 2 hybridized small donor bridges as donor: acceptor switches for optical and photovoltaic applications: DFT way. J Mol Model 2024; 30:36. [PMID: 38206469 DOI: 10.1007/s00894-024-05836-0] [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: 11/14/2023] [Accepted: 01/04/2024] [Indexed: 01/12/2024]
Abstract
CONTEXT This research aims to investigate the potential of pyrazine-based small donor moieties as donor-acceptor switches for optical and photovoltaic applications. The designed organic dyes have a high light harvesting efficiency (LHE) and can potentially generate significant electrical energy. METHODS The study focuses on understanding the structural and electronic properties of these dyes through the analysis of dihedral angles, bond lengths, and energies of frontier molecular orbitals The UV-Vis spectroscopy parameters of the designed organic dyes revealed their absorption characteristics, including transition energies, wavelengths (λmax), and oscillator strengths (f). The photovoltaic properties of the developed organic dyes show a range of values: a range of 0.95-0.99 for LHE and a range of 1.77-33.02 W for maximum power output (Pmax) with the highest value for dye DDP5. For their stabilization energies, their natural bond orbitals had values ranging from 0.56 to 128.48 kcal/mol, their E(j)E(i) values from 0.22 to 1.29 a.u, and their Fi,j values from 0.024 to 0.213 kcal/mol. Out of all dyes, the DDP5 produced highest push-pull effect and can be good choice for further studies. The design of these novel organic materials for effective and economical solar energy conversion will be aided by evaluating the potential of 5,10-diphenyl-5,10-dihydrophenazine as a donor moiety and determining the structure-property correlations controlling the photovoltaic performance of the compounds.
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Affiliation(s)
- Abrar U Hassan
- Lunan Research Institute, Beijing Institute of Technology, 888 Zhengtai Road, Tengzhou, 277599, China.
- School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China.
| | - Sajjad H Sumrra
- Department of Chemistry, University of Gujrat, Gujrat, 50700, Punjab, Pakistan.
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9
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Garratt D, Matthews M, Marangos J. Toward ultrafast soft x-ray spectroscopy of organic photovoltaic devices. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2024; 11:010901. [PMID: 38250136 PMCID: PMC10799687 DOI: 10.1063/4.0000214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 12/17/2023] [Indexed: 01/23/2024]
Abstract
Novel ultrafast x-ray sources based on high harmonic generation and at x-ray free electron lasers are opening up new opportunities to resolve complex ultrafast processes in condensed phase systems with exceptional temporal resolution and atomic site specificity. In this perspective, we present techniques for resolving charge localization, transfer, and separation processes in organic semiconductors and organic photovoltaic devices with time-resolved soft x-ray spectroscopy. We review recent results in ultrafast soft x-ray spectroscopy of these systems and discuss routes to overcome the technical challenges in performing time-resolved x-ray experiments on photosensitive materials with poor thermal conductivity and low pump intensity thresholds for nonlinear effects.
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10
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Liu S, Liu SS, Tang XM, Liu XY, Yang JJ, Cui G, Li L. Solvent effects on the photoinduced charge separation dynamics of directly linked zinc phthalocyanine-perylenediimide dyads: a nonadiabatic dynamics simulation with an optimally tuned screened range-separated hybrid functional. Phys Chem Chem Phys 2023; 25:28452-28464. [PMID: 37846460 DOI: 10.1039/d3cp03517d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
Herein, we have employed a combination of the optimally tuned screened range-separated hybrid (OT-SRSH) functional, the polarizable continuum model (PCM), and nonadiabatic dynamics (NAMD) simulations to investigate the photoinduced dynamics of directly linked donor-acceptor dyads formed using zinc phthalocyanine (ZnPc) and perylenediimide (PDI), in which ZnPc is the donor while PDI is the acceptor. Our simulations aim to analyze the behavior of these dyads upon local excitation of the ZnPc moiety in the gas phase and in benzonitrile. Our findings indicate that the presence of a solvent can significantly influence the excited state dynamics of ZnPc-PDI dyads. Specifically, the polar solvent benzonitrile effectively lowers the vertical excitation energies of the charge transfer (CT) state from ZnPc to PDI. As a result, the energetic order of the locally excited (LE) states of ZnPc and the CT states is reversed compared to the gas phase. Consequently, the photoinduced electron transfer (PET) dynamics from ZnPc to PDI, which is absent in the gas phase, takes place in benzonitrile with a time constant of 10.4 ps. Importantly, our present work not only qualitatively agrees with experimental results but also provides in-depth insights into the underlying mechanisms responsible for the photoinduced dynamics of ZnPc-PDI. Moreover, this study emphasizes the importance of appropriately considering solvent effects in NAMD simulation of organic donor-acceptor systems, taking into account the distinct excited state dynamics observed in the gas phase and benzonitrile. Furthermore, the combination of the OT-SRSH functional, the PCM solvent model, and nonadiabatic dynamics simulations shows promise as a strategy for investigating the complex excited state dynamics of organic donor-acceptor systems in solvents. These findings will be valuable for the future design of novel organic donor-acceptor structures with improved performance.
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Affiliation(s)
- Shuai Liu
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu 610068, China.
| | - Sha-Sha Liu
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu 610068, China.
| | - Xiao-Mei Tang
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu 610068, China.
| | - Xiang-Yang Liu
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu 610068, China.
| | - Jia-Jia Yang
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu 610068, China.
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
- Hefei National Laboratory, Hefei 230088, China
| | - Laicai Li
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu 610068, China.
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11
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Menger MFSJ, Ou Q, Shao Y, Faraji S, Subotnik JE, Cofer-Shabica DV. Nature of Hops, Coordinates, and Detailed Balance for Nonadiabatic Simulations in the Condensed Phase. J Phys Chem A 2023; 127:8427-8436. [PMID: 37782887 DOI: 10.1021/acs.jpca.3c03546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
Photoinduced processes play a crucial role in a multitude of important molecular phenomena. Accurately modeling these processes in an environment other than a vacuum requires a detailed description of the electronic states involved as well as how energy flows are coupled to the surroundings. Nonadiabatic effects must also be included in order to describe the exchange of energy between electronic and nuclear degrees of freedom correctly. In this work, we revisit the ring-opening reaction 1,3-cylohexadiene (CHD) in a solvent environment. Using our newly developed Interface for Non-Adiabatic Quantum mechanics/molecular mechanics in Solvent (INAQS) we trace the evolution of the reaction via hybrid quantum mechanics/molecular mechanics (QM/MM) surface hopping with a focus on the solvent's participation in the nonadiabatic relaxation process and the long-time approach to equilibrium. We explicitly include the MM solvent contribution to the nonadiabatic coupling vector─enabling an accurate approach to equilibrium at long times─and find that in highly multidimensional systems gradients can have little or nothing to do with the nonadiabatic couplings.
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Affiliation(s)
- Maximilian F S J Menger
- Theoretische Chemie, Physikalisch-Chemisches Institut, University Heidelberg, INF 229, 69120 Heidelberg, Germany
- Zernike Institute for Advanced Materials, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Qi Ou
- AI for Science Institute, Beijing 100084, China
| | - Yihan Shao
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Shirin Faraji
- Zernike Institute for Advanced Materials, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Joseph E Subotnik
- Chemistry, University of Pennsylvania, 231 S. 34 Street, Cret Wing 141D, Philadelphia, Pennsylvania 19104-6243, United States
| | - D Vale Cofer-Shabica
- Chemistry, University of Pennsylvania, 231 S. 34 Street, Cret Wing 141D, Philadelphia, Pennsylvania 19104-6243, United States
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12
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Wirsing S, Hänsel M, Craciunescu L, Belova V, Schreiber F, Broch K, Engels B, Tegeder P. Adsorption Structures Affecting the Electronic Properties and Photoinduced Charge Transfer at Perylene-Based Molecular Interfaces. Chem Asian J 2023; 18:e202300386. [PMID: 37428120 DOI: 10.1002/asia.202300386] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 07/07/2023] [Accepted: 07/10/2023] [Indexed: 07/11/2023]
Abstract
Perylene-based organic semiconductors are widely used in organic electronic devices. Here, we studied the ultrafast excited state dynamics after optical excitation at interfaces between the electron donor (D) diindenoperylene (DIP) and the electron acceptor (A) dicyano-perylene-bis(dicarboximide) (PDIR-CN2 ) using femtosecond time-resolved second harmonic generation (SHG) in combination with large scale quantum chemical calculations. Thereby, we varied in bilayer structures of DIP and PDIR-CN2 the interfacial molecular geometry. For an interfacial configuration which contains a edge-on geometry but also additional face-on domains an optically induced charge transfer (CT) is observed, which leads to a pronounced increase of the SHG signal intensity due to electric field induced second harmonic generation. The interfacial CT state decays within 7.5±0.7 ps, while the creation of hot CT states leads to a faster decay (5.3±0.2 ps). For the bilayer structures with mainly edge-on geometries interfacial CT formation is suppressed since π-π overlap perpendicular to the interface is missing. Our combined experimental and theoretical study provides important insights into D/A charge transfer properties, which is needed for the understanding of the interfacial photophysics of these molecules.
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Affiliation(s)
- Sara Wirsing
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Emil-Fischer-Straße 42, 97074, Würzburg, Germany
| | - Marc Hänsel
- Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Luca Craciunescu
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Emil-Fischer-Straße 42, 97074, Würzburg, Germany
| | - Valentina Belova
- European Synchrotron Radiation Facility (ESRF), 71, avenue des Martyrs CS 40220, 38043, Grenoble Cedex 9, France
| | - Frank Schreiber
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076, Tübingen, Germany
| | - Katharina Broch
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076, Tübingen, Germany
| | - Bernd Engels
- Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Emil-Fischer-Straße 42, 97074, Würzburg, Germany
| | - Petra Tegeder
- Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
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13
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Ferron T, Fiori ME, Ediger MD, DeLongchamp DM, Sunday DF. Composition Dictates Molecular Orientation at the Heterointerfaces of Vapor-Deposited Glasses. JACS AU 2023; 3:1931-1938. [PMID: 37502150 PMCID: PMC10369407 DOI: 10.1021/jacsau.3c00168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/22/2023] [Accepted: 06/09/2023] [Indexed: 07/29/2023]
Abstract
Physical vapor deposition (PVD) can prepare organic glasses with a preferred molecular orientation. The relationships between deposition conditions and orientation have been extensively investigated in the film bulk. The role of interfaces on the structure is less well understood and remains a key knowledge gap, as the interfacial region can govern glass stability and optoelectronic properties. Robust experimental characterization has remained elusive due to complexities in interrogating molecular organization in amorphous, organic materials. Polarized soft X-rays are sensitive to both the composition and the orientation of transition dipole moments in the film, making them uniquely suited to probe molecular orientation in amorphous soft matter. Here, we utilize polarized resonant soft X-ray reflectivity (P-RSoXR) to simultaneously depth profile the composition and molecular orientation of a bilayer prepared through the physical vapor deposition of 1,4-di-[4-(N,N-diphenyl)amino]styryl-benzene (DSA-Ph) on a film of aluminum-tris(8-hydroxyquinoline) (Alq3). The bulk orientation of the DSA-Ph layer is controlled by varying deposition conditions. Utilizing P-RSoXR to depth profile the films enables determination of both the bulk orientation of DSA-Ph and the orientation near the Alq3 interface. At the Alq3 surface, DSA-Ph always lies with its long axis parallel to the interface, before transitioning into the bulk orientation. This is likely due to the lower mobility and higher glass transition of Alq3, as the first several monolayers of DSA-Ph deposited on Alq3 appear to behave as a blend. We further show how orientation at the interface correlates with the bulk behavior of a codeposited glass of similar blend composition, demonstrating a straightforward approach to predicting molecular orientation at heterointerfaces. This work provides key insights into how molecules orient during vapor deposition and offers methods to predict this property, a critical step toward controlling interfacial behavior in soft matter.
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Affiliation(s)
- Thomas
J. Ferron
- National
Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Marie E. Fiori
- Department
of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - M. D. Ediger
- Department
of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Dean M. DeLongchamp
- National
Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Daniel F. Sunday
- National
Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
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14
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Liang K, Bi L, Zhu Q, Zhou H, Li S. Ultrafast Dynamics Revealed with Time-Resolved Scanning Tunneling Microscopy: A Review. ACS APPLIED OPTICAL MATERIALS 2023; 1:924-938. [PMID: 37260467 PMCID: PMC10227725 DOI: 10.1021/acsaom.2c00169] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 02/23/2023] [Indexed: 06/02/2023]
Abstract
A scanning tunneling microscope (STM) capable of performing pump-probe spectroscopy integrates unmatched atomic-scale resolution with high temporal resolution. In recent years, the union of electronic, terahertz, or visible/near-infrared pulses with STM has contributed to our understanding of the atomic-scale processes that happen between milliseconds and attoseconds. This time-resolved STM (TR-STM) technique is evolving into an unparalleled approach for exploring the ultrafast nuclear, electronic, or spin dynamics of molecules, low-dimensional structures, and material surfaces. Here, we review the recent advancements in TR-STM; survey its application in measuring the dynamics of three distinct systems, nucleus, electron, and spin; and report the studies on these transient processes in a series of materials. Besides the discussion on state-of-the-art techniques, we also highlight several emerging research topics about the ultrafast processes in nanoscale objects where we anticipate that the TR-STM can help broaden our knowledge.
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Affiliation(s)
- Kangkai Liang
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
- Materials
Science and Engineering Program, University
of California, San Diego, La Jolla, California 92093-0418, United States
| | - Liya Bi
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
- Materials
Science and Engineering Program, University
of California, San Diego, La Jolla, California 92093-0418, United States
| | - Qingyi Zhu
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
| | - Hao Zhou
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
- Materials
Science and Engineering Program, University
of California, San Diego, La Jolla, California 92093-0418, United States
| | - Shaowei Li
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
- Materials
Science and Engineering Program, University
of California, San Diego, La Jolla, California 92093-0418, United States
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15
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Sağlamkaya E, Musiienko A, Shadabroo MS, Sun B, Chandrabose S, Shargaieva O, Lo Gerfo M G, van Hulst NF, Shoaee S. What is special about Y6; the working mechanism of neat Y6 organic solar cells. MATERIALS HORIZONS 2023; 10:1825-1834. [PMID: 36857707 DOI: 10.1039/d2mh01411d] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Non-fullerene acceptors (NFAs) have delivered advancement in bulk heterojunction organic solar cell efficiencies, with a significant milestone of 20% now in sight. However, these materials challenge the accepted wisdom of how organic solar cells work. In this work we present a neat Y6 device with an efficiency above 4.5%. We thoroughly investigate mechanisms of charge generation and recombination as well as transport in order to understand what is special about Y6. Our data suggest that Y6 generates bulk free charges, with ambipolar mobility, which can be extracted in the presence of transport layers.
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Affiliation(s)
- Elifnaz Sağlamkaya
- Disordered Semiconductor Optoelectronics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany.
| | - Artem Musiienko
- Department Novel Materials and Interfaces for Photovoltaic Solar Cells, Helmholtz-Zentrum Berlin für Materialien und Energie, Kekuléstraße 5, 12489 Berlin, Germany
| | - Mohammad Saeed Shadabroo
- Disordered Semiconductor Optoelectronics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany.
| | - Bowen Sun
- Disordered Semiconductor Optoelectronics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany.
| | - Sreelakshmi Chandrabose
- Soft Matter Physics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany
| | - Oleksandra Shargaieva
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, HySPRINT Innovation Lab, Department "Solution Processing of Hybrid Materials & Devices" (SE-ALM), Kekuléstr. 5, Berlin 12489, Germany
| | - Giulia Lo Gerfo M
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Niek F van Hulst
- ICFO - Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
- ICREA - Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010 Barcelona, Spain
| | - Safa Shoaee
- Disordered Semiconductor Optoelectronics, Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany.
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16
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Narasimha K, Albert SK, Kim J, Kang H, Kang S, Park J, Park J, Park SJ. Charge-Transfer-Induced Self-Assembly of Doped Conjugated Block Copolymer Nanofibers. ACS Macro Lett 2023; 12:382-388. [PMID: 36866815 DOI: 10.1021/acsmacrolett.2c00752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Here, we report charge-transfer-driven self-assembly of conjugated block copolymers (BCP) into highly doped conjugated polymer nanofibers. The ground-state integer charge transfer (ICT) between a BCP composed of poly(3-hexylthiophene) and poly(ethylene oxide) (P3HT-b-PEO) and electron-deficient 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) induced spontaneous self-assembly of the donor and the acceptor into well-defined one-dimensional nanofibers. The presence of the PEO block plays an important role for the self-assembly by providing a polar environment that can stabilize nanoscale charge transfer (CT) assemblies. The doped nanofibers were responsive to various external stimuli such as heat, chemical, and light and exhibited efficient photothermal properties in the near-IR region. The CT-driven BCP self-assembly reported here provides a new platform for the fabrication of highly doped semiconductor nanostructures.
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Affiliation(s)
- Karnati Narasimha
- Department of Chemistry and Nanoscience, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea
| | - Shine K Albert
- Department of Chemistry and Nanoscience, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea
| | - Jongwook Kim
- Department of Chemistry and Nanoscience, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea
| | - Hyojung Kang
- Department of Chemistry and Nanoscience, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea
| | - Sungsu Kang
- School of Chemical and Biological Engineering, Institute of Chemical Process, Seoul National University, Seoul 08826, Republic of Korea
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, South Korea
| | - Jungwon Park
- School of Chemical and Biological Engineering, Institute of Chemical Process, Seoul National University, Seoul 08826, Republic of Korea
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, South Korea
| | - JaeHong Park
- Department of Chemistry and Nanoscience, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea
| | - So-Jung Park
- Department of Chemistry and Nanoscience, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Korea
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17
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Uratani H, Nakai H. Nanoscale and Real-Time Nuclear-Electronic Dynamics Simulation Study of Charge Transfer at the Donor-Acceptor Interface in Organic Photovoltaics. J Phys Chem Lett 2023; 14:2292-2300. [PMID: 36827224 DOI: 10.1021/acs.jpclett.2c03808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Charge-transfer (CT) processes in donor-acceptor interfaces of organic photovoltaics have been challenging targets for computational chemistry owing to their nanoscale and ultrafast nature. Herein, we report real-time nuclear-electronic dynamics simulations of CT processes in a nanometer-scale donor-acceptor interface model composed of a donor poly(3-hexylthiophene-2,5-diyl) crystal and an acceptor [6,6]-phenyl-C61-butyric acid methyl ester aggregate. The simulations were realized using our original reduced-scaling computational technique, namely, patchwork-approximation-based Ehrenfest dynamics. The results illustrated the CT pathway with atomic resolution, thereby rationalizing the observed excitation-energy dependence of the quantity of CT. Further, nuclear motion, which is affected by the electronic dynamics, was observed to play a significant role in the CT process by modulating molecular orbital energies. The present study suggests that microscopic CT processes strongly depend on local structures of disordered donor-acceptor interfaces as well as coupling between nuclear and electronic dynamics.
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Affiliation(s)
- Hiroki Uratani
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Hiromi Nakai
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
- Waseda Research Institute for Science and Engineering (WISE), 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
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18
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Wang T, Chen ZH, Qiao JW, Qin W, Liu JQ, Wang XZ, Pu YJ, Yin H, Hao XT. Correlating Charge Transfer Dynamics with Interfacial Trap States in High-Efficiency Organic Solar Cells. ACS APPLIED MATERIALS & INTERFACES 2023; 15:12109-12118. [PMID: 36813758 DOI: 10.1021/acsami.2c21470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The charge transfer between the donor and acceptor determines the photogenerated carrier density in organic solar cells. However, a fundamental understanding regarding the charge transfer at donor/acceptor interfaces with high-density traps has not been fully addressed. Herein, a general correlation between trap densities and charge transfer dynamics is established by adopting a series of high-efficiency organic photovoltaic blends. It is found that the electron transfer rates are reduced with increased trap densities, while the hole transfer rates are independent of trap states. The local charges captured by traps can induce potential barrier formation around recombination centers, leading to the suppression of electron transfer. For the hole transfer process, the thermal energy provides a sufficient driving force, which ensures an efficient transfer rate. As a result, a 17.18% efficiency is obtained for PM6:BTP-eC9-based devices with the lowest interfacial trap densities. This work highlights the importance of interfacial traps in charge transfer processes and proposes an underlying insight into the charge transfer mechanism at nonideal interfaces in organic heterostructures.
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Affiliation(s)
- Tong Wang
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, China
| | - Zhi-Hao Chen
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, China
| | - Jia-Wei Qiao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, China
| | - Wei Qin
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, China
| | - Jian-Qiang Liu
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, China
| | - Xing-Zhu Wang
- Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, China
| | - Yong-Jin Pu
- RIKEN Center for Emergent Matter Science (CEMS)2-1 Hirosawa, Wako 351-0198, Saitama, Japan
| | - Hang Yin
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, China
| | - Xiao-Tao Hao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, China
- ARC Centre of Excellence in Exciton Science, School of Chemistry, The University of Melbourne, Parkville 3010, Victoria, Australia
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19
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Roy P, Anandan GT, Nayak N, Kumar A, Dasgupta J. Raman Snapshots of Side-Chain Dependent Polaron Dynamics in PolyThiophene Films. J Phys Chem B 2023; 127:567-576. [PMID: 36599044 DOI: 10.1021/acs.jpcb.2c06185] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Photogenerated polarons in π-conjugated polymers are the precursors to free charges at donor-acceptor interfaces. Unraveling the relationship between film morphology and polaron formation is conjectured to enable efficient charge generation in organic photovoltaic devices. However, it has been challenging to track the ultrafast dynamics of polarons selectively and thus evaluate the molecular coordinates that drive charge generation in films. Using a combination of broadband femtosecond transient absorption and resonance-selective femtosecond stimulated Raman spectroscopy, here, we investigate the polaron generation dynamics exclusively in traditional crystalline poly(3-hexylthiophene) (P3HT) and its amorphous side-chain variant poly(3-(2-ethylhexyl)thiophene-2,5-diyl) (P3EHT) films. The transient Raman data unequivocally provides evidence for an initial delocalization of the polaronic states via thiophene backbone planarization in ∼100 fs while capturing the subsequent morphology-dependent cooling dynamics in a few picoseconds. Our work highlights the structural significance of crystalline morphology in generating hot-charges and thereby emphasizes the importance of side-chain engineering in designing highly efficient conjugated polymer films for hot-carrier photovoltaic devices.
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Affiliation(s)
- Palas Roy
- Department of Chemical Sciences, Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400005, India
| | - Gokul T Anandan
- Department of Chemical Sciences, Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400005, India
| | - Nagaraj Nayak
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Anil Kumar
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Jyotishman Dasgupta
- Department of Chemical Sciences, Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Mumbai 400005, India
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20
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Liu J, Zhang X, Lu G. Non-adiabatic Exciton Dynamics in van der Waals Heterostructures. J Phys Chem Lett 2022; 13:11760-11769. [PMID: 36516313 DOI: 10.1021/acs.jpclett.2c03148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
In this Perspective, we introduce a first-principles method that combines time-dependent density functional theory with non-adiabatic molecular dynamics (NAMD) to explore exciton dynamics in two-dimensional (2D) van der Waals (vdW) heterostructures. The theoretical foundation and computational efficiency of the method are discussed and compared with those of related methods (e.g., GW-BSE). Using three 2D vdW heterostructures as examples, we demonstrate that the proposed method can provide a reliable description of many-body electron-hole interactions crucial to exciton dynamics. With much lower computational costs than the GW-BSE method, the proposed method represents a particularly promising theoretical tool to probe exciton dynamics in solids. Moreover, we find that the NAMD simulations widely used in the literature cannot capture the excitonic effect in 2D materials and often yield incorrect results because they are formulated in a single-particle picture. The instances where the single-particle picture fails are pointed out and contrasted with the many-body simulation results.
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Affiliation(s)
- Junyi Liu
- Department of Physics and Astronomy, California State University, Northridge, California91330-8268, United States
| | - Xu Zhang
- Department of Physics and Astronomy, California State University, Northridge, California91330-8268, United States
| | - Gang Lu
- Department of Physics and Astronomy, California State University, Northridge, California91330-8268, United States
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21
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Biaggne A, Kim YC, Melinger JS, Knowlton WB, Yurke B, Li L. Molecular dynamics simulations of cyanine dimers attached to DNA Holliday junctions. RSC Adv 2022; 12:28063-28078. [PMID: 36320263 PMCID: PMC9530999 DOI: 10.1039/d2ra05045e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 09/20/2022] [Indexed: 11/07/2022] Open
Abstract
Dye aggregates and their excitonic properties are of interest for their applications to organic photovoltaics, non-linear optics, and quantum information systems. DNA scaffolding has been shown to be effective at promoting the aggregation of dyes in a controllable manner. Specifically, isolated DNA Holliday junctions have been used to achieve strongly coupled cyanine dye dimers. However, the structural properties of the dimers and the DNA, as well as the role of Holliday junction isomerization are not fully understood. To study the dynamics of cyanine dimers in DNA, molecular dynamics simulations were carried out for adjacent and transverse dimers attached to Holliday junctions in two different isomers. It was found that dyes attached to adjacent strands in the junction exhibit stronger dye-DNA interactions and larger inter-dye separations compared to transversely attached dimers, as well as end-to-end arrangements. Transverse dimers exhibit lower inter-dye separations and more stacked configurations. Furthermore, differences in Holliday junction isomer are analyzed and compared to dye orientations. For transverse dyes exhibiting the smaller inter-dye separations, excitonic couplings were calculated and shown to be in agreement with experiment. Our results suggested that dye attachment locations on DNA Holliday junctions affect dye-DNA interactions, dye dynamics, and resultant dye orientations which can guide the design of DNA-templated cyanine dimers with desired properties. Molecular dynamics simulations reveal dye attachment and DNA Holliday junction isomer effects on dye dimer orientations and excitonic couplings. These simulations can guide synthesis and experiments of dye-DNA structures for excitonic applications.![]()
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Affiliation(s)
- Austin Biaggne
- Micron School of Materials Science and Engineering, Boise State UniversityBoiseID 83725USA
| | - Young C. Kim
- Materials Science and Technology Division, U.S. Naval Research LaboratoryWashingtonDC20375USA
| | - Joseph. S. Melinger
- Electronics Science and Technology Division, U.S. Naval Research LaboratoryWashingtonDC20375USA
| | - William B. Knowlton
- Micron School of Materials Science and Engineering, Boise State UniversityBoiseID 83725USA,Department of Electrical and Computer Engineering, Boise State UniversityBoiseID 83725USA
| | - Bernard Yurke
- Micron School of Materials Science and Engineering, Boise State UniversityBoiseID 83725USA,Department of Electrical and Computer Engineering, Boise State UniversityBoiseID 83725USA
| | - Lan Li
- Micron School of Materials Science and Engineering, Boise State UniversityBoiseID 83725USA,Center for Advanced Energy StudiesIdaho FallsID 83401USA
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22
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Wang C, Jing Y, Chen L, Xiong W. Direct Interfacial Charge Transfer in All-Polymer Donor-Acceptor Heterojunctions. J Phys Chem Lett 2022; 13:8733-8739. [PMID: 36095150 PMCID: PMC9511559 DOI: 10.1021/acs.jpclett.2c02130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 09/07/2022] [Indexed: 06/15/2023]
Abstract
Direct charge transfer at wet-processed organic/organic heterojunction interfaces is observed using femtosecond interfacial sensitive spectroscopy. UV-vis absorption and ultraviolet photoelectron spectroscopy both indicate that a new interfacial energy gap (∼1.2 eV) exists when an interface is formed between regioregular poly(3-hexylthiophene-2,5-diyl) and poly(benzimidazobenzophenanthroline). Resonant pumping at 1.2 eV creates an electric field-induced second-order optical signal, suggesting the existence of a transient electric field due to separated electrons and holes at interfaces, which recombine through a nongeminate process. The fact that direct charge transfer exists at wet-processed organic/organic heterojunctions provides a physical foundation for the previously reported ground-state charge transfer phenomenon. Also, it creates new opportunities to better control charge transfer with preserved momentum and spins at organic material interfaces for spintronic applications.
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23
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Wu Klingler W, Giger N, Schneider L, Babu V, König C, Spielmann P, Wenger RH, Ferrari S, Spingler B. Low-Dose Near-Infrared Light-Activated Mitochondria-Targeting Photosensitizers for PDT Cancer Therapy. Int J Mol Sci 2022; 23:ijms23179525. [PMID: 36076920 PMCID: PMC9455738 DOI: 10.3390/ijms23179525] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/17/2022] [Accepted: 08/18/2022] [Indexed: 11/20/2022] Open
Abstract
Phthalocyanines (Pcs) are promising candidates for photodynamic therapy (PDT) due to their absorption in the phototherapeutic window. However, the highly aromatic Pc core leads to undesired aggregation and decreased reactive oxygen species (ROS) production. Therefore, short PEG chain functionalized A3B type asymmetric Pc photosensitizers (PSs) were designed in order to decrease aggregation and increase the aqueous solubility. Here we report the synthesis, characterization, optical properties, cellular localization, and cytotoxicity of three novel Pc-based agents (LC31, MLC31, and DMLC31Pt). The stepwise functionalization of the peripheral moieties has a strong effect on the distribution coefficient (logP), cellular uptake, and localization, as well as photocytotoxicity. Additional experiments have revealed that the presence of the malonic ester moiety in the reported agent series is indispensable in order to induce photocytotoxicity. The best-performing agent, MLC31, showed mitochondrial targeting and an impressive phototoxic index (p.i.) of 748 in the cisplatin-resistant A2780/CP70 cell line, after a low-dose irradiation of 6.95 J/cm2. This is the result of a high photocytotoxicity (IC50 = 157 nM) upon irradiation with near-infrared (NIR) light, and virtually no toxicity in the dark (IC50 = 117 μM). Photocytotoxicity was subsequently determined under hypoxic conditions. Additionally, a preliminarily pathway investigation of the mitochondrial membrane potential (MMP) disruption and induction of apoptosis by MLC31 was carried out. Our results underline how agent design involving both hydrophilic and lipophilic peripheral groups may serve as an effective way to improve the PDT efficiency of highly aromatic PSs for NIR light-mediated cancer therapy.
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Affiliation(s)
- Wenyu Wu Klingler
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
- Laboratory for Advanced Fibers, Empa Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland
| | - Nadine Giger
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Lukas Schneider
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Vipin Babu
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Christiane König
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Patrick Spielmann
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Roland H. Wenger
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Stefano Ferrari
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
- Correspondence: (S.F.); (B.S.); Tel.: +41-44-635-46-56 (B.S.)
| | - Bernhard Spingler
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
- Correspondence: (S.F.); (B.S.); Tel.: +41-44-635-46-56 (B.S.)
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24
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Maimaris M, Pettipher AJ, Azzouzi M, Walke DJ, Zheng X, Gorodetsky A, Dong Y, Tuladhar PS, Crespo H, Nelson J, Tisch JWG, Bakulin AA. Sub-10-fs observation of bound exciton formation in organic optoelectronic devices. Nat Commun 2022; 13:4949. [PMID: 35999214 PMCID: PMC9399228 DOI: 10.1038/s41467-022-32478-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 08/02/2022] [Indexed: 11/09/2022] Open
Abstract
Fundamental mechanisms underlying exciton formation in organic semiconductors are complex and elusive as it occurs on ultrashort sub-100-fs timescales. Some fundamental aspects of this process, such as the evolution of exciton binding energy, have not been resolved in time experimentally. Here, we apply a combination of sub-10-fs Pump-Push-Photocurrent, Pump-Push-Photoluminescence, and Pump-Probe spectroscopies to polyfluorene devices to track the ultrafast formation of excitons. While Pump-Probe is sensitive to the total concentration of excited states, Pump-Push-Photocurrent and Pump-Push-Photoluminescence are sensitive to bound states only, providing access to exciton binding dynamics. We find that excitons created by near-absorption-edge photons are intrinsically bound states, or become such within 10 fs after excitation. Meanwhile, excitons with a modest >0.3 eV excess energy can dissociate spontaneously within 50 fs before acquiring bound character. These conclusions are supported by excited-state molecular dynamics simulations and a global kinetic model which quantitatively reproduce experimental data. Ultrafast action spectroscopies of organic optoelectronic devices reveal that the formation of bound exciton state occurs as fast as 10 fs. Excitons having excess energy can dissociate spontaneously within 50-fs before acquiring bound character.
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Affiliation(s)
- Marios Maimaris
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
| | | | - Mohammed Azzouzi
- Department of Physics, Imperial College London, London, SW7 2AZ, UK
| | - Daniel J Walke
- Department of Physics, Imperial College London, London, SW7 2AZ, UK.,Helmholtz Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, Berlin, 14109, Germany
| | - Xijia Zheng
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
| | - Andrei Gorodetsky
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK.,School of Physics and Astronomy, University of Birmingham, Birmingham, B15 2TT, UK
| | - Yifan Dong
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK.,National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Pabitra Shakya Tuladhar
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
| | - Helder Crespo
- Department of Physics, Imperial College London, London, SW7 2AZ, UK.,IFIMUP and Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, R. do Campo Alegre 687, 4169-007, Porto, Portugal
| | - Jenny Nelson
- Department of Physics, Imperial College London, London, SW7 2AZ, UK
| | - John W G Tisch
- Department of Physics, Imperial College London, London, SW7 2AZ, UK
| | - Artem A Bakulin
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK.
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25
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Balzer D, Kassal I. Even a little delocalization produces large kinetic enhancements of charge-separation efficiency in organic photovoltaics. SCIENCE ADVANCES 2022; 8:eabl9692. [PMID: 35960797 PMCID: PMC9374333 DOI: 10.1126/sciadv.abl9692] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 06/28/2022] [Indexed: 05/25/2023]
Abstract
In organic photovoltaics, charges can separate efficiently even if their Coulomb attraction is an order of magnitude greater than the available thermal energy. Delocalization has been suggested to explain this fact, because it could increase the initial separation of charges in the charge-transfer (CT) state, reducing their attraction. However, understanding the mechanism requires a kinetic model of delocalized charge separation, which has proven difficult because it involves tracking the correlated quantum-mechanical motion of the electron and the hole in large simulation boxes required for disordered materials. Here, we report the first three-dimensional simulations of charge-separation dynamics in the presence of disorder, delocalization, and polaron formation, finding that even slight delocalization, across less than two molecules, can substantially enhance the charge-separation efficiency, even starting with thermalized CT states. Delocalization does not enhance efficiency by reducing the Coulomb attraction; instead, the enhancement is a kinetic effect produced by the increased overlap of electronic states.
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26
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Peng WT, Brey D, Giannini S, Dell’Angelo D, Burghardt I, Blumberger J. Exciton Dissociation in a Model Organic Interface: Excitonic State-Based Surface Hopping versus Multiconfigurational Time-Dependent Hartree. J Phys Chem Lett 2022; 13:7105-7112. [PMID: 35900333 PMCID: PMC9376959 DOI: 10.1021/acs.jpclett.2c01928] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 07/19/2022] [Indexed: 05/20/2023]
Abstract
Quantum dynamical simulations are essential for a molecular-level understanding of light-induced processes in optoelectronic materials, but they tend to be computationally demanding. We introduce an efficient mixed quantum-classical nonadiabatic molecular dynamics method termed eXcitonic state-based Surface Hopping (X-SH), which propagates the electronic Schrödinger equation in the space of local excitonic and charge-transfer electronic states, coupled to the thermal motion of the nuclear degrees of freedom. The method is applied to exciton decay in a 1D model of a fullerene-oligothiophene junction, and the results are compared to the ones from a fully quantum dynamical treatment at the level of the Multilayer Multiconfigurational Time-Dependent Hartree (ML-MCTDH) approach. Both methods predict that charge-separated states are formed on the 10-100 fs time scale via multiple "hot-exciton dissociation" pathways. The results demonstrate that X-SH is a promising tool advancing the simulation of photoexcited processes from the molecular to the true nanomaterials scale.
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Affiliation(s)
- Wei-Tao Peng
- Department
of Physics and Astronomy and Thomas Young Centre, University College London, London WC1E 6BT, United Kingdom
| | - Dominik Brey
- Institute
of Physical and Theoretical Chemistry, Goethe
University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main, Germany
| | - Samuele Giannini
- Department
of Physics and Astronomy and Thomas Young Centre, University College London, London WC1E 6BT, United Kingdom
| | - David Dell’Angelo
- Department
of Physics and Astronomy and Thomas Young Centre, University College London, London WC1E 6BT, United Kingdom
| | - Irene Burghardt
- Institute
of Physical and Theoretical Chemistry, Goethe
University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main, Germany
| | - Jochen Blumberger
- Department
of Physics and Astronomy and Thomas Young Centre, University College London, London WC1E 6BT, United Kingdom
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27
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Cofer-Shabica DV, Menger MFSJ, Ou Q, Shao Y, Subotnik JE, Faraji S. INAQS, a Generic Interface for Nonadiabatic QM/MM Dynamics: Design, Implementation, and Validation for GROMACS/Q-CHEM simulations. J Chem Theory Comput 2022; 18:4601-4614. [PMID: 35901266 DOI: 10.1021/acs.jctc.2c00204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The accurate description of large molecular systems in complex environments remains an ongoing challenge for the field of computational chemistry. This problem is even more pronounced for photoinduced processes, as multiple excited electronic states and their corresponding nonadiabatic couplings must be taken into account. Multiscale approaches such as hybrid quantum mechanics/molecular mechanics (QM/MM) offer a balanced compromise between accuracy and computational burden. Here, we introduce an open-source software package (INAQS) for nonadiabatic QM/MM simulations that bridges the sampling capabilities of the GROMACS MD package and the excited-state infrastructure of the Q-CHEM electronic structure software. The interface is simple and can be adapted easily to other MD codes. The code supports a variety of different trajectory-based molecular dynamics, ranging from Born-Oppenheimer to surface hopping dynamics. To illustrate the power of this combination, we simulate electronic absorption spectra, free-energy surfaces along a reaction coordinate, and the excited-state dynamics of 1,3-cyclohexadiene in solution.
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Affiliation(s)
- D Vale Cofer-Shabica
- Department of Chemistry, University of Pennsylvania, 231 S. 34 Street, Cret Wing 141D, Philadelphia, Pennsylvania 19104-6243, United States
| | - Maximilian F S J Menger
- Zernike Institute for Advanced Materials, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Qi Ou
- AI for Science Institute, Beijing 100080, China
| | - Yihan Shao
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Joseph E Subotnik
- Department of Chemistry, University of Pennsylvania, 231 S. 34 Street, Cret Wing 141D, Philadelphia, Pennsylvania 19104-6243, United States
| | - Shirin Faraji
- Zernike Institute for Advanced Materials, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
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28
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Green JD, Fuemmeler EG, Hele TJH. Inverse molecular design from first principles: tailoring organic chromophore spectra for optoelectronic applications. J Chem Phys 2022; 156:180901. [DOI: 10.1063/5.0082311] [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
The discovery of molecules with tailored optoelectronic properties such as specific frequency and intensity of absorption or emission is a major challenge in creating next-generation organic light-emitting diodes (OLEDs) and photovoltaics. This raises the question: how can we predict a potential chemical structure from these properties? Approaches that attempt to tackle this inverse design problem include virtual screening, active machine learning and genetic algorithms. However, these approaches rely on a molecular database or many electronic structure calculations, and significant computational savings could be achieved if there was prior knowledge of (i) whether the optoelectronic properties of a parent molecule could easily be improved and (ii) what morphing operations on a parent molecule could improve these properties. In this perspective we address both of these challenges from first principles. We firstly adapt the Thomas-Reiche-Kuhn sum rule to organic chromophores and show how this indicates how easily the absorption and emission of a molecule can be improved. We then show how by combining electronic structure theory and intensity borrowing perturbation theory we can predict whether or not the proposed morphing operations will achieve the desired spectral alteration, and thereby derive widely-applicable design rules. We go on to provide proof-of-concept illustrations of this approach to optimizing the visible absorption of acenes and the emission of radical OLEDs. We believe this approach can be integrated into genetic algorithms by biasing morphing operations in favour of those which are likely to be successful, leading to faster molecular discovery and greener chemistry.
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29
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Zeiske S, Sandberg OJ, Kurpiers J, Shoaee S, Meredith P, Armin A. Probing Charge Generation Efficiency in Thin-Film Solar Cells by Integral-Mode Transient Charge Extraction. ACS PHOTONICS 2022; 9:1188-1195. [PMID: 35571262 PMCID: PMC9097587 DOI: 10.1021/acsphotonics.1c01532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Indexed: 06/15/2023]
Abstract
The photogeneration of free charges in light-harvesting devices is a multistep process, which can be challenging to probe due to the complexity of contributing energetic states and the competitive character of different driving mechanisms. In this contribution, we advance a technique, integral-mode transient charge extraction (ITCE), to probe these processes in thin-film solar cells. ITCE combines capacitance measurements with the integral-mode time-of-flight method in the low intensity regime of sandwich-type thin-film devices and allows for the sensitive determination of photogenerated charge-carrier densities. We verify the theoretical framework of our method by drift-diffusion simulations and demonstrate the applicability of ITCE to organic and perovskite semiconductor-based thin-film solar cells. Furthermore, we examine the field dependence of charge generation efficiency and find our ITCE results to be in excellent agreement with those obtained via time-delayed collection field measurements conducted on the same devices.
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Affiliation(s)
- Stefan Zeiske
- Sustainable
Advanced Materials (Sêr-SAM), Department of Physics, Swansea University, Singleton Park, Swansea SA2 8PP, Wales, United Kingdom
| | - Oskar J. Sandberg
- Sustainable
Advanced Materials (Sêr-SAM), Department of Physics, Swansea University, Singleton Park, Swansea SA2 8PP, Wales, United Kingdom
| | - Jona Kurpiers
- Disordered Semiconductor Optoelectronics,
Institute
of Physics and Astronomy, University Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany
| | - Safa Shoaee
- Disordered Semiconductor Optoelectronics,
Institute
of Physics and Astronomy, University Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany
| | - Paul Meredith
- Sustainable
Advanced Materials (Sêr-SAM), Department of Physics, Swansea University, Singleton Park, Swansea SA2 8PP, Wales, United Kingdom
| | - Ardalan Armin
- Sustainable
Advanced Materials (Sêr-SAM), Department of Physics, Swansea University, Singleton Park, Swansea SA2 8PP, Wales, United Kingdom
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30
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Jiang K, Wang Y, Lin C, Zheng L, Du J, Zhuang Y, Xie R, Li Z, Lin H. Enabling robust and hour-level organic long persistent luminescence from carbon dots by covalent fixation. LIGHT, SCIENCE & APPLICATIONS 2022; 11:80. [PMID: 35351847 PMCID: PMC8964705 DOI: 10.1038/s41377-022-00767-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 02/13/2022] [Accepted: 03/08/2022] [Indexed: 05/04/2023]
Abstract
The first carbon dot (CD)-based organic long persistent luminescence (OLPL) system exhibiting more than 1 h of duration was developed. In contrast to the established OLPL systems, herein, the reported CDs-based system (named m-CDs@CA) can be facilely and effectively fabricated using a household microwave oven, and more impressively, its LPL can be observed under ambient conditions and even in aqueous media. XRD and TEM characterizations, afterglow decay, time-resolved spectroscopy, and ESR analysis were performed, showing the successful composition of CDs and CA, the formation of exciplexes and long-lived charged-separated states. Further studies suggest that the production of covalent bonds between CA and CDs plays pivotal roles in activating LPL and preventing its quenching from oxygen and water. To the best of our knowledge, this is a very rare example of an OLPL system that exhibits hour-level afterglow under ambient conditions. Finally, applications of m-CDs@CA in glow-in-the-dark paints for emergency signs and multicolored luminous pearls were preliminarily demonstrated. This work may provide new insights for the development of rare-earth-free and robust OLPL materials.
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Affiliation(s)
- Kai Jiang
- International Joint Research Center for Photo-responsive Molecules and Materials, School of Chemical and Material Engineering, Jiangnan University, 214122, Wuxi, China.
| | - Yuci Wang
- College of Chemistry, Zhengzhou University, 450001, Zhengzhou, China
| | - Cunjian Lin
- State Key Laboratory of Physical Chemistry of Solid Surface, Fujian Provincial Key Laboratory of Materials Genome, and College of Materials, Xiamen University, 361005, Xiamen, China
| | - Licheng Zheng
- International Joint Research Center for Photo-responsive Molecules and Materials, School of Chemical and Material Engineering, Jiangnan University, 214122, Wuxi, China
| | - Jiaren Du
- International Joint Research Center for Photo-responsive Molecules and Materials, School of Chemical and Material Engineering, Jiangnan University, 214122, Wuxi, China
| | - Yixi Zhuang
- State Key Laboratory of Physical Chemistry of Solid Surface, Fujian Provincial Key Laboratory of Materials Genome, and College of Materials, Xiamen University, 361005, Xiamen, China
| | - Rongjun Xie
- State Key Laboratory of Physical Chemistry of Solid Surface, Fujian Provincial Key Laboratory of Materials Genome, and College of Materials, Xiamen University, 361005, Xiamen, China
| | - Zhongjun Li
- College of Chemistry, Zhengzhou University, 450001, Zhengzhou, China
| | - Hengwei Lin
- International Joint Research Center for Photo-responsive Molecules and Materials, School of Chemical and Material Engineering, Jiangnan University, 214122, Wuxi, China.
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31
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Zhang T, Wang T, Grazioli C, Guarnaccio A, Brumboiu IE, Johansson FOL, Beranová K, Coreno M, de Simone M, Brena B, Liu L, Wang Y, Puglia C. Evidence of hybridization states at the donor/acceptor interface: case of m-MTDATA/PPT. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:214008. [PMID: 35245912 DOI: 10.1088/1361-648x/ac5aff] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
We performed a spectroscopic study on them-MTDATA (donor) and PPT (acceptor) molecular vertical heterostructure. The electronic properties of the donor/acceptor interface have been comprehensively characterized by synchrotron radiation-based photoelectron spectroscopy and near-edge x-ray absorption fine structure. The spectroscopic results reveal the existence of new hybridization states in the original molecular energy gap, likely attributed to the interaction between the donor and the acceptor molecules at the interface. Such hybridized states can have a significant impact on the charge transport in organic electronic devices based on donor-acceptor molecules and can explain the increased efficiency of device using such molecules.
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Affiliation(s)
- Teng Zhang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, 100081 Beijing, People's Republic of China
| | - Tingting Wang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, 100081 Beijing, People's Republic of China
| | - Cesare Grazioli
- IOM-CNR, Laboratorio TASC, Sincrotrone Trieste, 34149 Trieste, Italy
| | - Ambra Guarnaccio
- ISM-CNR, Istituto di Struttura della Materia, 85050 Tito Scalo (Pz) and 34149 Trieste (Ts), Italy
| | - Iulia Emilia Brumboiu
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), 37673 Pohang, Republic of Korea
| | - Fredrik O L Johansson
- Division of X-ray Photon Science, Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
- Division of Applied Physical Chemistry, Department of Chemistry, KTH Royal Institute of Technology, 10044 Stockholm, Sweden
- Institut des Nanosciences de Paris, UMR CNRS 7588, Sorbonne Université, F-75005 Paris, France
| | - Klára Beranová
- Elettra-Sincrotrone Trieste S. C. p. A., Strada Statale 14, km 163.5, Basovizza, 34149 Trieste, Italy
- FZU-Institute of Physics of the Czech Academy of Sciences, 18221 Prague, Czech Republic
| | - Marcello Coreno
- ISM-CNR, Istituto di Struttura della Materia, 85050 Tito Scalo (Pz) and 34149 Trieste (Ts), Italy
| | - Monica de Simone
- IOM-CNR, Laboratorio TASC, Sincrotrone Trieste, 34149 Trieste, Italy
| | - Barbara Brena
- Division of Materials Theory, Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - Liwei Liu
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, 100081 Beijing, People's Republic of China
| | - Yeliang Wang
- School of Integrated Circuits and Electronics, MIIT Key Laboratory for Low-Dimensional Quantum Structure and Devices, Beijing Institute of Technology, 100081 Beijing, People's Republic of China
| | - Carla Puglia
- Division of X-ray Photon Science, Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
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32
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Dimitriev OP. Dynamics of Excitons in Conjugated Molecules and Organic Semiconductor Systems. Chem Rev 2022; 122:8487-8593. [PMID: 35298145 DOI: 10.1021/acs.chemrev.1c00648] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The exciton, an excited electron-hole pair bound by Coulomb attraction, plays a key role in photophysics of organic molecules and drives practically important phenomena such as photoinduced mechanical motions of a molecule, photochemical conversions, energy transfer, generation of free charge carriers, etc. Its behavior in extended π-conjugated molecules and disordered organic films is very different and very rich compared with exciton behavior in inorganic semiconductor crystals. Due to the high degree of variability of organic systems themselves, the exciton not only exerts changes on molecules that carry it but undergoes its own changes during all phases of its lifetime, that is, birth, conversion and transport, and decay. The goal of this review is to give a systematic and comprehensive view on exciton behavior in π-conjugated molecules and molecular assemblies at all phases of exciton evolution with emphasis on rates typical for this dynamic picture and various consequences of the above dynamics. To uncover the rich variety of exciton behavior, details of exciton formation, exciton transport, exciton energy conversion, direct and reverse intersystem crossing, and radiative and nonradiative decay are considered in different systems, where these processes lead to or are influenced by static and dynamic disorder, charge distribution symmetry breaking, photoinduced reactions, electron and proton transfer, structural rearrangements, exciton coupling with vibrations and intermediate particles, and exciton dissociation and annihilation as well.
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Affiliation(s)
- Oleg P Dimitriev
- V. Lashkaryov Institute of Semiconductor Physics NAS of Ukraine, pr. Nauki 41, Kyiv 03028, Ukraine
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33
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Han G, Yi Y. Molecular Insight into Efficient Charge Generation in Low-Driving-Force Nonfullerene Organic Solar Cells. Acc Chem Res 2022; 55:869-877. [PMID: 35230078 DOI: 10.1021/acs.accounts.1c00742] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
ConspectusFor organic solar cells (OSCs), charge generation at the donor/acceptor interfaces is regarded as a two-step process: driven by the interfacial energy offsets, the excitons produced by light absorption are first dissociated into the charge-transfer (CT) states, and then the CT states are further separated into free charge carriers of holes and electrons by overcoming their Coulomb attraction. Meanwhile, the CT states can recombine through radiative and nonradiative decay. Owing to the emergence of narrow-band-gap A-D-A small-molecule acceptors, nonfullerene (NF) OSCs have developed rapidly in recent years and the power conversion efficiencies (PCEs) surpass 18% now. The great achievement can be attributed to the high-yield charge generation under low exciton dissociation (ED) driving forces, which ensures both high photocurrent and small voltage loss. However, it is traditionally believed that a considerable driving force (e.g., at least 0.3 eV in fullerene-based OSCs) is essential to provide excess energy for the CT states to achieve efficient charge separation (CS). Therefore, a fundamental question open to the community is how the excitons split into free charge carriers so efficiently under low driving forces in the state-of-the-art NF OSCs.In this Account, we summarize our recent theoretical advances on the charge generation mechanisms in the low-driving-force NF OSCs. First, the A-D-A acceptors are found to dock with the D-A copolymer or A-D-A small-molecule donors mainly via local π-π interaction between their electron-withdrawing units, and such interfacial geometries can provide sufficient electronic couplings, thus ensuring fast ED. Second, the polarization energies of holes and electrons are enhanced during CS, which is beneficial to reduce the CS energy barrier and even leads to barrierless CS in the OSCs based on fluorinated A-D-A acceptors. Moreover, the exciton binding energies (Eb) are substantially decreased by the strong polarization of charge carriers for the A-D-A acceptors; especially for the Y6 system with three-dimensional molecular packing structures, the remarkable small Eb can enable direct photogeneration of free charge carriers. Accordingly, the excess energy becomes unnecessary for CS in the state-of-the-art NF OSCs. Third, to simultaneously decrease the driving force and suppress charge recombination via the triplet channel, it is imperative to reduce the singlet-triplet energy difference (ΔEST) of the narrow-band-gap A-D-A acceptors. Importantly, the intermolecular end-group π-π stacking is demonstrated to effectively decrease the ΔEST while keeping strong light absorption. Finally, hybridization of the CT states with local excitation can be induced by small interfacial energy offset. Such hybridization will result in direct population of thermalized CT states upon light absorption and a significant increase of luminescence quantum efficiency, which is beneficial to concurrently promote CS and reduce nonradiative voltage loss. We hope this Account contributes to the molecular understanding of the mechanisms of efficient charge generation with low driving forces and would be helpful for further improving the performance of organic photovoltaics in the future.
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Affiliation(s)
- Guangchao Han
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Yuanping Yi
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- School of Chemical Sciences, University of Chinese Academy Sciences, Beijing 100049, China
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34
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Yamanaka T, Nakanotani H, Adachi C. Significant role of spin-triplet state for exciton dissociation in organic solids. SCIENCE ADVANCES 2022; 8:eabj9188. [PMID: 35235344 PMCID: PMC8890716 DOI: 10.1126/sciadv.abj9188] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 01/03/2022] [Indexed: 06/01/2023]
Abstract
Clarification of the role of the spin state that initiates exciton dissociation is critical to attaining a fundamental understanding of the mechanism of organic photovoltaics. Although an excited spin-triplet state with an energy lower than that of excited spin-singlet state is disadvantageous in exciton dissociation, a small electron exchange integral results in small singlet-triplet energy splitting in some material systems. This energy splitting leads to a nearly isoenergetic alignment of both excited states, raising a question about the role of excited spin states in exciton dissociation. Herein, we show that the spin-triplet rather than the spin-singlet plays a critical role in the exciton dissociation that leads to the formation of free carriers. This result indicates that the spin-triplet inherently acts as an intermediate, leading to exciton dissociation. Thus, our demonstration provides a fundamental understanding of the role of excited spin states of organic molecular systems in photoinduced charge-carrier generation.
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Affiliation(s)
- Takahiko Yamanaka
- Central Research Laboratory, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita-ku, Hamamatsu, Shizuoka 434-8601, Japan
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Hajime Nakanotani
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- International Institute for Carbon Neutral Energy Research (WPI-ICNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Chihaya Adachi
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- International Institute for Carbon Neutral Energy Research (WPI-ICNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
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35
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Chen WK, Cui G, Liu XY. Solvent effects on excited-state relaxation dynamics of paddle-wheel BODIPY-Hexaoxatriphenylene conjugates: Insights from non-adiabatic dynamics simulations. CHINESE J CHEM PHYS 2022. [DOI: 10.1063/1674-0068/cjcp2110214] [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]
Abstract
Understanding the excited state dynamics of donor-acceptor (D-A) complexes is of fundamental importance both experimentally and theoretically. Herein, we have first explored the photoinduced dynamics of a recently synthesized paddle-wheel BODIPY-hexaoxatriphenylene (BODIPY is the abbreviation for BF2-chelated dipyrromethenes) conjugates D-A complexes with the combination of both electronic structure calculations and non-adiabatic dynamics simulations. On the basis of computational results, we concluded that the BODIPY-hexaoxatriphenylene (BH) conjugates will be promoted to the local excited (LE) states of the BODIPY fragments upon excitation, which is followed by the ultrafast exciton transfer from LE state to charge transfer (CT). Instead of the photoinduced electron transfer process proposed in previous experimental work, such a exciton transfer process is accompanied with the photoinduced hole transfer from BODIPY to hexaoxatriphenylene. Additionally, solvent effects are found to play an important role in the photoinduced dynamics. Specifically, the hole transfer dynamics is accelerated by the acetonitrile solvent, which can be ascribed to significant influences of the solvents on the charge transfer states, i.e. the energy gaps between LE and CT excitons are reduced greatly and the non-adiabatic couplings are increased in the meantime. Our present work not only provides valuable insights into the underlying photoinduced mechanism of BH, but also can be helpful for the future design of novel donor-acceptor conjugates with better optoelectronic performance.
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Affiliation(s)
- Wen-Kai Chen
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Xiang-Yang Liu
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu 610068, China
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36
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Ferron TJ, Thelen JL, Bagchi K, Deng C, Gann E, de Pablo JJ, Ediger MD, Sunday DF, DeLongchamp DM. Characterization of the Interfacial Orientation and Molecular Conformation in a Glass-Forming Organic Semiconductor. ACS APPLIED MATERIALS & INTERFACES 2022; 14:3455-3466. [PMID: 34982543 DOI: 10.1021/acsami.1c19948] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The ability to control structure in molecular glasses has enabled them to play a key role in modern technology; in particular, they are ubiquitous in organic light-emitting diodes. While the interplay between bulk structure and optoelectronic properties has been extensively investigated, few studies have examined molecular orientation near buried interfaces despite its critical role in emergent functionality. Direct, quantitative measurements of buried molecular orientation are inherently challenging, and many methods are insensitive to orientation in amorphous soft matter or lack the necessary spatial resolution. To overcome these challenges, we use polarized resonant soft X-ray reflectivity (p-RSoXR) to measure nanometer-resolved, molecular orientation depth profiles of vapor-deposited thin films of an organic semiconductor Tris(4-carbazoyl-9-ylphenyl)amine (TCTA). Our depth profiling approach characterizes the vertical distribution of molecular orientation and reveals that molecules near the inorganic substrate and free surface have a different, nearly isotropic orientation compared to those of the anisotropic bulk. Comparison of p-RSoXR results with near-edge X-ray absorption fine structure spectroscopy and optical spectroscopies reveals that TCTA molecules away from the interfaces are predominantly planar, which may contribute to their attractive charge transport qualities. Buried interfaces are further investigated in a TCTA bilayer (each layer deposited under separate conditions resulting in different orientations) in which we find a narrow interface between orientationally distinct layers extending across ≈1 nm. Coupling this result with molecular dynamics simulations provides additional insight into the formation of interfacial structure. This study characterizes the local molecular orientation at various types of buried interfaces in vapor-deposited glasses and provides a foundation for future studies to develop critical structure-function relationships.
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Affiliation(s)
- Thomas J Ferron
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Jacob L Thelen
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Kushal Bagchi
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Chuting Deng
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Eliot Gann
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Juan J de Pablo
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - M D Ediger
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Daniel F Sunday
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Dean M DeLongchamp
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
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37
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Richings GW, Habershon S. Predicting Molecular Photochemistry Using Machine-Learning-Enhanced Quantum Dynamics Simulations. Acc Chem Res 2022; 55:209-220. [PMID: 34982533 DOI: 10.1021/acs.accounts.1c00665] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The processes which occur after molecules absorb light underpin an enormous range of fundamental technologies and applications, including photocatalysis to enable new chemical transformations, sunscreens to protect against the harmful effects of UV overexposure, efficient photovoltaics for energy generation from sunlight, and fluorescent probes to image the intricate details of complex biomolecular structures. Reflecting this broad range of applications, an enormously versatile set of experiments are now regularly used to interrogate light-driven chemical dynamics, ranging from the typical ultrafast transient absorption spectroscopy used in many university laboratories to the inspiring central facilities around the world, such as the next-generation of X-ray free-electron lasers.Computer simulations of light-driven molecular and material dynamics are an essential route to analyzing the enormous amount of transient electronic and structural data produced by these experimental sources. However, to date, the direct simulation of molecular photochemistry remains a frontier challenge in computational chemical science, simultaneously demanding the accurate treatment of molecular electronic structure, nuclear dynamics, and the impact of nonadiabatic couplings.To address these important challenges and to enable new computational methods which can be integrated with state-of-the-art experimental capabilities, the past few years have seen a burst of activity in the development of "direct" quantum dynamics methods, merging the machine learning of potential energy surfaces (PESs) and nonadiabatic couplings with accurate quantum propagation schemes such as the multiconfiguration time-dependent Hartree (MCTDH) method. The result of this approach is a new generation of direct quantum dynamics tools in which PESs are generated in tandem with wave function propagation, enabling accurate "on-the-fly" simulations of molecular photochemistry. These simulations offer an alternative route toward gaining quantum dynamics insights, circumventing the challenge of generating ab initio electronic structure data for PES fitting by instead only demanding expensive energy evaluations as and when they are needed.In this Account, we describe the chronological evolution of our own contributions to this field, focusing on describing the algorithmic developments that enable direct MCTDH simulations for complex molecular systems moving on multiple coupled electronic states. Specifically, we highlight active learning strategies for generating PESs during grid-based quantum chemical dynamics simulations, and we discuss the development and impact of novel diabatization schemes to enable direct grid-based simulations of photochemical dynamics; these developments are highlighted in a series of benchmark molecular simulations of systems containing multiple nuclear degrees of freedom moving on multiple coupled electronic states. We hope that the ongoing developments reported here represent a major step forward in tools for modeling excited-state chemistry such as photodissociation, proton and electron transfer, and ultrafast energy dissipation in complex molecular systems.
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Affiliation(s)
- Gareth W. Richings
- Department of Chemistry, University of Warwick, Coventry, United Kingdom CV4 7AL
| | - Scott Habershon
- Department of Chemistry, University of Warwick, Coventry, United Kingdom CV4 7AL
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38
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Mao D, Chen XR, Li DH, Liu XY, Cui G, Li L. Ultrafast charge transfer in a nonfullerene all-small-molecule organic solar cell: a nonadiabatic dynamics simulation with optimally tuned range-separated functional. Phys Chem Chem Phys 2022; 24:27173-27183. [DOI: 10.1039/d2cp03822f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The combination of nonadiabatic dynamics simulation and optimally tuned range-separated functional might be a powerful tool for elucidating the ultrafast charge transfer in nonfullerene all-small-molecule organic solar cells.
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Affiliation(s)
- Dan Mao
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu, 610068, China
| | - Xin-Rui Chen
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu, 610068, China
| | - Dong-Heng Li
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu, 610068, China
| | - Xiang-Yang Liu
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu, 610068, China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China
| | - Laicai Li
- College of Chemistry and Material Science, Sichuan Normal University, Chengdu, 610068, China
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39
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Nim GK, Ghosh S, Saini SK, Kumar M, Kar P. Charge transfer excitons in unfunctionalized graphite-wrapped MAPbBr 3 nanocrystal composites with different morphologies. NEW J CHEM 2022. [DOI: 10.1039/d2nj01116f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Charge transfer from perovskite nanocrystals to graphite sheets.
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Affiliation(s)
- Gaurav Kumar Nim
- Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
| | - Sukanya Ghosh
- Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
| | - Saurabh Kumar Saini
- Advanced Materials & Device Metrology division, National Physical Laboratory, New Delhi, 110012, India
| | - Mahesh Kumar
- Advanced Materials & Device Metrology division, National Physical Laboratory, New Delhi, 110012, India
| | - Prasenjit Kar
- Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India
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40
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Ulman K, Quek SY. Organic-2D Material Heterostructures: A Promising Platform for Exciton Condensation and Multiplication. NANO LETTERS 2021; 21:8888-8894. [PMID: 34661417 DOI: 10.1021/acs.nanolett.1c03435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We predict that high temperature Bose-Einstein condensation of charge transfer excitons can be achieved in organic-two-dimensional (2D) material heterostructures, at ∼50-100 K. Unlike 2D bilayers that can be angle-misaligned, organic-2D systems generally have momentum-direct low-energy excitons, thus favoring condensation. Our predictions are obtained for ZnPc-MoS2 using state-of-the-art first-principles calculations with the GW-BSE approach. The exciton energies we predict are in excellent agreement with recent experiments. The lowest energy charge transfer excitons in ZnPc-MoS2 are strongly bound with a spatial extent of ∼1-2 nm and long lifetimes (τ0 ∼ 1 ns), making them ideal for exciton condensation. We also predict the emergence of inter-ZnPc excitons that are stabilized by the interaction of the molecules with the 2D substrate. This novel way of stabilizing intermolecular excitons by indirect substrate mediation suggests design strategies for singlet fission and exciton multiplication, which are important to overcome the Shockley-Queisser efficiency limit in solar cells.
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Affiliation(s)
- Kanchan Ulman
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, Singapore 117546
| | - Su Ying Quek
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, Singapore 117546
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542
- NUS Graduate School, Integrative Sciences and Engineering Programme, National University of Singapore, Singapore 117456
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575
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41
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Günder D, Valencia AM, Guerrini M, Breuer T, Cocchi C, Witte G. Polarization Resolved Optical Excitation of Charge-Transfer Excitons in PEN:PFP Cocrystalline Films: Limits of Nonperiodic Modeling. J Phys Chem Lett 2021; 12:9899-9905. [PMID: 34610238 DOI: 10.1021/acs.jpclett.1c02761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Charge-transfer excitons (CTXs) at organic donor/acceptor interfaces are considered important intermediates for charge separation in photovoltaic devices. Crystalline model systems provide microscopic insights into the nature of such states as they enable microscopic structure-property investigations. Here, we use angular-resolved UV/vis absorption spectroscopy to characterize the CTXs of crystalline pentacene:perfluoro-pentacene (PEN:PFP) films allowing determination of the polarization of this state. This analysis is complemented by first-principles many-body calculations, performed on the three-dimensional PEN:PFP cocrystal, which confirm that the lowest-energy excitation is a CTX. Analogous simulations performed on bimolecular clusters are unable to reproduce this state. We ascribe this failure to the lack of long-range interactions and wave function periodicity in these cluster calculations, which appear to remain a valid tool for modeling properties of organic materials ruled by local intermolecular couplings.
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Affiliation(s)
- Darius Günder
- Philipps-Universität Marburg, Molekulare Festkörperphysik, 35032 Marburg, Germany
| | - Ana M Valencia
- Carl von Ossietzky Universität Oldenburg, Institute of Physics, Carl-von-Ossietzky-Straße 9, 26129 Oldenburg, Germany
| | - Michele Guerrini
- Carl von Ossietzky Universität Oldenburg, Institute of Physics, Carl-von-Ossietzky-Straße 9, 26129 Oldenburg, Germany
| | - Tobias Breuer
- Philipps-Universität Marburg, Molekulare Festkörperphysik, 35032 Marburg, Germany
| | - Caterina Cocchi
- Carl von Ossietzky Universität Oldenburg, Institute of Physics, Carl-von-Ossietzky-Straße 9, 26129 Oldenburg, Germany
- Humboldt-Universität zu Berlin, Physics Department and IRIS Adlershof, Zum Großen Windkanal 2, 12489 Berlin, Germany
| | - Gregor Witte
- Philipps-Universität Marburg, Molekulare Festkörperphysik, 35032 Marburg, Germany
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42
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Huang Y, Zhang L, Hao Y. Why ultrafast charge separation occurs in bulk-heterojunction organic solar cells: a multichain tight binding model study. Phys Chem Chem Phys 2021; 23:22685-22691. [PMID: 34604887 DOI: 10.1039/d1cp03686f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bulk-heterojunction (BHJ) organic solar cells (OSCs) exhibit ultrafast charge separation (UCS) which enables lower geminate charge recombination and high internal quantum efficiency. Unravelling why UCS occurs in BHJ-OSCs is important for the exploration of devices in future, however it is still far from clear. In this work, we build a multichain tight-binding model to study the conditions for realizing UCS. We propose that two conditions are important: (i) the BHJ-OSC has a morphology with donor and acceptor molecules being individually aggregated; (ii) the ratio of the donor/acceptor interfacial coupling to the internal donor/donor and acceptor/acceptor coupling should be smaller than a threshold. In addition, we suggest that increasing the donor/acceptor energetic offset will boost the UCS efficiency. As a fundamental theoretical analysis on the underlying mechanism of UCS, our work provides design rules for optimizing high-performance BHJ OSCs.
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Affiliation(s)
- Yujuan Huang
- College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan, 030024, China.
| | - Longlong Zhang
- College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan, 030024, China.
| | - Yuying Hao
- College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan, 030024, China.
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43
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Shimazaki T, Tachikawa M. A theoretical study on solvatofluorochromic asymmetric thiazolothiazole (TTz) dyes using dielectric-dependent density functional theory. Phys Chem Chem Phys 2021; 23:21078-21086. [PMID: 34523637 DOI: 10.1039/d1cp02047a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In this work, the excitation energies of asymmetric thiazolothizaole (TTz) dye molecules have been theoretically studied using dielectric-dependent density functional theory (DFT). In the dielectric-dependent DFT approach, the ratio (fraction) of the nonlocal Hartree exchange term incorporated into the DFT exchange-correlation functional is a system-dependent parameter, which is inversely proportional to the dielectric constant of the target material. The dielectric-dependent DFT method is closely related to the Coulomb hole and screened exchange (COHSEX) approximation in the GW method and therefore has been applied to crystalline systems with periodic boundary conditions, such as semiconductors and inorganic materials. By focusing on the solvatofluorochromic phenomena of asymmetric TTz dyes, we show that excitation energy calculations obtained from the dielectric-dependent DFT method can reproduce the corresponding experimental UV-vis absorption and emission spectra of dyes in solvents.
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Affiliation(s)
- Tomomi Shimazaki
- Department of Material System Science, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama, 236-0026, Japan.
| | - Masanori Tachikawa
- Department of Material System Science, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama, 236-0026, Japan.
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44
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Wanigasekara S, Kattel B, Rudayni F, Chan WL. Extracting Electrons from Delocalized Excitons by Flattening the Energetic Pathway for Charge Separation. J Phys Chem Lett 2021; 12:9047-9054. [PMID: 34516118 DOI: 10.1021/acs.jpclett.1c02228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
At organic donor-acceptor (D-A) interfaces, electron and hole are bound together to form charge transfer (CT) excitons. The electron and hole wave functions in these CT excitons can spatially delocalize. The electron delocalization opens up possibilities of extracting free charges from bound excitons by manipulating the potential energy landscape on the nanoscale. Using a prototype trilayer structure that has a cascade band structure, we show that the yield of charge separation can be doubled as compared to the bilayer counterpart when the thickness of the intermediate layer is around 3 nm. This thickness coincides with the electron delocalization size of CT excitons typically found in these organic films. Tight-binding calculation for the CT states in the trilayer structure further demonstrates that electron delocalization, together with the energy level cascade, can effectively flatten the energetic pathway for charge separation. Hence, it is possible to add nanometer-thick layers between the donor and the acceptor to significantly enhance the charge separation yield.
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Affiliation(s)
- Shanika Wanigasekara
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
| | - Bhupal Kattel
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
| | - Fatimah Rudayni
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
| | - Wai-Lun Chan
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
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45
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Ahmed I, Shi L, Pasanen H, Vivo P, Maity P, Hatamvand M, Zhan Y. There is plenty of room at the top: generation of hot charge carriers and their applications in perovskite and other semiconductor-based optoelectronic devices. LIGHT, SCIENCE & APPLICATIONS 2021; 10:174. [PMID: 34465725 PMCID: PMC8408272 DOI: 10.1038/s41377-021-00609-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 07/22/2021] [Accepted: 07/31/2021] [Indexed: 06/13/2023]
Abstract
Hot charge carriers (HC) are photoexcited electrons and holes that exist in nonequilibrium high-energy states of photoactive materials. Prolonged cooling time and rapid extraction are the current challenges for the development of future innovative HC-based optoelectronic devices, such as HC solar cells (HCSCs), hot energy transistors (HETs), HC photocatalytic reactors, and lasing devices. Based on a thorough analysis of the basic mechanisms of HC generation, thermalization, and cooling dynamics, this review outlines the various possible strategies to delay the HC cooling as well as to speed up their extraction. Various materials with slow cooling behavior, including perovskites and other semiconductors, are thoroughly presented. In addition, the opportunities for the generation of plasmon-induced HC through surface plasmon resonance and their technological applications in hybrid nanostructures are discussed in detail. By judiciously designing the plasmonic nanostructures, the light coupling into the photoactive layer and its optical absorption can be greatly enhanced as well as the successful conversion of incident photons to HC with tunable energies can also be realized. Finally, the future outlook of HC in optoelectronics is highlighted which will provide great insight to the research community.
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Affiliation(s)
- Irfan Ahmed
- State Key Laboratory of ASIC and System, Centre of Micro-Nano System, SIST, Fudan University, 200433, Shanghai, China.
- Department of Physics, Government Postgraduate College, (Higher Education Department-HED) Khyber Pakhtunkhwa, 21300, Mansehra, Pakistan.
| | - Lei Shi
- State Key Laboratory of Surface Physics, Key Laboratory of Micro- and Nano-Photonics, Fudan University, 200433, Shanghai, China
| | - Hannu Pasanen
- Faculty of Engineering and Natural Sciences, Tampere University, FI-33014, Tampere, Finland
| | - Paola Vivo
- Faculty of Engineering and Natural Sciences, Tampere University, FI-33014, Tampere, Finland
| | - Partha Maity
- KAUST Solar Center, Division of Physical Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Riyadh, Kingdom of Saudi Arabia
| | - Mohammad Hatamvand
- State Key Laboratory of ASIC and System, Centre of Micro-Nano System, SIST, Fudan University, 200433, Shanghai, China
| | - Yiqiang Zhan
- State Key Laboratory of ASIC and System, Centre of Micro-Nano System, SIST, Fudan University, 200433, Shanghai, China.
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46
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Wang Y, Das S, Iyikanat F, Dai Y, Li S, Guo X, Yang X, Cheng J, Hu X, Ghotbi M, Ye F, Lipsanen H, Wu S, Hasan T, Gan X, Liu K, Sun D, Dai Q, García de Abajo FJ, Zhao J, Sun Z. Giant All-Optical Modulation of Second-Harmonic Generation Mediated by Dark Excitons. ACS PHOTONICS 2021; 8:2320-2328. [PMID: 34476288 PMCID: PMC8377711 DOI: 10.1021/acsphotonics.1c00466] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Indexed: 05/23/2023]
Abstract
All-optical control of nonlinear photonic processes in nanomaterials is of significant interest from a fundamental viewpoint and with regard to applications ranging from ultrafast data processing to spectroscopy and quantum technology. However, these applications rely on a high degree of control over the nonlinear response, which still remains elusive. Here, we demonstrate giant and broadband all-optical ultrafast modulation of second-harmonic generation (SHG) in monolayer transition-metal dichalcogenides mediated by the modified excitonic oscillation strength produced upon optical pumping. We reveal a dominant role of dark excitons to enhance SHG by up to a factor of ∼386 at room temperature, 2 orders of magnitude larger than the current state-of-the-art all-optical modulation results. The amplitude and sign of the observed SHG modulation can be adjusted over a broad spectral range spanning a few electronvolts with ultrafast response down to the sub-picosecond scale via different carrier dynamics. Our results not only introduce an efficient method to study intriguing exciton dynamics, but also reveal a new mechanism involving dark excitons to regulate all-optical nonlinear photonics.
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Affiliation(s)
- Yadong Wang
- MOE
Key Laboratory of Material Physics and Chemistry under Extraordinary
Conditions, and Shaanxi Key Laboratory of Optical Information Technology,
School of Physical Science and Technology, Northwestern Polytechnical University, Xi’an 710129, China
- Department
of Electronics and Nanoengineering, Aalto
University, Espoo 02150, Finland
| | - Susobhan Das
- Department
of Electronics and Nanoengineering, Aalto
University, Espoo 02150, Finland
| | - Fadil Iyikanat
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute
of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Yunyun Dai
- Department
of Electronics and Nanoengineering, Aalto
University, Espoo 02150, Finland
| | - Shisheng Li
- International
Center for Young Scientists, National Institute
for Materials Science, Tsukuba 305-0044, Japan
| | - Xiangdong Guo
- CAS
Key Laboratory of Nanophotonic Materials and Devices, CAS Key Laboratory
of Standardization and Measurement for Nanotechnology, CAS Center
for Excellence in Nanoscience, National Center for Nanoscience and
Technology, Beijing 100190, China
| | - Xiaoxia Yang
- CAS
Key Laboratory of Nanophotonic Materials and Devices, CAS Key Laboratory
of Standardization and Measurement for Nanotechnology, CAS Center
for Excellence in Nanoscience, National Center for Nanoscience and
Technology, Beijing 100190, China
| | - Jinluo Cheng
- Changchun
Institute of Optics, Fine Mechanics and Physics, Chinese Academy of
Sciences, Changchun, Jilin 130033, China
| | - Xuerong Hu
- Department
of Electronics and Nanoengineering, Aalto
University, Espoo 02150, Finland
- International
Cooperation Base of Photoelectric Technology and Functional Materials,
and Institute of Photonics and Photon-Technology, Northwest University, Xi’an 710069, China
| | - Masood Ghotbi
- Department
of Physics, University of Kurdistan, Pasdaran St., Sanandaj 66177-15177, Iran
| | - Fangwei Ye
- School
of Physics and Astronomy, Shanghai Jiao
Tong University, Shanghai 200240, China
| | - Harri Lipsanen
- Department
of Electronics and Nanoengineering, Aalto
University, Espoo 02150, Finland
| | - Shiwei Wu
- State
Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano
Photonic Structures (MOE), and Department of Physics, Fudan University, Shanghai 200433, China
| | - Tawfique Hasan
- Cambridge
Graphene Centre, University of Cambridge, Cambridge CB3 0FA, United Kingdom
| | - Xuetao Gan
- MOE
Key Laboratory of Material Physics and Chemistry under Extraordinary
Conditions, and Shaanxi Key Laboratory of Optical Information Technology,
School of Physical Science and Technology, Northwestern Polytechnical University, Xi’an 710129, China
| | - Kaihui Liu
- State
Key Laboratory for Mesoscopic Physics and School of Physics, Peking University, Beijing 100871, China
| | - Dong Sun
- International
Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Qing Dai
- CAS
Key Laboratory of Nanophotonic Materials and Devices, CAS Key Laboratory
of Standardization and Measurement for Nanotechnology, CAS Center
for Excellence in Nanoscience, National Center for Nanoscience and
Technology, Beijing 100190, China
| | - F. Javier García de Abajo
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute
of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- ICREA-Institució
Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010 Barcelona, Spain
| | - Jianlin Zhao
- MOE
Key Laboratory of Material Physics and Chemistry under Extraordinary
Conditions, and Shaanxi Key Laboratory of Optical Information Technology,
School of Physical Science and Technology, Northwestern Polytechnical University, Xi’an 710129, China
| | - Zhipei Sun
- Department
of Electronics and Nanoengineering, Aalto
University, Espoo 02150, Finland
- QTF
Centre of Excellence, Department of Applied Physics, Aalto University, Espoo 02150, Finland
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47
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Varvelo L, Lynd JK, Bennett DIG. Formally exact simulations of mesoscale exciton dynamics in molecular materials. Chem Sci 2021; 12:9704-9711. [PMID: 34349941 PMCID: PMC8293828 DOI: 10.1039/d1sc01448j] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 05/31/2021] [Indexed: 02/04/2023] Open
Abstract
Excited state carriers, such as excitons, can diffuse on the 100 nm to micron length scale in molecular materials but only delocalize over short length scales due to coupling between electronic and vibrational degrees-of-freedom. Here, we leverage the locality of excitons to adaptively solve the hierarchy of pure states equations (HOPS). We demonstrate that our adaptive HOPS (adHOPS) methodology provides a formally exact and size-invariant (i.e., ) scaling algorithm for simulating mesoscale quantum dynamics. Finally, we provide proof-of-principle calculations for exciton diffusion on linear chains containing up to 1000 molecules. The adaptive hierarchy of pure states (adHOPS) algorithm leverages the locality of excitons in molecular materials to perform formally-exact simulations with size-invariant (i.e., ) scaling, enabling efficient simulations of mesoscale exciton dynamics.![]()
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Affiliation(s)
- Leonel Varvelo
- Department of Chemistry, Southern Methodist University PO Box 750314 Dallas TX USA
| | - Jacob K Lynd
- Department of Chemistry, Southern Methodist University PO Box 750314 Dallas TX USA
| | - Doran I G Bennett
- Department of Chemistry, Southern Methodist University PO Box 750314 Dallas TX USA
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48
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Madhu M, Ramakrishnan R, Vijay V, Hariharan M. Free Charge Carriers in Homo-Sorted π-Stacks of Donor-Acceptor Conjugates. Chem Rev 2021; 121:8234-8284. [PMID: 34133137 DOI: 10.1021/acs.chemrev.1c00078] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Inspired by the high photoconversion efficiency observed in natural light-harvesting systems, the hierarchical organization of molecular building blocks has gained impetus in the past few decades. Particularly, the molecular arrangement and packing in the active layer of organic solar cells (OSCs) have garnered significant attention due to the decisive role of the nature of donor/acceptor (D/A) heterojunctions in charge carrier generation and ultimately the power conversion efficiency. This review focuses on the recent developments in emergent optoelectronic properties exhibited by self-sorted donor-on-donor/acceptor-on-acceptor arrangement of covalently linked D-A systems, highlighting the ultrafast excited state dynamics of charge transfer and transport. Segregated organization of donors and acceptors promotes the delocalization of photoinduced charges among the stacks, engendering an enhanced charge separation lifetime and percolation pathways with ambipolar conductivity and charge carrier yield. Covalently linking donors and acceptors ensure a sufficient D-A interface and interchromophoric electronic coupling as required for faster charge separation while providing better control over their supramolecular assemblies. The design strategies to attain D-A conjugate assemblies with optimal charge carrier generation efficiency, the scope of their application compared to state-of-the-art OSCs, current challenges, and future opportunities are discussed in the review. An integrated overview of rational design approaches derived from the comprehension of underlying photoinduced processes can pave the way toward superior optoelectronic devices and bring in new possibilities to the avenue of functional supramolecular architectures.
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Affiliation(s)
- Meera Madhu
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, India 695551
| | - Remya Ramakrishnan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, India 695551
| | - Vishnu Vijay
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, India 695551
| | - Mahesh Hariharan
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, India 695551
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49
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Zhou Q, Liu ZF, Marks TJ, Darancet P. Electronic Structure of Metallophthalocyanines, MPc (M = Fe, Co, Ni, Cu, Zn, Mg) and Fluorinated MPc. J Phys Chem A 2021; 125:4055-4061. [PMID: 33961423 DOI: 10.1021/acs.jpca.0c10766] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We compute the electronic structure and optical excitation energies of metal-free and transition-metal phthalocyanines (H2Pc and MPc for M = Fe, Co, Ni, Cu, Zn, Mg) using density functional theory with optimally tuned range-separated hybrid functionals (OT-RSH). We show that the OT-RSH approach provides photoemission spectra in quantitative agreement with experiments as well as optical band gaps within 10% of their experimental values, capturing the interplay of localized d-states and delocalized π-π* states for these organometallic compounds. We examine the tunability of MPcs and H2Pc through fluorination, resulting in quasi-rigid shifts of the molecular orbital energies by up to 0.7 eV. Our comprehensive data set provides a new computational benchmark for gas-phase phthalocyanines, significantly improving upon other density-functional-theory-based approaches.
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Affiliation(s)
- Qunfei Zhou
- Materials Research Science and Engineering Center, Northwestern University, Evanston, Illinois 60208, United States.,Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Zhen-Fei Liu
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Tobin J Marks
- Materials Research Science and Engineering Center, Northwestern University, Evanston, Illinois 60208, United States.,Department of Chemistry and Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Pierre Darancet
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States.,Northwestern Argonne Institute for Science and Engineering, Evanston, Illinois 60208, United States
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50
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Song H, Freixas VM, Fernandez-Alberti S, White AJ, Zhang Y, Mukamel S, Govind N, Tretiak S. An Ab Initio Multiple Cloning Method for Non-Adiabatic Excited-State Molecular Dynamics in NWChem. J Chem Theory Comput 2021; 17:3629-3643. [PMID: 34014085 DOI: 10.1021/acs.jctc.1c00131] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The recently developed ab initio multiple cloning (AIMC) approach based on the multiconfigurational Ehrenfest (MCE) method provides a powerful and accurate way of describing the excited-state dynamics of molecular systems. The AIMC method is a controlled approximation to nonadiabatic dynamics with a particular strength in the proper description of decoherence effects because of the branching of vibrational wavepackets at a level crossing. Here, we report a new implementation of the AIMC algorithm in the open source NWChem computational chemistry program. The framework combines linear-response time-dependent density functional theory with Ehrenfest mean-field theory to determine the equations of motion for classical trajectories. The multidimensional wave function is decomposed into a superposition of Gaussian coherent states guided by Ehrenfest trajectories (i.e., MCE approach), which can clone with fully quantum mechanical amplitudes and phases. By using an efficient time-derivative based nonadiabatic coupling approach within the AIMC method, all observables are calculated on-the-fly in the nonadiabatic molecular dynamics process. As a representative example, we apply our implementation to study the ultrafast photoinduced electronic and vibrational energy transfer in a pyridine molecule. The effects of the cloning procedure on electronic and vibrational coherence, relaxation and unidirectional energy transfer are discussed. This new AIMC implementation provides a high-level nonadiabatic molecular dynamics framework for simulating photoexcited dynamics in complex molecular systems and experimentally relevant ultrafast spectroscopic probes, such as nonlinear coherent optical and X-ray signals.
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Affiliation(s)
- Huajing Song
- Physics and Chemistry of Materials, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Victor M Freixas
- Departamento de Ciencia y Tecnologia, Universidad Nacional de Quilmes/CONICET, B1876BXD, Bernal, Argentina
| | | | - Alexander J White
- Physics and Chemistry of Materials, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Yu Zhang
- Physics and Chemistry of Materials, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Shaul Mukamel
- Departments of Chemistry, Physics, and Astronomy, University of California, Irvine, California 92697, United States
| | - Niranjan Govind
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Sergei Tretiak
- Physics and Chemistry of Materials, Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.,Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
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