1
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Shakiba M, Akimov AV. Machine-Learned Kohn-Sham Hamiltonian Mapping for Nonadiabatic Molecular Dynamics. J Chem Theory Comput 2024; 20:2992-3007. [PMID: 38581699 DOI: 10.1021/acs.jctc.4c00008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2024]
Abstract
In this work, we report a simple, efficient, and scalable machine-learning (ML) approach for mapping non-self-consistent Kohn-Sham Hamiltonians constructed with one kind of density functional to the nearly self-consistent Hamiltonians constructed with another kind of density functional. This approach is designed as a fast surrogate Hamiltonian calculator for use in long nonadiabatic dynamics simulations of large atomistic systems. In this approach, the input and output features are Hamiltonian matrices computed from different levels of theory. We demonstrate that the developed ML-based Hamiltonian mapping method (1) speeds up the calculations by several orders of magnitude, (2) is conceptually simpler than alternative ML approaches, (3) is applicable to different systems and sizes and can be used for mapping Hamiltonians constructed with arbitrary density functionals, (4) requires a modest training data, learns fast, and generates molecular orbitals and their energies with the accuracy nearly matching that of conventional calculations, and (5) when applied to nonadiabatic dynamics simulation of excitation energy relaxation in large systems yields the corresponding time scales within the margin of error of the conventional calculations. Using this approach, we explore the excitation energy relaxation in C60 fullerene and Si75H64 quantum dot structures and derive qualitative and quantitative insights into dynamics in these systems.
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Affiliation(s)
- Mohammad Shakiba
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Alexey V Akimov
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
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2
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Toldo JM, Mattos RS, Pinheiro M, Mukherjee S, Barbatti M. Recommendations for Velocity Adjustment in Surface Hopping. J Chem Theory Comput 2024; 20:614-624. [PMID: 38207213 DOI: 10.1021/acs.jctc.3c01159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
This study investigates velocity adjustment directions after hopping in surface hopping dynamics. Using fulvene and a protonated Schiff base (PSB4) as case studies, we investigate the population decay and reaction yields of different sets of dynamics with the velocity adjusted in either the nonadiabatic coupling, gradient difference, or momentum directions. For the latter, in addition to the conventional algorithm, we investigated the performance of a reduced kinetic energy reservoir approach recently proposed. Our evaluation also considered velocity adjustment in the directions of approximate nonadiabatic coupling vectors. While results for fulvene are susceptible to the adjustment approach, PSB4 is not. We correlated this dependence to the topography near the conical intersections. When nonadiabatic coupling vectors are unavailable, the gradient difference direction is the best adjustment option. If the gradient difference is also unavailable, a semiempirical vector direction or the momentum direction with a reduced kinetic energy reservoir becomes an excellent option to prevent an artificial excess of back hoppings. The precise velocity adjustment direction is less crucial for describing the nonadiabatic dynamics than the kinetic energy reservoir's size.
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Affiliation(s)
- Josene M Toldo
- Aix-Marseille University, CNRS, ICR, Marseille 13397, France
| | - Rafael S Mattos
- Aix-Marseille University, CNRS, ICR, Marseille 13397, France
| | - Max Pinheiro
- Aix-Marseille University, CNRS, ICR, Marseille 13397, France
| | | | - Mario Barbatti
- Aix-Marseille University, CNRS, ICR, Marseille 13397, France
- Institut Universitaire de France, Paris 75231, France
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3
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Guo H, Zhang X, Lu G. Pseudo-heterostructure and condensation of 1D moiré excitons in twisted phosphorene bilayers. SCIENCE ADVANCES 2023; 9:eadi5404. [PMID: 37478184 PMCID: PMC10361592 DOI: 10.1126/sciadv.adi5404] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 06/20/2023] [Indexed: 07/23/2023]
Abstract
Heterostructures are not expected to form in a single homogeneous material. Here, we show that planar pseudo-heterostructures could emerge in a twisted bilayer of phosphorene (tbP), driving in-plane energy and charge transfer. The formation of moiré superlattices combined with electronic anisotropy in tbPs yields one-dimensional (1D) moiré excitons with long radiative and nonradiative lifetimes, large binding energies, and deep moiré potentials. Low-frequency moiré phonons and dynamic moiré potentials are revealed to be responsible for the in-plane energy/charge transfer and exciton dynamics. The 1D moiré excitons are predicted to exhibit Bose-Einstein condensation at high temperatures and may lead to exotic Tonks-Girardeau Bose gases.
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Affiliation(s)
- Hongli Guo
- Department of Physics and Astronomy, California State University Northridge, Northridge, CA 91330-8268, USA
| | - Xu Zhang
- Department of Physics and Astronomy, California State University Northridge, Northridge, CA 91330-8268, USA
| | - Gang Lu
- Department of Physics and Astronomy, California State University Northridge, Northridge, CA 91330-8268, USA
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4
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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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5
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Shakiba M, Stippell E, Li W, Akimov AV. Nonadiabatic Molecular Dynamics with Extended Density Functional Tight-Binding: Application to Nanocrystals and Periodic Solids. J Chem Theory Comput 2022; 18:5157-5180. [PMID: 35758936 DOI: 10.1021/acs.jctc.2c00297] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this work, we report a new methodology for nonadiabatic molecular dynamics calculations within the extended tight-binding (xTB) framework. We demonstrate the applicability of the developed approach to finite and periodic systems with thousands of atoms by modeling "hot" electron relaxation dynamics in silicon nanocrystals and electron-hole recombination in both a graphitic carbon nitride monolayer and a titanium-based metal-organic framework (MOF). This work reports the nonadiabatic dynamic simulations in the largest Si nanocrystals studied so far by the xTB framework, with diameters up to 3.5 nm. For silicon nanocrystals, we find a non-monotonic dependence of "hot" electron relaxation rates on the nanocrystal size, in agreement with available experimental reports. We rationalize this relationship by a combination of decreasing nonadiabatic couplings related to system size and the increase of available coherent transfer pathways in systems with higher densities of states. We emphasize the importance of proper treatment of coherences for obtaining such non-monotonic dependences. We characterize the electron-hole recombination dynamics in the graphitic carbon nitride monolayer and the Ti-containing MOF. We demonstrate the importance of spin-adaptation and proper sampling of surface hopping trajectories in modeling such processes. We also assess several trajectory surface hopping schemes and highlight their distinct qualitative behavior in modeling the excited-state dynamics in superexchange-like models depending on how they handle coherences between nearly parallel states.
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Affiliation(s)
- Mohammad Shakiba
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Elizabeth Stippell
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Wei Li
- School of Chemistry and Materials Science, Hunan Agricultural University, Changsha 410128, China
| | - Alexey V Akimov
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
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6
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Photo-induced ultrafast electron dynamics in anatase and rutile TiO 2: Effects of the electron-phonon interaction. CHINESE J CHEM PHYS 2022. [DOI: 10.1063/1674-0068/cjcp2111264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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7
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Akimov AV. Excited state dynamics in monolayer black phosphorus revisited: Accounting for many-body effects. J Chem Phys 2021; 155:134106. [PMID: 34624981 DOI: 10.1063/5.0065606] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The dynamics of electron-hole recombination in pristine and defect-containing monolayer black phosphorus (ML-BP) has been studied computationally by several groups relying on the one-particle description of electronic excited states. Our recent developments enabled a more sophisticated and accurate treatment of excited states dynamics in systems with pronounced excitonic effects, including 2D materials such as ML-BP. In this work, I present a comprehensive characterization of optoelectronic properties and nonadiabatic dynamics of the ground state recovery in pristine and divacancy-containing ML-BP, relying on the linear-response time-dependent density functional theory description of excited states combined with several trajectory surface hopping methodologies and decoherence correction schemes. This work presents a revision and new implementation of the decoherence-induced surface hopping methodology. Several popular algorithms for nonadiabatic dynamics algorithms are assessed. The kinetics of nonradiative relaxation of lower-lying excited states in ML-BP systems is revised considering the new methodological developments. A general mechanism that explains the sensitivity of the nonradiative dynamics to the presence of divacancy defect in ML-BP is proposed. According to this mechanism, the excited states' relaxation may be inhibited by the presence of energetically close higher-energy states if electronic decoherence is present in the system.
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Affiliation(s)
- Alexey V Akimov
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000, USA
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8
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Segalina A, Lebègue S, Rocca D, Piccinin S, Pastore M. Structure and Energetics of Dye-Sensitized NiO Interfaces in Water from Ab Initio MD and Large-Scale GW Calculations. J Chem Theory Comput 2021; 17:5225-5238. [PMID: 34324810 DOI: 10.1021/acs.jctc.1c00354] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The energy-level alignment across solvated molecule/semiconductor interfaces is a crucial property for the correct functioning of dye-sensitized photoelectrodes, where, following the absorption of solar light, a cascade of interfacial hole/electron transfer processes has to efficiently take place. In light of the difficulty of performing X-ray photoelectron spectroscopy measurements at the molecule/solvent/metal-oxide interface, being able to accurately predict the level alignment by first-principles calculations on realistic structural models would represent an important step toward the optimization of the device. In this respect, dye/NiO surfaces, employed in p-type dye-sensitized solar cells, are undoubtedly challenging for ab initio methods and, also for this reason, much less investigated than the n-type dye/TiO2 counterpart. Here, we consider the C343-sensitized NiO surface in water and combine ab initio molecular dynamics (AIMD) simulations with GW (G0W0) calculations, performed along the MD trajectory to reliably describe the structure and energetics of the interface when explicit solvation and finite temperature effects are accounted for. We show that the differential perturbative correction on the NiO and molecule states obtained at the GW level is mandatory to recover the correct (physical) interfacial energetics, allowing hole transfer from the semiconductor valence band to the highest occupied molecular orbital (HOMO) of the dye. Moreover, the calculated average driving force quantitatively agrees with the experimental estimate.
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Affiliation(s)
- Alekos Segalina
- Université de Lorraine & CNRS, LPCT, UMR 7019, F-54000 Nancy, France
| | - Sébastien Lebègue
- Université de Lorraine & CNRS, LPCT, UMR 7019, F-54000 Nancy, France
| | - Dario Rocca
- Université de Lorraine & CNRS, LPCT, UMR 7019, F-54000 Nancy, France
| | - Simone Piccinin
- Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali, 34136 Trieste, Italy
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9
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Syzgantseva MA, Stepanov NF, Syzgantseva OA. Effect of Ligand Functionalization on the Rate of Charge Carrier Recombination in Metal-Organic Frameworks: A Case Study of MIL-125. J Phys Chem Lett 2021; 12:829-834. [PMID: 33417462 DOI: 10.1021/acs.jpclett.0c03634] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Ligand functionalization is a powerful approach for modifying the electronic structure of metal-organic frameworks when targeting the optimal electronic properties for photocatalysis and photovoltaics. However, its effect on the charge carrier lifetimes and recombination pathways remains unexplored. In this work, first-principles simulations, including nonadiabatic molecular dynamics, are performed for the representative TiO2-based metal-organic framework systems MIL-125-X to unravel the impact of ligand functionalization on the nonradiative electron-hole recombination process, decoherence rates, and phonon modes giving the largest contribution to the nonradiative decay. Nonradiative recombination rates, simulated using the PBE0 density functional, are in excellent agreement with experiment. The ligand functionalization in MIL-125-X influences the recombination rates, unraveling the trend opposite to the evolution of the band gap and affecting the nonadiabatic coupling coefficients. Ligand modification impacts the phonon modes, which contribute most to the recombination process, altering the distribution between soft phonon modes and vibrational modes associated with specific structural motifs.
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Affiliation(s)
- Maria A Syzgantseva
- Laboratory of Quantum Mechanics and Molecular Structure, Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Nikolay F Stepanov
- Laboratory of Quantum Mechanics and Molecular Structure, Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Olga A Syzgantseva
- Laboratory of Quantum Photodynamics, Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
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10
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Smith B, Shakiba M, Akimov AV. Nonadiabatic Dynamics in Si and CdSe Nanoclusters: Many-Body vs Single-Particle Treatment of Excited States. J Chem Theory Comput 2021; 17:678-693. [DOI: 10.1021/acs.jctc.0c01009] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Brendan Smith
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260 United States
| | - Mohammad Shakiba
- Department of Materials Science and Engineering, Shahid Bahonar University of Kerman, Kerman 76169-14111, Iran
| | - Alexey V. Akimov
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260 United States
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11
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Yamijala SSRKC, Huo P. Direct Nonadiabatic Simulations of the Photoinduced Charge Transfer Dynamics. J Phys Chem A 2021; 125:628-635. [DOI: 10.1021/acs.jpca.0c10151] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Sharma S. R. K. C. Yamijala
- Department of Chemistry, University of Rochester, 120 Trustee Road, Rochester, New York 14627, United States
- Department of Chemistry, Indian Institute of Technology-Madras, Chennai 600036, India
| | - Pengfei Huo
- Department of Chemistry, University of Rochester, 120 Trustee Road, Rochester, New York 14627, United States
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12
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Ma W, Jiao Y, Li H, Guo H, Kaxiras E, Meng S. Role of Explicitly Included Solvents on Ultrafast Electron Injection and Recombination Dynamics at TiO 2/Dye Interfaces. ACS APPLIED MATERIALS & INTERFACES 2020; 12:49174-49181. [PMID: 33054176 DOI: 10.1021/acsami.0c12972] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Solvent effects are important for photovoltaic systems like dye-sensitized solar cells (DSCs) but remain largely unexplored, partly due to the complexity of explicitly including solvent molecules in atomistic simulations. To address these issues, we have systematically investigated the solvent effects in practical solar cells using ab initio excited state dynamics simulations. In this computational protocol and the extended model system, we considered giving a novel perspective on the excited state changes in response to solvation and finite temperature at the heterointerface of DSCs. By directly comparing the geometric stability of interface bonding, photoabsorption, interfacial electronic structure, and dynamics of vacuum and solvent systems, we obtain useful insights into how solvents influence the key factors that determine the efficiency of DSCs. Solvents significantly enhance the intensity of visible light absorption of chromophores (∼2 times) through two effects: (a) by inducing changes to the dye molecule structure due to intermolecular dye-solvent interactions, and (b) by the dielectric screening of the solvent. Furthermore, by adsorbing onto the TiO2 surface, solvent molecules adjust the interfacial band alignment to a favorable level and screen out the attraction force between injected electrons in the semiconductor substrate and holes left on the chromophore to a large extent, dramatically slowing down the recombination process (>8 times). Our findings provide a comprehensive picture of the explicit solvent effects on individual energy conversion steps in DSCs at the microscopic scale and lead to more accurate prediction of the performance of nanodevices in practical environments, contributing to the optimization of realistic renewable energy devices.
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Affiliation(s)
- Wei Ma
- Ningxia Key Laboratory of Photovoltaic Materials, Ningxia University, Yinchuan, Ningxia 750021, P.R. China
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P.R. China
| | - Yang Jiao
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P.R. China
| | - Haibo Li
- Ningxia Key Laboratory of Photovoltaic Materials, Ningxia University, Yinchuan, Ningxia 750021, P.R. China
| | - Haizhong Guo
- School of Physics and Engineering, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Efthimios Kaxiras
- Department of Physics and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Sheng Meng
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P.R. China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, P.R. China
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13
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Liu J, Zhang X, Lu G. Excitonic Effect Drives Ultrafast Dynamics in van der Waals Heterostructures. NANO LETTERS 2020; 20:4631-4637. [PMID: 32432887 DOI: 10.1021/acs.nanolett.0c01519] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Recent experiments revealed stacking-configuration-independent and ultrafast charge transfer in transition metal dichalcogenides van der Waals (vdW) heterostructures, which is surprising given strong exciton binding energies and large momentum mismatch across the heterojunctions. Previous theories failed to provide a comprehensive physical picture for the charge transfer mechanisms. To address this challenge, we developed a first-principles framework which can capture exciton-phonon interaction in extended systems. We find that excitonic effect does not impede, but actually drives ultrafast charge transfer in vdW heterostructures. The many-body electron-hole interaction affords cooperation among the electrons, which relaxes the constraint on momentum conservation and reduces energy gaps for charge transfer. We uncover a two-step process in exciton dynamics: ultrafast hole transfer followed by much longer relaxation of intermediate "hot" excitons. This work establishes that many-body excitonic effect is crucial to the ultrafast dynamics and provides a basis to understand relevant phenomena in vdW heterostructures.
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Affiliation(s)
- Junyi Liu
- Department of Physics and Astronomy, California State University Northridge, California 91330-8268, United States
| | - Xu Zhang
- Department of Physics and Astronomy, California State University Northridge, California 91330-8268, United States
| | - Gang Lu
- Department of Physics and Astronomy, California State University Northridge, California 91330-8268, United States
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14
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Intermolecular interaction between anthraquinone dyes and TEMPO mediator in dye-sensitized photocatalytic systems. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2020. [DOI: 10.1016/j.jpap.2020.100003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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15
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Ma W, Zhang X, Xu Z, Guo H, Lu G, Meng S. Reducing Anomalous Hysteresis in Perovskite Solar Cells by Suppressing the Interfacial Ferroelectric Order. ACS APPLIED MATERIALS & INTERFACES 2020; 12:12275-12284. [PMID: 32079393 DOI: 10.1021/acsami.9b20988] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Despite the booming research in organometal halide perovskite solar cells (PSCs) of recent years, considerable roadblocks remain for their large-scale deployment, ranging from undesirable current-voltage hysteresis to inferior device stability. Among various plausible origins of hysteresis, interfacial ferroelectricity is particularly intriguing and warrants a close scrutiny. Here, we examine interfacial ferroelectricity in MAPbI3 (FAPbI3)/TiO2 and MAPbI3/phenyl-C61-butyric-acid-methyl-ester (PCBM) heterostructures and explore the correlations between the interfacial ferroelectricity and the hysteresis from the perspective of nonadiabatic electronic dynamics. It is found that the ferroelectric order develops at the MAPbI3/TiO2 interface owing to the interaction between the polar MA ions and TiO2. The polarization switching of the MA ions under an applied gate field would drastically result in different rates in interfacial photoelectron injection and electron-hole recombination, contributing to the undesirable hysteresis. In sharp contrast, ferroelectricity is suppressed at the FAPbI3/TiO2 and MAPbI3/PCBM interfaces, thanks to elimination of the interfacial electric field between perovskite and TiO2 via substitution of strong polar MA (dipole moment: 2.29 debye) by weak polar FA ions (dipole moment: 0.29 debye) and interface passivation, leading to consistent interfacial electronic dynamics and the absence of hysteresis. The present work sheds light on the physical cause for hysteresis and points to the direction to which the hysteresis could be mitigated in PSCs.
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Affiliation(s)
- Wei Ma
- Ningxia Key Laboratory of Photovoltaic Materials, Ningxia University, Yinchuan 750021, People's Republic of China
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Xu Zhang
- Department of Physics and Astronomy, California State University Northridge, Northridge, Los Angeles, California 91330-8268, United States
| | - Zhe Xu
- School of Physics and Engineering, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
| | - Haizhong Guo
- School of Physics and Engineering, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
| | - Gang Lu
- Department of Physics and Astronomy, California State University Northridge, Northridge, Los Angeles, California 91330-8268, United States
| | - Sheng Meng
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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16
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Smith B, Akimov AV. Hot Electron Cooling in Silicon Nanoclusters via Landau-Zener Nonadiabatic Molecular Dynamics: Size Dependence and Role of Surface Termination. J Phys Chem Lett 2020; 11:1456-1465. [PMID: 31958367 DOI: 10.1021/acs.jpclett.9b03687] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We develop a new express methodology for modeling excited-state dynamics occurring in dense manifolds of electronic states in atomistic systems. The approach leverages a modified Landau-Zener formula, the neglect of a back-reaction approximation, and the highly efficient density functional tight-binding method. We study the hot electron dynamics in a series of H- and F-terminated silicon nanocrystals (NCs) containing up to several hundred atoms. We explain the slower electron cooling dynamics in F-terminated NCs by the larger energy gaps between the adjacent electronic states in these systems as well as their slower fluctuations. We conclude that both the mass and chemical identity of the surface termination groups equally influence the electron dynamics, on average. However, the mass effect becomes dominant for higher-energy excitations. We find that the electron decay dynamics in F-terminated NCs has a greater sensitivity to the mass of the surface ligands than do the H-terminated NCs and explain this observation by the details of the electron-phonon coupling in the systems. We find that in the H-terminated NCs, electronic transitions in the cooling process occur predominantly between the surface states, whereas in F-terminated Si NCs, both surface and NC core states are coupled to the nuclear vibrations. We find that electron energy relaxation is accelerated in larger NCs and attribute this effect to the higher densities of states and smaller energy gaps in these systems.
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Affiliation(s)
- Brendan Smith
- Department of Chemistry , University at Buffalo, The State University of New York , Buffalo , New York 14260 , United States
| | - Alexey V Akimov
- Department of Chemistry , University at Buffalo, The State University of New York , Buffalo , New York 14260 , United States
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17
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Smith B, Akimov AV. Modeling nonadiabatic dynamics in condensed matter materials: some recent advances and applications. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:073001. [PMID: 31661681 DOI: 10.1088/1361-648x/ab5246] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
This review focuses on recent developments in the field of nonadiabatic molecular dynamics (NA-MD), with particular attention given to condensed-matter systems. NA-MD simulations for small molecular systems can be performed using high-level electronic structure (ES) calculations, methods accounting for the quantization of nuclear motion, and using fewer approximations in the dynamical methodology itself. Modeling condensed-matter systems imposes many limitations on various aspects of NA-MD computations, requiring approximations at various levels of theory-from the ES, to the ways in which the coupling of electrons and nuclei are accounted for. Nonetheless, the approximate treatment of NA-MD in condensed-phase materials has gained a spin lately in many applied studies. A number of advancements of the methodology and computational tools have been undertaken, including general-purpose methods, as well as those tailored to nanoscale and condensed matter systems. This review summarizes such methodological and software developments, puts them into the broader context of existing approaches, and highlights some of the challenges that remain to be solved.
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Affiliation(s)
- Brendan Smith
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000, United States of America
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18
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Zheng F, Wang LW. Ultrafast Hot Carrier Injection in Au/GaN: The Role of Band Bending and the Interface Band Structure. J Phys Chem Lett 2019; 10:6174-6183. [PMID: 31538792 DOI: 10.1021/acs.jpclett.9b02402] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Plasmon photochemistry can potentially play a significant role in photocatalysis. To realize this potential, it is critical to enhance the plasmon excited hot carrier transfer and collection. However, the lack of atomistic understanding of the carrier transfer across the interface, especially when the carrier is still "hot", makes it challenging to design a more efficient system. In this work, we apply the nonadiabatic molecular dynamics simulation to study hot carrier dynamics in the system of a Au nanocluster on top of a GaN surface. By setting up the initial excited hole in Au, the carrier transfer from Au to GaN is found to be on a subpicosecond time scale. The hot hole first cools to the band edge of Au d-states while it transfers to GaN. After the hole has cooled down to the band edge of GaN, we find that some of the charges can return back to Au. By applying different external potentials to mimic the Schottky barrier band bending, the returning charge can be reduced, demonstrating the importance of the internal electric field. Finally, with the understanding of the carrier transfer's pathway, we suggest that a ZnO layer between GaN and Au can effectively block the "cold" carrier from returning back to Au but still allow the hot carrier to transfer from Au to GaN.
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Affiliation(s)
- Fan Zheng
- Joint Center for Artificial Photosynthesis and Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Lin-Wang Wang
- Joint Center for Artificial Photosynthesis and Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
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19
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Smith B, Akimov AV. A comparative analysis of surface hopping acceptance and decoherence algorithms within the neglect of back-reaction approximation. J Chem Phys 2019; 151:124107. [DOI: 10.1063/1.5122770] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Brendan Smith
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000, USA
| | - Alexey V. Akimov
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000, USA
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20
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Wang X, Li Y, Song P, Ma F, Yang Y. Second-Order Nonlinear Optical Switch Manipulation of Photosensitive Layer by an External Electric Field Coupled with Graphene Quantum Dots. J Phys Chem A 2019; 123:7401-7407. [DOI: 10.1021/acs.jpca.9b05249] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiaofei Wang
- College of Science, Northeast Forestry University, Harbin 150040, Heilongjiang, China
| | - Yuanzuo Li
- College of Science, Northeast Forestry University, Harbin 150040, Heilongjiang, China
| | - Peng Song
- Department of Physics, Liaoning University, Shenyang 110036, Liaoning, China
| | - Fengcai Ma
- Department of Physics, Liaoning University, Shenyang 110036, Liaoning, China
| | - Yanhui Yang
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, 211816 Nanjing, China
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21
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Daoudi S, Semmeq A, Badawi M, Assfeld X, Arfaoui Y, Pastore M. Electronic structure and optical properties of isolated and TiO
2
‐grafted free base porphyrins for water oxidation: A challenging test case for DFT and TD‐DFT. J Comput Chem 2019; 40:2530-2538. [DOI: 10.1002/jcc.26027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 06/19/2019] [Accepted: 06/20/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Syrine Daoudi
- CNRS & Université de LorraineLaboratoire de Physique et Chimie Théoriques Boulevard des Aiguillettes, BP 70239 54506 Vandoeuvre‐lès‐Nancy Cedex France
- Laboratory of Physical Chemistry of Condensed Materials, Faculty of Mathematical, Physical and Natural Sciences of TunisUniversity of Tunis El Manar Campus Farhat‐Hached, 1068 Tunis Tunisia
| | - Abderrahmane Semmeq
- CNRS & Université de LorraineLaboratoire de Physique et Chimie Théoriques Boulevard des Aiguillettes, BP 70239 54506 Vandoeuvre‐lès‐Nancy Cedex France
- Laboratoire Physique de la Matière Condensée, Faculté des Sciences Ben M'sikUniversité Hassan II de Casablanca Casablanca, Morocco
| | - Michael Badawi
- CNRS & Université de LorraineLaboratoire de Physique et Chimie Théoriques Boulevard des Aiguillettes, BP 70239 54506 Vandoeuvre‐lès‐Nancy Cedex France
| | - Xavier Assfeld
- CNRS & Université de LorraineLaboratoire de Physique et Chimie Théoriques Boulevard des Aiguillettes, BP 70239 54506 Vandoeuvre‐lès‐Nancy Cedex France
| | - Youssef Arfaoui
- Laboratory of Physical Chemistry of Condensed Materials, Faculty of Mathematical, Physical and Natural Sciences of TunisUniversity of Tunis El Manar Campus Farhat‐Hached, 1068 Tunis Tunisia
| | - Mariachiara Pastore
- CNRS & Université de LorraineLaboratoire de Physique et Chimie Théoriques Boulevard des Aiguillettes, BP 70239 54506 Vandoeuvre‐lès‐Nancy Cedex France
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22
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Zhou X, Tokina MV, Tomko JA, Braun JL, Hopkins PE, Prezhdo OV. Thin Ti adhesion layer breaks bottleneck to hot hole relaxation in Au films. J Chem Phys 2019; 150:184701. [DOI: 10.1063/1.5096901] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Xin Zhou
- College of Environment and Chemical Engineering, Dalian University, Dalian 116622, People’s Republic of China
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - Marina V. Tokina
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - John A. Tomko
- Department of Materials Science and Engineering, University of Virginia, Charlottesville, Virginia 22903, USA
| | - Jeffrey L. Braun
- Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22903, USA
| | - Patrick E. Hopkins
- Department of Materials Science and Engineering, University of Virginia, Charlottesville, Virginia 22903, USA
- Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22903, USA
- Department of Physics, University of Virginia, Charlottesville, Virginia 22903, USA
| | - Oleg V. Prezhdo
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, USA
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23
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Parker SM, Roy S, Furche F. Multistate hybrid time-dependent density functional theory with surface hopping accurately captures ultrafast thymine photodeactivation. Phys Chem Chem Phys 2019; 21:18999-19010. [DOI: 10.1039/c9cp03127h] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report an efficient analytical implementation of first-order nonadiabatic derivative couplings between arbitrary Born–Oppenheimer states in the hybrid time-dependent density functional theory (TDDFT) framework using atom-centered basis functions.
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Affiliation(s)
- Shane M. Parker
- Department of Chemistry
- University of California, Irvine
- Irvine
- USA
| | - Saswata Roy
- Department of Chemistry
- University of California, Irvine
- Irvine
- USA
| | - Filipp Furche
- Department of Chemistry
- University of California, Irvine
- Irvine
- USA
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24
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Lu TF, Li W, Chen J, Tang J, Bai FQ, Zhang HX. Promising pyridinium ylide based anchors towards high-efficiency dyes for dye-sensitized solar cells applications: Insights from theoretical investigations. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.07.108] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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25
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Zhang Z, Liu L, Fang WH, Long R, Tokina MV, Prezhdo OV. Plasmon-Mediated Electron Injection from Au Nanorods into MoS2: Traditional versus Photoexcitation Mechanism. Chem 2018. [DOI: 10.1016/j.chempr.2018.02.025] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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26
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Ooyama Y, Furue K, Enoki T, Kanda M, Adachi Y, Ohshita J. Development of type-I/type-II hybrid dye sensitizer with both pyridyl group and catechol unit as anchoring group for type-I/type-II dye-sensitized solar cell. Phys Chem Chem Phys 2018; 18:30662-30676. [PMID: 27790658 DOI: 10.1039/c6cp06513a] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A type-I/type-II hybrid dye sensitizer with a pyridyl group and a catechol unit as the anchoring group has been developed and its photovoltaic performance in dye-sensitized solar cells (DSSCs) is investigated. The sensitizer has the ability to adsorb on a TiO2 electrode through both the coordination bond at Lewis acid sites and the bidentate binuclear bridging linkage at Brønsted acid sites on the TiO2 surface, which makes it possible to inject an electron into the conduction band of the TiO2 electrode by the intramolecular charge-transfer (ICT) excitation (type-I pathway) and by the photoexcitation of the dye-to-TiO2 charge transfer (DTCT) band (type-II pathway). It was found that the type-I/type-II hybrid dye sensitizer adsorbed on TiO2 film exhibits a broad photoabsorption band originating from ICT and DTCT characteristics. Here we reveal the photophysical and electrochemical properties of the type-I/type-II hybrid dye sensitizer bearing a pyridyl group and a catechol unit, along with its adsorption modes onto TiO2 film, and its photovoltaic performance in type-I/type-II DSSC, based on optical (photoabsorption and fluorescence spectroscopy) and electrochemical measurements (cyclic voltammetry), density functional theory (DFT) calculation, FT-IR spectroscopy of the dyes adsorbed on TiO2 film, photocurrent-voltage (I-V) curves, incident photon-to-current conversion efficiency (IPCE) spectra, and electrochemical impedance spectroscopy (EIS) for DSSC.
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Affiliation(s)
- Yousuke Ooyama
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan.
| | - Kensuke Furue
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan.
| | - Toshiaki Enoki
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan.
| | - Masahiro Kanda
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan.
| | - Yohei Adachi
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan.
| | - Joji Ohshita
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan.
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27
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Nan G, Zhang X, Lu G. The lowest-energy charge-transfer state and its role in charge separation in organic photovoltaics. Phys Chem Chem Phys 2018; 18:17546-56. [PMID: 27306609 DOI: 10.1039/c6cp01622g] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Energy independent, yet higher than 90% internal quantum efficiency (IQE), has been observed in many organic photovoltaics (OPVs). However, its physical origin remains largely unknown and controversial. The hypothesis that the lowest charge-transfer (CT) state may be weakly bound at the interface has been proposed to rationalize the experimental observations. In this paper, we study the nature of the lowest-energy CT (CT1) state, and show conclusively that the CT1 state is localized in typical OPVs. The electronic couplings in the donor and acceptor are found to determine the localization of the CT1 state. We examine the geminate recombination of the CT1 state and estimate its lifetime from first principles. We identify the vibrational modes that contribute to the geminate recombination. Using material parameters determined from first principles and experiments, we carry out kinetic Monte Carlo simulations to examine the charge separation of the localized CT1 state. We find that the localized CT1 state can indeed yield efficient charge separation with IQE higher than 90%. Dynamic disorder and configuration entropy can provide the energetic and entropy driving force for charge separation. Charge separation efficiency depends more sensitively on the dimension and crystallinity of the acceptor parallel to the interface than that normal to the interface. Reorganization energy is found to be the most important material parameter for charge separation, and lowering the reorganization energy of the donor should be pursued in the materials design.
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Affiliation(s)
- Guangjun Nan
- Department of Physics and Astronomy, California State University Northridge, 18111 Nordhoff Street, Northridge, California 91330-8268, USA.
| | - Xu Zhang
- Department of Physics and Astronomy, California State University Northridge, 18111 Nordhoff Street, Northridge, California 91330-8268, USA.
| | - Gang Lu
- Department of Physics and Astronomy, California State University Northridge, 18111 Nordhoff Street, Northridge, California 91330-8268, USA.
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28
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Lu S, Ma W, Jin G, Zeng Q, Feng X, Feng T, Liu H, Meng S, Redfern SAT, Yang B. A combined experimental and theoretical investigation of donor and acceptor interface in efficient aqueous-processed polymer/nanocrystal hybrid solar cells. Sci China Chem 2018. [DOI: 10.1007/s11426-017-9177-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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29
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Sato K, Pradhan E, Asahi R, Akimov AV. Charge transfer dynamics at the boron subphthalocyanine chloride/C60 interface: non-adiabatic dynamics study with Libra-X. Phys Chem Chem Phys 2018; 20:25275-25294. [DOI: 10.1039/c8cp03841d] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The Libra-X software for non-adiabatic molecular dynamics is reported. It is used to comprehensively study the charge transfer dynamics at the boron subphtalocyanine chloride (SubPc)/fullerene (C60) interface.
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Affiliation(s)
- Kosuke Sato
- Toyota Central Research and Development Laboratories, Inc
- Nagakute
- Japan
| | - Ekadashi Pradhan
- Department of Chemistry
- University at Buffalo
- The State University of New York
- New York 14260-3000
- USA
| | - Ryoji Asahi
- Toyota Central Research and Development Laboratories, Inc
- Nagakute
- Japan
| | - Alexey V. Akimov
- Department of Chemistry
- University at Buffalo
- The State University of New York
- New York 14260-3000
- USA
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30
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Zhou X, Jankowska J, Li L, Giri A, Hopkins PE, Prezhdo OV. Strong Influence of Ti Adhesion Layer on Electron-Phonon Relaxation in Thin Gold Films: Ab Initio Nonadiabatic Molecular Dynamics. ACS APPLIED MATERIALS & INTERFACES 2017; 9:43343-43351. [PMID: 29135220 DOI: 10.1021/acsami.7b12535] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Electron-phonon relaxation in thin metal films is an important consideration for many ultrasmall devices and ultrafast applications. Recent time-resolved experiments demonstrate a significant, more than a factor of five, increase in the electron-phonon coupling and acceleration in the electron-phonon relaxation rate when a narrow Ti adhesion layer is introduced between an Au film and a nonmetal substrate. Using nonadiabatic molecular dynamics combined with real-time time-dependent density functional theory, we identify the reasons that give rise to this strong effect. First, the Ti layer greatly enhances the density of states (DOS) in the energy region starting at 1 eV below the Fermi level and extending several electronvolts above it. Second, Ti atoms are four times lighter than Au atoms and therefore generate larger nonadiabatic (NA) electron-phonon coupling. Because the transition rates depend on coupling and DOS, both the factors accelerate the dynamics. Showing good agreement with the experiments, the time-domain atomistic simulations provide a detailed mechanistic understanding of the electron-phonon relaxation dynamics in thin gold films and related nanomaterials.
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Affiliation(s)
- Xin Zhou
- College of Environment and Chemical Engineering, Dalian University , Dalian 116622, P. R. China
| | - Joanna Jankowska
- Institute of Physics, Polish Academy of Sciences , 02-668 Warsaw, Poland
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31
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Wei Y, Li L, Fang W, Long R, Prezhdo OV. Weak Donor-Acceptor Interaction and Interface Polarization Define Photoexcitation Dynamics in the MoS 2/TiO 2 Composite: Time-Domain Ab Initio Simulation. NANO LETTERS 2017; 17:4038-4046. [PMID: 28586230 DOI: 10.1021/acs.nanolett.7b00167] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
To realize the full potential of transition metal dichalcogenides interfaced with bulk semiconductors for solar energy applications, fast photoinduced charge separation, and slow electron-hole recombination are needed. Using a combination of time-domain density functional theory with nonadiabatic molecular dynamics, we demonstrate that the key features of the electron transfer (ET), energy relaxation and electron-hole recombination in a MoS2-TiO2 system are governed by the weak van der Waals interfacial interaction and interface polarization. Electric fields formed at the interface allow charge separation to happen already during the photoexcitation process. Those electrons that still reside inside MoS2, transfer into TiO2 slowly and by the nonadiabatic mechanism, due to weak donor-acceptor coupling. The ET time depends on excitation energy, because the TiO2 state density grows with energy, increasing the nonadiabatic transfer rate, and because MoS2 sulfur atoms start to contribute to the photoexcited state at higher energies, increasing the coupling. The ET is slower than electron-phonon energy relaxation because the donor-acceptor coupling is weak, rationalizing the experimentally observed injection of primarily hot electrons. The weak van der Waals MoS2-TiO2 interaction ensures a long-lived charge separated state and a short electron-hole coherence time. The injection is promoted primarily by phonons within the 200-800 cm-1 range. Higher frequency modes are particularly important for the electron-hole recombinations, because they are able to accept large amounts of electronic energy. The predicted time scales for the forward and backward ET, and energy relaxation can be measured by time-resolved spectroscopies. The reported simulations generate a detailed time-domain atomistic description of the complex interplay of the charge and energy transfer processes at the MoS2/TiO2 interface that are of fundamental importance to photovoltaic and photocatalytic applications. The results suggest that even though the photogenerated charge-separated state is long-lived, the slower charge separation, compared to the electron-phonon energy relaxation, can present problems in practical applications.
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Affiliation(s)
- Yaqing Wei
- College of Chemistry, Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, Beijing Normal University , Beijing, 100875, People's Republic of China
| | - Linqiu Li
- Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States
| | - Weihai Fang
- College of Chemistry, Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, Beijing Normal University , Beijing, 100875, People's Republic of China
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, Beijing Normal University , Beijing, 100875, People's Republic of China
| | - Oleg V Prezhdo
- Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States
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32
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Long R, Casanova D, Fang WH, Prezhdo OV. Donor–Acceptor Interaction Determines the Mechanism of Photoinduced Electron Injection from Graphene Quantum Dots into TiO2: π-Stacking Supersedes Covalent Bonding. J Am Chem Soc 2017; 139:2619-2629. [DOI: 10.1021/jacs.6b09598] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, P. R. China
| | - David Casanova
- Kimika Fakultatea,
Euskal Herriko Unibertsitatea and Donostia International Physics Center, 20018 Donostia, Euskadi, Spain
- IKERBASQUE, Basque
Foundation for Science, 48013 Bilbao, Euskadi, Spain
| | - Wei-Hai Fang
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, P. R. China
| | - Oleg V. Prezhdo
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
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33
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Akimov AV. Nonadiabatic Molecular Dynamics with Tight-Binding Fragment Molecular Orbitals. J Chem Theory Comput 2016; 12:5719-5736. [DOI: 10.1021/acs.jctc.6b00955] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Alexey V. Akimov
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000, United States
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34
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Hermann G, Tremblay JC. Ultrafast photoelectron migration in dye-sensitized solar cells: Influence of the binding mode and many-body interactions. J Chem Phys 2016; 145:174704. [PMID: 27825243 DOI: 10.1063/1.4966260] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In the present contribution, the ultrafast photoinduced electron migration dynamics at the interface between an alizarin dye and an anatase TiO2 thin film is investigated from first principles. Comparison between a time-dependent many-electron configuration interaction ansatz and a single active electron approach sheds light on the importance of many-body effects, stemming from uniquely defined initial conditions prior to photoexcitation. Particular emphasis is put on understanding the influence of the binding mode on the migration process. The dynamics is analyzed on the basis of a recently introduced toolset in the form of electron yields, electronic fluxes, and flux densities, to reveal microscopic details of the electron migration mechanism. From the many-body perspective, insight into the nature of electron-electron and hole-hole interactions during the charge transfer process is obtained. The present results reveal that the single active electron approach yields quantitatively and phenomenologically similar results as the many-electron ansatz. Furthermore, the charge migration processes in the dye-TiO2 model clusters with different binding modes exhibit similar mechanistic pathways but on largely different time scales.
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Affiliation(s)
- G Hermann
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
| | - J C Tremblay
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
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35
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Kumar P, Kumar S, Ghosh S, Pal SK. Femtosecond insights into direct electron injection in dye anchored ZnO QDs following charge transfer excitation. Phys Chem Chem Phys 2016; 18:20672-81. [PMID: 27412034 DOI: 10.1039/c6cp01721e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The role of the charge transfer (CT) state in interfacial electron transfer in dye-sensitized semiconductor nanocrystals is still poorly understood. To address this problem, femtosecond transient absorption (TA) spectroscopy is used as a probe to investigate the electron injection across a newly synthesized coumarin dye (8-hydroxy-2-oxo-4-phenyl-2 benzo[h]chromene-3-carbonitrile, coded BC5) and ZnO quantum dots (QDs). Steady state and time-resolved spectroscopic measurements reveal that BC5 dye interacts strongly with ZnO QDs in the ground state forming a CT complex. The BC5-ZnO QD complex absorbs more towards red compared to only the dye and QDs, and emits fluorescence due to radiative recombination of photogenerated charges. The formation of charges following the excitation of the CT complex has been demonstrated by observing the signature of dye radical cations and electrons in the conduction band (CB) of the QDs in the TA spectra. The TA signals of these charges grow sharply as a result of ultrafast direct electron injection into the QD. We have monitored the complete dynamics of photogenerated charges by measuring the TA signals of the charges up to a couple of nanoseconds. The injected electrons that are free or shallowly trapped recombine with a time constant of 625 fs, whereas deeply trapped electrons disappear slowly (526 ps) via radiative recombination. Furthermore, theoretical studies based on ab initio calculations have been carried out to complement the experimental findings.
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Affiliation(s)
- Pushpendra Kumar
- School of Basic Sciences and Advanced Material Research Center, Indian Institute of Technology Mandi, Kamand 175005, H.P., India.
| | - Sunil Kumar
- School of Basic Sciences and Advanced Material Research Center, Indian Institute of Technology Mandi, Kamand 175005, H.P., India.
| | - Subrata Ghosh
- School of Basic Sciences and Advanced Material Research Center, Indian Institute of Technology Mandi, Kamand 175005, H.P., India.
| | - Suman Kalyan Pal
- School of Basic Sciences and Advanced Material Research Center, Indian Institute of Technology Mandi, Kamand 175005, H.P., India.
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36
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Andermatt S, Cha J, Schiffmann F, VandeVondele J. Combining Linear-Scaling DFT with Subsystem DFT in Born–Oppenheimer and Ehrenfest Molecular Dynamics Simulations: From Molecules to a Virus in Solution. J Chem Theory Comput 2016; 12:3214-27. [DOI: 10.1021/acs.jctc.6b00398] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
| | - Jinwoong Cha
- Department
of Materials, ETH Zürich, Zürich, Switzerland
| | - Florian Schiffmann
- Department
of Materials, ETH Zürich, Zürich, Switzerland
- Centre
of Policy Studies, Victoria University, Melbourne, Australia
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37
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Zhang X, Bieberle-Hütter A. Modeling and Simulations in Photoelectrochemical Water Oxidation: From Single Level to Multiscale Modeling. CHEMSUSCHEM 2016; 9:1223-42. [PMID: 27219662 DOI: 10.1002/cssc.201600214] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Indexed: 05/11/2023]
Abstract
This review summarizes recent developments, challenges, and strategies in the field of modeling and simulations of photoelectrochemical (PEC) water oxidation. We focus on water splitting by metal-oxide semiconductors and discuss topics such as theoretical calculations of light absorption, band gap/band edge, charge transport, and electrochemical reactions at the electrode-electrolyte interface. In particular, we review the mechanisms of the oxygen evolution reaction, strategies to lower overpotential, and computational methods applied to PEC systems with particular focus on multiscale modeling. The current challenges in modeling PEC interfaces and their processes are summarized. At the end, we propose a new multiscale modeling approach to simulate the PEC interface under conditions most similar to those of experiments. This approach will contribute to identifying the limitations at PEC interfaces. Its generic nature allows its application to a number of electrochemical systems.
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Affiliation(s)
- Xueqing Zhang
- Photo-/Electrochemical Materials and Interfaces, Dutch Institute for Fundamental Energy Research (DIFFER), De Zaale 20, 5612 AJ, Eindhoven, The Netherlands
| | - Anja Bieberle-Hütter
- Photo-/Electrochemical Materials and Interfaces, Dutch Institute for Fundamental Energy Research (DIFFER), De Zaale 20, 5612 AJ, Eindhoven, The Netherlands.
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Zhou L, Zhang J, Zhuo Z, Kou L, Ma W, Shao B, Du A, Meng S, Frauenheim T. Novel Excitonic Solar Cells in Phosphorene-TiO2 Heterostructures with Extraordinary Charge Separation Efficiency. J Phys Chem Lett 2016; 7:1880-1887. [PMID: 27141996 DOI: 10.1021/acs.jpclett.6b00475] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Constructing van der Waals heterostructures is an efficient approach to modulate the electronic structure, to advance the charge separation efficiency, and thus to optimize the optoelectronic property. Here, we theoretically investigated the phosphorene interfaced with TiO2(110) surface (1L-BP/TiO2) with a type-II band alignment, showing enhanced photoactivity. The 1L-BP/TiO2 excitonic solar cell (XSC) based on the 1L-BP/TiO2 exhibits large built-in potential and high power conversion efficiency (PCE), dozens of times higher than conventional solar cells, comparable to MoS2/WS2 XSC. The nonadiabatic molecular dynamics simulation shows the ultrafast electron transfer time of 6.1 fs, and slow electron-hole recombination of 0.58 ps, yielding >98% internal quantum efficiency for charge separation, further guaranteeing the practical PCE. Moreover, doping in phosphorene has a tunability on built-in potential, charge transfer, light absorbance, as well as electron dynamics, which greatly helps to optimize the optoelectronic efficiency of a XSC.
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Affiliation(s)
- Liujiang Zhou
- Bremen Center for Computational Materials Science, University of Bremen , Am Falturm 1, 28359 Bremen, Germany
| | - Jin Zhang
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, P. R. China
| | - Zhiwen Zhuo
- Department of Materials Science and Engineering, University of Science and Technology of China , Hefei, Anhui 230026, China
| | - Liangzhi Kou
- School of Chemistry, Physics and Mechanical Engineering Faculty, Queensland University of Technology , Garden Point Campus, Brisbane, Queensland 4001, Australia
| | - Wei Ma
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, P. R. China
| | - Bin Shao
- Bremen Center for Computational Materials Science, University of Bremen , Am Falturm 1, 28359 Bremen, Germany
| | - Aijun Du
- School of Chemistry, Physics and Mechanical Engineering Faculty, Queensland University of Technology , Garden Point Campus, Brisbane, Queensland 4001, Australia
| | - Sheng Meng
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, P. R. China
- Collaborative Innovation Center of Quantum Matter, Beijing 100190, China
| | - Thomas Frauenheim
- Bremen Center for Computational Materials Science, University of Bremen , Am Falturm 1, 28359 Bremen, Germany
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39
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Long R, Guo M, Liu L, Fang W. Nonradiative Relaxation of Photoexcited Black Phosphorus Is Reduced by Stacking with MoS2: A Time Domain ab Initio Study. J Phys Chem Lett 2016; 7:1830-1835. [PMID: 27132486 DOI: 10.1021/acs.jpclett.6b00757] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Black phosphorus (BP) is an appealing material for applications in electronics and optoelectronics because of its tunable direct band gap and high charge carrier mobility. For real optoelectronic device utilization, nonradiative electron-hole recombination should be slow because it constitutes a major pathway for charge and energy losses. Using time-domain density functional theory combined with nonadiabatic (NA) molecular dynamics, we show that nonradiative electron-hole recombination occurs within several tens of picoseconds in bilayer BP, agreeing well with experimental data. When a single layer of BP is stacked with monolayer MoS2, the recombination is reduced because of the increased band gap and reduced electron-phonon NA coupling compared to bilayer BP. The slow electron-phonon energy losses in BP-MoS2 van der Waals heterojunction relative to bilayer BP indicate that rationally stacking BP with other two-dimensional materials is an attractive route for designing novel and efficient photovoltaic materials.
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Affiliation(s)
- Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University , Beijing, 100875, P. R. China
| | - Meng Guo
- Shandong Computer Science Center (National Supercomputer Center in Jinan) , Jinan, Shandong Province P. R. China , 250101
| | - Lihong Liu
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University , Beijing, 100875, P. R. China
| | - Weihai Fang
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University , Beijing, 100875, P. R. China
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40
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Pal S, Trivedi DJ, Akimov AV, Aradi B, Frauenheim T, Prezhdo OV. Nonadiabatic Molecular Dynamics for Thousand Atom Systems: A Tight-Binding Approach toward PYXAID. J Chem Theory Comput 2016; 12:1436-48. [DOI: 10.1021/acs.jctc.5b01231] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sougata Pal
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Dhara J. Trivedi
- Department
of Physics and Astronomy, University of Rochester, Rochester, New York 14627, United States
| | - Alexey V. Akimov
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000, United States
| | - Bálint Aradi
- Bremen
Center for Computational Materials Science, Universität Bremen, Otto-Hahn-Alle 1, 28359 Bremen, Germany
| | - Thomas Frauenheim
- Bremen
Center for Computational Materials Science, Universität Bremen, Otto-Hahn-Alle 1, 28359 Bremen, Germany
| | - Oleg V. Prezhdo
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
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41
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Long R, Prezhdo OV. Quantum Coherence Facilitates Efficient Charge Separation at a MoS2/MoSe2 van der Waals Junction. NANO LETTERS 2016; 16:1996-2003. [PMID: 26882202 DOI: 10.1021/acs.nanolett.5b05264] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Two-dimensional transition metal dichalcogenides (MX2, M = Mo, W; X = S, Se) hold great potential in optoelectronics and photovoltaics. To achieve efficient light-to-electricity conversion, electron-hole pairs must dissociate into free charges. Coulomb interaction in MX2 often exceeds the charge transfer driving force, leading one to expect inefficient charge separation at a MX2 heterojunction. Experiments defy the expectation. Using time-domain density functional theory and nonadiabatic (NA) molecular dynamics, we show that quantum coherence and donor-acceptor delocalization facilitate rapid charge transfer at a MoS2/MoSe2 interface. The delocalization is larger for electron than hole, resulting in longer coherence and faster transfer. Stronger NA coupling and higher acceptor state density accelerate electron transfer further. Both electron and hole transfers are subpicosecond, which is in agreement with experiments. The transfers are promoted primarily by the out-of-plane Mo-X modes of the acceptors. Lighter S atoms, compared to Se, create larger NA coupling for electrons than holes. The relatively slow relaxation of the "hot" hole suggests long-distance bandlike transport, observed in organic photovoltaics. The electron-hole recombination is notably longer across the MoS2/MoSe2 interface than in isolated MoS2 and MoSe2, favoring long-lived charge separation. The atomistic, time-domain studies provide valuable insights into excitation dynamics in two-dimensional transition metal dichalcogenides.
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Affiliation(s)
- Run Long
- College of Chemistry, Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, Beijing Normal University , Beijing, 100875, People's Republic of China
- School of Physics and Complex and Adaptive Systems Lab, University College Dublin , Dublin 4, Ireland
| | - Oleg V Prezhdo
- Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States
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42
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Guiglion P, Berardo E, Butchosa C, Wobbe MCC, Zwijnenburg MA. Modelling materials for solar fuel synthesis by artificial photosynthesis; predicting the optical, electronic and redox properties of photocatalysts. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:074001. [PMID: 26808228 DOI: 10.1088/0953-8984/28/7/074001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this mini-review, we discuss what insight computational modelling can provide into the working of photocatalysts for solar fuel synthesis and how calculations can be used to screen for new promising materials for photocatalytic water splitting and carbon dioxide reduction. We will extensively discuss the different relevant (material) properties and the computational approaches (DFT, TD-DFT, GW/BSE) available to model them. We illustrate this with examples from the literature, focussing on polymeric and nanoparticle photocatalysts. We finish with a perspective on the outstanding conceptual and computational challenges.
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Affiliation(s)
- Pierre Guiglion
- Department of Chemistry, University College London, 20 Gordon street, London WC1H 0AJ, UK
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43
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Nagaya K, Motomura K, Kukk E, Takahashi Y, Yamazaki K, Ohmura S, Fukuzawa H, Wada S, Mondal S, Tachibana T, Ito Y, Koga R, Sakai T, Matsunami K, Nakamura K, Kanno M, Rudenko A, Nicolas C, Liu XJ, Miron C, Zhang Y, Jiang Y, Chen J, Anand M, Kim DE, Tono K, Yabashi M, Yao M, Kono H, Ueda K. Femtosecond charge and molecular dynamics of I-containing organic molecules induced by intense X-ray free-electron laser pulses. Faraday Discuss 2016; 194:537-562. [DOI: 10.1039/c6fd00085a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We studied the electronic and nuclear dynamics of I-containing organic molecules induced by intense hard X-ray pulses at the XFEL facility SACLA in Japan. The interaction with the intense XFEL pulse causes absorption of multiple X-ray photons by the iodine atom, which results in the creation of many electronic vacancies (positive charges) via the sequential electronic relaxation in the iodine, followed by intramolecular charge redistribution. In a previous study we investigated the subsequent fragmentation by Coulomb explosion of the simplest I-substituted hydrocarbon, iodomethane (CH3I). We carried out three-dimensional momentum correlation measurements of the atomic ions created via Coulomb explosion of the molecule and found that a classical Coulomb explosion model including charge evolution (CCE-CE model), which accounts for the concerted dynamics of nuclear motion and charge creation/charge redistribution, reproduces well the observed momentum correlation maps of fragment ions emitted after XFEL irradiation. Then we extended the study to 5-iodouracil (C4H3IN2O2, 5-IU), which is a more complex molecule of biological relevance, and confirmed that, in both CH3I and 5-IU, the charge build-up takes about 10 fs, while the charge is redistributed among atoms within only a few fs. We also adopted a self-consistent charge density-functional based tight-binding (SCC-DFTB) method to treat the fragmentations of highly charged 5-IU ions created by XFEL pulses. Our SCC-DFTB modeling reproduces well the experimental and CCE-CE results. We have also investigated the influence of the nuclear dynamics on the charge redistribution (charge transfer) using nonadiabatic quantum-mechanical molecular dynamics (NAQMD) simulation. The time scale of the charge transfer from the iodine atomic site to the uracil ring induced by nuclear motion turned out to be only ∼5 fs, indicating that, besides the molecular Auger decay in which molecular orbitals delocalized over the iodine site and the uracil ring are involved, the nuclear dynamics also play a role for ultrafast charge redistribution. The present study illustrates that the CCE-CE model as well as the SCC-DFTB method can be used for reconstructing the positions of atoms in motion, in combination with the momentum correlation measurement of the atomic ions created via XFEL-induced Coulomb explosion of molecules.
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44
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Long R, Prezhdo OV. Dopants Control Electron-Hole Recombination at Perovskite-TiO₂ Interfaces: Ab Initio Time-Domain Study. ACS NANO 2015; 9:11143-11155. [PMID: 26456384 DOI: 10.1021/acsnano.5b05843] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
TiO2 sensitized with organohalide perovskites gives rise to solar-to-electricity conversion efficiencies reaching close to 20%. Nonradiative electron-hole recombination across the perovskite/TiO2 interface constitutes a major pathway of energy losses, limiting quantum yield of the photoinduced charge. In order to establish the fundamental mechanisms of the energy losses and to propose practical means for controlling the interfacial electron-hole recombination, we applied ab initio nonadiabatic (NA) molecular dynamics to pristine and doped CH3NH3PbI3(100)/TiO2 anatase(001) interfaces. We show that doping by substitution of iodide with chlorine or bromine reduces charge recombination, while replacing lead with tin enhances the recombination. Generally, lighter and faster atoms increase the NA coupling. Since the dopants are lighter than the atoms they replace, one expects a priori that all three dopants should accelerate the recombination. We rationalize the unexpected behavior of chlorine and bromine by three effects. First, the Pb-Cl and Pb-Br bonds are shorter than the Pb-I bond. As a result, Cl and Br atoms are farther away from the TiO2 surface, decreasing the donor-acceptor coupling. In contrast, some iodines form chemical bonds with Ti atoms, increasing the coupling. Second, chlorine and bromine reduce the NA electron-vibrational coupling, because they contribute little to the electron and hole wave functions. Tin increases the coupling, since it is lighter than lead and contributes to the hole wave function. Third, higher frequency modes introduced by chlorine and bromine shorten quantum coherence, thereby decreasing the transition rate. The recombination occurs due to coupling of the electronic subsystem to low-frequency perovskite and TiO2 modes. The simulation shows excellent agreement with the available experimental data and advances our understanding of electronic and vibrational dynamics in perovskite solar cells. The study provides design principles for optimizing solar cell performance and increasing photon-to-electron conversion efficiency through creative choice of dopants.
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Affiliation(s)
- Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University , Beijing, 100875, People's Republic of China
- School of Physics, Complex & Adaptive Systems Lab, University College Dublin , Dublin, Ireland
| | - Oleg V Prezhdo
- Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States
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45
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Ooyama Y, Kanda M, Uenaka K, Ohshita J. Effect of Substituents in Catechol Dye Sensitizers on Photovoltaic Performance of Type II Dye-Sensitized Solar Cells. Chemphyschem 2015; 16:3049-57. [PMID: 26296714 DOI: 10.1002/cphc.201500419] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 07/06/2015] [Indexed: 11/07/2022]
Abstract
In order to provide a direction in molecular design of catechol (Cat) dyes for type II dye-sensitized solar cells (DSSCs), the dye-to-TiO2 charge-transfer (DTCT) characteristics of Cat dyes with various substituents and their photovoltaic performance in DSSCs are investigated. The Cat dyes with electron-donating or moderately electron-withdrawing substituents exhibit a broad absorption band corresponding to DTCT upon binding to TiO2 films, whereas those with strongly electron-withdrawing substituents exhibit weak DTCT. This study indicates that the introduction of a moderately electron-withdrawing substituent on the Cat moiety leads to not only an increase in the DTCT efficiency, but also the retardation of back electron transfer. This results in favorable conditions for the type II electron-injection pathway from the ground state of the Cat dye to the conduction band of the TiO2 electrode by the photoexcitation of DTCT bands.
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Affiliation(s)
- Yousuke Ooyama
- Department of Applied Chemistry, Graduate School of Engineering Hiroshima University, Higashi-Hiroshima 739-8527 (Japan).
| | - Masahiro Kanda
- Department of Applied Chemistry, Graduate School of Engineering Hiroshima University, Higashi-Hiroshima 739-8527 (Japan)
| | - Koji Uenaka
- Department of Applied Chemistry, Graduate School of Engineering Hiroshima University, Higashi-Hiroshima 739-8527 (Japan)
| | - Joji Ohshita
- Department of Applied Chemistry, Graduate School of Engineering Hiroshima University, Higashi-Hiroshima 739-8527 (Japan)
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46
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Gomez T, Hermann G, Zarate X, Pérez-Torres JF, Tremblay JC. Imaging the Ultrafast Photoelectron Transfer Process in Alizarin-TiO2. Molecules 2015; 20:13830-53. [PMID: 26263959 PMCID: PMC6332195 DOI: 10.3390/molecules200813830] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 07/09/2015] [Accepted: 07/20/2015] [Indexed: 11/25/2022] Open
Abstract
In this work, we adopt a quantum mechanical approach based on time-dependent density functional theory (TDDFT) to study the optical and electronic properties of alizarin supported on TiO2 nano-crystallites, as a prototypical dye-sensitized solar cell. To ensure proper alignment of the donor (alizarin) and acceptor (TiO2 nano-crystallite) levels, static optical excitation spectra are simulated using time-dependent density functional theory in response. The ultrafast photoelectron transfer from the dye to the cluster is simulated using an explicitly time-dependent, one-electron TDDFT ansatz. The model considers the δ-pulse excitation of a single active electron localized in the dye to the complete set of energetically accessible, delocalized molecular orbitals of the dye/nano-crystallite complex. A set of quantum mechanical tools derived from the transition electronic flux density is introduced to visualize and analyze the process in real time. The evolution of the created wave packet subject to absorbing boundary conditions at the borders of the cluster reveal that, while the electrons of the aromatic rings of alizarin are heavily involved in an ultrafast charge redistribution between the carbonyl groups of the dye molecule, they do not contribute positively to the electron injection and, overall, they delay the process.
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Affiliation(s)
- Tatiana Gomez
- Dirección de Postgrado e Investigación, Universidad Autónoma de Chile, Llano Subercaceaux 2801, San Miguel, Santiago, Chile.
| | - Gunter Hermann
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany.
| | - Ximena Zarate
- Dirección de Postgrado e Investigación, Universidad Autónoma de Chile, Llano Subercaceaux 2801, San Miguel, Santiago, Chile.
| | - Jhon Fredy Pérez-Torres
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany.
| | - Jean Christophe Tremblay
- Institut für Chemie und Biochemie, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany.
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47
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Monti A, Negre CFA, Batista VS, Rego LGC, de Groot HJM, Buda F. Crucial Role of Nuclear Dynamics for Electron Injection in a Dye-Semiconductor Complex. J Phys Chem Lett 2015; 6:2393-8. [PMID: 26266622 DOI: 10.1021/acs.jpclett.5b00876] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We investigate the electron injection from a terrylene-based chromophore to the TiO2 semiconductor bridged by a recently proposed phenyl-amide-phenyl molecular rectifier. The mechanism of electron transfer is studied by means of quantum dynamics simulations using an extended Hückel Hamiltonian. It is found that the inclusion of the nuclear motion is necessary to observe the photoinduced electron transfer. In particular, the fluctuations of the dihedral angle between the terrylene and the phenyl ring modulate the localization and thus the electronic coupling between the donor and acceptor states involved in the injection process. The electron propagation shows characteristic oscillatory features that correlate with interatomic distance fluctuations in the bridge, which are associated with the vibrational modes driving the process. The understanding of such effects is important for the design of functional dyes with optimal injection and rectification properties.
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Affiliation(s)
- Adriano Monti
- †Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA, Leiden, The Netherlands
| | - Christian F A Negre
- §Theoretical Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545, United States
| | - Victor S Batista
- ‡Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520, United States
| | - Luis G C Rego
- ∥Department of Physics, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina 88040-900, Brazil
| | - Huub J M de Groot
- †Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA, Leiden, The Netherlands
| | - Francesco Buda
- †Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA, Leiden, The Netherlands
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48
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Fischer SA, Lingerfelt DB, May JW, Li X. Non-adiabatic molecular dynamics investigation of photoionization state formation and lifetime in Mn²⁺-doped ZnO quantum dots. Phys Chem Chem Phys 2015; 16:17507-14. [PMID: 25019366 DOI: 10.1039/c4cp01683a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The unique electronic structure of Mn(2+)-doped ZnO quantum dots gives rise to photoionization states that can be used to manipulate the magnetic state of the material and to generate zero-reabsorption luminescence. Fast formation and long non-radiative decay of this photoionization state is a necessary requirement for these important applications. In this work, surface hopping based non-adiabatic molecular dynamics are used to demonstrate the fast formation of a metal-to-ligand charge transfer state in a Mn(2+)-doped ZnO quantum dot. The formation occurs on an ultrafast timescale and is aided by the large density of states and significant mixing of the dopant Mn(2+) 3dt2 levels with the valence-band levels of the ZnO lattice. The non-radiative lifetime of the photoionization states is also investigated.
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Affiliation(s)
- Sean A Fischer
- Department of Chemistry, University of Washington, Seattle, Washington, USA.
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49
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Yin J, Cortecchia D, Krishna A, Chen S, Mathews N, Grimsdale AC, Soci C. Interfacial Charge Transfer Anisotropy in Polycrystalline Lead Iodide Perovskite Films. J Phys Chem Lett 2015; 6:1396-402. [PMID: 26263141 DOI: 10.1021/acs.jpclett.5b00431] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Solar cells based on organic-inorganic lead iodide perovskite (CH3NH3PbI3) exhibit remarkably high power conversion efficiency (PCE). One of the key issues in solution-processed films is that often the polycrystalline domain orientation is not well-defined, which makes it difficult to predict energy alignment and charge transfer efficiency. Here we combine ab initio calculations and photoelectron spectroscopy to unravel the electronic structure and charge redistribution at the interface between different surfaces of CH3NH3PbI3 and typical organic hole acceptor Spiro-OMeTAD and electron acceptor PCBM. We find that both hole and electron interfacial transfer depend strongly on the CH3NH3PbI3 surface orientation: while the (001) and (110) surfaces tend to favor hole injection to Spiro-OMeTAD, the (100) surface facilitates electron transfer to PCBM due to surface delocalized charges and hole/electron accumulation at the CH3NH3PbI3/organic interfaces. Molecular dynamic simulations indicate that this is due to strong orbital interactions under thermal fluctuations at room temperature, suggesting the possibility to further improve charge separation and extraction in perovskite-based solar cells by controlling perovskite film crystallization and surface orientation.
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Affiliation(s)
- Jun Yin
- †Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Daniele Cortecchia
- ‡Interdisciplinary Graduate School, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798
- §Energy Research Institute @ NTU (ERI@N), Research Techno Plaza, Nanyang Technological University, 50 Nanyang Drive, Singapore 637553
| | - Anurag Krishna
- ‡Interdisciplinary Graduate School, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798
| | - Shi Chen
- †Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Nripan Mathews
- §Energy Research Institute @ NTU (ERI@N), Research Techno Plaza, Nanyang Technological University, 50 Nanyang Drive, Singapore 637553
| | - Andrew C Grimsdale
- §Energy Research Institute @ NTU (ERI@N), Research Techno Plaza, Nanyang Technological University, 50 Nanyang Drive, Singapore 637553
- ∥School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798
| | - Cesare Soci
- †Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
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50
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Amat A, Miliani C, Romani A, Fantacci S. DFT/TDDFT investigation on the UV-vis absorption and fluorescence properties of alizarin dye. Phys Chem Chem Phys 2015; 17:6374-82. [DOI: 10.1039/c4cp04728a] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Potential energy curve for the ESIPT. Top inset: vibrationally resolved emission spectra computed for both tautomers. Bottom insets: main vibrational modes.
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Affiliation(s)
- Anna Amat
- Computational Laboratory for Hybrid/Organic Photovoltaics (CLHYO)
- CNR-ISTM
- Perugia
- Italy
| | - Costanza Miliani
- CNR-ISTM
- Perugia
- Italy
- Centro di Eccellenza SMAArt (Scientific Methodologies applied to Archaeology and Art)
- Dipartimento di Chimica
| | - Aldo Romani
- Centro di Eccellenza SMAArt (Scientific Methodologies applied to Archaeology and Art)
- Dipartimento di Chimica
- Biologia e Biotecnologie
- Università di Perugia
- Italy
| | - Simona Fantacci
- Computational Laboratory for Hybrid/Organic Photovoltaics (CLHYO)
- CNR-ISTM
- Perugia
- Italy
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