1
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Yang H, Wu R, Li W, Wen J. Ultrafast hydrogen production in boron/oxygen-codoped graphitic carbon nitride revealed by nonadiabatic dynamics simulations. Phys Chem Chem Phys 2024; 26:14205-14215. [PMID: 38689538 DOI: 10.1039/d4cp01085j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Graphitic carbon nitride (g-C3N4 or GCN) shows promise in photocatalytic water splitting, despite facing the challenge of rapid electron-hole recombination. In this study, we investigated the influence of boron/oxygen codoping on the photocatalytic performance of GCN systems for hydrogen generation. First-principles calculations and nonadiabatic molecular dynamics (NAMD) simulations were employed to reveal that the recombination time of photogenerated carriers could be increased by 16% to 64% in the codoped systems compared to the pristine GCN. The time-dependent density functional theory (TDDFT) scheme was utilized to select energy windows and initiate dynamics in cluster models of B/O co-doped heptazine with water molecules. Notably, we observed efficient direct photodissociation of hydrogen atoms from water molecules within 60 fs and proton hops within the hydrogen-bonded network within 80 fs in the co-doped system, diverging from the previously proposed mechanism for pristine heptazine in NAMD simulations. This discovery underscores the significant role of faster proton-coupled electron transfer (PCET) reactions and rapid radiationless relaxation in achieving high photocatalytic efficiency in water splitting. Our work enhances the understanding of the internal mechanism of highly efficient photocatalysts for water splitting and provides a new design strategy for doped GCN.
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Affiliation(s)
- Huijuan Yang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China.
| | - Rongliang Wu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China.
| | - Wei Li
- Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Jin Wen
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China.
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2
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Ghosh A, Das P, Kumar S, Sarkar P. Hot carrier relaxation dynamics of an aza-covalent organic framework during photoexcitation: An insight from ab initio quantum dynamics. J Chem Phys 2024; 160:164707. [PMID: 38647311 DOI: 10.1063/5.0200834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 04/01/2024] [Indexed: 04/25/2024] Open
Abstract
In order to develop an efficient metal-free solar energy harvester, we herein performed the electronic structure calculation, followed by the hot carrier relaxation dynamics of two dimensional (2D) aza-covalent organic framework by time domain density functional calculations in conjunction with non-adiabatic molecular dynamics (NAMD) simulation. The electronic structure calculation shows that the aza-covalent organic framework (COF) is a direct bandgap semiconductor with acute charge separation and effective optical absorption in the UV-visible region. Our study of non-adiabatic molecular dynamics simulation predicts the sufficiently prolonged electron-hole recombination process (6.8 nanoseconds) and the comparatively faster electron (22.48 ps) and hole relaxation (0.51 ps) dynamics in this two-dimensional aza-COF. According to our theoretical analysis, strong electron-phonon coupling is responsible for the rapid charge relaxation, whereas the electron-hole recombination process is slowed down by relatively weak electron-phonon coupling, relatively lower non-adiabatic coupling, and quick decoherence time. We do hope that our results of NAMD simulation on exciton relaxation dynamics will be helpful for designing photovoltaic devices based on this two dimensional aza-COF.
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Affiliation(s)
- Atish Ghosh
- Department of Chemistry, Visva-Bharati University, Santiniketan 731235, India
| | - Priya Das
- Department of Chemistry, Visva-Bharati University, Santiniketan 731235, India
| | - Subhash Kumar
- Department of Chemistry, Visva-Bharati University, Santiniketan 731235, India
| | - Pranab Sarkar
- Department of Chemistry, Visva-Bharati University, Santiniketan 731235, India
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3
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Agrawal S, Wang B, Wu Y, Casanova D, Prezhdo OV. Photocatalytic activity of dual defect modified graphitic carbon nitride is robust to tautomerism: machine learning assisted ab initio quantum dynamics. NANOSCALE 2024. [PMID: 38623607 DOI: 10.1039/d4nr00606b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Two-dimensional graphitic carbon nitride (GCN) is a popular metal-free polymer for sustainable energy applications due to its unique structure and semiconductor properties. Dopants and defects are used to tune GCN, and dual defect modified GCN exhibits superior properties and enhanced photocatalytic efficiency in comparison to pristine or single defect GCN. We employ a multistep approach combining time-dependent density functional theory and nonadiabatic molecular dynamics (NAMD) with machine learning (ML) to investigate coupled structural and electronic dynamics in GCN over a nanosecond timescale, comparable to and exceeding the lifetimes of photo-generated charge carriers and photocatalytic events. Although frequent hydrogen hopping transitions occur among four tautomeric structures, the electron-hole separation and recombination processes are only weakly sensitive to the tautomerism. The charge separated state survives for about 10 ps, sufficiently long to enable photocatalysis. The employed ML-NAMD methodology provides insights into rare events that can influence excited state dynamics in the condensed phase and nanoscale materials and extends NAMD simulations from pico- to nanoseconds. The ab initio quantum dynamics simulation provides a detailed atomistic mechanism of photoinduced evolution of charge carriers in GCN and rationalizes how GCN remains photo-catalytically active despite its multiple isomeric and tautomeric forms.
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Affiliation(s)
- Sraddha Agrawal
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA.
| | - Bipeng Wang
- Department of Chemical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Yifan Wu
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA.
| | - David Casanova
- Donostia International Physics Center (DIPC), 20018 Donostia, Euskadi, Spain
- IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Euskadi, Spain
| | - Oleg V Prezhdo
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA.
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USA
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4
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Jiang X, Tan J, Liu D, Feng Y, Chen KQ, Kazakova EA, Vasenko AS, Chulkov EV. Ferroelectric Polarization and Single-Atom Catalyst Synergistically Promoting CO 2 Photoreduction of CuBiP 2Se 6. J Phys Chem Lett 2024; 15:3611-3618. [PMID: 38530095 DOI: 10.1021/acs.jpclett.4c00687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
Further improving the activity and selectivity of photocatalytic CO2 reduction remains a challenge. Herein, we propose a new strategy for synergistically promoting photocatalytic CO2 reduction by combining two-dimensional (2D) ferroelectric polarization and single-atom catalysis. Our calculations showed that the ferroelectric polarization of CuBiP2Se6 provides the internal driving force for the separation and migration of photogenerated carriers, which provides a prerequisite for enhancing the photocatalytic efficiency. In addition, the introduction of single Ag atoms can act as an electron reservoir to significantly modify the bonding configurations on the surface through proper static electron transfer, thus effectively promoting the adsorption and activation of CO2 molecules. More importantly, we found that switching the ferroelectric polarization can synergistically optimize the limiting potential as well as control the final products. This study provides a new approach for enhancing the catalytic activity and selectivity of photocatalytic CO2 reduction.
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Affiliation(s)
- Xingxing Jiang
- College of Physics and Electronics Engineering, Hengyang Normal University, Hengyang 421002, China
- HSE University, 101000 Moscow, Russia
| | - Jieyao Tan
- College of Physics and Electronics Engineering, Hengyang Normal University, Hengyang 421002, China
| | | | - Yexin Feng
- Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Ke-Qiu Chen
- Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Elena A Kazakova
- Department of Biochemistry, Sechenov First Moscow State Medical University, 119991 Moscow, Russia
| | - Andrey S Vasenko
- HSE University, 101000 Moscow, Russia
- Donostia International Physics Center (DIPC), 20018 San Sebastián-Donostia, Euskadi Spain
| | - Evgueni V Chulkov
- Donostia International Physics Center (DIPC), 20018 San Sebastián-Donostia, Euskadi Spain
- Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, 20018 San Sebastián, Euskadi, Spain
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5
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Liu D, Wu Y, Samatov MR, Vasenko AS, Chulkov EV, Prezhdo OV. Compression Eliminates Charge Traps by Stabilizing Perovskite Grain Boundary Structures: An Ab Initio Analysis with Machine Learning Force Field. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2024; 36:2898-2906. [PMID: 38558914 PMCID: PMC10976646 DOI: 10.1021/acs.chemmater.3c03261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/23/2024] [Accepted: 02/27/2024] [Indexed: 04/04/2024]
Abstract
Grain boundaries (GBs) play an important role in determining the optoelectronic properties of perovskites, requiring an atomistic understanding of the underlying mechanisms. Strain engineering has recently been employed in perovskite solar cells, providing a novel perspective on the role of perovskite GBs. Here, we theoretically investigate the impact of axial strain on the geometric and electronic properties of a common CsPbBr3 GB. We develop a machine learning force field and perform ab initio calculations to analyze the behavior of GB models with different axial strains on a nanosecond time scale. Our results demonstrate that compressing the GB efficiently suppresses structural fluctuations and eliminates trap states originating from large-scale distortions. The GB becomes more amorphous under compressive strain, which makes the relationship between the electronic structure and axial strain nonmonotonic. These results can help clarify the conflicts in perovskite GB experiments.
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Affiliation(s)
| | - Yifan Wu
- Department
of Chemistry, University of Southern California, Los Angeles California 90089, United States
| | | | - Andrey S. Vasenko
- HSE
University, 101000 Moscow, Russia
- Donostia
International Physics Center (DIPC), 20018 San Sebastián - Donostia, Euskadi, Spain
| | - Evgueni V. Chulkov
- Donostia
International Physics Center (DIPC), 20018 San Sebastián - Donostia, Euskadi, Spain
- Centro
de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, 20018 San Sebastián - Donostia, Euskadi, Spain
- Departamento
de Polímeros y Materiales Avanzados: Física, Química
y Tecnología, Facultad de Ciencias Químicas, Universidad del País Vasco UPV/EHU, 20080 San Sebastián
- Donostia, Euskadi, Spain
| | - Oleg V. Prezhdo
- Department
of Chemistry, University of Southern California, Los Angeles California 90089, United States
- Department
of Physics & Astronomy, University of
Southern California, Los Angeles California 90089, United States
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6
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Dai D, Agrawal S, Prezhdo OV, Long R. Impact of large A-site cations on electron-vibrational interactions in 2D halide perovskites: Ab initio quantum dynamics. J Chem Phys 2024; 160:114704. [PMID: 38506296 DOI: 10.1063/5.0202251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 03/03/2024] [Indexed: 03/21/2024] Open
Abstract
Using ab initio nonadiabatic molecular dynamics, we study the effect of large A-site cations on nonradiative electron-hole recombination in two-dimensional Ruddlesden-Popper perovskites HA2APb2I7, HA = n-hexylammonium, A = methylammonium (MA), or guanidinium (GA). The steric hindrance created by large GA cations distorts and stiffens the inorganic Pb-I lattice, reduces thermal structural fluctuations, and maintains the delocalization of electrons and holes at ambient and elevated temperatures. The delocalized charges interact more strongly in the GA system than in the MA system, and the charge recombination is accelerated. In contrast, replacement of only some MA cations with GA enhances disorder and increases charge lifetime, as seen in three-dimensional perovskites. This study highlights the key influence of structural fluctuations and disorder on the properties of charge carriers in metal halide perovskites, providing guidance for tuning materials' optoelectronic performance.
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Affiliation(s)
- Dandan Dai
- College of Chemistry, Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Sraddha Agrawal
- Department of Chemistry, University of Southern California, Los Angeles, California 90007, USA
| | - Oleg V Prezhdo
- Department of Chemistry, University of Southern California, Los Angeles, California 90007, USA
| | - 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
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7
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Jiang X, Tan J, Liu D, Feng Y, Chen KQ, Long R, Vasenko AS. Improved Carrier Separation and Recombination by Ferroelectric Polarization in the CuBiP 2Se 6/C 2N Heterostructure: A Nonadiabatic Molecular Dynamics Study. J Phys Chem Lett 2024:2867-2875. [PMID: 38446846 DOI: 10.1021/acs.jpclett.4c00404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
The rapid recombination of photogenerated carriers heavily restricts the photocatalytic efficiency. Here, we propose a new strategy to improve catalytic efficiency based on the ferroelectric van der Waals heterostructure (CuBiP2Se6/C2N). Combining density functional theory and the nonadiabatic molecular dynamics (NAMD) method, we have systematically analyzed the ground-state properties and carrier dynamics images in the CuBiP2Se6/C2N heterostructure. Our calculations showed that the ferroelectric polarization of CuBiP2Se6 provides the internal driving force for the photogenerated carriers separation. NAMD results demonstrate that the excited-state carrier transfer and recombination processes in the CuBiP2Se6/C2N are consistent with a type II mechanism. Meanwhile, constructing the ferroelectric heterostructure can effectively prolong the carrier lifetime, from ∼65.98 to ∼124.54 ps. Moreover, the high quantum efficiency and tunable band edge positions mean that the CuBiP2Se6/C2N heterostructure is an excellent potential candidate material for photocatalytic water splitting.
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Affiliation(s)
- Xingxing Jiang
- College of Physics and Electronics Engineering, Hengyang Normal University, Hengyang 421002, China
- HSE University, 101000 Moscow, Russia
| | - Jieyao Tan
- College of Physics and Electronics Engineering, Hengyang Normal University, Hengyang 421002, China
| | | | - Yexin Feng
- Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Ke-Qiu Chen
- Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Run Long
- Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Andrey S Vasenko
- HSE University, 101000 Moscow, Russia
- Donostia International Physics Center (DIPC), 20018 San Sebastián-Donostia, Euskadi, Spain
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8
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Agrawal S, Casanova D, Trivedi DJ, Prezhdo OV. Enhanced Charge Separation in Single Atom Cobalt Based Graphitic Carbon Nitride: Time Domain Ab Initio Analysis. J Phys Chem Lett 2024; 15:2202-2208. [PMID: 38373150 PMCID: PMC10910588 DOI: 10.1021/acs.jpclett.3c03621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/07/2024] [Accepted: 02/14/2024] [Indexed: 02/21/2024]
Abstract
In recent years, single atom catalysts have been at the forefront of energy conversion research, particularly in the field of catalysis. Carbon nitrides offer great potential as hosts for stabilizing metal atoms due to their unique electronic structure. We use ab initio nonadiabatic molecular dynamics to study photoexcitation dynamics in single atom cobalt based graphitic carbon nitride. The results elucidate the positive effect of the doped cobalt atom on the electronic structure of GCN. Cobalt doping produces filled midgap states that serve as oxidation centers, advantageous for various redox reactions. The presence of midgap states enables the harvesting of longer wavelength photons, thereby extending the absorption range of solar light. Although doping accelerates charge relaxation overall, charge recombination is significantly slower than charge separation, creating beneficial conditions for catalysis applications. The simulations reveal the detailed microscopic mechanism underlying the improved performance of the doped system due to atomic defects and demonstrate an effective charge separation strategy to construct highly efficient and stable photocatalytic two-dimensional materials.
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Affiliation(s)
- Sraddha Agrawal
- Department
of Chemistry, University of Southern California, Los Angeles, California 90007, United States
| | - David Casanova
- Donostia
International Physics Center (DIPC), 20018 Donostia, Euskadi, Spain
- IKERBASQUE,
Basque Foundation for Science, 48009 Bilbao, Euskadi, Spain
| | - Dhara J. Trivedi
- Department
of Physics, Clarkson University, Potsdam, New York 13699, United States
| | - Oleg V. Prezhdo
- Department
of Chemistry, University of Southern California, Los Angeles, California 90007, United States
- Department
of Physics and Astronomy, University of
Southern California, Los Angeles, California 90007, United States
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9
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Dupuy L, Rikus A, Maitra NT. Exact-Factorization-Based Surface Hopping without Velocity Adjustment. J Phys Chem Lett 2024:2643-2649. [PMID: 38422391 DOI: 10.1021/acs.jpclett.4c00115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
While surface hopping has emerged as a powerful method for simulating non-adiabatic dynamics in large molecules, the ad hoc nature of the necessary velocity adjustments and decoherence corrections in the algorithm somewhat reduces its reliability. Here we propose a new scheme that eliminates these aspects by combining the nuclear equation from the quantum-trajectory surface-hopping approach with the electronic equation derived from the exact-factorization approach. The resulting method, denoted QTSH-XF, yields a surface-hopping method on firmer ground than previous and is shown to successfully capture dynamics in Tully models and in a linear vibronic coupling model of the photoexcited uracil cation.
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Affiliation(s)
- Lucien Dupuy
- Department of Physics, Rutgers University, Newark, New Jersey 07102, United States
| | - Anton Rikus
- Department of Physics, Rutgers University, Newark, New Jersey 07102, United States
- University of Münster, Organisch-Chemisches Institut and Center for Multiscale Theory and Computation, 48149 Münster, Germany
| | - Neepa T Maitra
- Department of Physics, Rutgers University, Newark, New Jersey 07102, United States
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10
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Mondal S, Chowdhury U, Dey S, Habib M, Mora Perez C, Frauenheim T, Sarkar R, Pal S, Prezhdo OV. Controlling Charge Carrier Dynamics in Porphyrin Nanorings by Optically Active Templates. J Phys Chem Lett 2023; 14:11384-11392. [PMID: 38078872 PMCID: PMC10749466 DOI: 10.1021/acs.jpclett.3c03304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/01/2023] [Accepted: 12/01/2023] [Indexed: 12/22/2023]
Abstract
Understanding the dynamics of photogenerated charge carriers is essential for enhancing the performance of solar and optoelectronic devices. Using atomistic quantum dynamics simulations, we demonstrate that a short π-conjugated optically active template can be used to control hot carrier relaxation, charge carrier separation, and carrier recombination in light-harvesting porphyrin nanorings. Relaxation of hot holes is slowed by 60% with an optically active template compared to that with an analogous optically inactive template. Both systems exhibit subpicosecond electron transfer from the photoactive core to the templates. Notably, charge recombination is suppressed 6-fold by the optically active template. The atomistic time-domain simulations rationalize these effects by the extent of electron and hole localization, modification of the density of states, participation of distinct vibrational motions, and changes in quantum coherence. Extension of the hot carrier lifetime and reduction of charge carrier recombination, without hampering charge separation, demonstrate a strategy for enhancing efficiencies of energy materials with optically active templates.
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Affiliation(s)
- Shrabanti Mondal
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
| | - Uttam Chowdhury
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
| | - Subhajit Dey
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
| | - Md Habib
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
- Department
of Chemistry, Sripat Singh College, Jiaganj 742122, India
| | - Carlos Mora Perez
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Thomas Frauenheim
- Bremen
Center
for Computational Materials Science, Universität
Bremen, Bremen 28359, Germany
- Beijing
Computational Science Research Center, Beijing 100193, China
- Shenzhen
JL Computational Science and Applied Research Institute, Shenzhen 518109, China
| | - Ritabrata Sarkar
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
- Bremen
Center
for Computational Materials Science, Universität
Bremen, Bremen 28359, Germany
| | - Sougata Pal
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
| | - Oleg V. Prezhdo
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
- Department
of Physics and Astronomy, University of
Southern California, Los Angeles, California 90089, United States
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11
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Lu TF, Chu W, Agrawal S, Zhang Z, Prezhdo OV. Lattice Distortion and Low-Frequency Anharmonic Phonons Suppress Charge Recombination in Lead Halide Perovskites upon Pseudohalide Doping: Time-Domain Ab Initio Analysis. J Phys Chem Lett 2023; 14:10685-10692. [PMID: 37988630 PMCID: PMC10694819 DOI: 10.1021/acs.jpclett.3c02850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/15/2023] [Accepted: 11/16/2023] [Indexed: 11/23/2023]
Abstract
Perovskite solar cells have witnessed a surge in interest as a promising technology for low-cost, high-efficiency photovoltaics with certified power conversion efficiencies beyond 25%. However, their commercial development is hindered by poor stability and nonradiative losses that restrict their approach to the theoretical efficiency limit. Using ab initio nonadiabatic molecular dynamics, we demonstrate that nonradiative charge recombination is suppressed when the iodide in formamidinium lead iodide (FAPbI3) is partially replaced with pseudohalide anions (SCN-, BF4-, and PF6-). The replacement breaks the symmetry of the system and creates local structural distortion and dynamic disorder, decreasing electron-hole overlap and nonadiabatic electron-vibrational coupling. The charge carrier lifetime is found to increase with increased structural distortion and is the longest for PF6-. This work is fundamentally relevant to the design of high-performance perovskite materials for optoelectronic applications.
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Affiliation(s)
- Teng-Fei Lu
- School
of Materials Science and Engineering, Dalian
Jiaotong University, Dalian 116028, Liaoning, China
| | - Weibin Chu
- Key
Laboratory of Computational Physical Sciences (Ministry of Education),
Institute of Computational Physical Sciences, Fudan University, Shanghai 200433, China
| | - Sraddha Agrawal
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Zhihua Zhang
- School
of Materials Science and Engineering, Dalian
Jiaotong University, Dalian 116028, Liaoning, China
| | - Oleg V. Prezhdo
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
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12
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Das A, Liu D, Wary RR, Vasenko AS, Prezhdo OV, Nair RG. Mn-Modified ZnO Nanoflakes for Optimal Photoelectrochemical Performance Under Visible Light: Experimental Design and Theoretical Rationalization. J Phys Chem Lett 2023; 14:9604-9611. [PMID: 37862673 PMCID: PMC10626631 DOI: 10.1021/acs.jpclett.3c02730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/12/2023] [Accepted: 10/18/2023] [Indexed: 10/22/2023]
Abstract
Doping of zinc oxide (ZnO) with manganese (Mn) tunes midbandgap states of ZnO to enhance its optical properties and makes it into an efficient photoactive material for photoelectrochemical water splitting, waste removal from water, and other applications. We demonstrate that ZnO modified with 1 at. % Mn exhibits the best performance, as rationalized by experimental, structural, and optical characterization and theoretical analysis. ZnO doped with the optimal Mn content possesses improved light absorption in the visible region and minimizes charge carrier recombination. The doping is substitutional and creates midgap states near the valence band. Mn atoms break localized charge traps at oxygen vacancy sites and eliminate photoluminescence peaks associated with oxygen vacancies. The optimal performance of Mn-modified ZnO is demonstrated with the photodegradation of Congo red and photoelectrochemical water splitting.
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Affiliation(s)
- Abinash Das
- HSE
University, 101000 Moscow, Russia
- PSG
Institute of Advanced Studies, Coimbatore, Tamil Nadu 641004, India
| | | | - Riu Riu Wary
- Solar
Energy Materials Research & Testing Laboratory (SMaRT lab), Department
of Physics, National Institute of Technology
Silchar, Silchar, Assam 788010, India
| | - Andrey S. Vasenko
- HSE
University, 101000 Moscow, Russia
- Donostia
International Physics Center (DIPC), 20018 San Sebastián-Donostia, Euskadi, Spain
| | - Oleg V. Prezhdo
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
- Department
of Physics & Astronomy, University of
Southern California, Los Angeles, California 90089, United States
| | - Ranjith G. Nair
- Solar
Energy Materials Research & Testing Laboratory (SMaRT lab), Department
of Physics, National Institute of Technology
Silchar, Silchar, Assam 788010, India
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13
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Zhu Y, Prezhdo OV, Long R, Fang WH. Twist Angle-Dependent Intervalley Charge Carrier Transfer and Recombination in Bilayer WS 2. J Am Chem Soc 2023; 145:22826-22835. [PMID: 37796526 DOI: 10.1021/jacs.3c09170] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/06/2023]
Abstract
A twist angle at a van der Waals junction provides a handle to tune its optoelectronic properties for a variety of applications, and a comprehensive understanding of how the twist modulates electronic structure, interlayer coupling, and carrier dynamics is needed. We employ time-dependent density functional theory and nonadiabatic molecular dynamics to elucidate angle-dependent intervalley carrier transfer and recombination in bilayer WS2. Repulsion between S atoms in twisted configurations weakens interlayer coupling, increases the interlayer distance, and softens layer breathing modes. Twisting has a minor influence on K valleys while it lowers Γ valleys and raises Q valleys because their wave functions are delocalized between layers. Consequently, the reduced energy gaps between the K and Γ valleys accelerate the hole transfer in the twisted structures. Intervalley electron transfer proceeds nearly an order of magnitude faster than hole transfer. The more localized wave functions at K than Q values and larger bandgaps result in smaller nonadiabatic couplings for intervalley recombination, making it 3-4 times slower in twisted than high-symmetry structures. B2g breathing, E2g in-plane, and A1g out-of-plane modes are most active during intervalley carrier transfer and recombination. The faster intervalley transfer and extended carrier lifetimes in twisted junctions are favorable for optoelectronic device performance.
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Affiliation(s)
- Yonghao Zhu
- 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
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, P.R. China
| | - Wei-Hai 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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14
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Wang B, Wu Y, Liu D, Vasenko AS, Casanova D, Prezhdo OV. Efficient Modeling of Quantum Dynamics of Charge Carriers in Materials Using Short Nonequilibrium Molecular Dynamics. J Phys Chem Lett 2023; 14:8289-8295. [PMID: 37681642 PMCID: PMC10518862 DOI: 10.1021/acs.jpclett.3c02187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Accepted: 09/05/2023] [Indexed: 09/09/2023]
Abstract
Nonadiabatic molecular dynamics provides essential insights into excited-state processes, but it is computationally intense and simplifications are needed. The classical path approximation provides critical savings. Still, long heating and equilibration steps are required. We demonstrate that practical results can be obtained with short, partially equilibrated ab initio trajectories. Once the system's structure is adequate and essential fluctuations are sampled, the nonadiabatic Hamiltonian can be constructed. Local structures require only 1-2 ps trajectories, as demonstrated with point defects in metal halide perovskites. Short trajectories represent anharmonic motions common in defective structures, an essential improvement over the harmonic approximation around the optimized geometry. Glassy systems, such as grain boundaries, require different simulation protocols, e.g., involving machine learning force fields. 10-fold shorter trajectories generate 10-20% time scale errors, which are acceptable, given experimental uncertainties and other approximations. The practical NAMD protocol enables fast screening of excited-state dynamics for rapid exploration of new materials.
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Affiliation(s)
- Bipeng Wang
- Department
of Chemical Engineering, University of Southern
California, Los Angeles, California 90089, United States
| | - Yifan Wu
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | | | - Andrey S. Vasenko
- HSE
University, 101000 Moscow, Russia
- Donostia
International Physics Center (DIPC), 20018 San Sebastián-Donostia, Euskadi, Spain
| | - David Casanova
- Donostia
International Physics Center (DIPC), 20018 San Sebastián-Donostia, Euskadi, Spain
- IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Euskadi, Spain
| | - Oleg V. Prezhdo
- Department
of Chemical Engineering, University of Southern
California, Los Angeles, California 90089, United States
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
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15
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Gumber S, Prezhdo OV. Zeno and Anti-Zeno Effects in Nonadiabatic Molecular Dynamics. J Phys Chem Lett 2023; 14:7274-7282. [PMID: 37556319 PMCID: PMC10440816 DOI: 10.1021/acs.jpclett.3c01831] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 08/01/2023] [Indexed: 08/11/2023]
Abstract
Decoherence plays an important role in nonadiabatic (NA) molecular dynamics (MD) simulations because it provides a physical mechanism for trajectory hopping and can alter transition rates by orders of magnitude. Generally, decoherence effects slow quantum transitions, as exemplified by the quantum Zeno effect: in the limit of infinitely fast decoherence, the transitions stop. If the measurements are not sufficiently frequent, an opposite quantum anti-Zeno effect occurs, in which the transitions are accelerated with faster decoherence. Using two common NA-MD approaches, fewest switches surface hopping and decoherence-induced surface hopping, combined with analytic examination, we demonstrate that including decoherence into NA-MD slows down NA transitions; however, many realistic systems operate in the anti-Zeno regime. Therefore, it is important that NA-MD methods describe both Zeno and anti-Zeno effects. Numerical simulations of charge trapping and relaxation in graphitic carbon nitride suggest that time-dependent NA Hamiltonians encountered in realistic systems produce robust results with respect to errors in the decoherence time, a favorable feature for NA-MD simulations.
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Affiliation(s)
- Shriya Gumber
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Oleg V. Prezhdo
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
- Department
of Physics and Astronomy, University of
Southern California, Los Angeles, California 90089, United States
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16
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Bian F, Wu X, Yang Z, Shao S, Meng X, Qin G. Quantitative Evaluation of the Carrier Separation Performance of Heterojunction Photocatalysts: The Case of g-C 3N 4/SrTiO 3. J Phys Chem Lett 2023; 14:2927-2932. [PMID: 36930040 DOI: 10.1021/acs.jpclett.3c00427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Heterojunction photocatalysts are of great interest in the energy and environmental fields, because of their potential to significantly increase the efficiency of harvesting solar energy. Advances in design have been hampered by the continued use of only qualitative analyses. Quantitative evaluation of the carrier separation performance is urgently needed for the design and application of heterojunction photocatalysts. Taking the g-C3N4/SrTiO3 heterojunction as an example, we address the conventional energy band and electronic structure issues by first-principles analysis. After interface coupling, the band edge alignment reverses from that of the respective isolated states of the heterojunction components, suggesting new ways of thinking about the catalytic mechanism of the heterojunction. More significantly, we show the carrier separation performance of heterojunction photocatalysts can be quantitatively predicted by the nonadiabatic molecular dynamics method, enabling more precisely directed research and promoting the quantified design and application of heterojunction photocatalysis, making a contribution of great scientific significance.
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Affiliation(s)
- Fang Bian
- Key Laboratory for Anisotropy and Texture of Materials (MoE), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China
- College of Sciences, Northeastern University, Shenyang 110819, China
| | - Xinge Wu
- College of Sciences, Northeastern University, Shenyang 110819, China
| | - Zhaoying Yang
- College of Sciences, Northeastern University, Shenyang 110819, China
| | - Shuai Shao
- College of Sciences, Northeastern University, Shenyang 110819, China
| | - Xiangying Meng
- College of Sciences, Northeastern University, Shenyang 110819, China
- Institute of Materials Intelligence Technology, Liaoning Academy of Materials, Shenyang 110167, China
| | - Gaowu Qin
- Key Laboratory for Anisotropy and Texture of Materials (MoE), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China
- Institute of Materials Intelligence Technology, Liaoning Academy of Materials, Shenyang 110167, China
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17
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Shi R, Long R, Fang WH, Prezhdo OV. Rapid Interlayer Charge Separation and Extended Carrier Lifetimes due to Spontaneous Symmetry Breaking in Organic and Mixed Organic-Inorganic Dion-Jacobson Perovskites. J Am Chem Soc 2023; 145:5297-5309. [PMID: 36826471 DOI: 10.1021/jacs.2c12903] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Promising alternatives to three-dimensional perovskites, two-dimensional (2D) layered metal halide perovskites have proven their potential in optoelectronic applications due to improved photo- and chemical stability. Nevertheless, photovoltaic devices based on 2D perovskites suffer from poor efficiency owing to unfavorable charge carrier dynamics and energy losses. Focusing on the 2D Dion-Jacobson perovskite phase that is rapidly rising in popularity, we demonstrate that doping of complementary cations into the 3-(aminomethyl)piperidinium perovskite accelerates spontaneous charge separation and slows down charge recombination, both factors improving the photovoltaic performance. Employing ab initio nonadiabatic (NA) molecular dynamics combined with time-dependent density functional theory, we demonstrate that cesium doping broadens the bandgap by 0.4 eV and breaks structural symmetry. Assisted by thermal fluctuations, the symmetry breaking helps to localize electrons and holes in different layers and activates additional vibrational modes. As a result, the charge separation is accelerated. Simultaneously, the charge carrier lifetime grows due to shortened coherence time between the ground and excited states. The established relationships between perovskite composition and charge carrier dynamics provide guidelines toward future material discovery and design of perovskite solar cells.
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Affiliation(s)
- Ran Shi
- College of Chemistry, Key Laboratory of Theoretical & 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 & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Wei-Hai Fang
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Oleg V Prezhdo
- Departments of Chemistry, and Physics and Astronomy, University of Southern California, Los Angeles, California 90089, United States
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18
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Wang H, Zhou Z, Long R, Prezhdo OV. Passivation of Hematite by a Semiconducting Overlayer Reduces Charge Recombination: An Insight from Nonadiabatic Molecular Dynamics. J Phys Chem Lett 2023; 14:879-887. [PMID: 36661401 DOI: 10.1021/acs.jpclett.2c03643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Hematite (α-Fe2O3) is a promising photoanode material for photoelectrochemical water splitting. Surface-passivating layers are effective in improving water oxidation kinetics; however, the passivation mechanism is not fully understood due to the complexity of interfacial reactions. Focusing on the Fe-terminated Fe2O3 (0001) surface that exhibits surface states in the band gap, we perform ab initio quantum dynamics simulations to study the effect of an α-Ga2O3 overlayer on charge recombination. The overlayer eliminates surface states and suppresses charge recombination 4-fold. This explains in part the observed cathodic shift in the onset potential for water oxidation. The increased charge carrier lifetime is an outcome of two factors, energy gap and electron-vibrational coupling, with a positive contribution from the former but a negative contribution from the latter. This work presents an advance in the atomistic time-domain understanding of the influence of surface passivation on charge recombination dynamics and provides guidance for designing novel α-Fe2O3 photoanodes.
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Affiliation(s)
- Hua Wang
- Department of Chemical Engineering, School of Water and Environment, Chang'an University, Xi'an710064, China
| | - Zhaohui Zhou
- Department of Chemical Engineering, School of Water and Environment, Chang'an University, Xi'an710064, China
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing100875, China
| | - Oleg V Prezhdo
- Deparment of Chemistry, University of Southern California, Los Angeles, California90089, United States
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19
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Shi R, Fang Q, Vasenko AS, Long R, Fang WH, Prezhdo OV. Structural Disorder in Higher-Temperature Phases Increases Charge Carrier Lifetimes in Metal Halide Perovskites. J Am Chem Soc 2022; 144:19137-19149. [PMID: 36206144 DOI: 10.1021/jacs.2c08627] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Solar cells and optoelectronic devices are exposed to heat that degrades performance. Therefore, elucidating temperature-dependent charge carrier dynamics is essential for device optimization. Charge carrier lifetimes decrease with temperature in conventional semiconductors. The opposite, anomalous trend is observed in some experiments performed with MAPbI3 (MA = CH3NH3+) and other metal halide perovskites. Using ab initio quantum dynamics simulation, we establish the atomic mechanisms responsible for nonradiative electron-hole recombination in orthorhombic-, tetragonal-, and cubic MAPbI3. We demonstrate that structural disorder arising from the phase transitions is as important as the disorder due to heating in the same phase. The carrier lifetimes grow both with increasing temperature in the same phase and upon transition to the higher-temperature phases. The increased lifetime is rationalized by structural disorder that induces partial charge localization, decreases nonadiabatic coupling, and shortens quantum coherence. Inelastic and elastic electron-vibrational interactions exhibit opposite dependence on temperature and phase. The partial disorder and localization arise from thermal motions of both the inorganic lattice and the organic cations and depend significantly on the phase. The structural deformations induced by thermal fluctuations and phase transitions are on the same order as deformations induced by defects, and hence, thermal disorder plays a very important role. Since charge localization increases carrier lifetimes but inhibits transport, an optimal regime maximizing carrier diffusion can be designed, depending on phase, temperature, material morphology, and device architecture. The atomistic mechanisms responsible for the enhanced carrier lifetimes at elevated temperatures provide guidelines for the design of improved solar energy and optoelectronic materials.
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Affiliation(s)
- Ran Shi
- Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing100875, People's Republic of China
| | - Qiu Fang
- Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing100875, People's Republic of China
| | | | - Run Long
- Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing100875, People's Republic of China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing100875, People's Republic of China
| | - Oleg V Prezhdo
- Departments of Chemistry, and Physics and Astronomy, University of Southern California, Los Angeles, California90089, United States
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20
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Ghosh A, Ball B, Pal S, Sarkar P. Ultrafast Charge Transfer and Delayed Recombination in Graphitic-CN/WTe 2 van der Waals Heterostructure: A Time Domain Ab Initio Study. J Phys Chem Lett 2022; 13:7898-7905. [PMID: 35980156 DOI: 10.1021/acs.jpclett.2c02196] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In search of an efficient solar energy harvester, we herein performed a time domain density functional study coupled with nonadiabatic molecular dynamics (NAMD) simulation to gain atomistic insight into the charge carrier dynamics of a graphitic carbon nitride (g-CN)-tungsten telluride (WTe2) van der Waals heterostructure. Our NAMD study predicted ultrafast electron (589 fs) and hole-transfer (807 fs) dynamics in g-CN/WTe2 heterostructure and a delayed electron-hole recombination process (2.404 ns) as compared to that of the individual g-CN (3 ps) and WTe2 (0.55 ps) monolayer. The ultrafast charge transfer is due to strong electron-phonon coupling during the charge-transfer process while comparatively weak electron-phonon coupling, sufficient band gap, comparatively lower nonadiabatic coupling (NAC), and fast decoherence time slow down the electron-hole recombination process. The NAMD results of exciton relaxation dynamics are valuable for insightful understanding of charge carrier dynamics and in designing photovoltaic devices based on organic-inorganic 2D van der Waals heterostructures.
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Affiliation(s)
- Atish Ghosh
- Department of Chemistry, Visva-Bharati University, Santiniketan 731235, India
| | - Biswajit Ball
- Department of Chemistry, Visva-Bharati University, Santiniketan 731235, India
| | - Sougata Pal
- Department of Chemistry, University of Gour Banga, Malda 732103, India
| | - Pranab Sarkar
- Department of Chemistry, Visva-Bharati University, Santiniketan 731235, India
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