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Zhang XW, Xie K, Wang EG, Li XZ, Cao T. Phonon-Mediated Exciton Relaxation in Two-Dimensional Semiconductors: Selection Rules and Relaxation Pathways. J Phys Chem Lett 2024; 15:7584-7590. [PMID: 39025480 DOI: 10.1021/acs.jpclett.4c01433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Exciton-phonon coupling (ExPC) is crucial for energy relaxation in semiconductors, yet the first-principles calculation of such coupling remains challenging, especially for two-dimensional (2D) systems. Here, an accurate method for calculating ExPC is developed and applied in exciton relaxation problems in monolayer WSe2. Considering the interplay between the exciton wave functions and electron-phonon coupling (EPC) matrix elements, we find that ExPC shows selection rules distinct from the ones of EPC. By employing the Wannier exciton model, we generalize these selection rules, which state that the angular quantum numbers of the exciton must match the winding numbers of the EPC matrix elements for the ExPC to be allowed. To verify our theory and method, we calculate intervalley exciton relaxation pathways, which agree well with a recent experiment.
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Affiliation(s)
- Xiao-Wei Zhang
- International Center for Quantum Materials and School of Physics, Peking University, Beijing 100871, People's Republic of China
| | - Kaichen Xie
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
| | - En-Ge Wang
- International Center for Quantum Materials and School of Physics, Peking University, Beijing 100871, People's Republic of China
- School of Physics, Liaoning University, Shenyang 110036, People's Republic of China
| | - Xin-Zheng Li
- Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Frontier Science Center for Nano-optoelectronics and School of Physics, Peking University, Beijing 100871, People's Republic of China
| | - Ting Cao
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
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2
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Chan YH, Naik MH, Haber JB, Neaton JB, Louie SG, Qiu DY, da Jornada FH. Exciton-Phonon Coupling Induces a New Pathway for Ultrafast Intralayer-to-Interlayer Exciton Transition and Interlayer Charge Transfer in WS 2-MoS 2 Heterostructure: A First-Principles Study. NANO LETTERS 2024; 24:7972-7978. [PMID: 38888269 PMCID: PMC11229060 DOI: 10.1021/acs.nanolett.4c01508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 06/10/2024] [Accepted: 06/12/2024] [Indexed: 06/20/2024]
Abstract
Despite the weak, van der Waals interlayer coupling, photoinduced charge transfer vertically across atomically thin interfaces can occur within surprisingly fast, sub-50 fs time scales. An early theoretical understanding of charge transfer is based on a noninteracting picture, neglecting excitonic effects that dominate optical properties of such materials. We employ an ab initio many-body perturbation theory approach, which explicitly accounts for the excitons and phonons in the heterostructure. Our large-scale first-principles calculations directly probe the role of exciton-phonon coupling in the charge dynamics of the WS2/MoS2 heterobilayer. We find that the exciton-phonon interaction induced relaxation time of photoexcited excitons at the K valley of MoS2 and WS2 is 67 and 15 fs at 300 K, respectively, which sets a lower bound to the intralayer-to-interlayer exciton transfer time and is consistent with experiment reports. We further show that electron-hole correlations facilitate novel transfer pathways that are otherwise inaccessible to noninteracting electrons and holes.
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Affiliation(s)
- Yang-hao Chan
- Institute
of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- Physic
Division, National Center of Theoretical Sciences, Taipei 10617, Taiwan
| | - Mit H. Naik
- Department
of Physics, University of California, Berkeley, California 94720-7300, United
States
- Materials
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Jonah B. Haber
- Department
of Physics, University of California, Berkeley, California 94720-7300, United
States
- Materials
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Jeffrey B. Neaton
- Materials
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
- Department
of Physics, University of California, Berkeley, California 94720-7300, United
States
| | - Steven G. Louie
- Materials
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
- Department
of Physics, University of California, Berkeley, California 94720-7300, United
States
| | - Diana Y. Qiu
- Department
of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06520, United States
| | - Felipe H. da Jornada
- Department
of Materials Science and Engineering, Stanford
University, Stanford, California 94305, United States
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3
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Cohen G, Haber JB, Neaton JB, Qiu DY, Refaely-Abramson S. Phonon-Driven Femtosecond Dynamics of Excitons in Crystalline Pentacene from First Principles. PHYSICAL REVIEW LETTERS 2024; 132:126902. [PMID: 38579218 DOI: 10.1103/physrevlett.132.126902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 08/24/2023] [Accepted: 02/11/2024] [Indexed: 04/07/2024]
Abstract
Nonradiative exciton relaxation processes are critical for energy transduction and transport in optoelectronic materials, but how these processes are connected to the underlying crystal structure and the associated electron, exciton, and phonon band structures, as well as the interactions of all these particles, is challenging to understand. Here, we present a first-principles study of exciton-phonon relaxation pathways in pentacene, a paradigmatic molecular crystal and optoelectronic semiconductor. We compute the momentum- and band-resolved exciton-phonon interactions, and use them to analyze key scattering channels. We find that both exciton intraband scattering and interband scattering to parity-forbidden dark states occur on the same ∼100 fs timescale as a direct consequence of the longitudinal-transverse splitting of the bright exciton band. Consequently, exciton-phonon scattering exists as a dominant nonradiative relaxation channel in pentacene. We further show how the propagation of an exciton wave packet is connected with crystal anisotropy, which gives rise to the longitudinal-transverse exciton splitting and concomitant anisotropic exciton and phonon dispersions. Our results provide a framework for understanding the role of exciton-phonon interactions in exciton nonradiative lifetimes in molecular crystals and beyond.
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Affiliation(s)
- Galit Cohen
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Jonah B Haber
- Department of Physics, University of California Berkeley, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Jeffrey B Neaton
- Department of Physics, University of California Berkeley, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Kavli Energy Nanosciences Institute at Berkeley, Berkeley, California 94720, USA
| | - Diana Y Qiu
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06520, USA
| | - Sivan Refaely-Abramson
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
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4
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Chan YH, Haber JB, Naik MH, Neaton JB, Qiu DY, da Jornada FH, Louie SG. Exciton Lifetime and Optical Line Width Profile via Exciton-Phonon Interactions: Theory and First-Principles Calculations for Monolayer MoS 2. NANO LETTERS 2023; 23:3971-3977. [PMID: 37071728 DOI: 10.1021/acs.nanolett.3c00732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Exciton dynamics dictates the evolution of photoexcited carriers in photovoltaic and optoelectronic devices. However, interpreting their experimental signatures is a challenging theoretical problem due to the presence of both electron-phonon and many-electron interactions. We develop and apply here a first-principles approach to exciton dynamics resulting from exciton-phonon coupling in monolayer MoS2 and reveal the highly selective nature of exciton-phonon coupling due to the internal spin structure of excitons, which leads to a surprisingly long lifetime of the lowest-energy bright A exciton. Moreover, we show that optical absorption processes rigorously require a second-order perturbation theory approach, with photon and phonon treated on an equal footing, as proposed by Toyozawa and Hopfield. Such a treatment, thus far neglected in first-principles studies, gives rise to off-diagonal exciton-phonon self-energy, which is critical for the description of dephasing mechanisms and yields exciton line widths in excellent agreement with experiment.
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Affiliation(s)
- Yang-Hao Chan
- Institute of Atomic and Molecular Sciences, Academia Sinica, and Physics Division, National Center of Theoretical Physics, Taipei 10617, Taiwan
- Department of Physics, University of California, Berkeley, California 94720-7300, United States
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jonah B Haber
- Department of Physics, University of California, Berkeley, California 94720-7300, United States
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Mit H Naik
- Department of Physics, University of California, Berkeley, California 94720-7300, United States
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Jeffrey B Neaton
- Department of Physics, University of California, Berkeley, California 94720-7300, United States
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Kavli Energy NanoSciences Institute at Berkeley, University of California, Berkeley, California 94720, United States
| | - Diana Y Qiu
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06520, United States
| | - Felipe H da Jornada
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Steven G Louie
- Department of Physics, University of California, Berkeley, California 94720-7300, United States
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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5
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Zhang L, Shu Y, Xing C, Chen X, Sun S, Huang Y, Truhlar DG. Recommendation of Orbitals for G0W0 Calculations on Molecules and Crystals. J Chem Theory Comput 2022; 18:3523-3537. [PMID: 35580263 DOI: 10.1021/acs.jctc.2c00242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The many-body GW approximation, especially the G0W0 method, has been widely used for condensed matter and molecules to calculate quasiparticle energies for ionization, electron attachment, and band gaps. Because G0W0 calculations are well-known to have a strong dependence on the orbitals, the goal of the present work is to provide guidance on the choice of density functional used to generate orbitals and to recommend a choice that gives the most broadly accurate results. We have systematically investigated the dependence of G0W0 calculations on the orbitals for 100 molecules and 8 crystals by considering orbitals obtained with a diverse set of Kohn-Sham (KS) and generalized KS (GKS) functionals (63 functionals plus Hartree-Fock). The percentage of Hartree-Fock exchange employed in density functionals has been found to have strong influence on the predicted molecular ionization energy and crystal fundamental band gaps (with optimum values between 40 and 56%), but to have less effect on predicting molecular electron affinities. The low cost of the Gaussian implementation, even with hybrid functionals in periodic calculations, the better performance of global hybrids as compared to range-separated hybrids of either than screened exchange or long-range-corrected type, and the relatively low cost of global-hybrid-functional periodic calculations using Gaussians means that one can employ global-hybrid functionals at a very reasonable cost and obtain more accurate band gaps of semiconductors than are obtained by the methods currently widely employed, namely local gradient approximations. We single out three global-hybrid functionals that give especially good results for both molecules (100 in the test set) and crystals (8 in the test set, for all of which our benchmark data are the proper band gap rather than an optical band gap uncorrected for exciton effects).
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Affiliation(s)
- Linyao Zhang
- School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, PR China.,School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China
| | - Yinan Shu
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Chang Xing
- School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, PR China.,School of Astronautics, Harbin Institute of Technology, Harbin 150001, PR China
| | - Xiye Chen
- School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, PR China.,School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China
| | - Shaozeng Sun
- School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, PR China
| | - Yudong Huang
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China
| | - Donald G Truhlar
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
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6
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Zacharias M, Kelires PC. Quantum Confinement of Electron-Phonon Coupling in Graphene Quantum Dots. J Phys Chem Lett 2021; 12:9940-9946. [PMID: 34614351 DOI: 10.1021/acs.jpclett.1c02899] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
On the basis of first-principles calculations and the special displacement method, we demonstrate the quantum confinement scaling law of the phonon-induced gap renormalization of graphene quantum dots (GQDs). We employ zigzag-edged GQDs with hydrogen passivation and embedded in hexagonal boron nitride. Our calculations for GQDs in the sub-10 nm region reveal strong quantum confinement of the zero-point renormalization ranging from 20 to 250 meV. To obtain these values we introduce a correction to the Allen-Heine theory of temperature-dependent energy levels that arises from the phonon-induced splitting of 2-fold degenerate edge states. This correction amounts to more than 50% of the gap renormalization. We also present momentum-resolved spectral functions of GQDs, which are not reported in previous contributions. Our results lay the foundation to systematically engineer temperature-dependent electronic structures of GQDs for applications in solar cells, electronic transport, and quantum computing devices.
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Affiliation(s)
- Marios Zacharias
- Research Unit for Nanostructured Materials Systems, Cyprus University of Technology, P.O. Box 50329, 3603 Limassol, Cyprus
- Department of Mechanical and Materials Science Engineering, Cyprus University of Technology, P.O. Box 50329, 3603 Limassol, Cyprus
| | - Pantelis C Kelires
- Research Unit for Nanostructured Materials Systems, Cyprus University of Technology, P.O. Box 50329, 3603 Limassol, Cyprus
- Department of Mechanical and Materials Science Engineering, Cyprus University of Technology, P.O. Box 50329, 3603 Limassol, Cyprus
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