Breaking the size limitation of nonadiabatic molecular dynamics in condensed matter systems with local descriptor machine learning

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(36)

Published: Aug. 30, 2024

Nonadiabatic molecular dynamics (NA-MD) is a powerful tool to model far-from-equilibrium processes, such as photochemical reactions and charge transport. NA-MD application condensed phase has drawn tremendous attention recently for development of next-generation energy optoelectronic materials. Studies matter allow one employ efficient computational tools, density functional theory (DFT) classical path approximation (CPA). Still, system size simulation timescale are strongly limited by costly ab initio calculations electronic energies, forces, NA couplings. We resolve the limitations developing fully machine learning (ML) approach in which all above properties obtained using neural networks based on local descriptors. The ML models correlate target NA-MD, implemented with DFT CPA, directly structure. Trained small systems, applied large systems long timescales, extending capabilities orders magnitude. demonstrate dependence trapping recombination defect concentration MoS 2 . Defects provide main mechanism losses, resulting performance degradation. Charge slows decreasing concentration; however, exhibits complex dependence, conditional whether it occurs between free or trapped charges, relative concentrations carriers defects. Delocalized shallow traps can become localized increasing temperature, changing behavior. Completely ML, bridges gap theoretical realistic experimental conditions enables thousand-atom many nanoseconds.

Language: Английский

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Time-resolved momentum microscopy with fs-XUV photons at high repetition rates with flexible energy and time resolution

Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)

Published: Jan. 29, 2025

Time-resolved momentum microscopy is an emerging technique based on photoelectron spectroscopy for characterizing ultrafast electron dynamics and the out-of-equilibrium electronic structure of materials in entire Brillouin zone with high efficiency. In this article, we introduce a setup time-resolved energy-filtered microscope coupled to custom-made high-harmonic generation photon source driven by multi-100 kHz commercial Yb-ultrafast laser that delivers fs pulses extreme ultraviolet range. The includes nonlinear pulse compression stage employing spectral broadening Herriott-type bulk-based multi-pass cell. This element allows flexible tuning driving duration, providing versatile featuring two operational modes designed enhance either energy or time resolution. We show capabilities system tracing conduction band valleys bulk crystal 2D semiconductor WS2. Using uncompressed pulses, demonstrate resolution better than (107 ± 2) meV, while compressed lead (48.8 17) fs.

Language: Английский

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Understanding Twist-Angle-Dependent Carrier Lifetimes in MoSSe Bilayer

The Journal of Physical Chemistry Letters, Journal Year: 2025, Volume and Issue: unknown, P. 2072 - 2079

Published: Feb. 19, 2025

Two-dimensional (2D) materials with tunable interlayer interactions hold immense potential for optoelectronic and photocatalytic applications. Understanding the dependence of carrier dynamics on twist angle in Janus bilayers is essential, as it directly impacts device efficiency. This study employs time-dependent density functional theory (TD-DFT) nonadiabatic molecular (NAMD) to investigate twist-angle-dependent MoSSe type-II band alignment. Simulations reveal ultrafast charge transfer times approximately 70 500 fs, largely independent due multiple intermediate states. In contrast, electron-hole recombination depend strongly angles, extending up 133 ns twisted configurations (21.8° 38.2°) compared 57 high-symmetry (0.0° 60.0°). Structural randomness weakens interactions, reducing coupling coherence time, which collectively prolong lifetimes. These findings offer valuable guidance designing 2D high-efficiency photovoltaics long-durable photocatalysts.

Language: Английский

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Nuclear Quantum Effects Accelerate Charge Recombination but Boost the Stability of Inorganic Perovskites in Mild Humidity

Nano Letters, Journal Year: 2024, Volume and Issue: 24(11), P. 3476 - 3483

Published: March 6, 2024

Experiments have demonstrated that mild humidity can enhance the stability of CsPbBr3 perovskite, though underlying mechanism remains unclear. Utilizing ab initio molecular dynamics, ring polymer and non-adiabatic our study reveals nuclear quantum effects (NQEs) play a crucial role in stabilizing lattice rigidity perovskite while simultaneously shortening charge carrier lifetime. NQEs reduce extent geometric disorder number atomic fluctuations, diminish hole localization, thereby improve electron–hole overlap coupling. Concurrently, these significantly suppress phonon modes slow decoherence. As result, factors collectively accelerate recombination by factor 1.42 compared to scenarios excluding NQEs. The resulting sub-10 ns time scales align remarkably well with experimental findings. This research offers novel insight into how moisture resistance impacts lifetime all-inorganic perovskites.

Language: Английский

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Self-passivation of Halide Interstitial Defects by Organic Cations in Hybrid Lead-Halide Perovskites: Ab Initio Quantum Dynamics

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(42), P. 29255 - 29265

Published: Oct. 11, 2024

Halide interstitial defects severely hinder the optoelectronic performance of metal halide perovskites, making research on their passivation crucial. We demonstrate, using ab initio nonadiabatic molecular dynamics simulations, that hydrogen vacancies (H

Language: Английский

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Impact of large A-site cations on electron–vibrational interactions in 2D halide perovskites: Ab initio quantum dynamics

The Journal of Chemical Physics, Journal Year: 2024, Volume and Issue: 160(11)

Published: March 20, 2024

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 GA distorts and stiffens inorganic Pb-I lattice, reduces thermal structural fluctuations, maintains delocalization electrons holes at ambient elevated temperatures. delocalized charges interact more strongly system than MA system, charge is accelerated. In contrast, replacement only some with enhances disorder increases lifetime, as seen three-dimensional perovskites. This highlights key influence fluctuations properties carriers metal halide perovskites, providing guidance for tuning materials' optoelectronic performance.

Language: Английский

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Enhanced high-temperature iodine capture through band-edge control in covalent organic frameworks

Chemical Engineering Journal, Journal Year: 2024, Volume and Issue: 496, P. 153777 - 153777

Published: July 6, 2024

Language: Английский

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Circular Dichroism and Interlayer Exciton Hall Effect in Transition Metal Dichalcogenides Homobilayers

Nano Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 8, 2025

In van der Waals (vdW) architectures of transition metal dichalcogenides (TMDCs), the coupling between interlayer exciton and quantum degrees freedom opens unprecedented opportunities for excitonic physics. Taking MoSe2 homobilayer as representative, we identify that registry defines nature dynamics lowest-energy exciton. The large layer polarization (Pn) is proved, which ensures formation layer-resolved excitons. particular, sliding ferroelectric couples to dipole orientation exciton, thus achieving long-sought electric control states. line with phase winding Bloch states under C3 rotational symmetry, clarify valley optical circular dichroism, enriching valleytronics. We also elucidate Hall effect layer- valley-polarized excitons, advances our understanding spatial transport properties composite particles provides new insights into exciton-based applications.

Language: Английский

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Theoretical study on the photogenerated carrier dynamics in direct Z-scheme heterojunction C3B/C3

Minghua Niu,

S. Zhang,

Yanyan Guo

et al.

Physica B Condensed Matter, Journal Year: 2025, Volume and Issue: unknown, P. 416898 - 416898

Published: Feb. 1, 2025

Language: Английский

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Relaxation of Photoexcited Electron–Hole Pairs at Si(111) Surfaces with Adsorbed Ag Monolayered Clusters of Increasing Size

The Journal of Physical Chemistry Letters, Journal Year: 2025, Volume and Issue: unknown, P. 2905 - 2913

Published: March 11, 2025

The efficiency of silicon solar cells is affected by the light absorption and recombination losses photoexcited charge carries. One possible way to improve through deposition transition metal nanoparticles on Si surfaces. Here, we first carry out density functional theory (DFT) calculations obtain electronic structures for Agn (n = 1–7) monolayered clusters adsorbed Si(111)/H Results are presented in form states, band gaps, absorption, which allow investigation interaction Ag with Si. Different behaviors can be expected depending size deposited clusters. Overall, leads smaller red-shifts, large increases compared pristine slab. We then study relaxation dynamics electron–hole pairs slabs based nonadiabatic couplings using reduced matrix approach within Redfield formalism. Nonradiative rates noticeably different various transitions. observes higher surfaces adsorbates than surface due transfer events involving orbitals. also compute emission spectra from excited-state dynamics. gap dark indirect nature its gap. addition larger breaks symmetry slabs, enabling These thus exhibit bright emission. introduction advantageous applications photovoltaics photocatalysis.

Language: Английский

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