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

Proceedings of the National Academy of Sciences, Год журнала: 2024, Номер 121(36)

Опубликована: Авг. 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.

Язык: Английский

---

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

Nano Letters, Год журнала: 2024, Номер 24(11), С. 3476 - 3483

Опубликована: Март 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.

Язык: Английский

---

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

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(42), С. 29255 - 29265

Опубликована: Окт. 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

Язык: Английский

---

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

Scientific Reports, Год журнала: 2025, Номер 15(1)

Опубликована: Янв. 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.

Язык: Английский

---

Understanding Twist-Angle-Dependent Carrier Lifetimes in MoSSe Bilayer

The Journal of Physical Chemistry Letters, Год журнала: 2025, Номер unknown, С. 2072 - 2079

Опубликована: Фев. 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.

Язык: Английский

---

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

The Journal of Chemical Physics, Год журнала: 2024, Номер 160(11)

Опубликована: Март 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.

Язык: Английский

---

Controlling Charge Carrier Dynamics in Porphyrin Nanorings by Optically Active Templates

The Journal of Physical Chemistry Letters, Год журнала: 2023, Номер 14(50), С. 11384 - 11392

Опубликована: Дек. 11, 2023

Understanding the dynamics of photogenerated charge carriers is essential for enhancing performance solar and optoelectronic devices. Using atomistic quantum simulations, we demonstrate that a short π-conjugated optically active template can be used to control hot carrier relaxation, separation, recombination in light-harvesting porphyrin nanorings. Relaxation holes slowed by 60% with an compared analogous inactive template. Both systems exhibit subpicosecond electron transfer from photoactive core templates. Notably, suppressed 6-fold The time-domain simulations rationalize these effects extent hole localization, modification density states, participation distinct vibrational motions, changes coherence. Extension lifetime reduction recombination, without hampering strategy efficiencies energy materials

Язык: Английский

---

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

Chemical Engineering Journal, Год журнала: 2024, Номер 496, С. 153777 - 153777

Опубликована: Июль 6, 2024

Язык: Английский

---

Semiclassical approaches to perturbative time-convolution and time-convolutionless quantum master equations for electronic transitions in multistate systems

The Journal of Chemical Physics, Год журнала: 2024, Номер 160(17)

Опубликована: Май 2, 2024

Understanding the dynamics of photoinduced processes in complex systems is crucial for development advanced energy-conversion materials. In this study, we investigate nonadiabatic using time-convolution (TC) and time-convolutionless (TCL) quantum master equations (QMEs) based on treating electronic couplings as perturbation within framework multistate harmonic (MSH) models. The MSH model Hamiltonians are mapped from all-atom simulations such that all pairwise reorganization energies consistently incorporated, leading to a heterogeneous environment couples multiple states differently. Our exploration encompasses charge transfer organic photovoltaic carotenoid–porphyrin–C60 triad dissolved liquid solution excitation energy (EET) photosynthetic Fenna–Matthews–Olson complexes. By systematically comparing perturbative TC TCL QME approaches with exact quantum-mechanical various semiclassical approximate kernels, demonstrate their efficacy accuracy capturing essential features dynamics. calculations show QMEs generally yield more accurate results than QMEs, especially EET, although both methods offer versatile adaptable across different systems. addition, approximations featuring Wigner-transformed classical nuclear densities well governing during coherence period, highlighting trade-off between computational cost. This work provides valuable insights into applicability performance via model, offering guidance realistic applications condensed-phase atomistic level.

Язык: Английский

---

Exciton Localization Modulated by Ultradeep Moiré Potential in Twisted Bilayer γ-Graphdiyne

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(21), С. 14593 - 14599

Опубликована: Май 8, 2024

Twisted moiré superlattice is featured with its potential energy, the depth of which renders an effective approach to strengthening exciton–exciton interaction and exciton localization toward high-performance quantum photonic devices. However, it remains as a long-standing challenge further push limit depth. Herein, owing pz orbital induced band edge states enabled by unique sp-C in bilayer γ-graphdiyne (GDY), ultradeep ∼289 meV yielded. After being twisted into hole-to-hole layer stacking configuration, interlayer coupling substantially intensified augment lattice GDY up 475%. The presence lateral constrained shifts spatial distribution electrons holes excitons from regular alternating mode their respective separated localized mode. According well-established wave function contained excitons, AA-stacked site identified serve for localization. This work extends materials systems available design serial carbon allotropes benzene ring-alkyne chain coupling, unlocking tremendous twistronic-based device applications.

Язык: Английский

---