Controlling Charge Carrier Dynamics in Porphyrin Nanorings by Optically Active Templates

The Journal of Physical Chemistry Letters, Journal Year: 2023, Volume and Issue: 14(50), P. 11384 - 11392

Published: Dec. 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

Language: Английский

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Nuclear Quantum Effects Accelerate Charge Separation and Recombination in g-C₃N₄/TiO₂ Heterojunctions

The Journal of Physical Chemistry Letters, Journal Year: 2024, Volume and Issue: 15(23), P. 6002 - 6009

Published: May 30, 2024

We combined ring–polymer molecular dynamics (MD) and ab initio MD with nonadiabatic to study the effects of nuclear quantum (NQEs) on interlayer electron transfer electron–hole recombination at g-C3N4/TiO2 interface. Our simulations indicate that NQEs significantly affect dynamics, accelerating both processes. deform g-C3N4 layer expedite movement carbon nitrogen atoms, thus, enhancing charge delocalization coupling. This improved overlap between electronic state wave functions enhances couplings, facilitating recombination. In addition enhanced couplings transfer, presence narrows energy gap delays decoherence by mitigating overall fluctuations, because restricted TiO2 movements overwhelming thereby making faster. work provides valuable insights into in light-element systems contributes guiding development highly efficient photocatalysts.

Language: Английский

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Nonadiabatic Molecular Dynamics in Momentum Space Beyond Harmonic Approximation: Hot Electron Relaxation in Photoexcited Black Phosphorus

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(28), P. 19547 - 19554

Published: July 8, 2024

We simulated hot-electron relaxation in black phosphorus using the nonadiabatic molecular dynamics (NA-MD) approach with a non-Condon effect momentum space beyond harmonic approximation. By comparing simulations at Γ point large supercell those few

Language: Английский

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Quantum Dynamics of Charge Carriers in Fullerenes Encapsulated by Covalent Organic Polyhedra: Choice of Fullerene Matters

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 28, 2025

Charge separation is at the heart of solar energy applications, and efficient materials require fast photoinduced electron transfer (ET) slow charge recombination (CR). Using time-dependent self-consistent density functional tight-binding theory combined with nonadiabatic (NA) molecular dynamics, we report a detailed analysis ET CR in hybrids composed photoactive covalent organic polyhedra (COP) encapsulated fullerenes. The occurs on subpicosecond time scale accelerates increasing fullerene diameter, C60 to C70 C84. As size increases, π-electron system available for interaction COP grows, fullerene-COP decreases, number states accept photoexcited accelerating ET. In comparison, nanosecond correlates length shortest axis because relevant state polarized that direction. largest least symmetrical C84 exhibits fastest slowest CR, making COP@C84 most promising hybrid. Both high-frequency bond stretching bending vibrations low-frequency breathing modes are involved processes, more present due its lower symmetry. 10–20 fs vibrationally induced coherence loss electronic subsystem contributes long lifetimes charge-separated states. comprehensive investigation structure–property relationship carrier dynamics COP@fullerene provides atomistic understanding interfacial processes generates guidelines rational design high-performance related applications.

Language: Английский

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Twist Angle-Dependent Exciton Mobility in WS₂ Bilayers

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

Published: March 3, 2025

Bilayer WS2 shows exceptional promise for excitonic devices due to its defect tolerance, high carrier density, and angle-tunable electronic properties. However, fundamental understanding of twist angle-dependent exciton transport remains limited challenges in sample preparation interplays between interlayer coupling moiré potential. Using transient reflection microscopy (TRM), we systematically studied mobility chemical vapor deposition-grown (CVD-grown) bilayer with different angles. At 0°, strong without potential effects yielded the highest (87.3 cm2/V s)- 10-fold greater than monolayer WS2-with a 1.06 μm diffusion length, while 25° showed reduced (44.5 cm2/(V s)) shorter length (0.88 μm) weakened effects, 60° case exhibited intermediate characteristics. This work demonstrates that modulation critically determine dynamics layered two-dimensional semiconductors, providing essential guidelines device engineering.

Language: Английский

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Lattice Expansion Enables Large Surface Carrier Diffusion in WS₂ Monolayer

ACS Energy Letters, Journal Year: 2025, Volume and Issue: unknown, P. 1741 - 1750

Published: March 17, 2025

Language: Английский

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Small Twist Angles Accelerate Electron and Hole Transfer in MoSe₂/WSe₂ Heterostructures

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

Published: March 18, 2025

Van der Waals (vdW) heterostructures host interlayer excitons that act as robust carriers of valley information and sensitive probes strongly correlated electronic phases. The formation properties these critically depend on efficient charge transfer across the heterointerface. Among various factors influencing processes, twist angle emerges a key degree freedom, allowing precise modulation stacking configuration band structure heterostructure. In this study, we perform ultrafast pump-probe measurements MoSe2/WSe2 with angles. Counterintuitively, results show both electron hole rates are influenced by angles, peaking at 0 60° respectively. Theoretical calculations indicate behavior stems from reduced energy offsets enhanced hybridization small which collectively promotes more transfer. Our findings demonstrate influence twist-angle engineering interfacial carrier dynamics its impact optoelectronic vdW heterostructures.

Language: Английский

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Regulating transient optical responses in twisted bilayer WS₂

Nanotechnology, Journal Year: 2025, Volume and Issue: 36(18), P. 185202 - 185202

Published: March 28, 2025

Abstract The optical response manipulation of two-dimensional materials is crucial for designing and optimizing high-performance optoelectronic devices. Previously, modulation in semiconductors primarily relied on adjusting carrier density through excitation or charge injection using the energy band-filling effect. Recently, twist angle has been found to tune properties van der Waals structure, but its impact transient remains unexplored. Herein, we demonstrate that can effectively regulate behaviors by tracing evolution responses twisted bilayer WS 2 from 0° 60°. Both Raman PL spectra consistently show bilayers are highly dependent angle. Exciton behavior phonon modes exhibit similarity at angles near 60°, significantly change as approaches 30°. Moreover, was carefully investigated a femtosecond pump-probe technique. results reveal significant decrease thermalization/relaxation time exciton formation/recombination with ∼31.0°, compared ∼2.9° ∼58.9°, which be attributed accumulation intralayer carriers due weakened interlayer coupling. These modulate 2D materials. Our study elucidates dynamic provides new insights future photonic

Language: Английский

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

The Journal of Chemical Physics, Journal Year: 2024, Volume and Issue: 160(17)

Published: May 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.

Language: Английский

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

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(21), P. 14593 - 14599

Published: May 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.

Language: Английский

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