Nonradiative Charge Recombination Dynamics in Fully Hydroxylated Hematite Surface: A Time-Domain Ab Initio Study DOI
Yi Liu, Bipeng Wang, Hua Wang

et al.

The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 3, 2024

Hematite (α-Fe2O3) is a typical semiconducting transition metal oxide that exhibits attractive properties for photoelectrochemical (PEC) water splitting and other applications. However, it has been widely reported charge recombination in α-Fe2O3 photoanodes serious problem, hindering further improvement the efficiency of PEC splitting. We used ab initio nonadiabatic molecular dynamics (NAMD) to investigate bulk surface phases α-Fe2O3. The NAMD simulations employ decoherence-induced hopping (DISH) method implemented within time-dependent density functional theory. test demonstrate need incorporate both phase-consistency correction all-electron calculation NA coupling, latter needed metals with d-shell electrons. show time scale intrinsic can reach microseconds, accordance existence long-lived photogenerated carriers observed transient absorption measurements on electrodes. hydroxylated iron-termination α-Fe2O3(0001) surface, one most stable surfaces aqueous solution, much faster recombination, about 1 order magnitude compared key factor fast mainly be assigned strong fluctuations NAC energy gap between conduction band minimum (CBM) valence maximum (VBM) quantum anti-Zeno effect. This work extends from phase interfacial α-Fe2O3, approaching reaction conditions, thus assists understanding underlying oxygen evolution (OER) at Fe2O3–water interface design new efficient Fe2O3-based photoanode materials.

Language: Английский

Sub-bandgap charge harvesting and energy up-conversion in metal halide perovskites: ab initio quantum dynamics DOI Creative Commons
Bipeng Wang, Weibin Chu, Yifan Wu

et al.

npj Computational Materials, Journal Year: 2025, Volume and Issue: 11(1)

Published: Jan. 11, 2025

Metal halide perovskites (MHPs) exhibit unusual properties and complex dynamics. By combining ab initio time-dependent density functional theory, nonadiabatic molecular dynamics machine learning, we advance quantum simulation to nanosecond timescale demonstrate that large fluctuations of MHP defect energy levels extend light absorption longer wavelengths enable trapped charges escape into bands. This allows low photons contribute photocurrent through up-conversion. Deep can become shallow transiently vice versa, altering the traditional classification deep. While fluctuate more in MHPs than semiconductors, some levels, e.g., Pb interstitials, remain far from band edges, acting as charge recombination centers. Still, many defects deemed detrimental based on static structures, are fact benign The extended harvesting up-conversion provide strategies for design novel solar, optoelectronic, information devices.

Language: Английский

Citations

2
Band Gap Narrowing in Lead-Halide Perovskites by Dynamic Defect Self-Doping for Enhanced Light Absorption and Energy Upconversion DOI Creative Commons

Yongliang Shi,

Weibin Chu, Lili Zhang

et al.

Chemistry of Materials, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 6, 2025

Metal halide perovskites (MHP) have attracted great attention in the photovoltaic industry due to their high and rapidly rising power conversion efficiencies, currently over 25%. However, hybrid organic-inorganic MHPs are inherently chemically unstable, limiting application. All-inorganic perovskites, such as CsPbI3, many merits, but stable efficiency is lower, around 18%, a larger band gap causing mismatch with solar spectrum. Choosing α-CsPbI3 prototypical system, we demonstrate new general concept of dynamic defects that fluctuate between deep shallow states, increase range absorbed photons, without accelerating nonradiative electron-hole recombination. In deeper energy state, narrow allow harvesting light longer wavelengths. Fluctuating shallower energies, escape photogenerated charges into bands, enabling charge transport resulting defect-mediated upconversion thermal electricity. Defect covalency participation low-frequency anharmonic vibrations decouple trapped from free carriers, minimizing carrier losses. Our findings defect dynamics unique important properties MHPs, can be used optimize for efficient optoelectronic applications.

Language: Английский

Citations

1
Nuclear Quantum Effects Accelerate Hot Carrier Relaxation but Slow Down Recombination in Metal Halide Perovskites DOI
Yulong Liu, Shiying Shen, Oleg V. Prezhdo

et al.

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

Published: March 19, 2025

Inorganic semiconductors are composed of heavy elements whose vibrational motions well described by classical mechanics. Heavy elements, such as Pb and I, support charge carriers in metal halide perovskites. Nevertheless, the soft structure strong coupling between organic inorganic components create conditions which nuclear quantum effects (NQEs) can play important roles. By combining ab initio, ring-polymer, nonadiabatic molecular dynamics approaches with time-domain density functional theory, we demonstrate how NQEs influence structural electronic properties electron-vibrational hybrid organic-inorganic (MAPbI3) all-inorganic (CsPbI3) Quantum zero-point fluctuations enhance disorder, reduce band gap, accelerate elastic scattering responsible for coherence loss. have opposite influences on intraband carrier relaxation interband recombination. These inelastic events governed product overlap-like electron-phonon matrix element atomic velocity. overlap increases The involves many states. Reduction some states is offset other pathways, while an increased velocity makes faster. Electron-hole band-edge plays a key role recombination, its reduction NQEs-enhanced disorder recombination slower. This phenomenon seen both MAPbI3 CsPbI3 much more pronounced when light component present. study offers detailed understanding processes perovskites, offering theoretical insights into hot that govern performance solar cells optoelectronic devices.

Language: Английский

Citations

1
Self-passivation of Halide Interstitial Defects by Organic Cations in Hybrid Lead-Halide Perovskites: Ab Initio Quantum Dynamics DOI
Xinbo Ma, Xue Tian,

Elizabeth Stippell

et al.

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

Citations

7
Detrimental Defect Cooperativity at TiO2/CH3NH3PbI3 Interface: Decreased Stability, Enhanced Ion Diffusion, and Reduced Charge Lifetime and Transport DOI
Kaiping Wang, Zhiwei Wu, K. L. Wang

et al.

ACS Energy Letters, Journal Year: 2024, Volume and Issue: unknown, P. 5888 - 5897

Published: Nov. 18, 2024

Interfaces are essential for solar cell performance since they govern charge separation and transport. Using quantum dynamics simulation, we demonstrate that at interfaces, common defects benign on their own, iodine vacancy in CH3NH3PbI3 (VI) oxygen TiO2 (VO), responsible synergistically poor stability losses. VO promotes VI diffusion accelerates migration. A midgap trap state appears, inhibiting transport accelerating recombination by an order of magnitude. Strong structural distortions strengthen electron-vibrational interactions activate high-frequency phonons. Because the widely reported high defect-tolerance lead-halide perovskites, synergistic detrimental influence perovskite with other materials is often overlooked. The interfacial defect pairing could be a major reason losses cells. results suggest either high-quality or extraction layer may sufficient to achieve performance.

Language: Английский

Citations

6
Strain Engineering of Two-Dimensional Hybrid Perovskites with Band Edge Modulation and Charge Separation DOI

Jiali Liao,

Xi-Meng Tang,

Long Zhang

et al.

The Journal of Physical Chemistry Letters, Journal Year: 2025, Volume and Issue: unknown, P. 4401 - 4409

Published: April 24, 2025

Strain engineering in two-dimensional (2D) perovskites has been widely explored recent years. In this study, first-principles and nonadiabatic molecular dynamics simulations reveal that biaxial strain (exceeding 6%) introduces an abnormal transition of the conduction band minimum (CBM) from inorganic to organic contributions 2D Dion-Jacobson perovskite (3AMPY)PbI4 (3AMPY, 3-(aminomethyl)pyridinium). Further research demonstrates such CBM transitions under tensile compressive are primarily attributed competition between Pb-I interaction organic-inorganic hydrogen bonding interaction. The reconfiguration effectively promotes charge separation, which shortens quantum coherence time suppresses coupling, so it enhances carrier lifetime, particularly 6% strain. findings highlight a novel strain-engineering strategy for optimizing edge modulation transport perovskites, providing valuable insights design high-performance solar cells.

Language: Английский

Citations

0
Atomistic Origin of Microsecond Carrier Lifetimes at Perovskite Grain Boundaries: Machine Learning-Assisted Nonadiabatic Molecular Dynamics DOI Creative Commons
Yifan Wu, Weibin Chu, Bipeng Wang

et al.

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

Published: Jan. 29, 2025

The polycrystalline nature of perovskites, stemming from their facile solution-based fabrication, leads to a high density grain boundaries (GBs) and point defects. However, the impact GBs on perovskite performance remains uncertain, with contradictory statements found in literature. We developed machine learning force field, sampled GB structures nanosecond time scale, performed nonadiabatic (NA) molecular dynamics simulations charge carrier trapping recombination stoichiometric doped GBs. reveal long, microsecond lifetimes, approaching experimental data, separation at small NA coupling, 0.01-0.1 meV. Stoichiometric exhibit transient trap states, which, however, are not particularly detrimental lifetime. Halide dopants form interstitial defects bulk, but have stabilizing influence structure by passivating undersaturated Pb atoms reducing state formation. On contrary, excess destabilizes GBs, allowing formation persistent midgap states that charges. Still, lifetime reduces relatively little, because decouple bands, charges more likely escape back into bands upon structural fluctuation. atomistic study its provides valuable insights complex properties perovskites intricate role material performance.

Language: Английский

Citations

0
Nonradiative Charge Recombination Dynamics in Fully Hydroxylated Hematite Surface: A Time-Domain Ab Initio Study DOI
Yi Liu, Bipeng Wang, Hua Wang

et al.

The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 3, 2024

Hematite (α-Fe2O3) is a typical semiconducting transition metal oxide that exhibits attractive properties for photoelectrochemical (PEC) water splitting and other applications. However, it has been widely reported charge recombination in α-Fe2O3 photoanodes serious problem, hindering further improvement the efficiency of PEC splitting. We used ab initio nonadiabatic molecular dynamics (NAMD) to investigate bulk surface phases α-Fe2O3. The NAMD simulations employ decoherence-induced hopping (DISH) method implemented within time-dependent density functional theory. test demonstrate need incorporate both phase-consistency correction all-electron calculation NA coupling, latter needed metals with d-shell electrons. show time scale intrinsic can reach microseconds, accordance existence long-lived photogenerated carriers observed transient absorption measurements on electrodes. hydroxylated iron-termination α-Fe2O3(0001) surface, one most stable surfaces aqueous solution, much faster recombination, about 1 order magnitude compared key factor fast mainly be assigned strong fluctuations NAC energy gap between conduction band minimum (CBM) valence maximum (VBM) quantum anti-Zeno effect. This work extends from phase interfacial α-Fe2O3, approaching reaction conditions, thus assists understanding underlying oxygen evolution (OER) at Fe2O3–water interface design new efficient Fe2O3-based photoanode materials.

Language: Английский

Citations

2