Computational Screening of 2D Materials for Photocatalysis

The Journal of Physical Chemistry Letters, Journal Year: 2015, Volume and Issue: 6(6), P. 1087 - 1098

Published: Feb. 26, 2015

Two-dimensional (2D) materials exhibit a range of extraordinary electronic, optical, and mechanical properties different from their bulk counterparts with potential applications for 2D emerging in energy storage conversion technologies. In this Perspective, we summarize the recent developments field solar water splitting using review computational screening approach to rapidly efficiently discover more that possess suitable splitting. Computational tools based on density-functional theory can predict intrinsic photocatalyst such as electronic properties, optical absorbance, solubility aqueous solutions. enable exploration possible routes enhance photocatalytic activity by use strain, bias potential, doping, pH. We discuss future research directions needed method design optimization photocatalysis.

Language: Английский

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Picosecond photoresponse in van der Waals heterostructures

Nature Nanotechnology, Journal Year: 2015, Volume and Issue: 11(1), P. 42 - 46

Published: Oct. 5, 2015

Language: Английский

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2D materials advances: from large scale synthesis and controlled heterostructures to improved characterization techniques, defects and applications

2D Materials, Journal Year: 2016, Volume and Issue: 3(4), P. 042001 - 042001

Published: Dec. 8, 2016

The rise of two-dimensional (2D) materials research took place following the isolation graphene in 2004. These new 2D include transition metal dichalcogenides, mono-elemental sheets, and several carbide- nitride-based materials. number publications related to these emerging has been drastically increasing over last five years. Thus, through this comprehensive review, we aim discuss most recent groundbreaking discoveries as well opportunities remaining challenges. This review starts out by delving into improved methods producing via controlled exfoliation, organic chemical vapor deposition, wet means. We look studies doping optical properties their heterostructures. Recent advances towards applications electronics are also reviewed, tunnel MOSFET ways reduce contact resistance for fabricating high-quality devices. Finally, unique innovative recently explored discussed perspectives exciting fast moving field.

Language: Английский

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Emerging Low‐Dimensional Materials for Nonlinear Optics and Ultrafast Photonics

Advanced Materials, Journal Year: 2017, Volume and Issue: 29(14)

Published: Feb. 22, 2017

Low-dimensional (LD) materials demonstrate intriguing optical properties, which lead to applications in diverse fields, such as photonics, biomedicine and energy. Due modulation of electronic structure by the reduced structural dimensionality, LD versions metal, semiconductor topological insulators (TIs) at same time bear distinct nonlinear (NLO) properties compared with their bulk counterparts. Their interaction short pulse laser excitation exhibits a strong character manifested NLO absorption, giving rise limiting or saturated absorption associated excited state Pauli blocking different materials. In particular, saturable these emerging including two-dimensional semiconductors well colloidal TI nanoparticles has recently been utilized for Q-switching mode-locking ultra-short generation across visible, near infrared middle wavelength regions. Beside large operation bandwidth, ultrafast photonics are especially benefit from high recovery rate facile processibility The prominent response have also provided new avenues development novel devices all-optical control circuits beyond lasers.

Language: Английский

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Nonlinear optical properties and applications of 2D materials: theoretical and experimental aspects

Nanophotonics, Journal Year: 2018, Volume and Issue: 8(1), P. 63 - 97

Published: Dec. 10, 2018

Abstract In this review, we survey the recent advances in nonlinear optics and applications of two-dimensional (2D) materials. We briefly cover key developments pertaining to research graphene, quintessential 2D material. Subsequently, discuss linear optical properties several other layered materials, including transition metal chalcogenides, black phosphorus, hexagonal boron nitride, perovskites, topological insulators, as well progress hybrid nanostructures containing such composites with dyes, plasmonic particles, crystals, silicon integrated structures. Finally, highlight a few representative current materials photonic optoelectronic devices.

Language: Английский

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Photo-Induced Bandgap Renormalization Governs the Ultrafast Response of Single-Layer MoS₂

ACS Nano, Journal Year: 2015, Volume and Issue: 10(1), P. 1182 - 1188

Published: Dec. 21, 2015

Transition metal dichalcogenides (TMDs) are emerging as promising two-dimensional (2d) semiconductors for optoelectronic and flexible devices. However, a microscopic explanation of their photophysics -- pivotal importance the understanding optimization device operation is still lacking. Here we use femtosecond transient absorption spectroscopy, with pump pulse tunability broadband probing, to monitor relaxation dynamics single-layer MoS2 over entire visible range, upon photoexcitation different excitonic transitions. We find that, irrespective excitation photon energy, spectrum shows simultaneous bleaching all transitions corresponding red-shifted photoinduced bands. First-principle modeling ultrafast optical response reveals that bandgap renormalization, caused by presence photo-excited carriers, primarily responsible observed features. Our results demonstrate strong impact many-body effects in TMDs even low-excitation-density regime.

Language: Английский

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Photonics of time-varying media

Advanced Photonics, Journal Year: 2022, Volume and Issue: 4(01)

Published: Feb. 14, 2022

Time-varying media have recently emerged as a new paradigm for wave manipulation, thanks to thesynergy between the discovery of novel, highly nonlinear materials, such epsilon-near-zero and questfor novel applications, magnet-free nonreciprocity, multi-mode light shaping, ultrafast switching. Inthis review we provide comprehensive discussion recent progress achieved with photonic metamaterials whoseproperties stem from their modulation in time. We basic concepts underpinning temporal switching itsrelation spatial scattering, deploy resulting insight time-crystals emergentresearch avenues topological non-Hermitian physics. then extend our account spa-tiotemporal its applications synthetic motion, giant anisotropy, amplification andother effects. Finally, conclude most attractive experimental demonstrated,and few perspectives on emerging trends future implementations time-modulation photonics.

Language: Английский

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2D Black Phosphorus Saturable Absorbers for Ultrafast Photonics

Advanced Optical Materials, Journal Year: 2018, Volume and Issue: 7(1)

Published: Sept. 17, 2018

Abstract 2D nanomaterials are emerging as a promising platform for ultrashort‐pulse fiber laser technology. This review presents catalog of the factors affecting nonlinear optical properties and recent progress in processing integration strategies into saturable absorber devices versatile, wideband ultrafast switches fiber‐based‐laser short‐pulse generation. Particular focus is on black phosphorus, summary current status black‐phosphorus‐based pulsed lasers given, which provide new potential efficacy this other photonic

Language: Английский

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Ab initio nonadiabatic molecular dynamics investigations on the excited carriers in condensed matter systems

Wiley Interdisciplinary Reviews Computational Molecular Science, Journal Year: 2019, Volume and Issue: 9(6)

Published: March 14, 2019

The ultrafast dynamics of photoexcited charge carriers in condensed matter systems play an important role optoelectronics and solar energy conversion. Yet it is challenging to understand such multidimensional at the atomic scale. Combining real‐time time‐dependent density functional theory with fewest‐switches surface hopping scheme, we develop ab initio nonadiabatic molecular (NAMD) code Hefei‐NAMD simulate excited carrier systems. Using this method, have investigated interfacial transfer dynamics, electron–hole recombination spin‐polarized hole different are studied energy, real momentum spaces. In addition, coupling phonons, defects adsorptions investigated. state‐of‐art NAMD studies provide unique insights This article categorized under: Structure Mechanism > Computational Materials Science Molecular Statistical Mechanics Dynamics Monte‐Carlo Methods Electronic Theory Ab Initio Software Simulation

Language: Английский

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Quantum Coherence Facilitates Efficient Charge Separation at a MoS₂/MoSe₂ van der Waals Junction

Nano Letters, Journal Year: 2016, Volume and Issue: 16(3), P. 1996 - 2003

Published: Feb. 16, 2016

Two-dimensional transition metal dichalcogenides (MX2, M = Mo, W; X S, Se) hold great potential in optoelectronics and photovoltaics. To achieve efficient light-to-electricity conversion, electron-hole pairs must dissociate into free charges. Coulomb interaction MX2 often exceeds the charge transfer driving force, leading one to expect inefficient separation at a heterojunction. Experiments defy expectation. Using time-domain density functional theory nonadiabatic (NA) molecular dynamics, we show that quantum coherence donor-acceptor delocalization facilitate rapid MoS2/MoSe2 interface. The is larger for electron than hole, resulting longer faster transfer. Stronger NA coupling higher acceptor state accelerate further. Both hole transfers are subpicosecond, which agreement with experiments. promoted primarily by out-of-plane Mo-X modes of acceptors. Lighter S atoms, compared Se, create electrons holes. relatively slow relaxation "hot" suggests long-distance bandlike transport, observed organic recombination notably across interface isolated MoS2 MoSe2, favoring long-lived separation. atomistic, studies provide valuable insights excitation dynamics two-dimensional dichalcogenides.

Language: Английский

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