The role of collective motion in the ultrafast charge transfer in van der Waals heterostructures

Wang, H.; Bang, Junhyeok; Sun, Yiyang; Liang, Liangbo; West, Damien; Meunier, Vincent; Zhang, Shou-Cheng

doi:10.1038/ncomms11504

Cited by 125 publications

(149 citation statements)

References 48 publications

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“…In MoS 2 / WS 2 , it was proposed that the ultrafast charge transfer is provoked by the A 1 mode excitation. Furthermore, in MoSe 2 /WSe 2 , 133 In their work they also found the A 1 and LA modes play important role in the MD. They found the hole transfer from MoS 2 to WS 2 happen with a timescale of 100 fs, accompanying charge oscillation between the two layers.…”

Section: Phonon-coupled Charge Oscillation At Mose 2 /Wse 2 Interfacementioning

confidence: 88%

“…It should also be noticed that the charge transfer dynamics at TMD interface have also been investigated by other theoretical works. Wang et al used Erhenfest NAMD based on TDDFT (TDAP code) to investigate the hole transfer process in MoS 2 . In their work they also found the A 1 and LA modes play important role in the MD.…”

Section: Ultrafast Charge Transfer At Van Der Waals Heterostructure Imentioning

confidence: 99%

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

Zheng

Chu

Zhao

et al. 2019

WIREs Comput Mol Sci

271

258

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

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Section: Phonon-coupled Charge Oscillation At Mose 2 /Wse 2 Interfacementioning

confidence: 88%

Section: Ultrafast Charge Transfer At Van Der Waals Heterostructure Imentioning

confidence: 99%

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

Zheng

Chu

Zhao

et al. 2019

WIREs Comput Mol Sci

271

258

View full text Add to dashboard Cite

show abstract

“…The emerging properties (e.g., ultrafast charge transfer between van der Waals-coupled layers and tunable optoelectronic properties) [180] and new physical features (e.g., superlattice Dirac points [181] and Hofstadter butterfly in magnetic field [182] ) of 2D hetero-nanosheets are originates from interlayer interactions between different nanosheets. The emerging properties (e.g., ultrafast charge transfer between van der Waals-coupled layers and tunable optoelectronic properties) [180] and new physical features (e.g., superlattice Dirac points [181] and Hofstadter butterfly in magnetic field [182] ) of 2D hetero-nanosheets are originates from interlayer interactions between different nanosheets.…”

Section: D Hetero-nanosheetsmentioning

confidence: 99%

Emergent Pseudocapacitance of 2D Nanomaterials

Yun

Yeon

et al. 2018

Advanced Energy Materials

261

190

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naming of energy storage devices after their own core materials: conventional batteries such as lead-acid batteries, which are named after the lead-based active material and the acidic electrolyte; nickelcadmium batteries named after the nickeland cadmium-based active materials; nickel-metal hybrid batteries named after the nickel-and metal hydride-based active materials; state-of-the-art lithium-ion batteries (LIBs), named after the lithiated host materials and lithium-ion carriers; and next-generation batteries such as sodiumion, lithium-sulfur, and lithium-air batteries, which are named after the lithium metal anode and sulfur or O 2 cathode. [4][5][6][7][8][9] In short, whenever energy storage materials made a breakthrough, new-generation energy storage devices appeared. Among electrochemical energy storage devices, supercapacitors (SCs), which can store charges at the surface, have advantages over LIB and conventional batteries in terms of high power, fast charging/ discharging rates, and long cyclability, as will be discussed in Section 2.1. However, the low energy density of SCs remains a critical challenge for emerging applications such as next-generation electronic systems, electrical vehicles (EVs), and renewable energy storage systems (ESSs). [10,11] Based on the long history of energy storage research, new and emerging materials are expected to provide solutions to this problem.Returning to the chronological development of SCs, SCs have been revolutionized by the emergence of new materials, as Two dimensional (2D) nanomaterials are very attractive due to their unique structural and surface features for energy storage applications. Motivated by the recent pioneering works demonstrating "the emergent pseudocapacitance of 2D nanomaterials," the energy storage and nanoscience communities could revisit bulk layered materials though state-of-the-art nanotechnology such as nanostructuring, nanoarchitecturing, and compositional control. However, no review has focused on the fundamentals, recent progress, and outlook on this new mechanism of 2D nanomaterials yet. In this study, the key aspects of emergent pseudocapacitors based on 2D nanomaterials are comprehensively reviewed, which covers the history, classification, thermodynamic and kinetic aspects, electrochemical characteristics, and design guidelines of materials for extrinsically surface redox and intercalation pseudocapacitors. The structural and compositional controls of graphene and other carbon nanosheets, transition metal oxides and hydroxides, transition metal dichalcogenides, and metal carbide/nitride on both microscopic and macroscopic levels will be particularly addressed, emphasizing the important results published since 2010. Finally, perspectives on the current impediments and future directions of this field are offered. Unlimited combinations and modifications of 2D nanomaterials can provide a rational strategy to overcome intrinsic limitations of existing materials, offering a new-generation energy storage materials toward a high and new p...

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“…Each of the trion consists of a bright exciton in one valley electrostatically bound with an electron in the lower spin-split conduction band from the opposite valley. Since inter-layer transfer is ultra-fast (∼sub-ps [12,[27][28][29]), which is faster than trion radiative decay (∼tens of ps [?, 2,9,10,19,[30][31][32]), the whole negatively charged trion can be transferred to the bottom monolayer graphene driven by the built-in electric field, as illustrated in Figure 2d. To account for charge neutrality, the top layer graphene injects an electron to the WS 2 , completing the circuit.…”

Section: The Difference In Doping Induced Workfunction Between the Tomentioning

confidence: 99%

Gate-tunable trion switch for excitonic device applications

et al. 2020

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Trions are excitonic species with a positive or negative charge, and thus, unlike neutral excitons, the flow of trions can generate a net detectable charge current. Trions under favourable doping conditions can be created in a coherent manner using resonant excitation. In this work, we exploit these properties to demonstrate a gate controlled trion switch in a few-layer graphene/monolayer WS 2 /monolayer graphene vertical heterojunction. By using a high resolution spectral scan through a temperature controlled variation of the bandgap of the WS 2 sandwich layer, we obtain a gate voltage dependent vertical photocurrent strongly relying on the spectral position of the excitation, and the photocurrent maximizes when the excitation energy is resonant with the trion peak position. Further, the resonant photocurrent thus generated can be effectively controlled by a back gate voltage applied through the incomplete screening of the bottom monolayer graphene, and the photocurrent strongly correlates with the gate dependent trion intensity, while the non-resonant photocurrent exhibits only a weak gate dependenceunambiguously proving a trion driven photocurrent generation under resonance. We estimate a sub-100 fs switching time of the device. The findings are useful towards demonstration of ultra-fast excitonic devices in layered materials. Introduction:The monolayer semiconducting transition metal dichalcogenides (MoS 2 , WS 2 , MoSe 2 , and WSe 2 ) exhibit strongly bound two-dimensional excitons with a binding energy on the order of few hundreds of meV, making these ultra-thin monolayers an excellent test bed for excitonic manipulation even at room temperature [1][2][3][4][5]. The neutral excitons (X 0 ) show excellent valley polarization and valley coherence properties that can be readily probed through initialization by circularly and linearly polarized photons, respectively, followed by detection through a circular or linear analyzer [6][7][8][9][10][11]. However, controlling these excitonic states electrically remains a challenge due to the charge neutral nature of these excitons. In addition, transport of the exciton also remains challenging due to the ultra-fast radiative recombination of exciton [12][13][14][15][16] resulting from the high oscillator strength [17][18][19] -limiting the application of excitonic devices.Recently, this problem has been addressed by creating inter-layer exciton [20][21][22][23][24] to suppress the fast radiative decay, and exciton transport over several micrometer in the plane of the layered material has been demonstrated [4]. An external gate control has also been achieved by modulating the binding energy of the neutral exciton [4,5].In this regard, the charged exciton or trion (X − ) is promising since its intensity can be readily controlled electrically by modulating the doping density using a gate voltage. In addition, the trion, while being optically initiated, can be electrically detected in a spatially nonlocal manner through measuring a charge current [25]. The relatively longe...

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The role of collective motion in the ultrafast charge transfer in van der Waals heterostructures

Cited by 125 publications

References 48 publications

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

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

Emergent Pseudocapacitance of 2D Nanomaterials

Gate-tunable trion switch for excitonic device applications

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