Electron redistribution and energy transfer in graphene/MoS2 heterostructure

Lin, Weiyi; Zhuang, Pingping; Chou, Harry; Gu, Yanqing; Roberts, Richard H.; Li, Wei; Banerjee, Sanjay K.; Cai, Weiwei; Akinwande, Deji

doi:10.1063/1.5088512

Cited by 16 publications

(18 citation statements)

References 29 publications

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“…The ET nature of the process established here suggests that the photogating effects [14,26] and associated photodetection capabilities demonstrated in TMD-Gr-based optoelectronic devices [25,29] result from an additional conversion mechanism into a much slower, less efficient, net CT.…”

Section: Discussionmentioning

confidence: 76%

“…Such photogating processes [14,[26][27][28] are strongly environment-dependent and relatively slow, involving CT to Gr and subsequent back-transfer to the TMD monolayer on timescales ranging from ns to seconds [29]. Alternatively, in vertically-biased Gr/few-layer TMD/Gr junctions, exciton dissociation in the TMD and carrier drift towards the Gr electrodes lead to considerably faster (sub-nanosecond) photocurrent generation.…”

Section: Introductionmentioning

confidence: 99%

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Picosecond energy transfer in a transition metal dichalcogenide-graphene heterostructure revealed by transient Raman spectroscopy

Ferrante,

Di Battista,

López

et al. 2021

Preprint

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Intense light-matter interactions and unique structural and electrical properties make Van der Waals heterostructures composed by Graphene (Gr) and monolayer transition metal dichalcogenides (TMD) promising building blocks for tunnelling transistors, flexible electronics, as well as optoelectronic devices, including photodetectors, photovoltaics and QLEDs, bright and narrowline emitters using minimal amounts of active absorber material. The performance of such devices is critically ruled by interlayer interactions which are still poorly understood in many respects.Specifically, two classes of coupling mechanisms have been proposed: charge transfer (CT) and energy transfer (ET), but their relative efficiency and the underlying physics is an open question.Here, building on a time resolved Raman scattering experiment, we determine the electronic temperature profile of Gr in response to TMD photo-excitation, tracking the picosecond dynamics of the G and 2D bands. Compelling evidence for a dominant role ET process accomplished within a characteristic time of ∼ 3 ps is provided. Our results suggest the existence of an intermediate process between the observed picosecond ET and the generation of a net charge underlying the slower electric signals detected in optoelectronic applications.

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Section: Discussionmentioning

confidence: 76%

Section: Introductionmentioning

confidence: 99%

Picosecond energy transfer in a transition metal dichalcogenide-graphene heterostructure revealed by transient Raman spectroscopy

Ferrante,

Di Battista,

López

et al. 2021

Preprint

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“…This photodoping leads to a stationary Fermi level shift in graphene and complementary fingerprints of charge transfer in the TMD monolayer [17,29]. The Fermi level of graphene ultimately saturates as the photon flux increases [17,29]. Although such extrinsic effects could be of practical use for photodetection [40,41], they may hamper access to the intrinsic photophysics of the heterostructure.…”

Section: Optical Characterization At Room Temperaturementioning

confidence: 99%

“…For instance, investigations in high vacuum prevents physisorption of water and organic molecules. Besides, it is known that conventional transparent susbtrates such as SiO 2 can host trapped charges and favor photoinduced doping [17,[27][28][29]. A workaround is to use a more inert material such as hexagonal boron nitride (hBN).…”

Section: Introductionmentioning

confidence: 99%

“…Under light illumination above the TMD bandgap, a net photoinduced charge transfer to graphene has been observed on SiO 2supported samples on timescales that are orders of magnitude longer than the TMD excitonic lifetime, hence with no sizeable effect on the PL intensity[17,40,41]. This photodoping leads to a stationary Fermi level shift in graphene and complementary fingerprints of charge transfer in the TMD monolayer[17,29]. The Fermi level of graphene ultimately saturates as the photon flux increases[17,29].…”

mentioning

confidence: 98%

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Single- and narrow-line photoluminescence in a boron nitride-supported MoSe 2 /graphene heterostructure

López¹,

Moczko²,

Wolff³

et al. 2022

Comptes Rendus. Physique

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Heterostructures made from van der Waals (vdW) materials provide a template to investigate a wealth of proximity effects at atomically sharp two-dimensional (2D) heterointerfaces. In particular, nearfield charge and energy transfer in vdW heterostructures made from semiconducting transition metal dichalcogenides (TMD) have recently attracted interest to design model 2D "donor-acceptor" systems and new optoelectronic components. Here, using Raman scattering and photoluminescence spectroscopies, we report a comprehensive characterization of a molybedenum diselenide (MoSe 2 ) monolayer deposited onto hexagonal boron nitride (hBN) and capped by mono-and bilayer graphene. Along with the atomically flat hBN susbstrate, a single graphene epilayer is sufficient to passivate the MoSe 2 layer and provides a homogenous environment without the need for an extra capping layer. As a result, we do not observe photo-induced doping in our heterostructure and the MoSe 2 excitonic linewidth gets as narrow as 1.6 meV, approaching the homogeneous limit. The semi-metallic graphene layer neutralizes the 2D semiconductor and enables picosecond non-radiative energy transfer that quenches radiative recombination from long-lived states. Hence, emission from the neutral band edge exciton largely dominates the photoluminescence spectrum of the MoSe 2 /graphene heterostructure. Since this exciton has a picosecond radiative lifetime at low temperature, comparable with the non-radiative transfer time, its low-temperature photoluminescence is only quenched * Corresponding author.

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Synthesis of Wafer‐Scale Graphene with Chemical Vapor Deposition for Electronic Device Applications

Sun

Pang

Cheng

et al. 2021

Adv Materials Technologies

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The first isolation of graphene opens the avenue for new platforms for physics, electronic engineering, and materials sciences. Among several kinds of synthesis approaches, chemical vapor deposition is most promising for the growth at wafer‐scale, which is compatible with the Si‐based electronic device integration protocols. In this review, the types, properties, and synthesis methods of graphene are first introduced. Many details of wafer‐scale graphene synthesis by chemical vapor deposition strategies are given, including the wafer‐scale single crystal metal and alloy preparation, roll to roll synthesis over Cu, roll to roll electrochemical transfer technique. Besides, the batch‐to‐batch synthesis are highlighted for direct graphene over dielectric substrates such as sapphire and Si/SiO2. The electronic transport and transparent conductance of the wafer‐scale graphene are compared with high‐quality single crystal. The progress and proof‐of‐the‐concept are briefly recalled in graphene‐based electronics such as transistors, sensors, integrated circuits, and spin transport valves. Eventually, the readers are provoked with the current challenges as well as the future opportunities.

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Electron redistribution and energy transfer in graphene/MoS2 heterostructure

Cited by 16 publications

References 29 publications

Picosecond energy transfer in a transition metal dichalcogenide-graphene heterostructure revealed by transient Raman spectroscopy

Picosecond energy transfer in a transition metal dichalcogenide-graphene heterostructure revealed by transient Raman spectroscopy

Single- and narrow-line photoluminescence in a boron nitride-supported MoSe 2 /graphene heterostructure

Synthesis of Wafer‐Scale Graphene with Chemical Vapor Deposition for Electronic Device Applications

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