Ultrafast charge transfer in atomically thin MoS2/WS2 heterostructures

Xiaoping Hong, Jonghwan Kim, Su Fei Shi, Yu Zhang, Chenhao Jin, Yinghui Sun, Sefaattin Tongay, Junqiao Wu, Yanfeng Zhang, Feng Wang

    Research output: Contribution to journalArticlepeer-review

    1152 Scopus citations

    Abstract

    Van der Waals heterostructures have recently emerged as a new class of materials, where quantum coupling between stacked atomically thin two-dimensional layers, including graphene, hexagonal-boron nitride and transition-metal dichalcogenides (MX2), give rise to fascinating new phenomena. MX2 heterostructures are particularly exciting for novel optoelectronic and photovoltaic applications, because two-dimensional MX 2 monolayers can have an optical bandgap in the near-infrared to visible spectral range and exhibit extremely strong light-matter interactions. Theory predicts that many stacked MX2 heterostructures form type II semiconductor heterojunctions that facilitate efficient electron-hole separation for light detection and harvesting. Here, we report the first experimental observation of ultrafast charge transfer in photoexcited MoS2/WS 2 heterostructures using both photoluminescence mapping and femtosecond pump-probe spectroscopy. We show that hole transfer from the MoS2 layer to the WS2 layer takes place within 50 fs after optical excitation, a remarkable rate for van der Waals coupled two-dimensional layers. Such ultrafast charge transfer in van der Waals heterostructures can enable novel two-dimensional devices for optoelectronics and light harvesting.

    Original languageEnglish (US)
    Pages (from-to)682-686
    Number of pages5
    JournalNature nanotechnology
    Volume9
    Issue number9
    DOIs
    StatePublished - Sep 2014

    ASJC Scopus subject areas

    • Bioengineering
    • Atomic and Molecular Physics, and Optics
    • Biomedical Engineering
    • Materials Science(all)
    • Condensed Matter Physics
    • Electrical and Electronic Engineering

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