An approach to grow 2D materials heterostructures directly based on pulsed laser deposition of solid oxide precursors

    Activity: Talks and presentations › Conference presentations

    Description

    Background: 2D layers of MoS2, WS2, MoSe2, and WSe2 are promising candidates for various optoelectronics, which have attracted increased scientific attention due to their wide range of unique physical properties, and a direct bandgap of 1-2 eV. Additionally, 2D crystals can be vertically stacked to construct van der Waals heterostructures (vdWHs) with an arbitrary bandgap order. However, before any far-reaching applications can be targeted, a method for the large-scale synthesis of vdWHs is needed.
    Objective: To investigate the application of PLD and solid oxide precursors’ influence for direct growth of 2D materials vdWHs
    Methods: We employed PLD-CVD two-step synthesis method to grow MoS2/WS2 heterostructure. The method consists of: 1) oxide films deposition by PLD; 2) sulfurization in a sulfur-rich environment at high temperature. A key advantage of this method is a high precursor composition tunability. Raman and Photoluminescence spectroscopies, Raman mapping, XPS, AFM, SEM, optical microscopy, and STEM were used for MoS2/WS2 vdWHs characterization
    Results: PLD-deposited oxide films exhibit high oxygen vacancy concentration in both MoOx and WOx. The oxygen vacancies play an important role in the sulfurization process by serving as niches for sulfur atoms, and facilitating MoS2 and WS2 lateral crystal growth upon sulfurization. Also, we studied bilayer MoOx/WOx film sulfurization as an alternative path to achieve MoS2/WS2 heterostructure.
    Conclusion: We demonstrate a possibility to synthesize MoS2/WS2 heterostructure directly using PLD-based two-step process of epitaxial oxides sulfurization. These results may serve as a potential step towards dissimilar 2D TMDs heterolayers integration.
    Period7 Nov 2022 → 8 Nov 2022
    Event title4th European Congress on Graphene & 2D Materials: Rising era of Graphene-beyond 2D Materials
    Event typeConference
    Conference number4
    LocationParis, FranceShow on map
    Degree of RecognitionInternational

    Keywords

    • 2D materials
    • Graphene
    • Heterostructures
    • TMD
    • Thin films
    • oxides
    • deposition
    • DFT
    • Synthesis

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