Preparation of single phase 2H-MoTe2 films by molecular beam epitaxy

• Published in: Applied surface science Vol. 523; p. 146428
• Main Authors: Pham, Trung T., Castelino, Roshan, Felten, Alexandre, Sporken, Robert
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-09-2020
• Subjects: Graphene; Molecular beam epitaxy; MoTe2; Reflection high energy electron diffraction; Transition metal dichalcogenides (TMDs); Twin boundary; Molecular beam epitaxy; Transition metal dichalcogenides (TMDs); Twin boundary; Reflection high energy electron diffraction; Graphene; MoTe2
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2020.146428

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•Develop two distinct processes which achieve better layer-by-layer controllability of stoichiometric MoTe2 films.•Flat, high crystalline quality and large area of mono-layer/double-layer MoTe2 on graphene.•A coherent explanation for the Moiré patterns of both monolayer and twisted bi-layers of 2H-MoTe2 on graphene which provides insight into the atomic structure 2H-MoTe2 films together with the formation of semi-coherent twin boundaries (TBs) in the films.•Electronic structure of the 2H-MoTe2 films.
The controlled growth of mono-/double-layer 2H-MoTe2 fully covering the substrate is highly desirable for the future of device fabrication but still remains a challenge. In this study, we present growth of mono-/double-layer 2H-MoTe2 films on graphene terminated 6H-SiC(0 0 0 1) substrates by molecular beam epitaxy (MBE). We develop two distinct processes which achieve better layer-by-layer controllability of stoichiometric films. We further provide a coherent explanation for the Moiré patterns together with the formation of semi-coherent twin boundaries (TBs) in the films and the electronic structure of the films. Our materials are analyzed in detail by reflection high energy electron diffraction (RHEED), X-ray photoemission spectroscopy (XPS), and scanning tunneling microscopy/spectroscopy (STM/STS).