Growth, stabilization and conversion of semi-metallic and semiconducting phases of MoTe2 monolayer by molecular-beam epitaxy

Abstract

Monolayer (ML) transition-metal dichalcogenides exist in different phases, such as the hexagonal (2H) and distorted octahedral or monoclinic (1T') phases. The different structures show vastly different properties. For example, the 2H MoTe2 ML is a direct-gap semiconductor while 1T' MoTe2 is a semi-metal. It has been suggested that the formation energies between 2H and 1T' MoTe2 differ very little, so there is a high chance to tune the structures of MoTe2 and thereby to bring in new applications such as phase-change electronics. In this work, we report growth of both 2H and 1T' MoTe2 ML by molecular-beam epitaxy (MBE). We demonstrate the tunability of the structural domains in epitaxial MoTe2 by changing the growth conditions of MBE and by annealing. We present experimental and theoretical evidences showing the important role of Te surface adsorption in promoting and stabilizing the otherwise metastable 1T'-MoTe2 during MBE.

arXiv comment24 pages, 9 figures

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Cited by in corpus (8)

• Observation of topological states residing at step edges of WTe2
• Observation of Topologically Protected States at Crystalline Phase Boundaries in Single-layer WSe2
• MBE growth of 2H-MoTe2 and 1T'-MoTe2 on 3D substrates
• Metastable polymorphic phases in monolayer TaTe2
• Correlating the Electronic Structures of Metallic/Semiconductor MoTe2 Interface to its Atomic Structures
• Electronic structure of molecular beam epitaxy grown 1T${}^{\prime }$-MoTe${}_2$ film and strain effect
• Discovery of smectic charge and pair-density-wave orders in topological monolayer 1T${}^{\prime }$-MoTe${}_2$
• Controlled chemical vapor deposition for synthesis of emerging Mo(W)Te2 systems