Controllable Growth and Electronic Structures of 2D Transition Metal Dichalcogenides Thin Films

The 2D transition metal dichalcogenides (TMDCs) have attracted extensive interest due to their remarkable properties. Using molecular beam epitaxial (MBE) method, we achieved the controllable growth of atomically thin TMDCs MoSe₂ and WSe₂ films. Combining with the in-situ angle-resolved photoemission spectroscopic (ARPES) measurements, we directly characterized the electronic structures of them and studied the evolution of their electronic structures in 2D limit [1-2]. Moreover, we achieved band structuring engineering in epitaxial TMDCs Mo_xW_1-xSe₂ alloy monolayers with controllable stoichiometric ratio x. We also realized the growth of meta-stable 1T'-WSe₂ monolayer, and studied its thermo-driven structure phase transition to stable 2H-WSe₂ [3]. Our findings not only help understanding of TMDC materials but also enrich the family of epitaxial 2D materials toward a fully MBE grown epitaxial heterostructures for light emission and photon-voltage devices.
References
[1] Yi Zhang et al., Nature Nanotechnology. 9, 111 (2014).
[2] Yi Zhang et al., Nano Letters 16, 2485 (2016).
[3] W. Chen et al., Scientific Reports, 9, 2685 (2019)