Visualizing Van der Waals Epitaxial Growth of 2D Heterostructures.

Zhang, Kenan; Ding, Changchun; Pan, Baojun; Wu, Zhen; Marga, Austin; Zhang, Lijie; Zeng, Hao; Huang, Shaoming · Adv Mater · 2021

basic_science · Level V

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Abstract

Understanding the growth mechanisms of 2D van der Waals (vdW) heterostructures is of great importance in exploring their functionalities and device applications. A custom-built system integrating physical vapor deposition and optical microscopy/Raman spectroscopy is employed to study the dynamic growth processes of 2D vdW heterostructures in situ. This allows the identification of a new growth mode with a distinctly different growth rate and morphology from those of the conventional linear growth mode. A model that explains the difference in morphologies and quantifies the growth rates of the two modes by taking the role of surface diffusion into account is proposed. A range of material combinations including CdI<sub>2</sub> /WS<sub>2</sub> , CdI<sub>2</sub> /MoS<sub>2</sub> , CdI<sub>2</sub> /WSe<sub>2</sub> , PbI<sub>2</sub> /WS<sub>2</sub> , PbI<sub>2</sub> /MoS<sub>2</sub> , PbI<sub>2</sub> /WSe<sub>2</sub> , and Bi<sub>2</sub> Se<sub>3</sub> /WS<sub>2</sub> is systematically investigated. These findings may be generalized to the synthesis of many other 2D heterostructures with controlled morphologies and physical properties, benefiting future device applications.