Atomically resolved two-dimensional amorphous nuclei formed during MoS2 chemical vapor deposition

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Source: Science Magazine

Original: https://www.science.org/doi/abs/10.1126/science.adz8243?af=R...

Published: 2026-02-05T07:00:12Z

Scientists have observed atomically resolved two-dimensional amorphous cores of MoS₂ formed during chemical vapor deposition.[1] They used thin amorphous films of MoS₂ deposited on free-standing graphene membranes as substrates for high-resolution STEM microscopy.[1] During STEM imaging, the electron beam induces crystallization and restructuring of amorphous MoS₂ into crystalline domains, mimicking synthesis conditions at elevated temperature.[1] They directly captured the nucleation, growth, crystallization and restructuring processes in the evolution of MoS₂ films in situ at the atomic level.[1] For thin amorphous MoS₂ films, in-plane crystallization occurs towards layered nc-MoS₂ with layers parallel to the substrate.[1] Thicker amorphous MoS₂ films evolve into a two-segment nc-MoS₂ morphology with an in-plane MoS₂ interface.[1] They observed homonuclear stacking next to 2H stacking, indicating crystallization towards the equilibrium 2H type.[1] This atomically resolved approach visualizes the basic processes of growth and restructuring of 2D materials.[1]