Thank you for visiting nature. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser or turn off compatibility mode in Internet Explorer. In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. Ultraflat metal foils are essential for semiconductor nanoelectronics applications and nanomaterial epitaxial growth.
Numerous efforts have been devoted to metal surface engineering studies in the past decades. However, various challenges persist, including size limitations, polishing non-uniformities, and undesired contaminants. Thus, further exploration of advanced metal surface treatment techniques is essential. Here, we report a physical strategy that utilizes surface acoustic wave assisted annealing to flatten metal foils by eliminating the surface steps, eventually transforming commercial rough metal foils into ultraflat substrates.
Large-area, high-quality, smooth 2D materials, including graphene and hexagonal boron nitride hBN , were successfully grown on the resulting flat metal substrates.
Further investigation into the oxidation of 2D-material-coated metal foils, both rough and flat, revealed that the hBN-coated flat metal foil exhibits enhanced anti-corrosion properties. Molecular dynamics simulations and density functional theory validate our experimental observations. Metal foils with single crystallinity and ultraflat surface are considered ideal substrates for epitaxial growth of high-quality two-dimensional 2D materials owing to their exceptional catalytic effects, lattice matching, and affordability 1 , 2.
(mh=qpmn0diSioDjiTPb)0.jpg "Escort girls in Jena")
In recent years, numerous studies in substrate engineering have been reported to enhance the quality of metal foils 3 , 4 , 5. Previous work has achieved the single-crystallization of metal substrates through various methods, such as contact-free annealing 6 , seeded growth of high-index-facet metals 7 , and single-crystal sapphire epitaxy growth 8. Using these single-crystal foils, large-area single-crystal hexagonal boron nitride hBN , graphene, and 2D van der Waals heterostructures have been synthesized on Cu , Cu , Ni , and CuNi 9 , 10 , 11 , 12 , 13 , highlighting the substantial importance of metal substrate properties in producing high-quality nanomaterials.
