Centimeter-Sized Single-Orientation Monolayer h-BN with or without Nanovoids.

Large-area hexagonal boron nitride (h-BN) promises many new applications of two-dimensional materials, such as the protective packing, of reactive surfaces or as membranes in liquids. However, scalable production beyond exfoliation from bulk single Crystals remained a major challenge. Single-orientation monolayer h-BN nanomesh is :grown, on 4 in. wafer single crystalline rhodium films and transferred on arbitrary substrates such as SiO2, germanium, or transmission electron microscopy grids. The transfer process involves application of tetraoctylammonium bromide before electrochemical hydrogen delamination. The material performance is demonstrated with two applications. First, protective sealing of h-BN is shown by preserving germanium from Oxidation in air at high temperatures. Second, the membrane functionality,of the single h-BN layer is demonstrated in aqueous solutions. Here, we employ a growth substrate intrinsic preparation scheme to create regular 2 nm holes that serve as ion channels in liquids.