Dongguk University and other Korean researchers have made wafer scale hexagonal boron nitride films with a nearly perfect single-crystalline structure. The film self-assembles on top of liquid gold.
Hexagonal boron nitride (hBN) is also called white graphite. They can be single atom thick crystalline films. They have an insulating effect that has found uses in various types of scientific research.
It can be a protective layer against metal oxidation (rust) and as a gas-diffusion barrier for water vapor transmission.
Layers of graphene can be created on top of the Hexagonal boron nitride.
Although wafer-scale polycrystalline films of insulating hexagonal boron nitride (hBN) can be grown, the grain boundaries can cause both scattering or pinning of charge carriers in adjacent conducting layers that impair device performance. Lee et al. grew wafer-scale single-crystal films of hBN by feeding the precursors into molten gold films on tungsten substrates. The low solubility of boron and nitrogen in gold caused micrometer-scale grains of hBN to form that coalesced into single crystals. These films in turn supported the growth of epitaxial wafer-scale films of graphene and tungsten disulfide.