Two dimensional hexagonal boron nitride (2D h-BN) is a material of comparable structure to graphene with potential applications in e.g.
[3] On the other hand, the number of defects on the produced nanosheets has been found to be smaller compared to chemical methods.
[9] Sonication is used to break Van der Waals forces in h-BN crystals which allows the solvent molecules to expand the atomic layers.
[7] These methods are quite simple and can also provide a higher yield compared to mechanical exfoliation, although the samples are easily contaminated.
Historically, ultra-high vacuum CVD (UHVCVD) has been used for thin h-BN deposition on transition metals.
[12] Liquid precursors, such as borazine, have equal amounts of boron and nitrogen, and do not produce highly toxic side products.
In h-BN, as in graphene, transition metals such as Cu or Ni are popular choices for CVD substrate materials.
[17] The drawback with catalytic transition metal wafer materials is the need to transfer the result to a target substrate, such as silicon.
[25] Molten boron oxide reacts with gaseous ammonia to form an ultrathin h-BN film at the reaction interface.
[26] The film grows to 20-30 nm in thickness, after which the process self-terminates, the setup is cooled down, and the boron oxide can be dissolved in water.