Single layer h-BN (Boron Nitride) film grown in copper foil.
h-BN is an insulator with a direct band gap of 5.97 eV. Due to its strong covalent sp2 bonds in the plane, the in-plane mechanical strength and thermal conductivity of h-BN has been reported to be close to that of graphene. h-BN has an even higher chemical stability than graphene; it can be stable in air up to 1000 °C (in contrast, for graphene the corresponding temperature is 600 °C).
During Chemical Vapor Deposition, BN is grown on both sides of the copper foil
Close to complete coverage (90-95%), with some minor holes
Thickness of the copper foil is 20 microns
High crystalline quality, see SAD (Selected area [electron] diffraction) data
Quality is confirmed by TEM. TEM shows perfect hexagonal structure.