Boron nitride nanosheet
Owing to their hexagonal atomic structure, small lattice mismatch with graphene (~2%), and high uniformity they are used as substrates for graphene-based devices.
These 2D structures can stack on top of each other and are held by Van der Waals forces to form few-layer boron nitride nanosheets.
[5][6] Chemical vapor deposition is the most common method to produce BN nanosheets because it is a well-established and highly controllable process that yields high-quality material over areas exceeding 10 cm2.
[5][6][7] Mechanical cleaving methods of boron nitride use shear forces to break the weak van der Waals interactions between the BN layers.
[5][6] BN nanosheets can be synthesized by the unzipping boron nitride nanotubes via potassium intercalation or etching by plasma or an inert gas.
[5] Many solvents suitable for BN exfoliation are rather toxic and expensive, but they can be replaced by water and isopropyl alcohol without significantly sacrificing the yield.
The thermal conductivity of atomically thin boron nitride is one of the highest among semiconductors and electrical insulators; it increases with reduced thickness due to less intra-layer coupling.
The synergic effect of the atomic thickness, high flexibility, stronger surface adsorption capability, electrical insulation, impermeability, high thermal and chemical stability of BN nanosheets can increase the Raman sensitivity by up to two orders, and in the meantime attain long-term stability and extraordinary reusability not achievable by other materials.
Atomically thin hexagonal boron nitride is an excellent dielectric substrate for graphene, molybdenum disulphide (MoS2), and many other 2D material-based electronic and photonic devices.
Cai et al. conducted systematic experimental and theoretical studies of the intrinsic Raman spectrum of atomically thin boron nitride.
[4][6] Owing to their hexagonal atomic structure, small lattice mismatch with graphene (~2%), and high uniformity, BN nanosheets are used as substrates for graphene-based devices.
