Growth of High Quality 2D Hexagonal Boron Nitride on a Liquid Metal Catalyst

Published : 1 January 2023

Two-dimensional (2D) materials are crystals of one or a few atoms in thickness with high stability and physical properties governed by extreme quantum confinement. Due to its unique crystal structure, graphene exhibits a plethora of unconventional electronic phenomena. Hexagonal boron nitride (h-BN) shares the same crystal lattice but has different properties. For example, it is a wide bandgap semiconductor that can serve as a hyperbolic material in the infrared and has defects that allow the design of quantum light sources. In addition, it is the ideal dielectric material to encapsulate fragile 2D materials, thus preserving their properties, allowing the construction of multifunctional artificial materials consisting of 2D material stacks.

However, the elaboration of 2D h-BN with controlled thickness and high structural quality remains a challenge even using the state of the art chemical vapor deposition (CVD) synthesis method. Recently, we have demonstrated that graphene of the highest quality can be grown over large areas using CVD on liquid rather than solid metal catalyst substrate. We have optimized the growth in situ and in real-time by combining four techniques around a dedicated CVD reactor: synchrotron X-ray diffraction and reflectivity, optical microscopy and Raman spectroscopy. We propose here to apply the same approach to the elaboration of h-BN.

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