Ni Foam Assisted Synthesis of High Quality Hexagonal Boron Nitride with Large Domain Size and Controllable Thickness

TL;DR

This paper presents a novel Ni foam-assisted method for scalable, high-quality hexagonal boron nitride synthesis with large domains and controllable thickness, advancing applications in electronic devices.

Contribution

Introduces a new Ni foam-assisted technique enabling the growth of highly-crystalline, large-domain h-BN with controllable layer number and alignment, surpassing previous methods.

Findings

High-crystalline h-BN domains up to hundreds of microns

Surface mediated self-limiting growth of monolayer h-BN

Bilayer h-BN synthesis via remote catalysis breaking the self-limiting effect

Abstract

The scalable synthesis of two-dimensional (2D) hexagonal boron nitride (h-BN) is of great interest for its numerous applications in novel electronic devices. Highly-crystalline h-BN films, with single-crystal sizes up to hundreds of microns, are demonstrated via a novel Ni foam assisted technique reported here for the first time. The nucleation density of h-BN domains can be significantly reduced due to the high boron solubility, as well as the large specific surface area of the Ni foam. The crystalline structure of the h-BN domains is found to be well aligned with, and therefore strongly dependent upon, the underlying Pt lattice orientation. Growth-time dependent experiments confirm the presence of a surface mediated self-limiting growth mechanism for monolayer h-BN on the Pt substrate. However, utilizing remote catalysis from the Ni foam, bilayer h-BN films can be synthesized breaking the self-limiting effect. This work provides further understanding of the mechanisms involved in the growth of h-BN and proposes a facile synthesis technique that may be applied to further applications in which control over the crystal alignment, and the numbers of layers is crucial.