Growth and characterization of high-quality h-BN single-layer films on Si-incorporated Ni (111) via molecular beam epitaxy

Reliable synthesis of high-quality two-dimensional (2D) hexagonal boron nitride (h-BN) is essential for its implementation as a dielectric in next-generation electronics. In this study, we demonstrate that controlled silicon (Si) incorporation into nickel (Ni) substrates significantly enhances their catalytic activity, enabling the growth of uniform monolayer h-BN films. Introducing a small amount of Si up to ∼4.5 at. % effectively tunes the catalytic strength of Ni substrate to promote the growth of continuous h-BN films while suppressing 3D adlayer formation. As-grown films were systematically characterized to evaluate their structural, optical, and electrical properties. Electrical characterization of metal–insulator–metal devices fabricated on the films reveals a maximum breakdown field of ∼11 MV/cm. This work highlights substrate engineering via elemental incorporation as an effective strategy for tailoring catalytic behavior of transition metal substrates and achieving scalable synthesis of 2D h-BN for electronic applications.