Growth of suspended hexagonal boron nitride on GaN substrate by MOCVD (Conference Presentation)

Hexagonal boron nitride (h-BN), an insulating two-dimensional layered material, has recently attracted a great attention due to its fascinating optical, electrical, and thermal properties, and promising applications across the fields of photonics, quantum optics, and electronics. Here, we exploit the scalable approach to grow h-BN on epitaxial gallium nitride (GaN) substrate by using metal-organic chemical vapor deposition (MOCVD). It was found that at a specific MOCVD growth condition, a very unique h-BN film can be grown on GaN substrates, in which few-layer h-BN film is suspended on GaN nanoneedles. The combination of state-of-the-art microscopic and spectroscopic analyses revealed that the suspended h-BN films exhibit unprecedented DUV photoluminescence spectra. In addition, the h-BN films show unprecedented atomic stacking configuration, the mechanism of which will be discussed with optical and structural characterizations and theoretical calculations.