Epitaxial Growth of Hexagonal Boron Nitride and the Ultraviolet Luminescence Properties

Abstract

Hexagonal BN (h-BN) is graphite-like sp2-bonded crystal phase, which is the most stable among crystalline BN phases, and has a potential for optical device applications in the deep ultraviolet spectral region. Crystalline phase of BN film grown on a foreign substrate is turbostratic BN (t-BN) or mixed phase with t-BN, h-BN and cubic BN due to the large lattice mismatch and its various crystalline BN phases. Therefore, control of the crystalline phase in the BN film is challenging for single-phase BN growth. Here, we demonstrate that single-phase h-BN epitaxial films can be grown on nearly lattice-matched substrates by optimizing growth conditions during metalorganic vapor phase epitaxy and molecular beam epitaxy (MBE). We also investigate the ultraviolet luminescence properties of near band-gap emission in the h-BN epitaxial films grown by MBE.