Optical Properties of Hexagonal Boron Nitride

Abstract

For several decades, hexagonal boron nitride (hBN) has been used as a refractory material such as a lubricant and a high-temperature material due to its promising properties and advantages. hBN was recently reset and considered a semiconductor with a wide indirect bandgap. In this study, we used UV-vis spectrophotometry to analyse the absorbance spectrum of a 100nm-thick hBN sample that was grown on a sapphire substrate and produced with metal-organic chemical vapour deposition (MOCVD) to find the indirect bandgap verified by Cassabois et al. [2] as equal to 5.729±0.004 eV at room temperature. The Urbach's energy for the hBN sample was 176 meV, which was higher than the values reported in literature. The last result we analysed was the shoulder value, which was about 5.1 eV.