Improved visibility of boron nitride on oxidized silicon substrates at pseudo-Brewster incidence
In the previous works, the visibility of BN is improved by carefully selecting the thickness of the oxide layer and choosing the appropriate incident wavelength. In our study, we show that it can be further improved by adjusting the incident angle at the pseudo-Brewster configuration. We analyze the visibility of BN monolayers using two common models for flat 2D materials: the thin film and the perfect sheet models. We show that the visibility magnitude of the BN on SiO2/Si under 594-nm illumination at pseudo-Brewster incidence is better than the the equivalent visibility magnitude taken at normal incidence. The estimated increase factors for the magnitude of the BN visibility are –11.6 when the thin film model is used, and +4.6 for the perfect sheet model. This implies that the two models cannot be used as an alternative for each other when calculating for visibility at non-zero incident angle. This results can be used as a standpoint for experimental confirmation.