INVERSION OF THE ELECTRICAL AND OPTICAL PROPERTIES OF PARTIALLY OXIDIZED HEXAGONAL BORON NITRIDE

Abstract

By acoustically irradiating pristine, white, electrically insulating h- BN in aqueous environment we were able to invert its material properties. The resulting dark, electrically conductive h- BN (referred to as partially oxidized h- BN or PO- hBN ) shows a significant decrease in optical transmission (>60%) and bandgap (from 5.46 eV to 3.97 eV). Besides employing a wide variety of analytical techniques (optical and electrical measurements, Raman spectroscopy, SEM imaging, EDS, X-Ray diffraction, XPS and TOF-SIMS) to study the material properties of pristine and irradiated h- BN , our investigation suggests the basic mechanism leading to the dramatic changes following the acoustic treatment. We find that the degree of inversion arises from the degree of h- BN surface or edge oxidation which heavily depends on the acoustic energy density provided to the pristine h- BN platelets during the solution-based process. This provides a facile avenue for the realization of materials with tuned physical and chemical properties that depart from the intrinsic behavior of pristine h- BN .