Abstract
Recently several experimental transmission electron microscopy (TEM) studies have reported the observation of nanoscale triangular defects in mono- and multilayer hexagonal boron nitride (-BN). First-principles calculations are employed to study the thermodynamical stability and spectroscopic properties of these triangular defects and the chemical nature of their edge termination. Oxygen-terminated defects are found to be significantly more stable than defects with nitrogen-terminated edges. Simulated x-ray absorption spectra of the boron edge for oxygen-terminated defects show excellent agreement with experimental x-ray absorption near-edge spectroscopy (XANES) measurements on defective -BN films with oxygen impurities. Finally, we show that the structural model for oxygen defects in -BN as deduced from the simulated core-level spectroscopy is intrinsically linked to the equilateral triangle shape of defects as observed in many recent electron microscopy measurements.
- Received 27 August 2015
- Revised 10 December 2015
DOI:https://doi.org/10.1103/PhysRevB.92.245310
©2015 American Physical Society