Effects of the Core Hole Potential on the B 1s Emission in Hexagonal BN

Abstract

We have investigated the anisotropy of the spectra and the polarization degree of the B 1s emission in hexagonal boron nitride using synchrotron radiation as a light source. Spectator emission appears when the B 1s hole is radiatively filled with the valence electron while the core exciton state being occupied. It has been found that π emission is absent or very weak in the spectator emission, while both π and σ components are present in the normal emission. This result has been explained in terms of the Coulombic effect of the core hole on the localized B 2p_z valence orbital.