Deep levels of nitrogen vacancy complexes in graphite-like boron nitride

This paper presents the results of a theoretical study of deep nitrogen vacancy levels and of small clusters of nitrogen di- and trivacancies, including the nearest neighbor defects in one layer of graphite-like boron nitride, made using the model-pseudopotential and supercell methods. The calculated spectra and oscillator strengths were used to interpret the local bands of optical absorption, luminescence, and photoconductivity in pyrolytic boron nitride before and after irradiation by fast neutrons, protons, and carbon ions (50-150 keV). The shallow activation levels of thermally stimulated luminescence and conductivity existing before and arising after irradiation were identified.