Cathodoluminescence of cubic boron nitride films deposited by chemical vapor deposition

Cathodoluminescence (CL) characteristics of cubic boron nitride (cBN) films deposited by chemical vapor deposition were investigated. Combined with the results from Fourier-transformed infrared spectroscopy and Raman spectroscopy, the dependence of the emission energy and intensity on the phase composition and crystallinity of the films was revealed. A broad emission band centered at about 3.12 eV for UCL (or US-1) as observed previously in undoped cBN single crystals synthesized by high-temperature, high-pressure method, and an emission band at about 2.48 eV for the A and B bands, due to multivacancy complexes of boron and nitrogen vacancies, were observed in the cBN films with high phase purity and high crystallinity. For the hexagonal boron nitride (hBN) phase, the main emission band up-shifted to high energy of 3.48-3.68 eV. A peak centered at 5.28 eV was observed in the spectra, which is believed the near-band-gap UV emission of hBN. (C) 2002 American Institute of Physics.