Edge-defined film-fed material was investigated by using deep-level transient spectroscopic and surface photo-voltage techniques. An impurity energy level of CrB was found at 0.27eV above the valence band in samples which were contaminated with Cr. The Cr diffusion coefficient in this material was deduced to be equal to 2 x 10-17cm2/s at room temperature on the basis of the association and dissociation of CrB pairs during a 210C dissociation anneal. Most of the deep-level transient spectra could not be analyzed by using conventional methods, due to the appearance of abnormally broad peaks. The spectra of as-grown material were modelled by using a Gaussian distribution of impurity energy states. The simulated peaks agreed well with the experimental data; thus explaining the origin of the deep-level impurities in this material.

S.H.Park, D.K.Schroder: Journal of Applied Physics, 1995, 78[2], 801-10