Deep impurity centers in single crystals were studied by using deep-level transient spectroscopic analysis to obtain the emission rate spectrum. One deep level was found below the conduction band, and the activation energy and the capture cross-section were distributed around central values of 0.31eV and 4.0 x 10-16cm2; with widths of 0.013eV and 9.3 x 10-17cm2, respectively.

J.Yoshino, K.Tanaka, Y.Okamoto, J.Morimoto, T.Miyakawa: Japanese Journal of Applied Physics, 1994, 33[I-6A], 3480-1