1. J. I. Pankove,Optical Processes in Semiconductors (Prentice-Hall, Englewood Cliffs, 1971) pp. 160–169.
2. A. G. Milnes,Deep Impurities in Semiconductors (Wiley-Interscience, New York, 1973) especially pp. 287–297.
3. R. N. Bhargava, Philips Tech. Rev.32, 261 (1971); A. A. Bergh and P. J. Dean, Proc. IEEE60, 156 (1972); O. G. Lorimor, P. D. Dapkus, and W. H. Hackett, J. Electrochem. Soc.122, 407 (1975).
4. E. Pinkas, B. I. Miller, I. Hayashi and P. W. Foy, J. Appl. Phys.43, 827 (1972).
5. D. V. Lang and R. A. Logan, this conference; C. H. Henry, this conference.