The effect of transition metal impurities, such as Cu, Ni and Fe, upon the D-band photoluminescence of deformed crystals was investigated. In the case of Cu, the intensity of the D-band photoluminescence went through a maximum with respect to the Cu concentration. This was consistent with a similar behavior which had been observed in the case of extrinsic stacking faults. The use of electron spin resonance methods showed that the intensity of electron spin resonance absorption, due to Si-K1 centers, exhibited the opposite behavior to that of the photoluminescence, with respect to the Cu concentration. It was concluded that this strongly suggested that Cu, in intermediate concentrations, passivated non-radiative recombination centers. The intensity of the D-band photoluminescence did not depend upon the concentrations of Fe and Ni; contrary to previous results.

T.Okuyama, M.Suezawa, I.Yonenaga, K.Sumino: Materials Science Forum, 1995, 196-201, 1213-8