Phonon spectroscopy was used to analyze low-lying photon scattering states from defects that were introduced by the diffusion of Zn into thick Si wafers. It was concluded that Zn was an effective recombination center. Thus, illumination of the samples, although it produced changes in the depth of various absorption lines, did not lead to appreciable changes in the resistivity; as compared with the analogous situation for single acceptors in Si.

J.Staiger, P.Gross, K.Lassmann, H.Bracht, N.A.Stolwijk: Materials Science Forum, 1994, 143-147, 675-80