A Mossbauer study of a two-electron acceptor impurity of zinc in silicon

Mossbauer emission spectroscopy of the Ga-67(Zn-67) isotope was used to show that the two-electron acceptor impurity of Zn is present in silicon only in the form of neutral (Zn-0) or doubly ionized (Zn2-) centers, depending on the Fermi-level position. Broadening of the spectra corresponding to the above centers indicates that the local symmetry of these centers is not cubic. The absence of the line corresponding to the singly ionized state (Zn2-) of zinc in the Mossbauer spectra of partially compensated samples is regarded as evidence that the correlation energy is negative. (C) 2000 MAIK "Nauka/Interperiodica".