MODEL FOR THE ACCEPTOR STATE IN II-VI COMPOUNDS

The binding energy and the spatial distribution of an acceptor in an ionic semiconductor are calculated on the Anderson model with three parameters. The result is applied to the case of Li+, Na+, Cu+ and Ag+ in II-VI semiconductors. The parameters are evaluated by the dielectric theory of a chemical bond. It is shown that Li+ in ZnO, CdS, and CdSe forms an acceptor state with a larger amplitude at nearest-neighbor anion sites than at an impurity site; while Cu+ and Ag+ in Zn and Cd compounds have the opposite properties. The Na+ ion forms an acceptor state more localized densely at the impurity site in Zn compounds and vice versa in Cd compounds. © 1979.