Shallow donor muonium states in II-VI semiconductor compounds - art. no. 075205

Experimental data on shallow donor muonium states in the II-VI semiconducto r compounds CdS, CdSe, CdTe, and ZnO are presented. These are characterized by very weak hyperfine interactions amounting to approximately 10(-4) of t he free-atom value, and by donor levels with binding energies comparable to those calculated on the hydrogenic model of the shallow centers. The data are discussed in terms of a model generalizing the knowledge of muonium and hydrogen states in tetrahedrally bonded semiconductors. Within this model the shallow muonium state is attributed to muonium bound to the anion of th e II-VI compound and located at the antibonding site or close to it in the bond direction.