UNIFIED DESCRIPTION OF CU-RELATED LUMINESCENCE PROCESSES IN II-VI SEMICONDUCTORS

An empirical model of t(2)- and e-type one-electron levels is constructed. compatible with the energy-band scheme of the host material. A great variety of optical processes involving the charge states A(0)(Cu2+) and A(-)(Cu+) of the copper acceptor can thus be described, including several previously unrelated effects. Bound-exciton formation and annihilation are demonstrated to play an important role in various absorption and emission transitions. Alignment of the t(2) Cu level for ZnS and CdS leads to an evaluation of band discontinuities For these semiconductors.