LUMINESCENT TRANSITIONS ASSOCIATED WITH DIVALENT COPPER IMPURITIES AND GREEN EMISSION FROM SEMICONDUCTING ZINC OXIDE

Luminescent transitions at divalent copper impurities in ZnO give rise to a close-spaced, no-phonon doublet at 2.8590 eV, as well as a broad multiphonon side band. The transition is found to be an optical charge transfer between a highly shielded localized level of the copper impurity and a level which is strongly perturbed by the valence-band states of the crystal. The analysis provides information about the role of deep acceptor states in electronic processes in covalent solids. © 1969 The American Physical Society.