Microscopic models for Cu, Ag and Au cationic substitutional impurities and the metal vacancy in ZnSe

Abstract

Rigorous self-consistent field electronic structure calculations have been carried out for the substitutional Cu, Ag, Au and for the metal vacancy in cubic ZnSe. The multiple-scattering X α molecular cluster model utilized in the calculations reproduces the main features of the band structure of the perfect crystal. According to our ca 1 culations Cu Zn introduces e (d) and T 2 (d) resonant atomic-like levels close to the bottom of the uppermost valence band. Ag Zn and Au Zn introduce similar e (d) and t 2 (d) hyppe r deep levels. Dangling-bond-like t 2 acceptor states are introduced in the band gap by the IB group impurities as well as by the metal vacancy (single acceptors in the former case and a double acceptor in the later case).