Theoretical Investigation on the Luminescence Transition Probabilities in the Phosphor ZnO:Cu

Abstract

Optical properties of ZnO:Cu have been studied using the ASW (augmented spherical wave) band structure method and a supercell approximation to simulate copper impurities. The imaginary part of the dielectric function ϵ2(ω) is calculated in two different ways. In the first calculation, it is assumed that ϵ2(ω) is proportional to the joint density j(E) whereas in a second calculation the dependence of the dipole transitions on the wave vector is taken into account. The comparison of both calculations gives relative oscillator strengths for the different dipole transitions. Furthermore the influence of the choice of atomic sphere radii on the calculated j(E) is studied.