Positron Characteristics in Cadmium and Zinc Chalcogenides

Electron energy levels and positron states have been calculated for cadmium and zinc chalcogenide compounds within the pseudo-potential approach and the independent particle model. Furthermore, the present contribution deals with the electron and positron chemical potentials allowing the calculation of the positron affinity to different materials of interest and hetero-structures formed by these materials. Besides, we here determine the positron diffusion constant by means of the positron deformation potential. An attempt has been made to scale positron affinity and diffusion constant with the lattice constant and the band gap energy, respectively. Such scaling is found to be not possible. The information gathered by the present study is of prime importance for a better understanding of positron trapping at interfaces and precipitates and should be useful in slow positron beam experiments. (paper)