Positron effective mass and positronium work function in ZnxCd1−xS

Abstract

Electron and positron chemical potentials, positron affinity and bulk lifetime, positronium work function and positron effective mass have been computed for Zn_xCd_1−xS using a pseudo-potential approach within the virtual crystal approximation (VCA) and the independent particle model. A correction to VCA is included taking into consideration the disorder effect. This has permitted the computation of the positron affinity to separate materials of interest. The performances indicated that the positron annihilates differently in CdS than in ZnS. The bulk lifetime of positron has been obtained as 241.17 ps for CdS and 215.47 ps for ZnS. Hence, it decreases when going from CdS to ZnS. The positronium work function increases from 2.245 to 3.08 eV when augmenting the composition x from 0 to 1, indicating that only fewer positronium atoms are figured in a specimen surface and ejected for the vacuum. The positron effective mass augments from 0.96 to 1.34 m₀ when going from CdS to ZnS materials. The details collected from the assisted investigation are of a former significance for an ameliorate accordance of positron annihilation in Zn_xCd_1−xS.