Positron Energy Levels in Cd-Based Semiconductors

Using the full potential linearized augmented plane wave FP-LAPW method within local density ap-proximation LDA, we have studied positron diffusion and surface emission in Cd-based semiconductors. This requires the calculation of electron and positron band structures. In the absence of experimental and theoretical data for CdX (X=S,Se,Te) we have treated the Si, which has been studied by several authors, as a test case. Predictive results on positron effective masses, deformation potentials, positron work functions, diffusion constants and positron mobilities are presented for CdX (X=S, Se, Te). Our calculated data for Si are compared with experimental and recent theoretical results.