Positron energy levels in semiconductors

Positron affinities, deformation potentials, and lifetimes are calculated i n diamond, Si, SiC, and BN bulk cubic semiconductors using the first princi ples pseudopotential and linear-muffin-tin-orbital (LMTO) methods. Both the electron and positron energies are calculated within the local density app roximation and generalized gradient approximation (GGA). It is observed tha t the LMTO calculated values of quantities of interest are systematically l ower than those calculated with the pseudopotential method. Results further show that the GGA correction for the electron energy levels is not very im portant in positron calculations. The calculated positron affinity in SIC i s found to be in reasonable agreement with experiment. Positron properties for other materials are also compared with available experimental data.