WORK FUNCTION AND ENERGY-LEVELS OF POSITRONS IN CRYSTALLINE SILICON

We have studied the behaviour of a positron inside a Si crystal by calculating its energy levels and wave functions at different points of the reciprocal space. By establishing a common energy reference between the positron and the electron energy bands, we obtain a value of the positron work function which is in good agreement with the experimental result. The value of the positronium work function is also predicted. Finally, we investigate the influence of the mass on the excitation spectra of other positively charged particles, like muon, proton and deuteron.