Effects of Hydrogen on the Deep Levels in Si, ZnO and Diamond Studied by Cathodoluminescence

摘要

The effects of hydrogen on the deep level luminescence in Si, ZnO and diamond were studied by means of Cathodoluminescence. It is well known that most of the deep levels in Si are passivated by hydrogen. Scratch lines on Si surface, which do not show any characteristic luminescence, obtain so-called D-line luminescence by hydrogen plasma treatment. It indicates that only nonradiative defects are passivated but D-line luminescence is not passivated by hydrogenation. Contrarily, typical ZnO crystal shows the green emission, which is attributed to the point defects or impurities. Hydrogen completely passivates this green emission, and in turn, enhances the band edge emission. The effect of hydrogen passivation disappeared by the annealing at temperatures higher than 600℃. Hydrogen behaves more peculiarly in diamond. The hydrogenated diamond film shows the characteristic emission around 2.3 eV in photon energy. Since it disappears by oxidization treatment, this emission is attributed to hydrogen at the subsurface region. The detailed study indicated that hydrogen in diamond has bistable states.