Study of hydrogen configurations by infrared spectroscopy, effusion and nuclear analysis in A-Si/sub x/Ge/sub y/H/sub z/ alloys

International audienceInfrared spectroscopy, thermal effusion, and nuclear analysis were used to perform a systematic investigation of hydrogen incorporation and types of bonding in glow discharge deposited a-Si/sub x/Ge/sub y/H/sub z/ thin films. The study is focused on samples with a low germanium content corresponding to an optical gap EO4 varying between 1.9 eV (a-SiH) and 1.6 eV (35% Ge). From infrared measurements the authors deduce the preferential attachment of hydrogen on Si or Ge atoms and the presence of polysilanes groups, according to the deposition conditions. They also propose a quantitative correlation between (SiH/sub 2/)n (n>or=1) concentrations deduced from IR stretching bands (2080-2090 cm/sup -1/) and weakly bonded hydrogen measured by thermal effusion