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The need to grow high quality semiconducting hydrogenated amorphous carbon (a-C:H) thin films to allow n-type electronic doping by nitrogenation has lead us to deposit films with low paramagnetic defect density (1017 cm−3). The films were grown on the earthed electrode of a radio frequency driven plasma enhanced chemical vapor deposition system using methane, helium and a range of nitrogen concentrations as the precursor gases. The deposited films are shown to be polymer like. Changes in the chemical structure and relative bond fractions as a function of the nitrogen flow rate into the plasma chamber and ex situ annealing are reported. Particular attention is paid to changes in the film structure after annealing at 100 °C, since an increase in the E04 optical band gap is observed as a function of nitrogen flow after the anneal. This suggests a decrease in the defect density of the film.

Rare-earth element erbium implanted into silicon was studied by photoluminescence and Rutherford backscattering analysis. Two sets of luminescent bands related to the weakly crystal field split spin-orbit levels 4I13/2→4I15/2 of Er 3+ (4f 11) at different lattice sites having different symmetries were observed.