Nitrogen incorporation in a homoepitaxial diamond thin film

The influence of nitrogen incorporated in a homoepitaxial diamond thin film on such optical properties such as excitonic emission and optical transition via defect centers was studied in detail by high-resolution cathodoluminescence. It was found that the emission line associated with a nitrogen-vacancy complex center (H3 center) showed spectral narrowing as well as a shift in the peak position to the low-energy side by nitrogen doping. Furthermore, the temperature dependence of the excitonic emission line indicated that the exciton ground state, which is six-fold degenerated in the undoped diamond, was split by nitrogen doping. These results strongly indicate that that nitrogen incorporation in diamond induced an internal stress which modified the exciton ground state as well as the electronic structure of nitrogen-related defects.