Characterization of Cvd Diamond Films by Optical Spectroscopies

Raman and photoluminescence spectroscopy was used to investigate radiation damage by 5 MeV He+ ions at room temperature in prototype CVD-diamond detector material. Amorphization of the diamond is not observed at fluences up to 8×1015 cm−2. A threshold behavior is seen in the formation of the H3 vacancy-dinitrogen color center. The defect is not observed for fluences in the range 1.6×1012 to 1.6×1013 cm−2; a linear behavior increase in H3 intensity is observed over the range 1.6×1014 to 1.6×1015 cm−2. The formation mechanism of the H3 color center under He+ irradiation involves a self-annealing effect that allows vacancies to diffuse to, and complex with, nitrogen complexes.