Radiation hardness of polycrystalline diamond

Abstract

Undoped and B-doped polycrystalline diamond films have been irradiated with 2-MeV alpha particles and 3-MeV protons at doses ranging from D = 1012 to D = 1017 cm-2. The radiation damage has been studied using conductivity measurements and Raman/photoluminescence spectroscopy. For undoped diamond films, the H3 luminescent center (N-V-N) is detected around 2.45 eV for D≥1014 He+ cm-2. The diamond peak broadens and shifts to lower wavenumbers for D≥1016 He+ cm-2, indicative of the appearance of crystalline defects and tensile stress. No graphite is detected. On the contrary we observe an annealing of the as-grown sp2 defects as evidenced by a decrease in the intensity of the Raman band at 1500 ..