Creation of Blue Light Emitting Color Centers in Nanosized Diamond for Different Applications

Plasma immersion ion implantation and focused ion beam treatment techniques were used to create nitrogen-related complex defect centers in detonation nanodiamond crystals. Helium implantation was used to produce vacancies in the crystal structure, which was followed by the introduction of nitrogen ions (with the same method). Heat treatment at 1,023 K was applied to initiate vacancy diffusion and formation of complex defect centers. The sp2 carbon content of the samples formed during the implantation and the high-temperature annealing was decreased by oxidation at 723 K in air. Changes in the bonding structure were monitored by Raman and infrared spectroscopic measurements after each step of the defect creation process. It was found that the photoluminescence of nanosized diamond changes remarkably as a consequence of different treatments and a new, narrow, intense emission band develops in the deep blue wavelength region. The N3 nitrogen-related complex defect center was considered as source of this fine structured emission band in the luminescence spectrum.