Oxygen Ion Implantation Enhanced Silicon-Vacancy Photoluminescence and n-Type Conductivity of Ultrananocrystalline Diamond Films

We report the enhanced silicon-vacancy (Si-V) photoluminescence (PL) intensity and n-type conductivity of ultrananocrystalline diamond (UNCD) films by oxygen ion (O⁺) implantation. With O⁺ dose increasing from 10¹⁴ to 10¹⁵ cm^?2, the PL intensity and n-type conductivity significantly increase by 6 and 45 times, respectively, after 1000°C annealing. The secondary ion mass spectroscopy mapping measurements show that the content of oxygen is larger in the zone, which has larger content of silicon, indicating that oxygen tends to adhere to silicon. It is suggested that oxygen related Si-V defects are formed, which will enhance the PL intensity and n-type conductivity of UNCD films.