Creation efficiency of nitrogen-vacancy centres in diamond

Nitrogen-vacancy (NV) colour centres in diamond are attracting growing attention due to potential applications in solid-state quantum information processing and magnetometry. Although proof-of-principle experiments have been demonstrated, further development requires the controllable production of defects with a high yield. In this paper, we experimentally show that the production efficiency of NV defects strongly depends on the ion implantation energy. This can be explained in terms of the number of vacancies produced per implanted ion and surface proximity. The dependence on ion fluence is also underlined, revealing a nonlinear regime and showing how the diamond lattice is damaged at higher fluences.