Effect of the Nanodiamond Host on a Nitrogen-Vacancy Color-Centre Emission State

Control over the quantum states of individual luminescent nitrogen‐vacancy (NV) centres in nanodiamonds (NDs) is demonstrated by careful design of the crystal host: its size, surface functional groups, and interfacing substrate. By progressive etching of the ND host, the NV centres are induced to switch from latent, through continuous, to intermittent or “blinking” emission states. The blinking mechanism of the NV centre in NDs is elucidated and a qualitative model proposed to explain this phenomenon in terms of the centre electron(s) tunnelling to acceptor site(s). These measurements suggest that the substrate material and its proximity to the NV are responsible for the fluorescence intermittency. The emission state of nitrogen‐vacancy (NV) centres in nanodiamonds (NDs) can be manipulated by controlling the size, the surface moieties of the crystal host, and the bandgap structure of the adjacent dielectric environment. These factors also explain the observed luminescence intermittency (“blinking”) of the NV centre in terms of tunnelling of its electron(s) to acceptor site(s) located in the substrate.