Improving NV centre density during diamond growth by CVD process using N2O gas

Nitrogen-vacancy (NV) centres in diamond are point-like defects that have attracted a lot of attention as promising candidates for quantum technologies particularly sensing and imaging nanoscale magnetic fields. For this application, the use high NV density within high-quality layer is prime interest. In previous works, it has been demonstrated situ doping with N2O rather than N2 during chemical vapour deposition (CVD), limits formation macroscopic improves NV's photostability. work, we focus on optimization CVD growth conditions to obtain keeping constant concentration gas phase (100 ppm). purpose, freestanding layers prepared varying two main parameters: methane content substrate temperature. High energy electron irradiation followed by annealing finally carried out order increase yield through partial conversion N impurities. Defect concentrations spin properties investigated. We find under lower temperatures enhances doping. ensembles 2 ppm obtained narrow resonance linewidth. addition, higher 1200 °C following found efficiently remove thus improving properties.