Fabrication of high-density nitrogen-vacancy (NV) center-enriched diamond particles through methyl trityl amine (C20H19N) seeding

Diamond particles (DPs) show promise for advanced applications in bioimaging and quantum sensing due to the presence of defect centers. This work reports a unique growth process for diamond particles composed of nitrogen-vacancy centers (NV-DPs) using a methyl trityl amine (C20H19N) diamondoid seed, which acts as a nitrogen source for NV creation. Growth was performed via microwave plasma-assisted chemical vapor deposition in a CH4/H-2 plasma. Tantalum plates were chosen as the substrate to facilitate the release of the NV-rich DPs after growth. Raman spectra of NV-DPs grown at 550 degrees C showed a sharp, intense peak at similar to 1334 cm(-1), while those grown at 750 degrees C exhibited a broader, high intensity peak at 1336 cm(-1). Photoluminescence revealed the formation of high-density NV centers, with the highest intensity for NV-DPs grown at 750 degrees C and 20 Torr. Optically detected magnetic resonance confirmed the presence of NV centers, especially for DPs grown at 750 degrees C. This seeding process enables precise nitrogen incorporation into diamond crystals to generate required spin properties by growing high-quality, well-faceted NV-DPs with customizable NV densities.