Low‐Temperature Silicon‐Vacancy Luminescence of Individual Chemical Vapor Deposition Nanodiamonds Grown by Seeding and Spontaneous Nucleation

Diamond nanoparticles with optically active color centers can be used in nanoscale devices for quantum networking and sensing. A particular interest is focused on nanodiamonds (NDs) containing a small ensemble of negatively charged silicon‐vacancy (SiV) centers. Such NDs can be integrated with on‐chip optical structures. Here, chemical vapor deposition (CVD) is used to synthesize diamond particles of less than 100 nm in size containing 10–20 centers per ND. Two types of NDs grown on a Si substrate are studied, seeded with detonation NDs and without any seeding. The SiV luminescence under off‐resonant and resonant laser excitation at the temperature of 15 K is investigated. The emission lines of SiVs of individual NDs are well resolved and found to be spread in the range of 730–750 nm. The typical SiV linewidth is within 1–2 GHz for spontaneous NDs, which is only a factor of 2.5–5 broader than the lifetime limited linewidth of the SiV at 15 K. The emission of a single SiV is highly stable for both types of samples. This work is a critical step toward the synthesis of SiVs suitable for the realization of integrated quantum photonic devices.