High-quality diamond microparticles containing SiV centers grown by chemical vapor deposition with preselected seeds

The superior properties of diamond have made it a versatile platform for many promising applications in a wide range of areas. Thus, various methods, like chemical vapor deposition (CVD), have been developed to fabricate diamond materials with desired properties. However, the CVD-grown diamond that employs conventional detonation nanodiamonds (DNDs) as seeds is not suitable for many demanding applications that require diamond with high crystallinity, stable color centers, highly emissive features, etc. Here, we propose to use our previously developed salt-assisted air-oxidized (SAAO) nanodiamonds (NDs) as CVD seeds to grow high-quality diamond microparticles that contain silicon vacancy (SiV) centers. The resulting SiV centers hosted in diamond microparticles show superior properties, i.e., significantly increased photoluminescence (PL), narrow PL linewidths, and small inhomogeneous distributions, enabling a wide range of practical applications. We further demonstrate ultrasensitive all-optical thermometry measurement by utilizing the fabricated high-quality microparticle sample.