On studying the optical properties of NV/SiV color centers in ultrasmall nanodiamonds

In this work, we study the optical properties of NV centers in detonation nanodiamonds and SiV centers in HPHT nanodiamonds with the size about 10 nm. We experimentally measure the size of nanodiamonds with color centers on the substrate. We demonstrate that detonation nanodiamonds have tendency to aggregate, whereas HPHT diamond may lay as single digit crystals. In despite of the aggregation and ultrasmall size, these nanodiamonds still contain bright single color center with antibunching photon statistics.