Abstract
Over the past two decades, nanosized diamond particles with various luminescent defects have found numerous applications in many areas from quantum technologies to medical science. The size and shape of diamond particles can affect drastically the luminescence of embedded color centers. Here we study diamond particles of 250–450 nm in size containing silicon-vacancy (SiV) centers. Using dark-field scattering spectroscopy, we found that fundamental Mie resonances are excited in the spectral range of interest. We then measured the fluorescence saturation curves under continuous excitation to estimate the effects of the excitation and Purcell factor enhancement on the luminescent properties of the studied particles. The results show that the saturation excitation intensity differs by several times for particles of different sizes which is well explained by the numerical model that takes into account both the Parcell factor enhancement and resonant excitation.
Rapid thermal annealing of electron irradiated nanoscale type Ib diamond particles facilitates formation of various nitrogen-related fluorescent color centers, providing either red, yellow, green, or blue fluorescence for downstream multiplex imaging applications.
Hot Filament Chemical Vapor Deposition technique was used to synthesize diamond particles with germanium-vacancy color centers on a germanium substrate. The formation of color centers occurred during the growth of diamond particles due to the incorporation of germanium atoms formed as a result of a crystalline germanium wafer etching with atomic hydrogen. The conditions of Chemical Vapor Deposition process which affect the photoluminescence of color centers of germanium vacancy in diamond particles, are considered. The highest photoluminescence intensity of germanium-vacancy color centers was achieved for diamond particles obtained on a substrate at a surface temperature close to the melting temperature of germanium. The photoluminescence spectra of the diamond particles also showed lines presumably associated with the optical centers which contain tungsten.
Purcell enhancement of fluorescence from silicon-vacancy color centers in Mie-resonant luminescent diamond particles
