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.

Diamond particles with germanium-vacancy and silicon-vacancy color centers were synthesized by Hot Filament Chemical Vapor Deposition technique. The next step was the reactive ion-plasma etching of the particles. As a result, the diamond nanoparticles were obtained whose photoluminescence spectra consist of two narrow intense zero phonon lines of the embedded centers. Such fluorescent diamond nanoparticles are promising as dual-wavelength narrow-band light emitters for luminescent nanothermometry.