Photoluminescence of germanium-vacancy color centers in diamond particles obtained by chemical vapor deposition

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.