Photoluminescence of SiV centers in single crystal CVD diamond in situ doped with Si from silane

Homoepitaxial single crystal diamond layers with bright photoluminescence (PL) of silicon-vacancy (SiV) color centers at 738 nm wavelength have been grown on (100) diamond substrates by a microwave plasma CVD using a controlled Si doping via adding silane to CH4-H-2 reaction gas mixture in the course of the deposition process. In the range of the silane concentrations SiH4/CH4 explored, from 0 to 2.4%, the SiV PL intensity shows a nonmonotonic behavior with silane addition, with a maximum at 0.6% SiH4/CH4, and a rapid PL quenching at higher Si doping. The maximum SiV concentration of approximate to 450 ppb in the samples has been determined from optical absorption spectra. It is found that the SiV PL intensity can strongly, an order of magnitude, increase within non-epitaxial inclusions in single crystal diamond film. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim