Investigation of the spectral characteristics of silicon-vacancy centers in ultrananocrystalline diamond nanostructures and single crystalline diamond

Abstract

Silicon-vacancy (SiV) centers were produced in single crystalline diamond (SCD) and ultrananocrystalline diamond (UNCD) nanostructures via Si ion implantation or in situ Si doping. SiV-embedded UNCD (SiV-UNCD) was fabricated by both top-down and bottom-up methods. The spectral properties of the SiV centers, including the zero phonon line (ZPL) width and decay time, were investigated in the SCD and UNCD nanostructures. All the SiV-UNCD nanostructures showed bright emission regardless of the preparation method. However, the decay time of the SiV centers was affected by the synthesis procedure. A SiV decay time of tau similar to 0.19 ns was observed for UNCD nanostructures formed by in situ doping, whereas the SiV decay time was similar to 0.43 ns for SiV-UNCD clusters prepared by Si ion implantation into UNCD deposited on Ti/sapphire substrates. The ultrasonication of UNCD clusters on Ti/sapphire pyramids produced bright SiV-UNCD nanoclusters with sizes of similar to 50 nm, a ZPL width of 13.5 nm, and a decay time of 0.35 ns, suggesting promising potential in bioimaging applications. SiV-containing SCD (type Ia or type IIa) showed enhanced SiV spectral properties with a ZPL width of 6.08 nm and longer decay time of 1.3 ns. Published under license by AIP Publishing.