Formation mechanism and regulation of silicon vacancycenters in polycrystalline diamond films br

Diamond silicon vacancy centers (SiV centers) have important application prospects in quantuminformation technology and biomarkers. In this work, the formation mechanism and regulation method of SiVcenter during the growth of polycrystalline diamond on silicon substrate are studied. By changing the ratio ofnitrogen content to oxygen content in the growing atmosphere of diamond, the photoluminescence intensity ofSiV center can be controlled effectively, and polycrystalline diamond samples with the ratios of SiV centerphotoluminescence peak to diamond intrinsic peak as high as 334.46 and as low as 1.48 are prepared. It is foundthat nitrogen promotes the formation of SiV center in the growth process, and the inhibition of oxygen. Thesurface morphology and photoluminescence spectrum for each of these samples show that the photoluminescencepeak intensity of SiV center is positively correlated with the grain size of diamond, and the SiV center'sphotoluminescence peak in the diamond film with obvious preferred orientation of crystal plane is higher. Thedistribution of Si centers and SiV centers on the surface of polycrystalline diamond are further characterizedand analyzed by photoluminescence, Raman surface scanning and depth scanning spectroscopy. It is found thatduring the growth of polycrystalline diamond, the substrate silicon diffuses first into the diamond grain andthen into the crystal structure to form the SiV center. This paper provides a theoretical basis for thedevelopment and application of SiV centers in diamond