The properties of prominent optical centres, such as the nitrogen vacancy, the silicon vacancy or the so-called NE8 centre were considered, as well as recently found centres attributed to defects containing Ni, Si, Cr and Xe. Besides suitable intrinsic properties, it was necessary for practical applications that optical centres can be created artificially on demand. Of all known methods, only ion implantation allows for the most controlled creation of such defect centres. It was analysed how nanoscalability (nanometre placement and the deterministic creation of optical centres) could, or could not, be achieved by using available ion implantation techniques. Fine analysis of individual optical centres was now possible, thanks to the recently developed sub-diffraction optical microscopy methods.

Creation and Nature of Optical Centres in Diamond for Single-Photon Emission -Overview and Critical Remarks. S.Pezzagna, D.Rogalla, D.Wildanger, J.Meijer, A.Zaitsev: New Journal of Physics, 2011, 13[3], 035024