Nitrogen-Vacancy (NV) centers in Nano diamonds: Toward optimization and photo stability

Nitrogen-Vacancy (NV) centers in Nano diamonds (NDs) are one of the most promising room temperature atom like system for an array of present and future technological applications. These include bio imaging, nano metrology and quantum information processing (QIP). All of these applications depend upon the optimized concentration of NV centers (NV- ) in NDs and their photo stability over continuous excitation. Both of these factors i.e. optimization of concentration of NV centers and their stable photo-physical behavior are major hurdles for different applications. In the present work, we have optimized the fabrication condition for the efficient creation of NV centers. Interestingly, we have successfully created the uniform concentration of NV centers in NDs by dispersed low energy ion irradiation . While investigating the effect of surface functionalization, it was revealed that different degree of surface oxidation of NDs leads to different photo-stability of NV centers. With the optimized concentration of NV centers, we have observed the single photon emission at room temperature and optical bio imaging. Our findings provide new insight to achieve the optimized as well as photo-stable concentration of NV centers and prepare the platform for wide range of applications of NDs.