Luminescent Properties of Carbon Nanodots Bound to the Surface of Spherical Microresonator

Hybrid structures consisting of emitting carbon nanodots bound to the surface of monodisperse spherical silica particles, which function as microresonators, are synthesized. The carbon nanodots are deposited onto the particle surface through controllable coagulation in three different solvents: ammonia, hydrochloric acid, and glycerol. In photoluminescence spectra of hybrid structures, throughout the entire range of carbon nanodot emission, which extends from UV to near IR, we observe the presence of intensive narrow bands related to emission of the nanodots in the whispering gallery modes of a spherical microresonator. All the observed bands are identified by comparing the spectral positions of whispering gallery modes calculated using the transfer matrix method for spherical waves to the experimental data.