Fluctuation kinetics of fluorescence hopping quenching in the Nd3+:Y2O3 spherical nanoparticles

We study the peculiarities of energy transfer kinetics from the 4F3/2 laser level in the Nd3+ doped Y2O3 spherical nanoparticles of monoclinic phase synthesized by laser ablation of solid targets with subsequent recondensation in flow of air at atmospheric pressure comparing to the similar bulk crystal. We show that the fluorescence quenching in the nanoparticles is determined by two processes depending on Nd3+ concentration and the degree of dehydration. At concentrations less than 1% the fluorescence quenching is mainly determined by direct (static) quenching by vibrations of OH− molecular groups associated with oxygen vacancies. At concentrations greater than 1 at % quenching is due to energy migration over neodymium ions, followed by the Nd3+–OH− quenching. In the latter case, the first time in a solid-state impurity laser medium we observe non-stationary kinetics on the entire length of a time-dependent luminescence quenching, starting from static decay and ending with fluctuation kinetics of fluorescence hopping quenching.