Microemulsion-derived ZrO2:Ce3Â + nanoparticles: Phase transformation and photoluminescence characterization

Bluish green-emitting ZrO2:Ce3 + nanoparticles were synthesized via a microemulsion route. The effects of the annealing temperature on the phase evolution and luminescence properties were investigated in detail. As the aqueous micelles confined the constituent cations during crystallization, nanosized particles were formed. The formed ZrO2 nanoparticles were observed to undergo a phase transition from tetragonal to monoclinic structure with the increase in annealing temperatures. The reduction of structural defects with annealing temperatures promoted the phase transformation. When the annealing temperature exceeded 900 °C, only the monoclinic phase was present. The photoluminescence emission appeared in the bluish green region around 487 nm under ultraviolet excitation. The emission intensity increased with the annealing temperatures. The optimal Ce3 +-dopant concentration in ZrO2 nanoparticles was determined, and the concentration quenching mechanism was discussed. The present work suggests that microemulsion-derived ZrO2:Ce3 + nanoparticles are suitable for optoelectronic applications.