Optical properties of Tb and Eu doped cubic YAlO3 phosphors synthesized by sol–gel method

Abstract

In this work, terbium and europium doped YAlO3 phosphors were synthesized by sol–gel method. It has been shown that after annealing at 1000°C these phosphors crystallize in the cubic garnet phase, similar to Y3Al5O12. As evidenced by the time-resolved photoluminescence spectroscopy and Maximum Entropy Method, the photoluminescence decay of both europium 5D0 and terbium 5D4 states has two lifetime components: short and long, both of the order of milliseconds. Moreover, for both phosphors the short photoluminescence lifetime was ascribed to the ions occupying low-symmetry sites in the vicinity of the nanocrystal surface, while the long decay component was related to the ions present in the bulk of YAlO3 nanocrystal. For both dopants, the long lifetime component of Tb3+ and Eu3+ emission is longer than the equivalent lifetimes in bulk Y3Al5O12 crystal.