Synthesis and optical property studies of nanocrystalline ZrO ₂:Ti long-lasting phosphors

A facile synthetic route to synthesize the nanocrystalline zirconia particles via preparing polyzirconoxane with zirconium tetraalkoxide is reported, and the luminescent properties of the so-obtained Zr O2:Ti nanophosphors are systematically investigated in this paper. The bluish-white photoluminescence and phosphorescence originating from the recombination of electrons trapped by anion vacancies and the holes created in the valence band, and the Ti3+ ion substituting for Zr4+ is assumed to be the luminescent center. The long afterglow from Zr O2:Ti is attributed to the oxygen vacancies caused by the addition of Ti3+ ions into Zr O2 host. Compared with the bulk Zr O2:Ti, the nanosized phosphors exhibit a longer persistent time because of the increased surface traps due to the large surface-to-volume ratio in the nanoparticles. This long persistent process can be elucidated by a simple possible mechanism.