Structural and Optical Properties of Size and Morphology Controllable Nanoscale SrAl2O4: Eu2+, Dy3+

Nanoscale SrAl2O4: Eu2+, Dy3+ with controllable size and morphology was synthesized by sol-gel auto-combustion method. The surface morphology and structural characterization were carried out with TEM and XRD. Optical properties were analyzed by comparing excitation spectra, emission spectra and afterglow decay of the nanoscale phosphor with that of the bulk phosphor. The results showed that citric acid acted as a soft template in the reaction system. The morphology and size changed clearly with pH value and sintering temperature. The crystallinity was affected by the quantity of citric acid. Both the nanoscale phosphors with different particle size and the bulk one have the strongest emission at 525 nm. But their strongest peaks in excitation spectra are very different from each other. The phosphorescence of nanoscale phosphor decays more rapidly than that of the bulk phosphor.