Effect of sol-gel combustion temperature on the luminescent properties of trivalent Dy doped SrAl2O4

Trivalent dysprosium doped strontium aluminates (SrAl2O4:Dy3+) were synthesized by firing the sol-gel at 600, 700 and 800 degrees C. The morphology, crystal structure, photoluminescence and long afterglow of the synthesized SrAl2O4:Dy3+ phosphors were characterized with scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy and photoluminescence spectroscopy, respectively. It is found that SrAl2O4:Dy3+ phosphors exhibit broadband afterglows with its peak at about 510 nm. As the sol-gel synthesis temperature increases from 600 to 800 degrees C, the green afterglow of the SrAl2O4:Dy3+ phosphors becomes weaker in intensity and shorter in lifetime. The results are discussed in terms of thermally generated point defects in the host material. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.