Investigation on Luminescence Properties of a Long Afterglow Phosphor Ca2SnO4:Tm3+

摘要

A series of new long afterglow phosphors Ca2SnO4:xTm(3+) were synthesized by using traditional solid-state reactions. XRD measurements and Rietveld refinement revealed that the incorporation of the Tm3+ dopants generated no second phase other than the original one of Ca2SnO4, which indicated that the dopants completely merged into the host. The corresponding optical properties were further systematically studied by photoluminescence, phosphorescence, and thermoluminescence (TL) spectroscopy. The results show that the Tm3+-related defects account for the bright bluish green afterglow emission from the characteristic f-f transitions of Tm3+ ions. The bluish green long-lasting phosphorescence could be observed for 5h by the naked eye in a dark environment after the end of UV irradiation. Two TL peaks at 325 and 349K from the TL curves were adopted to calculate the depth of the traps, which were 0.45 and 0.78eV, respectively. The mechanism of the long afterglow emission was also explored.