The photoluminescence and afterglow properties of Ca2SnO4:Sm3+ phosphor

Abstract

A reddish orange emissive long afterglow phosphors Ca2−xSnO4:xSm3+ (x = 0.001–0.05) are prepared by solid-state reaction in air atmosphere. The synthesized phosphors are characterized and analyzed by X-ray diffraction, photoluminescence spectra, afterglow decay curves, and absorption spectra. Under excitation at 407 nm, three emission peaks locate at 565, 610 and 654 nm, respectively, which can be assigned to the 4G5/2→6HJ (J = 5/2, 7/2, 9/2) transitions of Sm3+ ion. The fluorescent intensity and the afterglow characteristic depend on the concentration of Sm3+. The optimal Sm3+ concentration is x = 0.01. The CIE 1931 chromaticity coordinates of the emission and afterglow are (x = 0.6103, y = 0.3891) and (x = 0.5668, y = 0.4325) located in the range of reddish orange light emission. The afterglow decay curves of the Ca2SnO4:Sm3+ phosphor indicate both fast and slow decay components. The striking difference of the afterglow luminescence intensities of the phosphor after irradiation under 254 and 365 nm UV is discussed in deeply with absorption spectrum.