Synthesis and luminescent properties of Sr2SnO4: Pr3+, M+ (M=Li, Na and K) phosphors with layered perovskite-related structure

A series of novel red-emitting stannate phosphors Sr2SnO4: xPr(3+) (0 <= x <= 0.01) are developed through high temperature sintering reaction method. The crystal structure and phase purity are identified by X-ray diffraction and Rietveld structure refinement. The microstructure and element composition are characterized through scanning electron microscopy and energy dispersive spectrometer. To elaborate the characteristic luminescent property, the photoluminescence excitation and emission spectra, decay lifetimes as well as Commission Internationale de l'E'clairage color coordinates of Sr2SnO4: xPr(3+) (0. x. 0.01) series phosphors are investigated. The results show that Sr2SnO4: xPr(3+) (0 <= x <= 0.01) phosphors have prominent excitation about 450 nm and can show red emissions peaking at 623, 652, 714 and 738 nm, respectively, ascribed to the P-3(0)-H-3(6), P-3(0)-F-3(2), P-3(0)-F-3(3) and P-3(0)-F-3(4) transitions of Pr3+ ions. The influences of the content of Pr3+ as well as charge compensation by co-doping with M+ (Li+, Na+ and K+) ions on the luminescent properties were discussed. The result reveals that co-doping Li+ ions can simultaneously increase the emission intensity and thermal stability. Furtherly, the mechanism of charge compensation and thermal quenching property are well studied through the temperature dependent decay curves and emission spectra.