Synthesis and luminescent property of Sm3+ doped and (Sm3+, Zr4+) co-doped calcium stannate phosphors via co-precipitation and sintering

Abstract

Sm 3+ doped calcium stannate (CaSnO 3 :Sm 3+ ) and (Sm 3+ , Zr 4+ )-co-doped calcium stannate (CaSnO 3 :Sm 3+ , Zr 4+ ) photoluminescent phosphors were synthesized via co-precipitation and subsequent sintering in oxidizing atmosphere at 1400 °C for 60 min with SnCl 4 ·5H 2 O, CaCl 2 ·2H 2 O, ZrO(NO 3 ) 2 · x H 2 O and Sm 2 O 3 as main raw materials. The synthesized samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, photoluminescent spectroscopy, luminescent decay curves, afterglow spectroscopy and thermo-luminescent glow curves. The results show that CaSnO 3 pure phase is synthesized in co-precipitation reaction at an optimum molar ratio of CaCl 2 ·2H 2 O:SnCl 4 ·5H 2 O of 1.4:1.0 and subsequent sintering at 1400 °C for 60 min. Calcium stannate as a host matrix can be doped with Sm 3+ ions or co-doped with Sm 3+ /Zr 4+ ions for the formation of white photoluminescent phosphors. CaSnO 3 :0.03Sm 3+ phosphor has an optimum photoluminescent intensity. Also, the fluorescent emission intensity of CaSnO 3 :0.03Sm 3+ ，0.04Zr 4+ phosphor under excitation of 365 nm wavelength can be enhanced due to Zr 4+ ions doping at an optimum doping amount y of 0.04. The CIE 1931 chromaticity coordinates change from (0.3600, 0.3535) for CaSnO 3 :0.03Sm 3+ phosphor to (0.3622, 0.3574) for CaSnO 3 :0.03Sm 3+ , 0.04Zr 4+ phosphor as the average crystalline size decreases from 71.5 to 68.3 nm and the unit cell volume increases from 0.2686 to 0.2775 nm 3 . In addition, the electron transition mechanism for the photoluminescent and long afterglow properties was also discussed. • The CaSnO 3 : x Sm 3+ , y Zr 4+ phosphors were prepared by co-precipitation and subsequent sintering in oxidizing atmosphere at 1400℃. • The incorporation of Zr 4+ into CaSnO 3 :0.03Sm 3+ phosphor increased the photoluminescent intensity and luminescent decay times.