Synthesis and photoluminescence properties of novel orange-emitting Sm3+-activated LaTiSbO6 phosphors for WLEDs

Abstract

In this report, a Sm3+-activated LaTiSbO6 (LTSO) orange-red-emitting double-perovskite antimonate phosphor was realized via a solid-state reaction process. The synthetic LTSO:Sm3+ phosphors were fully analyzed in terms of phase purity, elemental composition, and luminescence properties. The X-ray diffraction (XRD) pattern confirmed that all diffraction peaks are well-matched with the standard data card (PDF#33-0726). The crystal structure consists of the trigonal cell with the space group P31 m (No.162). At excitation level of 403 nm, the emission of LTSO:Sm3+ presents four distinct peaks located at 567, 598, 645, and 711 nm, corresponding to the 4G5/2–6HJ/2 (J = 5, 7, 9, and 11) transitions, respectively. Experimental results verify that the optimal doping concentration of Sm3+ is 0.05 mol. The concentration quenching mechanism of the dipole–dipole interaction according to Dexter theory. The LTSO:0.05Sm3+ phosphor exhibits good thermal quenching behavior with a high activation energy (Ea = 0.308 eV). The fabricated white light-emitting diode (WLED) device presents a high rendering index value (Ra) of 90 and a good correlated color temperature (CCT) of 5536 K. These results indicate the LTSO:Sm3+ products have great potential for WLEDs applications.