Synthesis of SrSiO3:Tb3+, Eu3+, Li+ red phosphors for WLED and study of their luminescence properties

A series of Tb3+, Eu3+, Li+ co-doped SrSiO3 phosphors were prepared using the high-temperature solid-phase method. The X-ray diffraction results showed that Tb3+ and Eu3+ successfully entered into the SrSiO3 matrix lattice. Strong energy transfer from Tb3+ to Eu3+ is exhibited with a calculated energy transfer efficiency of 94.7%. Doping of the charge compensator Li+ increased the luminescence intensity of the SrSiO3:6%Tb3+, 6%Eu3+, 3%Li+ phosphor at a wavelength of 614 nm by 4.2 times and significantly improved the color purity of this phosphor (Cp = 85.9%). Based on color coordinate analysis, the phosphor color coordinates are located near (0.615, 0.365), which belongs to the red region. The phosphor was integrated into a white LED. The resultant package exhibited a color temperature of 6479 K and a color rendering index of 93.8. Its luminous performance was also very stable under different drive currents.