Temperature Dependent Emission of Strontium-Barium Orthosilicate (Sr_2−xBa_x)SiO₄:Eu₂₊ Phosphors for High-Power White Light-Emitting Diodes

Samples of (Sr_1.9−xBa_x)SiO₄:Eu_0.1 were synthesized by a solid-state reaction. The maximum emission intensity under 460 nm excitation was obtained at a Ba content, x, of 1.6. All Sr_1.9−xBa_xSiO₄:Eu_0.1 samples except for Ba_1.9SiO₄:Eu_0.1 exhibited a temperature-driven blue-shift of the emission band. The thermostability of emission in (Sr_1.9−xBa_x)SiO₄:Eu_0.1 depended strongly on the Ba/Sr ratio. The thermal quenching temperature reached its maximum at a Ba concentration x of 1.2–1.6 and was much lower for Ba_1.9SiO₄:Eu_{2+ 0.1}.