La1−x−0.025Ce0.025Sr2+xAl1−xSixO5 solid solutions as tunable yellow phosphors for solid state white lighting

Abstract

Solid solutions of two isotypic compounds from the end members LaSr₂AlO₅ and Sr₃SiO₅ are hosts for Ce³⁺ activator ions, allowing for careful tuning of the various parameters associated with efficient solid state (blue + yellow =) white lighting. By incorporating this phosphor with an encapsulant on InGaN light-emitting diodes (λ_max = 430 nm), we obtain white light with a color rendering index (R_a) between 67 and 70 and color temperatures between 6550 and 7345 K, with relatively high efficacies, suggesting these solid solutions are promising for applications in solid state white lighting.