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

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 (λmax = 430 nm), we obtain white light with a color rendering index (Ra) 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.