Mining Unexplored Chemistries for Phosphors for High-Color-Quality White-Light-Emitting Diodes

There is a critical need for new earth-abundant phosphors to enable next-generation, highly efficient solid-state lighting. Here we report the discovery of Sr2LiAlO4, the first known Sr-Li-Al-O quaternary crystal, via a carefully targeted data-driven structure prediction and screening effort using density functional theory calculations. Sr2LiAlO4 is predicted and experimentally confirmed to be a thermodynamically and thermally stable phosphor host that can be excited with near-UV/blue sources. The Eu2+- and Ce3+-activated Sr2LiAlO4 phosphors exhibit broad emissions at lambda(max) similar to 512 nm (green-yellow) and lambda(max) similar to 434 nm (blue), respectively, with excellent thermal quenching resistance of >88% intensity at 150 degrees C. A prototype phosphor-converted white LED utilizing Sr2LiAlO4-based phosphors yields an excellent color-rendering index exceeding 90. Sr2LiAlO4 therefore exhibits great potential for industrial applications in low-cost, high-color-quality WLEDs.