Sandwich-like transparent ceramic demonstrates ultraviolet and visible broadband downconversion luminescence

We report a novel sandwich-like Ce, Yb:Y1.76La0.18Zr0.06Ox transparent ceramic, which shows efficient UV/Vis to NIR downconversion luminescence with a broad conversion window (250 nm to 650 nm), owing to its graded defective structure. The solar spectrum conversion efficiency is improved by 3.6 fold, compared with the homogenous material.