Highly Stable Cyan‐Emitting Phosphor Ceramics for Violet‐Laser‐Driven Full‐Spectrum Lighting

Abstract Laser‐driven lighting has been extensively studied, and it is of great significance to plan ahead for laser‐driven full‐spectrum sun‐like lighting, but there is a lack of corresponding color converters, especially cyan‐emitting ones. Herein, new Li 2 CaSiO 4 : Eu 2+ (LCS: Eu 2+ ) ceramics are fabricated, which produce cyan emission with a peak position of 482 nm and a full width at half maximum of 30 nm. These can be attributed to low electron‐phonon couple, individual lattice location of Eu 2+ in a highly structural rigid host, and the incorporation of high relative density ceramic morphology. As a result, the best LCS: Eu 2+ ceramic exhibits minimal internal quantum efficiency lossbrk (0.7 %), high relative density (97.7 %), superior thermal stability (92.3 % at 200 °C), hydrothermal stability (T 90 > 1800 h), irradiation stabilities (≈100% under continuous 120 min violet laser irradiation at 86.7 mW·mm −2 ), and a luminous efficiency of 30.2 lm W −1 . Correspondingly, a full‐spectrum laser‐driven lighting prototype is further constructed, demonstrating superior color rendering performance (Ra = 96.5, R5 = 98, R6 = 97) and remarkable hue retention (deviation ≤ 1) in the cyan region, outperforming YAG: Ce 3+ and common high‐color‐rendering light sources. This exploration in cyan‐emitting ceramics is poised to facilitate the development of violet‐laser‐driven full‐spectrum lighting technology.