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

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 one. Herein, new Li₂CaSiO₄: Eu²⁺ (LCS: Eu²⁺) ceramics are fabricated, which produces cyan emission with peak position of 482 nm and full width at half maximum of 30 nm. These can be attributed to low electron-phonon couple, individual lattice location of Eu²⁺ in high structural rigid host, and the incorporation of high relative density ceramic morphology. As a result, the best LCS: Eu²⁺ ceramic exhibits minimal internal quantum efficiency loss (0.7 %), high relative density (97.7 %), superior thermal stability (92.3 % at 200 °C), hydrothermal stability (T₉₀ > 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. 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: Ce³⁺ 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.

http://doi.org/10.1002/adfm.202515542