Transparent Ceramics Enabling High Luminous Flux and Efficacy for the Next-Generation High-Power LED Light.

By designing novel chemical compositions and controlling precursor powders, perfect transparent ceramics (TCs) of Gd3Al4GaO12:2%Ce3+ garnets (GAGG:2%Ce3+) were achieved for the first time. Ce3+ distributions in ceramics were revealed by micromorphology and micro-cathodoluminescence. Benefiting from the components that are rich in red emission, warm light with a correlated color temperature of about 2800 K was generated when TC was used in high-power (hp) blue light emitting diodes (LEDs) (∼450 nm, ∼34 W driven at 1 A). The hp LED device shows high brightness with a luminous flux nearly 2100 lm. The luminous efficacy even reaches 388 lm/W, which is the highest value reported till now, indicating that the use of GAGG:2%Ce3+ TCs promises energy saving. We believe that this work will open a new perspective to develop TCs for next-generation hp LED lighting to substitute traditional hp xenon lamps and high-pressure sodium lamps.