Tunable YAG:Ce3+ ceramic phosphors for white laser-diode lighting in transmissive/reflective models

Y3Al5O12:Ce3+ (YAG:Ce3+) transparent ceramic phosphor (TCP) is one of the most promising converters for the laser-diode (LD) lighting because it has good capacity for absorbing blue light and prominent luminous efficiency (LE). A challenge is how to achieve a high-quality YAG:Ce3+ TCP to realize a high LE value. We propose a strategy to depress the defects by using the charge-balanced Mg2+-Si4+ to substitute the Al3+-Al3+. Benefiting from the flux effect of MgO and SiO2, the transmittance of the YAG:Ce3+ TCP (thickness of 1 mm) increases from 13 % to 70 % by controlling the pores in the TCP. By introducing Al2O3 to be one kind of light scatters to enhance the blue light absorption, the LE reaches 185.7 lm/W, which is much higher than the value (137 lm/W) of the same TCP previously reported. These results evidence that the optimized YAG:Ce3+ TCP has an excellent performance in LD lighting. Prototype white LD devices are demonstrated in both the transmissive and the reflective models.

Automated summary

The Y3Al5O12:Ce3+ transparent ceramic phosphor shows great potential for laser-diode lighting due to its high efficiency in absorbing blue light. By substituting certain elements and controlling the porosity, the luminous efficiency of the YAG:Ce3+ TCP can be significantly improved. Introducing specific elements to modify the phosphor and enhance blue light absorption can further increase the luminous efficiency, providing more efficient technical support for LED lighting.