Thermal properties of AlN-Ce:YAG composite ceramic phosphor for laser lighting

The AlN-Ce:YAG composite ceramic is an effective phosphor for high-power laser illumination. The thermal properties of an AlN-Ce:YAG composite phosphor were studied to suppress thermal quenching. This composite ceramic has a high heat dissipation effect owing to the dispersion of AlN particles, which exhibit high thermal conductivity. Exciting the phosphor with a high-power-density laser beam concentrates heat in a narrow area. The heat is efficiently dissipated by the AlN particles, thereby reducing the phosphor temperature. A new technique was developed to estimate the thermal conductivity from the emission spectrum and the spot center temperature of the composite ceramic. The heat value was calculated by subtracting the power of the emission spectrum from the incident laser power. The spot center temperature was measured using a thermographic camera. The thermal conductivity was simulated by inputting the heat value and spot center temperature into the model of the phosphor sample. It was clarified that the thermal conductivity improved, as the AlN particle content increased. This result is consistent with the measurements obtained using the laser flash method. This technique is useful for designing lighting systems, as it enables the estimation of thermal conductivity when light is emitted from a condensing spot.

Automated summary

The thermal properties of an AlN-Ce:YAG composite phosphor were studied, and it was found to have a high heat dissipation effect, making it suitable for high-power laser illumination.