Preparation of YAG∶Ce-CaF2 Phosphor Ceramics for Laser Lighting Through Cold Sintering
Phosphor ceramics are the key materials for laser lighting,and this paper aims to explore the feasibility of preparing phosphor ceramics at low temperature.YAG∶Ce-CaF2 composite phosphor ceramics with high density,uniform grain size and clear phase boundary were successfully prepared at 425 ℃.The results show that there is no detectable interfacial reaction between the luminescent phase and the matrix;the prepared phosphor ceramics have higher quantum efficiency(74.3％),better thermal conductivity(room temperature up to 9.4 W·m-1·K-1),excellent thermal stability,only 4.3％loss of illumination intensity at 400 K.Under excitation by blue light laser(451 nm),the composite phosphor ceramics have good yellow light emission and high brightness white laser illumination with light flux of 910.7 lm and lumen efficiency of 91.07 lm·W-1.Their fluorescence life have no attenuation(66 ns),and the associated color temperature is 4 483-8 247 K,and the color development index is 73.4-83.6.Cold sintering process is a new method to prepare phosphor ceramics with excellent performance at low temperature.
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