Thermally stable green Ba3Y(PO4)(3):Ce3+,Tb3+ and red Ca3Y(AlO)(3)(BO3)(4):Eu3+ phosphors for white-light fluorescent lamps

Abstract

A class of thermal stable of green-emitting phosphors Ba3Y(PO4)(3):Ce3+,Tb3+ (BYP:Ce3+,Tb3+) and red-emitting phosphors Ca3Y(AlO)(3)(BO3)(4):Eu3+ (CYAB:Eu3+) for white-light fluorescent lamps were synthesized by high temperature solid-state reaction. We observed a decay of only 3% at 150 degrees C for BYP:0.25Ce(3+),0.25Tb(3+) (3% for LaPO4:Ce3+,Tb3+), and a decay of 4% for CYAB:0.5Eu(3+) (7% for Y2O3:Eu3+, 24% for Y2O2S:Eu3+). The emission intensity of composition-optimized Ba-3(Y0.5Ce0.25Tb0.25)(PO4)(3) is 70% of that of commercial LaPO4:Ce3+,Tb3+ phosphors, and the CIE chromaticity coordinates are found to be (0.323, 0.534). The emission intensity of Ca-3(Y0.5Eu0.5)(AlO)(3)(BO3)(4) is 70% and 83% of those of Y2O3:Eu3+ and Y2O2S:Eu3+ phosphors, respectively, and the CIE chromaticity coordinates are redder (0.652, 0.342) than those of Y2O3:Eu3+ (0.645, 0.347) and Y2O2S:Eu3+ (0.647, 0.343). A white-light fluorescent lamp is fabricated using composition-optimized Ba-3(Y0.5Ce0.25Tb0.25)(PO4)(3) and Ca-3(Y0.5Eu0.5)(AlO)(3)(BO3)(4) phosphors and matching blue-emitting phosphors. The results indicate that the quality of the brightness and color reproduction is suitable for application in shortwave UV fluorescent lamps. The white-light fluorescent lamp displays CIE chromaticity coordinates of x = 0.33, y = 0.35, a warm white light with a correlated color temperature of 5646 K, and a color-rendering index of Ra = 70. (C) 2010 Optical Society of America