Thermally stable green Ba(3)Y(PO(4))3:Ce(3+),Tb(3+) and red Ca(3)Y(AlO)(3)(BO(3))4:Eu(3+) phosphors for white-light fluorescent lamps.
A class of thermal stable of green-emitting phosphors Ba(3)Y(PO(4))(3):Ce(3+),Tb(3+) (BYP:Ce(3+),Tb(3+)) and red-emitting phosphors Ca(3)Y(AlO)(3)(BO(3))(4):Eu(3+) (CYAB:Eu(3+)) for white-light fluorescent lamps were synthesized by high temperature solid-state reaction. We observed a decay of only 3% at 150 °C for BYP:0.25Ce3+,0.25Tb3+ (3% for LaPO4:Ce(3+),Tb(3+)), and a decay of 4% for CYAB:0.5Eu(3+) (7% for Y(2)O(3):Eu(3+), 24% for Y(2)O(2)S:Eu(3+)). The emission intensity of composition-optimized Ba(3)(Y(0.5)Ce(0.25)Tb(0.25))(PO(4))(3) is 70% of that of commercial LaPO(4):Ce(3+),Tb(3+) phosphors, and the CIE chromaticity coordinates are found to be (0.323, 0.534). The emission intensity of Ca(3)(Y(0.5)Eu(0.5))(AlO)(3)(BO(3))(4) is 70% and 83% of those of Y(2)O(3):Eu(3+) and Y(2)O(2)S:Eu(3+) phosphors, respectively, and the CIE chromaticity coordinates are redder (0.652, 0.342) than those of Y(2)O(3):Eu(3+) (0.645, 0.347) and Y(2)O(2)S:Eu(3+) (0.647, 0.343). A white-light fluorescent lamp is fabricated using composition-optimized Ba(3)(Y(0.5)Ce(0.25)Tb(0.25))(PO(4))(3) and Ca(3)(Y(0.5)Eu(0.5))(AlO)(3)(BO(3))(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.
Phosphors Research Laboratory and Department of Applied Chemistry, National Chiao Tung University, Hsinchu 30010, Taiwan.
Chien-Hao
CH
Huang
Te-Wen
TW
Kuo
Teng-Ming
TM
Chen
D000537:Aluminum Oxide / Q000737:chemistry; D001464:Barium / Q000737:chemistry; D002118:Calcium / Q000737:chemistry; D002586:Cesium / Q000737:chemistry; D005063:Europium / Q000737:chemistry; D008027:Light; D008856:Microscopy, Fluorescence / Q000379:methods*; D010758:Phosphorus / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013725:Terbium / Q000737:chemistry; D014466:Ultraviolet Rays; D014961:X-Ray Diffraction; D015019:Yttrium / Q000737:chemistry
D013725:Terbium; D002586:Cesium; D001464:Barium; D010758:Phosphorus; D005063:Europium; D015019:Yttrium; D000537:Aluminum Oxide; D002118:Calcium