Luminescent Properties of Calcium Halophosphate Phosphor for White Light Emitting Diode

Tb 3+ and Eu 3+ activated Ca5(PO4)Cl phosphors were synthesized by a solid state reaction. From powder X-ray diffraction analysis, Ca5(PO4)Cl with a hexagonal structure was confirmed. The excitation spectra indicate the phosphor can be excited by near ultraviolet (NUV) light, which makes it attractive for white light emitting diode (WLED) applications. When the phosphor was excited by 394 nm light, it exhibits blue emission, green emission, orange-red emission and red emission at 465 nm, 543 nm, 591 nm and 615 nm, respectively. The phosphor had been found to have chromaticity coordinates of x=0.31 and y=0.28, which was depicted by white near to “ideal white” in chromaticity diagram. The properties shows that Ca5(PO4)Cl: Eu 3+ , Tb 3+ was a single-phased whiteemitting phosphors, which can be excited by NUV chip.