Ca9La(PO4)5(SiO4)Cl2:Dy3+: A white-emitting apatite-type phosphor pumped for n-UV w-LEDs

The Ca9La(PO4)5(SiO4)Cl2:Dy3+ (CLPSCl:Dy3+) powder phosphor with apatite structure has been successfully synthesized via high-temperature solid state method. Single phase in such phosphor was verified through X-ray diffraction (XRD) technique. The Dy ions concentration dependent luminescence properties including emission, excitation and lifetimes of Dy ions were characterized using photoluminescence (PL) spectroscopy. The results showed that CLPSCl:Dy3+ phosphor could efficiently assimilate the n-UV light and emit blue (~486 nm) and yellow light (~578 nm), originating from the f-f transitions of Dy3+. The critical Dy3+ quenching concentration (QC) was determined to be about 12 mol%. The concentration quenching mechanism was also determined to be dipole-dipole interaction.