Novel thermally robust warm white light emitting phosphor Ca18Li3Y(PO4)14:Dy3+: synthesis, crystal structure and luminescence property investigation

Abstract To explore novel single phase warm white light emitting phosphor, a series of phosphate phosphors Ca18Li3Y(PO4)14:Dy3+ were prepared. The phase purity, crystal structure, morphology and element component were confirmed by XRD Rietveld structure refinement, SEM and EDS analysis. The luminescence process of Ca18Li3Y(PO4)14:Dy3+ were systematically studied by photoluminescence spectroscopy and decay curves. The results indicated Ca18Li3Y(PO4)14:Dy3+ phosphors had strong excitation from 300 nm to 420 nm. Under the excitation of 350 nm, warm white light emission was achieved with the CIE color coordinates of (0.399, 0.448) and low CCT of ∼ 3992 K. The concentration quenching mechanism and quantum efficiency of Dy3+ in Ca18Li3Y(PO4)14:Dy3+ were calculated and discussed in detail. The thermal quenching behavior revealed that Ca18Li3Y(PO4)14:Dy3+ had excellent thermal stability with stable color rendition. The thermal activation energy was finally calculated. All the results indicated the potential application of Ca18Li3Y(PO4)14:Dy3+ white light emission phosphor to be used in solid state lighting.