Synthesis, crystal structure and photoluminescence properties of new blue-green Ba1−x(PO3)2:Eux2+ (0 < x ≤ 0.040) phosphors for near ultraviolet based white light-emitting diodes

A series of new blue-green Ba1−x(PO3)2:Eux2+ (x = 0.005, 0.010, 0.020, 0.030, 0.035, 0.040) phosphors were synthesized by a solid-state reaction. The phase purities and crystal structures of the series were characterized by X-ray diffraction (XRD) and Rietveld refinements. Their photoluminescence properties were investigated by means of excitation, emission spectra and Commission International de L'Eclairage (CIE) chromaticity coordinates. The concentration quenching mechanism of Eu2+ emission in Ba(PO3)2 hosts was studied. Thermal stability was evaluated by temperature-dependent luminescence of Ba0.970(PO3)2:Eu0.0302+ phosphor. Moreover, the activation energy (Ea) for thermal quenching was calculated. The photoluminescence of Ba0.970(PO3)2:Eu0.0302+ phosphor shows higher thermal stability than that of the commercial blue phosphor BaMgAl10O17:Eu2+ (BAM). All the results show that Ba(PO3)2:Eu2+ phosphor is a potential blue-green phosphor for near ultraviolet-based white light-emitting diodes (WLED).