Preparation and thermally stable luminescence properties of a new blue Sr5Cl0.75F0.25(PO4)(3): Eu2+ phosphor for WLEDs
Journal of Alloys and Compounds, 2015-09-25, 644:274-279
A series of new blue-emitting phosphors Sr5(1-x)Cl0.75F0.25(PO4)(3): 5xEu(2+) (x = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 mol%) were synthesized by high-temperature solid state reaction. X-ray powder diffraction (XRD) and field-emission scanning electron microscope (FE-SEM) were used to characterize the crystal structure and micro-morphology of the prepared samples. The photoluminescence properties of these phosphors were investigated by excitation and emission spectra. The effect of Eu2+ concentration on emission of the phosphor was investigated and the concentration quenching mechanism was discussed in detail. Also, the temperature-dependence luminescence properties of Sr5Cl0.75F0.25(PO4)(3): Eu2+ were compared with those of the commercial blue phosphor BaMgAl10O17: Eu2+ (BAM). With the increase of temperature, the emission band exhibited blue shift and decreasing emission intensities. The phosphor Sr5Cl0.75F0.25(PO4)(3): Eu2+ possesses higher thermal stability than BAM. Furthetmore, a bright blue LED was fabricated by combination of n-UV InGaN chip and the phosphor. The results reveal that Sr5Cl0.75F0.25(PO4)(3): Eu2+ is a potential blue phosphor for n-UV-pumped white light-emitting-diodes (WLEDs).
WLED; Thermally stable luminescence; Phosphor; Phosphate