Investigation of Spectroscopic Properties in Eu 2+ Activated Ba5-xSrx(PO4)3Cl

Eu 2+ doped Ba 5-xSr x(PO 4) 3Cl (x=0,1,2,3,4,5)blue phosphors particle were prepared by the conventional solid-state reaction method. It can be clearly exhibited that XRD peaks of the samples shift to the smaller angle side with the increasing content of Ba 2+.In excitation spectra, two peaks fell toward each other of all the samples and their intensities decreased with increasing content of Ba 2+, which can be explained by the configuration-coordinate model. Seen from the emission spectra, the position of the emission peaks did not change with the excitation wavelengths, which indicated that two emission peaks did not come from two different sites of Eu 2+ ions. It can be attributed to two Stark levels of 4f 65d 1 configuration. The broader emission bands can be attributed to the increase of inhomogeneous line width from changed crystal field by introducing Ba 2+ ions. The excitation and emission spectra show that Eu 2+ doped Ba 3Sr 2(PO 4) 3Cl is a promising blue phosphor for ultraviolet light emitting diode (LED).