Preparation and Luminescent Properties of Ca_3B_2O_6:Eu~(3+) Red Phosphor

Ca3B2O6:Eu3+ red phosphor was synthesized by high temperature solid state reaction and its luminescent properties were investigated.XRD analysis indicated the pure Ca3B2O6:Eu3+ crystallite was obtained at 1 100 ℃ for 2 h.Excitation spectrum consists of wide band located at 220 to 350 nm and a series of narrow bands located at 350 to 500 nm which are attributed to f-f transitions of Eu3+ ion.The peaks of excitation spectra are 280,396 and 469 nm,respectively.This phosphor can be excited effectively by near-ultraviolet light-emitting diodes(UVLED).The peaks of emitting spectra are 578,590,610,618 and 650 nm,corresponding to 5D4→7FJ(J=0,1,2,3)typical transitions of Eu3+,respectively.The effects of charge compensations and the molar concentration of Eu3+ on the emission intensity were also studied.The intensity of Ca3B2O6:Eu3+ was improved obviously with the increasing concentration of Eu3+,but the concentration quench did not observed.The role of charge compensations of Li+,Na+ and K+ ions can all increased the luminescent intensity of Ca3B2O6:Eu3+.Li+ ion gave the best improvement to enhance the intensity of the emission obviously.Li+ ion is the optimal charge compensation.