Preparation And Study On Red Phosphors Based On White Light LED

The fabrication and properties of phosphor used for white LED were paid more attention with the extension of applied field and the development of preparation technology in white LED. Especially, the properties of phosphor excited by blue and UV light can effect directly the color rendering of white LED.A novel stable red phosphor Li_(2-x)(MoO₄)₂:Eu_x³⁺ and Sr_(1-X)MoO₄:Eu_x³⁺ were prepared by solid state method and sol-gel process combined. The influence of the concentration of Eu3+ ,the reaction temperature , the reaction time, PH, the dosage of citric acid and the reaction time on the luminescent properties were studied. It can be seen that the excitation spectra of Li_(2-x)(MoO₄)₂:Eu_x³⁺ included from 300nm to 500nm,which had three excitation peaks at 306nm,395nm and 466nm;the emission spectra are composed of a set of aiguilles included the peaks at 536nm,554nm,591nm,615nm and 654nm,which were corresponded with the transition of 5DJ(J=0,1)-7FJ(J=1～4) in Eu3+.The excitation spectra show effective absorption wave lengths at ultraviolet (UV) (395nm) and blue (465nm) corresponding to the f-f transition of Eu³⁺.These wave lengths coincide with the wave lengths of commercial GdN based LED, so that the phosphor may be a better candidate for red component for white LED.