Study On Preparation And Properties Of White Long-lasting Phosphor Y₂O₂S:Tb³⁺,Eu³⁺,Mg²⁺,Ti⁴⁺

Long afterglow luminescence materials of doping rare earth have beenwidely used in lighting, display, ceramic, plastic, luminous paint, glass, laserdevice, and optical communications fields. Colours of the developedlong-lasting phosphors cover from blue to red. However, no phosphor withwhite long afterglow has been developed into a commercial application so far,while white light is the most suitable for illuminating light sources. It is hardto obtain white-light long afterglow phosphorescence from the combination ofcurrent available threeprimary color (blue, green and red) phosphors since wecan hardly ensure the very consistent afterglow decay processesfor the threeprimary colors phosphors In this paper, white light long afterglow phosphorsY2O3++2S:Tb, Eu3, Mg2+, Ti4+are prepared by the sol-gel method andhydrothermal method. In all samples, Y2O2S is used as matrix,(Tb3+and Eu3+)are used as double activators, and (Mg2+and Ti4+) are used as double auxiliaryactivators. The excitation and emission spectrum, morphology, phase, andafterglow decay curves of samples are characterized by the fluorescencespectroscopy, scanning electron microscope, X-ray diffraction, and phosphoroph-Otometer.The samples are prepared through the sol-gel method, and also we study theeffect of doping different concentration of Eu3+, sulfuretted temperature, heatingrate and soak time on the performances of samples. The results show that thewhite light is derived from emission peaks mixing of Tb3+and Eu3+. They belong to the energy level transition from5D573andD4toFJ(J=1,2,3,4,5,6) of Tb3+ions and from5Di(i=0,1,2) to7Fj(j=1,2,3,4) of Eu3+ions. It is mainly comesfrom the blue light emission at417nm (5D3â†'7F5) and the yellowish-greenlight emission at544nm (5D4â†'7F5) of Tb3+ions and the red light emission at626nm (5D70â†'F2) of Eu3+ions. The0.75%Eu3+is considered as appropriatedoping concentration of Y+2O3+2S:Tb, Eu3, Mg2+, Ti4+. Under this concentration,sample has pure Y2O2S phase, and the CIE chromaticity diagram is (0.311,0.308) and the decay time can last for over1451s (≥1mcd/m2). Moreover, thesamples have better luminescence properties at heating rate6oC/min with1200oCfor2h in reduced atmosphere.In order to obtain the Y2O2S:Tb3+, Eu3+, Mg2+, Ti4+white light long-lastingphosphors with specific morphology structure, we synthesis Y3+2O2S:Tb, Eu3+,Mg2+, Ti4+phosphors samples with hydrothermal method. The research resultsshow that samples with tubular morphology can be prepared at low temperature.The samples can keep complete morphology structure can not exceed800oC.when the doping concentration of Eu3+is0.90%, it has good luminescenceproperties.