Preparation And Properties Of Rare Earth Doped LiBi（MoO₄）₂ Phosphor

With the development of society,people’s demand for light is increasing day by day.In the cutting-edge field,based on invisible light related applications are more,and in the civil field,people also have more demand for the cool and warm tones of visible light,the intensity of light,the energy efficiency of light,the color types of light and the brightness of color,and the concept of green environmental protection has always run through the cutting-edge field and the civil field.The manufacture of incandescent lamps,display screens and atmosphere lamps used in life are inseparable from phosphors.In this study,we synthesized a series of rare earth ion doped Li Bi（Mo O₄）₂ phosphor samples.Using less pollution and widely used high temperature solid phase method to prepare non-toxic phosphor samples,in order to fit the concept of green environmental protection.Through X-ray diffraction test,fluorescence spectroscopy test,SEM scanning electron microscope test,the optimal preparation process for Li Bi（Mo O₄）₂phosphor samples was determined.The Li Bi（Mo O₄）₂ phosphor sample was doped Yb³⁺and Ho³⁺to make its high intensity of orange light.On this basis,Li Bi（Mo O₄）₂:Yb³⁺,Ho³⁺phosphors were modified by Na⁺doping to further improve their luminous intensity,and the principle was analyzed At present,due to the insufficient performance of red phosphors used for white LEDs,its hue is cold,which limits its luminous intensity.The Li Bi（Mo O₄）₂ phosphor showed excellent color rendering performance in the experiment,so the Eu³⁺-doped Li Bi（Mo O₄）₂ phosphor sample was prepared.The main work contents and conclusions of this study are as follows:（1）LiBi（MoO₄）₂:Yb³⁺,Ho³⁺phosphors were prepared by high temperature solid phase method,and the optimal synthesis process was determined.Fluorescence spectrum data of sample Li Bi_0.99-x（Mo O₄）₂:x Yb³⁺,0.01Ho³⁺（x=0～0.4）synthesized at 550℃for 5h was tested.The intensity of the sample emitted bright orange light under near-infrared excitation at980 nm,and the sample with a Yb³⁺concentration of 30%has the strongest luminous intensity.（2）In the prepared Li_1-xNa_xBi（MoO₄）₂:0.3Yb³⁺,0.01Ho³⁺（x=0～1）phosphor sample,Rietveld analysis was performed at 10%to 90%Na⁺concentrations,which confirmed that the substitution of Na⁺to Li⁺led to a gradual increase in lattice size,and along with polarization,lattice distortion was resulted.The luminescence intensity was increased after Na⁺doping,which was the strongest at 30%and 80%Na⁺concentration.The color purity of fluorescence is above 90%,which provides a new reference for exploring ion-replaced doped phosphors.（3）The Eu³⁺-doped LiBi（MoO₄）₂ phosphor sample emits bright red light under excitation light irradiation with a wavelength of 465 nm,among which the Eu³⁺doping concentration of60%has the strongest luminous intensity,and the color purity of the red light of the all samples is more than 90%.With the decrease of Eu³⁺concentration,the red light emitted by the prepared phosphor（0.6509,0.3469）gradually approaches the standard red light source（0.67,0.33）,and Eu³⁺-doped Li Bi（Mo O₄）₂ phosphor may be a potential candidate for red solid state LED applications.