The Prepartion And Properties Of Dy³⁺,Eu³⁺ Co-doped Single Matrix White Phosphor

White Light Emitting Diode?WLED?is a new type of solid-state semiconductor light-emitting device and a new generation of lighting source,so the preparation and research of white fluorescent powder has become a hot spot.wavelength of 470-490 nm,the ⁴F_9/2?⁶H_13/2transition can emit yellow light with a wavelength of 570-580 nm,and the ⁵D₀?⁷F₂transition of Eu³⁺can emit red light with a wavelength of 610-620 nm.The mixing of these three kinds of light can obtain white light with blue,yellow and red components.Therefore,Dy³⁺,Eu³⁺co-doped single substrate white fluorescent powder has great research and development potential.But in order to get high quality white light,we must enhance the composition of blue light in the emission spectrum.In this study,the single substrate white phosphor of KGd F₄:Dy³⁺,Eu³⁺and KGd F₄:Dy³⁺,Eu³⁺@GQDs were prepared by precipitation method.The single substrate white green phosphor of Gd-MOFs:Dy³⁺was prepared by hydrothermal method.The Gd-MOFs:Dy³⁺@Gd-MOFs:Eu³⁺was prepared by precipitation method.The composite of phosphor and glass was synthesized by high temperature solid phase method.The samples were analyzed by X-ray diffraction?XRD?,scanning electron microscope?SEM?,Energy-dispersive spectroscopy?EDS?,fluorescence spectrum,fluorescence lifetime and thermal decomposition.The research results are as follows:Through the analysis of the emission spectrum of the materials,Eu³⁺have successfully realized the high-quality white light emission,and the natural white light,warm white light and orange red light emission can be realized by adjusting the doping ratio of Eu³⁺,and the color temperature value of the material is controlled below 6000 K.Graphene carbon quantum dots?GQDs?coating KGd F₄:Dy³⁺,Eu³⁺can effectively enhance the luminescent intensity of the material.At the same time,through the study of the thermal quenching of KGd F₄:Dy³⁺,Eu³⁺@GQDs,it is found that the positive and negative quenching occurs with the increase of temperature.Through the thermal decomposition analysis of Gd-MOFs:Dy³⁺at12?.min^-1,the initial decomposition temperature of the material is about420?,when the temperature reaches 590.8?,the decomposition rate is the largest,when the temperature reaches 720?,the thermal decomposition basically ends.According to the non isothermal kinetic theory,the thermal decomposition mechanism function,decomposition principle and activation energy of the phosphor were obtained.Through the thermal quenching analysis of Gd-MOFs:Dy³⁺@Gd-MOFs:Eu³⁺,it is found that when the temperature is lower than 120?,the luminescence of the fluorescent material is white light,when the temperature reaches 150?,the emission light changes from white light to orange red,and the color temperature gradually decreases with the increase of temperature,which makes the fluorescent powder have a great application prospect in the fluorescent temperature sensor.Through the preliminary analysis of the fluorescence spectrum of KGd F₄:Dy³⁺,Eu³⁺and glass composite,it is found that the emission spectrum of the composite has a blue shift phenomenon and the white light temperature is increased.