Preparation And Fluorescence Properties Of Bi³⁺/Rare Earth Ions Doped Metal Oxides Phosphors

Rare earth ions doped luminescent materials have very important application in the fields of optical communication,laser,illumination,plant photosynthesis and so on.However,most of the current luminescent ions are doped with trivalent rare earth ions with f-f transition,which have the disadvantages of weak absorption,narrow spectral lines,and fixed emission band,and greatly limits the practical application.In addition,non-contact optical temperature sensors have been widely studied due to drawbacks of traditional contact sensors,such as low sensitivity and slow response.Therefore,based on the above key issues,the following aspects have been studied:1.Fluorescence characteristics and energy transfer of BaGd₂O₄:Bi³⁺,Eu³⁺phosphors:BaGd₂O₄:Bi³⁺,Eu³⁺phosphors were prepared by traditional high temperature solid phase method.The crystal structure and fluorescence properties of the phosphors were systematically studied by XRD,SEM and spectroscopy.In the BaGd₂O₄:Bi³⁺phosphor,broadband absorption at 337 nm and blue emission at 432nm were obtained.Excited by 337 nm light,BaGd₂O₄:Bi³⁺,Eu³⁺phosphors are adjustable from blue to red light and the the main energy transfer mechanism from Bi³⁺to Eu³⁺via quadrupole-quadrupole interaction.It is indicated that Bi³⁺can effectively broaden the ultraviolet absorption of Eu³⁺in BaGd₂O₄ matrix and enhance the fluorescence emission of Eu³⁺under ultraviolet excitation.It has certain application prospects in plant lighting.2.Temperature sensing properties of SrY₂O₄:Yb³⁺,Er³⁺phosphors:Adjustable emission from blue to red light is achieved by adjusting the content of Yb³⁺ions under980 nm laser excitation.The temperature measurement performance was studied by the fluorescence intensity ratio technique based on the thermal coupling level,and the maximum relative sensitivity S_R was 1.32%K^-1.Cycling tests of FIR have shown good repeatability.The results show that SrY₂O₄:Yb³⁺,Er³⁺phosphors are promising candidates for optical thermometers.3.Temperature measurement performance of BaGd₂O₄:Bi³⁺,Sm³⁺phosphor:The luminescence of BaGd₂O₄:Bi³⁺,Sm³⁺phosphor was achieved under the excitation of337 nm ultraviolet light.The maximum absolute sensitivity value S_A was 1.64%K^-1by temperature-dependent spectroscopy.It indicates that BaGd₂O₄:Bi³⁺,Sm³⁺phosphors have potential applications in the field of temperature sensing.