Preparation And Optical Properties Of Tellurite-based Double Perovskite Phosphor And Phosphor In Glass

In recent years,white light-emitting diodes（w LEDs）have come to replacing traditional light sources,due to long working hours,high luminescent efficiency,good stability,environmental friendliness,small size and flexible design.At present,the most commonly used method to prepare w LEDs is to encapsulate monochromatic or multicolor phosphors with blue or ultraviolet chips,that is,phosphor conversion white light-emitting diodes.Rare earth ions doped phosphors have a wide range of applications in optoelectronics,visible solid-state lighting,various fluorescent devices,and color displays.Trivalent lanthanide rare earth ions such as Ce³⁺,Eu³⁺and Pr³⁺have been widely studied as activator ions of yellow,green and red phosphors,respectively.The phosphors and blue or ultraviolet LED chips encapsulated with organic resin or silicone resin are easily aged and yellowed due to the high temperature of the chip,which eventually leads to the drift of the luminescent color.At low temperatures,the phosphor in glass（Pi G）prepared by co-sintering the phosphor and glass power has the advantages of good thermal conductivity and high stability,which has attracted the attention of researchers.The main research contents are as follows:Tellurite-based double perovskite was used as the matrix material for the preparation of phosphors.yellow,green and red phosphors were prepared by doping rare earth ions Ce³⁺,Eu³⁺,and Pr³⁺,respectively.In addition,phosphor in glass was prepared by low temperature co-sintering of phosphor and glass powder.The phase structure and luminescence properties of the phosphors were studied by X-ray diffraction,scanning electron microscopy,fluorescence spectroscopy and other characterization methods.1.The(Ba_0.3Sr_0.7)₂Zn Te O₆:Ce³⁺double perovskite yellow phosphor was successfully synthesized by a two-step high-temperature solid-phase method in an air atmosphere.The phosphor has a broadband emission at530 nm.The best luminescence intensity is when the Ce³⁺doping concentration adjusted to 1 mol%.By replacing the Zn O in the matrix raw material with Zn powder and controlling the solid solution,the luminescence intensity of(Ba_ySr_1-y)₂Zn Te O₆:Ce³⁺phosphor is enhanced.2.Sr₂Zn Te O₆:Pr³⁺green phosphor and(Ba_0.3Sr_0.7)₂Zn Te O6:Eu³⁺red phosphor were synthesized.By adjusting the doping concentration of Pr³⁺and Eu³⁺,the optimal luminescence intensity of the phosphor can be obtained.Sr₂Zn Te O₆:Pr³⁺has multiple spectrum emission from the blue region to the red region under excitation at 451 nm and 474 nm,respectively.The luminescence intensity of(Ba_0.3Sr_0.7)₂Zn Te O₆:Eu³⁺was enhanced by manipulating the solid solution.The phosphor has a sharp red light emission peak at a wavelength of 618 nm,and the luminescence intensity at 150°C can still maintain 84.4%of room temperature.3.Bismuth glass powders and commercial red phosphor（Sr,Ca）Al Si N:Eu²⁺successfully synthesizad red phosphor in glass by low-temperature co-sintering method.The composition of the Pi G was analyzed by X-ray diffraction and scanning electron microscopy,and the luminescence properties were analyzed by photoluminescence（PL）spectroscopy.The influence of factors such as sintering temperature,sintering time,and thickness on the luminescence properties of Pi G were investigated.The results show that the morphology and optical properties of the phosphor are completely preserved in the phosphor in glass,and the optimal sintering temperature is 430℃.The Pi G has the best luminescence intensity when the sintering time is 30 min,and the luminescence intensity increases with the increase of Pi G thickness.After prepared into Pi G,its thermal stability has been improved very well,and the luminescence performance at 150℃can still maintain 97.41%of room temperature.In this experiment,w LED was successfully assembled with red Pi G,green phosphor and blue chip.