Luminescent Properties And Structure Of Rare Earth Doped AlON Phosphors

With the advancement of science and technology and the improvement of the quality of life,people’s demands for various areas of life are increasingly high,and lighting is one of them.Green and energy saving have become the new demand trend,and LEDs have become the focus of research in the lighting and display field because of its advantages in luminous efficiency,energy consumption and environmental protection and energy saving.Due to the excellent optical properties,low thermal conductivity and the expansibility of nitride and oxynitride based phosphors,they have been paid more and more attention in recent years.Among them,nitrogen alumina has been widely studied because of its excellent luminescent properties.AlON is a stable single-phase solid solution with excellent optical transparency and thermal stability,which makes it a good choice for phosphor substrates.In recent years,many doped AlON phosphors have been synthesized by different methods,and their luminescence properties,such as blue to green luminescence,have been studied in detail.However,the position of doped rare earth elements(Eu²⁺,Ce³⁺,etc.)in the crystal lattice have not been studied in depth,which affects the better understanding and deeper exploration of their luminescence mechanism.In this paper,the AlON phosphor doped with rare earth element Eu was taken as the main object of research.In this study,the luminescence properties of the sample are characterized and analyzed,and the microstructure of the Eu²⁺doped AlON-based phosphor sample is studied and analyzed in depth.In the experiment,the phosphor samples were prepared by the conventional high-temperature solid phase method,and the Eu-Mg co-doped AlON phosphor was synthesized by Al₂O₃,AlN,Mg O and Eu₂O₃chemicals(referred to as AlON:Eu²⁺in the following articles).The main research contents of this paper are as follows:（1）Through the spectral analysis of the prepared Eu doped AlON phosphor,the emission spectrum of AlON:Eu²⁺phosphor sample shows a wide band emission with the wavelength of 479 nm as the center under the excitation of near ultraviolet light at 325 nm,because of the Eu²⁺4f⁶ 5d–4f⁷ transition.（2）The effects of Eu doping concentration on the optical properties of AlON:Eu²⁺phosphors were discussed by setting different Eu concentration gradients.（3）The effect of temperature on AlON:Eu²⁺phosphors was discussed by setting different temperature gradients.（4）The structure of AlON:Eu²⁺phosphors was characterized and analyzed by X-ray diffraction pattern refinement,high resolution transmission electron microscope,scanning transmission electron microscopy and EDS-Mapping characterization,etc.,to study the position of Eu²⁺points in the matrix lattice of AlON:Eu²⁺phosphors.（5）By analyzing the X-ray absorption near-edge structure of AlON:Eu²⁺phosphors,it is concluded that the Eu ion in AlON:Eu²⁺mainly exists in the form of Eu²⁺.In addition,the photoluminescence spectra of AlON:Eu²⁺phosphors and Eu Mg Al₁₀O₁₇ phosphors and the coordination environment of Eu ions in the two phosphors were analyzed and compared to study the similarity between the layered structure of Eu in the sample and the common layered structure of Eu Mg Al₁₀O₁₇ phosphors.In this paper,the optical properties,the effects of temperature and doping concentration of AlON:Eu²⁺phosphors and their microstructure have been deeply explored,and it proves that doping of Eu²⁺does not change AlON:Eu²⁺phosphors.The spinel structure of the matrix lattice of Eu²⁺phosphors is embedded in it in a layered structure similar to that of Eu Mg Al₁₀O₁₇,which will play a positive role in future research on the location structure and optical properties of the rare earth ions doped by AlON phosphors.