The Study On The Preparation And Properties Of Manganese-based Halide Light Emitting Materials

Metal halide perovskites have sparked continued research interest due to their high-performance optoelectronic properties.However,the blue light-excitable near-infrared(NIR)emitting metal halide perovskite materials are rarely studied,and the realization of such materials with roboust thermal quenching performance remains a great challenge.This thesis is divided into three chapters,including two aspects:one is design and synthsize blue-light excitable metal halide perovskite materials and then doping lanthanides ions into them;Another is the changing of alkaline ions to design and synthsize of new low-dimensional perovskite materials.The first chapter firstly summarizes the development status of perovskite materials and then gives a detailed overview on the classification and synthesis methods of all-inorganic metal halide perovskites.At the same time,the research background and significance of this topic are also introduced.The second and third chapters detailedly introduce the specific research ideas,experimental results and analysis and discussion of this thesis in detail,the deytails are as follows:(1)Through non-stoichiometric synthesis,an optimal ratio was finally found to successfully synthesize pure Cs Mn Cl₃single crystals without crystal water.The crystal structure was analyzed by single crystal X-ray diffraction,and the luminescence properties of the material were systematically studied by photoluminescence,fluorescence decay and temperature-variable spectroscopy.The synthesized Cs Mn Cl₃single crystal was used as a sensitizer to realize the energy transfer from Mn²⁺to Ln³⁺(Ln=Yb,Er and Ho)ions to achieve blue-excited multi-band near-infrared emission.By doping with different lanthanide elements,not only blue light excitation near-infrared emission but also the emission wavelength of near-infrared can be adjusted.The intrinsic energy transfer mechanism was studied by powder XRD,SEM,low-and high-temperature fluorescence spectra,and temperature-variable decay curves.By controlling the doping concentration of rare earth ions,the thermal quenching resistance of the material is regulated,and the nearly zero thermal quenching and even thermal quenching resistance of Cs Mn Cl₃:Ln³⁺are realized.Finally,the obtained Cs Mn Cl₃:5%Yb³⁺phosphor was combined with a commercial blue LED chip to form an NIR-LED device,thus confirming the practical possibility of blue light-excited near-infrared emission of this type of material.This work not only provides a general strategy for unlocking the blue-excitable NIR emission generated by the f-f transition of Ln³⁺ions,but also fundamentally understands the sensitization activation mechanism of Ln³⁺-functionalized manganese(II)-based perovskite phosphors.Moreover,it also endows metal halide perovskites with optical functions,and has extremely high application potential in the fields of optical communication in the future.(2)The zero-dimensional K₄Mn Cl₆perovskite with red light emission was successfully synthesized by using alkali metal potassium ions.The crystal structure and high temperature stability was studied through single crystal XRD and high temperature PL spectra,respectively.This work not only expands the research scope of the rarely reported all-inorganic low-dimensional perovskite materials,but also provides some ideas and approaches for the design of new high-stability low-dimensional perovskite luminescent materials in the future.