Preparation And Luminescence Properties Of Double Rare Earth Organic Complex Thin Films

The complexes made of rare earth ions and organic compounds have wide application prospects in the field of fluorescent materials due to their excellent fluorescence properties.Many years of research have revealed that the choice of ligand organics has a great influence on the fluorescence emission intensity of rare earth organic complexes.After the preparation of efficient luminescent rare-earth complexes,in order to make their application areas wider,researchers usually use rare-earth complexes and polymers to prepare composite materials,which form rare-earth polymer materials can have the optical,electrical and magnetic properties of rare-earth complexes,but also have the characteristics of polymer materials such as easy processing and impact resistance,greatly increasing the value of the material applications.In this paper,the effects of different ligands,co-ligands and doping with another rare earth ion on the fluorescence properties of the complexes were investigated,and then the prepared rare earth organic complexes were doped into PVA and EVA to form composite luminescent films to investigate their optical performance.The main work was done as follows:Three different organic compounds were selected as ligands:salicylic acid（hsal）,benzoic acid（BA）,and 2-thiophene trifluorocarbonylacetone（TTA）to form complex materials with Eu³⁺,compare their fluorescence intensities,and analyze the reasons for the fluorescence differences from the perspective of matching the vibrational energy levels of rare-earth ions with the triplet state energy levels of the ligands;then 1,10-o-phenanthroline（phen）was used as a co-ligand The effect of the addition of the co-ligand on the luminescence properties of the rare-earth complexes was investigated;on this basis,Tb³⁺was doped to form Eu,Tb double rare-earth organic complexes,and the effect of the doping amount of Tb³⁺on the fluorescence intensity was investigated,and the reasons for the effect of the doping of Tb³⁺on the fluorescence intensity were analyzed;Fourier transform infrared spectroscopy（FTIR）and X-ray diffraction analysis（XRD）were used to verify whether the complexes The results of FTIR and XRD were used to verify whether the complexes were successfully synthesized,the content of various elements was examined using elemental analysis.The possible structures of the complexes were inferred from the above results;the heat loss analysis was used to test the heat resistance of the complexes and to infer the presence of free ligands in the complexes;the microscopic morphology,dimensions and other parameters of the complexes were observed by field emission electron scanning microscopy（FE-SEM）;Among the above-mentioned rare earth complexes,the one with the highest luminescence intensity was selected and doped into PVA（polyvinyl alcohol）and EVA（ethylene vinyl acetate copolymer）to form a composite luminescent film material.The fluorescence and heat resistance of the two films were compared,and the reasons for the differences were analyzed;the fluorescence intensity was measured under the same conditions after the two films were left in the natural state for 6 months to test the stability of the light-emitting films;the doping of the rare-earth complexes in the films was analyzed by FTIR and XRD;The microscopic morphology of the composite luminescent films was analyzed by field emission electron scanning microscopy FE-SEM observation to observe the distribution of the complexes in the films.