Rare-Earth Organic/Inorganic Hybrid Micro-Nanoluminescent Luminescent Materials Containing Conjugated Organic Functional Ligands

OLED is a kind of green light source.It has small volume,light weight,quick response and environmen-friend.Organic luminescent material is a critical factor to OLED,but there are some problems such as luminescence decay and poor thermal stability.Rare-earth complexes are assembled into molecular sieves to obtain organic-inorganic hybrid luminescent materials.It not only has good monochromaticity of emitted light,high quantum yield of emitted light,coverage of visible light region,but also has the advantages of optical,thermal,chemical and mechanical stability of inorganic materials.It has a broad prospect of Research and development.We have prepared salicylic acid-phenanthroline europium rare-earth complexes,salicylaldehyde ethylenediamine europium?samarium?rare-earth complexes and salicylaldehyde benzoylhydrazone europium?samarium?rare-earth complexes.Meanwhile the MCM-41 nano-molecular sieves and ZSM-5 nano-molecular sieves of different crystal forms and sizes were prepared by hydrothermal method.Findlly the prepared series of rare earth complexes were assembled into MCM-41 and ZSM-5molecular sieve to obtain organic/inorganic hybrid luminescent materials.The structure and properties of hybrid luminescent materials were characterized by XRD,IR,UV,SEM,PL.The results show that the hybrid luminescent materials not only improve the stability of the rare earth complexes,but also increase the luminescence intensity of the rare earth complexes.Molecular sieves and rare earth complexes are connected by weak interaction forces such as intermolecular forces and coordination bonds.The larger specific surface of molecular sieves makes effectively rare earth complexes uniformly to improve their fluorescence performance.The triplet energy level of rare earth ions,the conjugated rigid chain of organic ligands,and the structure of molecular sieves are the main factors affecting the luminescence intensity and stability of hybrid luminescent materials.Compared to salicylaldehyde benzoyl hydrazone rare-earth complexes,the fluorescence intensity of salicylaldehyde benzoylhydrazone europium???/MCM-41 has increased by 2 times,the fluorescence intensity of salicylaldehyde benzoylhydrazone europium???/ZSM-5 has increased by3.5 times,the fluorescence intensity of salicylaldehyde benzoylhydrazone samarium???/MCM-41 has increased by 5 times and the fluorescence intensity of salicylaldehyde benzoylhydrazone samarium???/ZSM-5 has increased by 8 times.However salicylaldehyde ethylenediamine europium???/MCM-41 and salicylaldehyde ethylenediamine europium???/ZSM-5 hybrid luminescent materials'fluorescence intensity has increased 1.4¹.6 times.It can prove that the difference of molecular sieve composition has little effect on the luminescence properties of hybrid luminescent materials.The degree of matching between the triplet energy level of the ligand and the excited state energy level of rare earth ions is the key to determine the energy transfer efficiency between the ligand and the rare earth ions.Samarium???⁴G_5/2?565 nm?and salicylaldehyde benzoylhydrazone ligand?525 nm?has good matching properties.Conjugated organic ligands can efficiently transfer energy to rare earth ions and sensitize samarium ions.The fluorescence properties are best.In the fluorescence decay test,the fluorescence intensity of the hybrid luminescent material was 2 times of the similar rare earth complexes after 150 days.The properties and stability of the hybrid luminescent material are related to the structure of the ligand an and the composition of the molecular sieve.Adjusting rigid conjugate structure and molecular sieve structure of organic ligands is an important means to realize the performsnce control of organic/inorganic hybrid luminescent materials.