Synthesis And Characterization Of Iridium-based Phosphorescent Materials For OLED

In phosphorescent materials,the coupling effect of heavy metals in the spin-orbit makes the luminescent materials phosphorescent,which makes the theory of phosphorescent OLED doped devices up to 100%,and the heavy metal iridium complexes are the most widely studied and applied electrophosphorescent materials.Despite the phosphorescent materials has been used in the market,but the blue light emitting material because of its structure and performance requirements are often not stable and short service life,has always been the focus of experts and scholars.The paper mainly focuses on how to design synthetic stable and efficient blue phosphorescent materials.In this paper,the nature of baicalein and baicalin is studied.Baicalein is the glycoside of baicalin,and the hydroxyl group of baicalein is replaced by glucodoglycoside.The structure of baicalein and baicalin contains hydroxyl and ketone groups which are similar with acetyl acetone.The strong absorption electron effect of the polyhydroxyl structure greatly reduces the conjugated system of the molecule,increasing the molecular orbital HOMO and LUMO energy level,which can be used as the ligand of blue phosphor materials.In this paper,the synthesis of iridium phosphatide and baicalin metal complexes were summarized.Baicalein and baicalin were used as the ligands reaction with hydrated iridium to synthesize complexes.The factors affecting its synthesis were molar ratio,solvent,pH value,reflux temperature and reflux time.The optimum synthesis technology of baicalein-iridium complex was determined by single factor experiment,and the preparation technology of baicalin-iridium complex was determined.In this paper,baicalein-iridium complex and baicalin-iridium complex were first prepared by chemical precipitation method,and the structure and properties of the complex were characterized.Structure characterization results: complex was iridium ion as the core,the ligands with hydroxyl,ketone group or carboxyl as side loci ring of metal complex with iridium ion.Performance characterization results: the fluorescence emission spectra of baicalin-iridium complex were measured by fluorescence emission spectra of 539 nm and 35 ms respectively,which was a green phosphorescent material,and thermal analysis showed that the decomposition temperature of the baicalein-Ir complex was 300?.The fluorescence emission spectra of baicalin-iridium complex was measured with the maximum emission wavelength and luminous life of 442 nm and 20 ms respectively,which was a blue phosphorescent material.Thermal analysis showed that the decomposition temperature of the baicalin-Ir complex was 200?.