Iridium complex and preparation method thereof as well as electroluminescent device applying iridium complex

Abstract

The invention relates to iridium complexes having novel main ligands and taking tetraphenylphosphonium imide as an auxiliary ligand. The main ligands in the series of iridium complex molecules are (R-)4-piperidine-2-phenylpyridine or (S-)4-piperidine-2-phenylpyridine derivatives containing chiral phenylpyridine groups. Compared with an iridium complex which is widely researched and reported, the novel iridium complex covered by the invention has the advantages of high light-emitting efficiency, small luminescent quenching effect caused by concentration factors, high electronic mobility, stable chemical properties, easiness for sublimation and purification, and the like; in addition, the device is excellent in performance. By modifying a molecular structure of the main ligand, the luminous intensity and efficiency of the complex can be adjusted within a wavelength range of visible light, which provides convenience for design and production of an organic light emitting diode display and an illuminating light source. Meanwhile, the series of novel iridium complexes introduced in the invention are simple in synthesis method, higher in yield and flexible in chemical modification aiming at the ligands.

Description

【Technical field】 [0001] The invention relates to the technical field of organic electroluminescent devices, in particular to a class of iridium complexes, a preparation method thereof and an electroluminescent device using the iridium complexes. 【Background technique】 [0002] Against the background of increasing global energy demand and worrying ecological environment, governments of various countries have vigorously developed sustainable energy-saving technologies and industries based on high technology. Organic electroluminescent devices (OLEDs) have attracted much attention because of their advantages such as wide viewing angle, high brightness, low energy consumption and flexible devices, and are known as the key technology that will dominate the future display world. In recent years, a large number of studies have shown that among many complexes of heavy metal elements, iridium complexes are considered to be the most ideal choice of phosphorescent materials for OLEDs....

AI Technical Summary

Problems solved by technology

In addition, in the current commonly used materials, the hole mobility of hole transport materials is much higher than that of electron transport materials, and the commonly used host materials are mainly hole transport, which will lead to a large number of redundant holes. Aggregation of holes at the interface between the light-emitting layer and the electron-transporting layer

These factors can lead to reduced efficiency and severe efficiency roll-off

Studies have shown that if the iridium complex has a high electron transport ability, it can effectively increase the transport and distribution of electrons in the light-emitting layer, broaden the electron-hole area, balance the number of electron-hole pairs, and greatly improve the device. efficiency, the reduced efficiency of the roll-off

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