Iridium complexes and preparation method thereof and electroluminescent devices using iridium complexes

Abstract

The invention relates to a class of iridium complexes which have novel main ligands and uses tetrakis(4-trifluoromethyl-3-pyridyl)phosphonimides or tetrakis(4-trifluoromethyl-3,5-pyrimidinyl)phosphonimides as auxiliary ligands. The main ligands in the molecule of this class of iridium complexes is any one selected from 2-(4,6-bis-trifluoromethylpyridine-3-)quinoline, 2-(4,6- bis-tribenzymethylpyridine-4-)quinoline, 2-(4,6-bis-trifluoromethylpyridine-3-)isoquinoline, 2-(4,6-bis-tribenzymethylpyridine-4-)isoquinoline, 2-(4,6-(bis-trifluoromethylpyridine-3-)quinazoline, 2-(4,6-bis-tribenzymethylpyridine-4-)quinazoline, 2-(4,6-bis-tribenzymethylpyridine-3-)phthalazie and 2-(4,6-bis-tribenzymethylpyridine-4-)phthalazine derivatives. Not only the novel iridium complexes have the advantages of being high in luminous efficiency, stable in chemical properties, easy to sublimate and purify and the like, but also the electroluminescent devices using the iridium complexes are excellent in the performance. By modifying the molecular structure of the ligands, it is possible to adjust the luminous intensity and efficiency of the complexes in the red wavelength range, and the design and production of both organic electroluminescent displays and illumination light sources are facilitated.

Description

[0001] 【Technical field】 [0002] 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. [0003] 【Background technique】 [0004] 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 mater...

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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