Aromatic ring compound, display panel and display device

Abstract

The invention belongs to the technical field of organic electroluminescence, and provides an aromatic ring compound, wherein the aromatic ring compound has a structure represented by a chemical formula i; wherein m is 0, 1 or 2; X1-X6 are each independently selected from N atoms or C atoms, and 1 to 3 of the X1-X6 are nitrogen atoms; and Ar1-Ar4 are each independently selected from substituted orunsubstituted C6-C60 aromatic rings, C8-C60 fused aromatic rings, C4-C60 heteroaromatic rings, and C8-C60 fused heteroaromatic rings. When the compound is used as a CPL (cap layer) of an organic light-emitting device (such as an OLED), the light extraction efficiency and light emission efficiency of a top emission organic light-emitting display device can be improved (especially the most effectivefor blue light pixels), and the angular dependence of light emission of the OLED device can be alleviated (the most effective for red / green pixels). At the same time, the CPL can effectively block water and oxygen in the external environment and protect an OLED display panel from being corroded by water and oxygen.

Description

technical field [0001] The present invention relates to the technical field of organic electroluminescent materials, in particular to an aromatic ring compound, a display panel and a display device containing the aromatic ring compound. Background technique [0002] After decades of development, OLED has come a long way. Although the internal quantum efficiency of OLED is close to 100%, the external quantum efficiency is only about 20%. Most of the light emitted by OLEDs is confined inside the light-emitting device due to factors such as substrate mode loss, surface plasmon loss, and waveguide effect, resulting in a large amount of energy loss. [0003] In the top-emitting device, an organic covering layer (capping layer, CPL) is evaporated on the translucent metal aluminum electrode to adjust the optical interference distance, suppress the reflection of external light, and suppress the extinction caused by the movement of surface plasmons. , thereby improving the light ex...

AI Technical Summary

Problems solved by technology

However, the refractive index of existing CPL materials is generally below 1.9, which cannot meet the requirements of high refractive index; amine derivatives with specific structures and materials with high refractive index and the use of materials that meet specific parameters have improved the light extraction efficiency, but there is no solution. The problem of luminous efficiency (especially for blue light emitting elements)

In order to increase the molecular density and achieve high thermal stability of the materials in the prior art, the molecular structure is designed to be large and loose, and the molecules cannot be tightly packed, resulting in too many holes in the molecular gel during evaporation. , poor coverage tightness

For example, there are many electron transport materials used in the market, such as batho-phenanthroline (BPhen), bathocuproine (BCP) and TmPyPB (1,3,5-Tri(m-pyrid- 3-yl-phenyl)benzene), which can generally meet the market demand of organic electroluminescent panels, but their glass transition temperature is relatively low, generally less than 85 ° C, when the organic light-emitting device is running, the Joule heat generated will cause Degradation of molecules and changes in molecular structure, making panels less efficient and less thermally stable

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