Aromatic amine compound, and application thereof in organic electroluminescent display device

Abstract

The invention discloses an aromatic amine compound, and application thereof in an organic electroluminescent display device, and belongs to the field of organic electroluminescent materials. The aromatic amine compound has a chemical structure as shown in a formula, wherein L1 is a direct bond, a substituted or unsubstituted arylene with a ring-forming carbon atom number of 6-30, or a substituted or unsubstituted heteroarylene with a ring-forming carbon atom number of 5-30; R1 is selected from X1 and X which are both single bonds, X1 is selected from O, S and N atoms, and X is C or N atom; and R2 is substituted or unsubstituted aryl or heteroaryl with the carbon atom number of 6-30, alkylaryl substituted or unsubstituted amido with the carbon atom number of 6-30, and multi-substituent substituted or unsubstituted heterocyclic radical with the carbon atom number of 1-30. The aromatic amine compound provided by the invention has high refractive index and excellent crystallization resistance and solubility, can improve the luminous efficiency and stability of an OLED as a covering layer material, and is suitable for large-scale industrial production.

Description

technical field [0001] The invention belongs to the field of organic electroluminescent materials, in particular to aromatic amine compounds and their application in organic electroluminescent display devices. Background technique [0002] At present, the capping layer materials of organic electroluminescent display devices (OLED) require compound molecules to have high refractive index, low extinction coefficient, excellent crystallization resistance and good solubility. In general, increasing the rigid group is conducive to increasing the refractive index, but at the same time it will increase the extinction coefficient, and it is prone to crystallization and poor solubility, making it difficult to apply materials with high refractive index in OLEDs. [0003] Series compounds such as benzoxazole, benzothiazole and benzimidazole have the characteristics of strong rigidity and good ultraviolet absorption, and are used in OLED devices. As described in patent documents such as...

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Problems solved by technology

In general, increasing the rigid group is conducive to increasing the refractive index, but at the same time it will increase the extinction coefficient, and it is prone to crystallization and poor solubility, which makes it difficult to apply materials with high refractive index in OLEDs.

[0003] Series compounds such as benzoxazole, benzothiazole and benzimidazole have the characteristics of strong rigidity and good ultraviolet absorption, and are used in OLED devices. As described in patent documents such as KR102059550B1 and CN111869326A, these compounds have higher The refractive index is close to or exceeds 2.1 at a wavelength of 460nm, but benzoxazole, benzothiazole, and benzimidazole series compounds will crystallize after long-term device use

In order to obtain a compound with a higher refractive index, more rigid naphthooxazole, naphthothiazole, and naphtimidazole are usually added, but this compound is currently difficult to use in mass production, mainly due to poor solubility and easy crystallization

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