Electron transport layer, organic electroluminescent device containing the electron transport layer and preparation thereof

Abstract

The invention discloses an electron transport layer, which contains an organic electron transport material of formula 1 and an organic electron transport material of formula 2, wherein the organic electron transport material of formula 1 is one or any combination of two or more compounds with the structure of formula 1 , the organic electron transport material of formula 2 is one or any combination of two or more compounds with the structure of formula 2, formula 1, in formula 1, Ar is selected from condensed ring aromatic hydrocarbons with 6 to 30 carbon atoms, or Selected from condensed heterocyclic aromatic hydrocarbons with 6 to 30 carbon atoms; R1 is phenyl, biphenyl, naphthyl, alkyl with 1 to 5 carbons or hydrogen; n is selected from integers from 2 to 3; Formula 2, in formula 2, Ar is selected from condensed ring aromatic hydrocarbons with 6 to 30 carbon atoms, or selected from condensed heterocyclic aromatic hydrocarbons with 6 to 30 carbon atoms; n is selected from integers from 1 to 3; formula The weight ratio of the organic electron transport material of 1 to the organic electron transport material of formula 2 is: 90:10-10:90.

Description

technical field [0001] The invention belongs to the field of organic electroluminescent devices, and relates to an electron transport layer, an organic electroluminescent device with the electron transport layer and a preparation method thereof. Background technique [0002] The lifetime of organic electroluminescent devices (OLEDs) is usually defined as the time required for the luminance to decay to 50% of the initial luminance (LT50), however such a definition is not practical. Nokia published an article at the 2007 International Display Information Conference (SID). In the article, OLED displays were used for mobile phone panels, and six different display screens were compared. The brightness of these six screens will vary with the extension of operating time. Attenuation, the picture quality will also decline. Using the actual human eye to evaluate the picture quality, it is found that when the picture brightness is attenuated to 5%, the human eye can judge the differen...

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Problems solved by technology

However, this literature does not mention the impact on lifespan

[0005] In summary, although the above patent documents have improved the performance of the device, they have not specifically improved the life of the LT90, and there is still a lot of room for improvement in the device performance in the above patent documents

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