An organic electroluminescent device

Abstract

The invention provides an organic electroluminescent device, comprising a cathode, an anode and an organic thin film layer, at least one layer of the organic thin film layer comprising a single compound or a compound represented by the following formula (1) as a mixture component: In formula (1), X is selected from nitrogen atom or with R 1 bonded carbon atom, C 1 to C 5 are independently selected from R 2 bonded carbon atom, R 1 and R 2 independently selected from a hydrogen atom, a cyano group, a linear or fluoroalkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms , a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaromatic hydrocarbon group having 5 to 30 carbon atoms. The present invention also provides novel compounds selected from the above general formula (1). The electrical performance of the organic electroluminescence device of the invention is very good, and the compound of the general formula of the invention can be used as a luminescent material, and the stability is very good.

Description

technical field [0001] The invention relates to a novel organic electroluminescent device which can be used in the field of light emission, in particular to an organic electroluminescent device using a novel stable luminescent material. Background technique [0002] Organic electroluminescent devices (hereinafter referred to as OLEDs) have a series of advantages such as self-luminescence, low-voltage DC drive, full curing, wide viewing angle, light weight, simple composition and process. Compared with liquid crystal displays, organic electroluminescent displays are not It needs a backlight source, has a large viewing angle, low power, and its response speed can reach 1000 times that of a liquid crystal display, but its manufacturing cost is lower than that of a liquid crystal display with the same resolution. Therefore, organic electroluminescent devices have broad application prospects. [0003] With the continuous advancement of OLED technology in the two major fields of l...

AI Technical Summary

Problems solved by technology

Studies have reported that the reason why many luminescent materials are unstable in the excited state is that the excitation energy is equivalent to the energy of the weakest bond in the molecule, so the weakest bond is easily broken in the excited state, which leads to the degradation of the material and the reduction of the device life. For TADF materials, the weakest bond in the molecule is generally the bond between the electron donor and the linker

On the other hand, the electron donors of most luminescent materials have the problems of low oxidation potential and much higher hole-transporting ability than electron-transporting ability, which makes them prone to charge injection imbalance or oxidation during the working process. It will also lead to a decrease in device efficiency and lifetime.

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