A compound and its light-emitting device and display device

Abstract

The invention relates to the technical field of organic light-emitting materials, in particular to a compound, a light-emitting device and a display device thereof. The structural formula of the compound is shown in general formula I. The present invention proposes a TADF material based on tetraphenylethylene structure, which has both TADF and AIE effects. It can not only use triplet excitons that are forbidden by the transition of traditional fluorescent molecules to emit light, but also avoid high current density and doping concentration. Exciton quenching, which can significantly improve the efficiency of the device.

Description

technical field [0001] The invention relates to the technical field of organic light-emitting materials, in particular to a compound, a light-emitting device and a display device thereof. Background technique [0002] Organic electroluminescent devices (OLEDs) can be divided into fluorescent devices and phosphorescent devices according to the type of light-emitting excitons. Compared with traditional fluorescent devices that can only emit light using singlet exciton energy (25%), phosphorescent devices have a broader application prospect because they can theoretically achieve 100% internal quantum efficiency. However, phosphorescent devices are also criticized for their high cost (almost several times that of fluorescent materials) and poor stability (short lifetime) due to the presence of heavy metals. [0003] In the past two years, a new kind of luminescent material - Thermally Activated Delayed Fluorescence (TADF) material, using the principle of E-type up conversion, c...

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Problems solved by technology

[0005] In OLED devices, the luminescent material exists in the form of a solid film. Since the organic luminescent material is a large π conjugated system, it is prone to aggregation-induced fluorescence quenching (Aggregation Caused Quenching, ACQ) caused by the "π-π" stacking effect. resulting in inefficiencies

Tetraphenylethylene (TPE) is a blue-light AIE (Aggregation Induced Emission) material discovered earlier, but the efficiency of blue-light devices based on TPE is only 0.45cd / A, so how to modify TPE and design high-efficiency AIE materials still remains is a challenge

[0006] Since the current AIE materials based on tetraphenylethylene are all pure P-type, there are few bipolar (bipolar) type material designs, which are not conducive to the reduction of the potential barrier of the device and the carrier injection and transmission, thus affecting the efficiency and life of the device.

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