Compounds, display panel and display device

Abstract

The invention relates to the technical field of OLEDs, and provides compounds having TADF properties. The compounds have a structure represented by a formula (1) shown in the description, wherein L1 and L2 are each independently selected from the group consisting of a hydrogen atom, phenyl, naphthyl, anthryl, pyridyl, pyrimidinyl, and pyrazinyl; and R1 and R2 are each independently selected from aromatic or heteroaryl groups such as substituted or unsubstituted carbazolyl and a derivative group of the substituted or unsubstituted carbazolyl, acridinyl and a derivative group of the acridinyl, diarylamino and a derivative group of the diarylamino. According to the compounds provided by the invention, the bis-boron heterocyclic structure is used not only as an electron acceptor group but alsoas a linking group; and in the compounds, a large-steric-hindrance group is linked to a boron atom of a boron heterocyclic ring, so that aggregation of the compound molecules is avoided, pi-aggregation or an excimer is prevented from being formed due to direct accumulation of a conjugate plane, and the luminous efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of organic electroluminescent materials, in particular to a compound, a display panel and a display device including the compound. Background technique [0002] The light-emitting materials used in traditional OLEDs mainly include fluorescent materials and phosphorescent materials. Fluorescent materials can only use singlet light emission, which can achieve an internal quantum efficiency of 25%. Phosphorescent materials can simultaneously utilize their singlet and triplet luminescence to achieve 100% internal quantum efficiency. However, the efficiency of phosphorescent materials is severely attenuated, and most of them contain precious metals platinum and iridium, which greatly limits their development. [0003] In recent years, pure organic thermally induced delayed fluorescent materials (TADF) have made up for the shortcomings of phosphorescent and traditional fluorescent materials at the same time. Thi...

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Problems solved by technology

[0005] (1) The wide energy band (3.0eV) of the blue light material limits the conjugation length of the aromatic compound, the molecule cannot have a large conjugated structure, and the molecular size of the luminescent material cannot be too large, but the small molecular structure will make The thermal stability of the luminescent material is not high;

[0006] (2) A large rigid molecular structure is a necessary condition for obtaining high-efficiency blue light, but it is difficult to obtain a phase-stable film material if the rigid molecular structure is too large;

[0007] (3) The wide energy band makes the simultaneous injection of electrons and holes extremely difficult, which will break the balance of electrons and holes, resulting in a decrease in luminous efficiency

[0010] Although this type of compound with a propeller structure can well avoid quantum quenching caused by agglomeration, its free volume is large, which makes the glass transition temperature of the material drop, and the final thermal stability cannot meet the requirements.

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