Condensed ring compound containing two boron atoms and one or three chalcogen atoms and organic electroluminescent device

Abstract

The invention provides a fused ring compound containing two boron atoms and one or three chalcogen atoms, and the fused ring compound is shown as a formula (I) or a formula (II). Compared with the prior art, the condensed ring compound containing two boron atoms and one or three chalcogenide atoms is adopted as the light emitting unit, on one hand, separation of HOMO and LUMO can be achieved through the resonance effect between the boron atoms and the chalcogenide atoms, and therefore small delta EST and TADF effects are achieved; meanwhile, a hybrid condensed ring unit of boron atoms and oxygen atoms has a rigid skeleton structure, and the relaxation degree of an excited state structure can be reduced, so that a relatively narrow half-peak width is realized; on the other hand, different substituent groups are introduced into the skeleton of the fused ring unit, so that the delayed fluorescence lifetime and the half-peak width can be further adjusted. Experimental results show that when the luminescent compound is used as a luminescent layer of the electroluminescent device, narrow electroluminescent half-peak width can be realized without an optical filter and a microcavity structure, and high external quantum efficiency of the device can also be realized.

Description

technical field [0001] The invention belongs to the technical field of materials, and specifically relates to a condensed ring compound containing two boron atoms and one or three oxygen group atoms and an organic electroluminescence device. Background technique [0002] Organic light-emitting devices (OLEDs) are usually composed of a cathode, an anode, and an organic layer inserted between the cathode and the anode, generally including a transparent ITO anode, a hole injection layer (TIL), a hole transport layer (HTL), and a light emitting layer (EL). ), hole blocking layer (HBL), electron transport layer (ETL), electron injection layer (EIL) and cathode, 1~2 organic layers can be omitted as required, the mechanism of action is to form a voltage between the two electrodes, from the cathode When electrons are injected, holes are injected from the anode. The electrons and holes combine to form an excited state in the light-emitting layer, and the excited state radiates back t...

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Problems solved by technology

However, this D-A structure exhibits a large Stokes shift due to the vibrational relaxation of its excited state, and the luminescence spectrum is wide, and the half-maximum width (FWHM) is generally 70-100nm. In practical applications, filters or Constructing optical microcavities to improve color purity, but this will lead to a decrease in the external quantum efficiency of the device or a complex device structure

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