Condensed ring compound containing two boron atoms and four chalcogen atoms and organic electroluminescent device

Abstract

The invention provides a fused ring compound containing boron atoms and selenium or tellurium atoms. The fused ring compound is shown as a formula (I). Compared with the prior art, the condensed ring compound containing boron atoms and selenium or tellurium atoms is adopted as the light-emitting unit, on one hand, the relaxation degree of an excited state structure can be reduced by utilizing a rigid framework structure of the organic boron condensed ring compound, and therefore the narrow half-peak width is achieved; on the other hand, intersystem crossing is promoted through the heavy atom effect of selenium or tellurium atoms, the delayed fluorescence effect is activated, and therefore high luminous efficiency is achieved. Meanwhile, by changing the types of aromatic rings or heteroaromatic rings contained in the fused ring compound, 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, in particular to a condensed ring compound containing two boron atoms and four oxygen group atoms and an organic electroluminescent 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-transporting layer (ETL), electron-injecting layer (EIL) and cathode, and 1-2 organic layers can be omitted as required. The mechanism of action is to form a voltage between 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 to the ground stat...

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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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