Electroluminescence device based on boron-containing organic compound

Abstract

The present invention relates to an electroluminescence device based on a boron-containing organic compound, wherein a main body material comprises a first organic compound and a second organic compound, the difference between a singlet state energy level and a triplet state energy level of the first organic compound is not greater than 0.2 eV, the singlet energy level of the second organic compound is greater than the singlet energy level of the first organic compound by more than 0.1 eV, and the triplet energy level of the second organic compound is greater than the triplet energy level of the first organic compound by more than 0.1 eV; the first organic compound and the second organic compound have the different carrier transport characteristics, wherein an object material is the boron-containing organic compound, the singlet energy level of the object material is lower than that of the first organic compound, and the triplet energy level of the object material is lower than that ofthe first organic compound. An organic light-emitting device prepared by the method has the characteristics of high efficiency and long service life.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to an organic electroluminescent device with high efficiency and long life. Background technique [0002] Organic light emitting diodes (OLEDs) have been actively researched and developed. The simplest basic structure of an organic electroluminescent device consists of a light emitting layer sandwiched between opposing cathode and anode. Organic electroluminescent devices are considered to be the next generation of flat panel display materials and have attracted widespread attention due to their ultra-thin, ultra-light weight, fast response to input signals, and low-voltage DC drive. [0003] It is generally believed that organic electroluminescent devices have the following light-emitting mechanism: when a voltage is applied between electrodes sandwiching a light-emitting layer, electrons injected from the anode and holes injected from the cathode recombine in the light-emi...

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Problems solved by technology

[0006] Although theoretically TADF materials can achieve 100% exciton utilization, there are actually the following problems: (1) The T1 and S1 states of the designed molecules have strong CT characteristics, and the very small S1-T1 state energy gap, although it can A high T1→S1 state exciton conversion rate is achieved through the TADF process, but at the same time it leads to a low S1 state radiative transition rate. Therefore, it is difficult to achieve both (or simultaneously) high exciton utilization efficiency and high fluorescence radiation efficiency;

[0007] (2) Due to the current use of TADF materials with D-A, D-A-D or A-D-A structures, due to their greater molecular flexibility, the configuration of molecules in the ground state and excited state changes greatly, and the half-maximum width (FWHM) of the spectrum of the material is too large. Large, resulting in a reduction in the color purity of the material;

[0008] (3) Even if doped devices have been used to alleviate the T-exciton concentration quenching effect, the efficiency of most TADF materials has a serious roll-off at high current densities

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