A kind of fluorescent material and its synthesis method

Abstract

The present application discloses a fluorescent material and a synthesis method thereof. The fluorescent material has the following structural formula: wherein, Y is an N atom or a B atom; X 1 and x 2 same or different and selected from C atom or Si atom; R 1 , R 2 , R 3 , R 4 The same or different, selected from hydrogen atom, alkyl, hydrocarbon aryl or heteroaryl; R 5 , R 6 , R 7 , R 8 same or different, selected from alkyl, hydrocarbon aryl or heteroaryl; or R 5 and R 6 form a cyclic group; or R 7 and R 8 form a cyclic group. The material has good fluorescence characteristics and high quantum efficiency, and can be used in the light-emitting layer of organic electroluminescent devices. The synthesis method of the fluorescent material is simple, avoiding the use of rare metals, and has huge applications in the field of OLEDs. prospect.

Description

technical field [0001] The application belongs to the field of organic luminescent materials, and in particular relates to a fluorescent material and a synthesis method thereof. Background technique [0002] With the continuous development of OLED technology in the fields of display and lighting, people will pay more attention to the research on its core materials, especially organic electroluminescent materials. The early OLED light-emitting materials are traditional fluorescent materials. Since the ratio of singlet and triplet excitons in OLEDs is 1:3, but traditional fluorescent materials can only use singlet excitons to emit light, so the OLDE theory of traditional fluorescent materials The internal quantum efficiency is 25%. Although in terms of theoretical research, organic fluorescent materials have made great progress. For example, Professor Adachi developed a thermally induced delayed fluorescent material (TADF), which realizes the intersystem transition from triple...

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Problems solved by technology

The early OLED light-emitting materials are traditional fluorescent materials. Since the ratio of singlet and triplet excitons in OLEDs is 1:3, but traditional fluorescent materials can only use singlet excitons to emit light, so the OLDE theory of traditional fluorescent materials The internal quantum efficiency is 25%. Although in terms of theoretical research, organic fluorescent materials have made great progress. For example, Professor Adachi developed a thermally induced delayed fluorescent material (TADF), which realizes the intersystem transition from triplet to singlet state of excitons. Leaping, theoretically the internal quantum efficiency can reach 100% (Adv.Mater., 2009, 21, 4802), but the actual situation is not, it depends on the number of electrons transitioning from singlet state to ground state per unit time and triplet state crossing The ratio of the number of electrons to the singlet state, if the electrons in the triplet state do not quickly cross to the singlet state, it will gradually return to the ground state in the form of heat, resulting in energy loss

And because the spectrum is too wide, the emitted light color is impure, the luminous efficiency of blue light materials is low, and the life is short, so the application of TADF materials in the display field is limited

[0003] OLED is composed of red, green and blue organic light-emitting molecules to produce three primary colors and then display various colors. Among them, blue light-emitting materials are difficult to inject carriers due to their short light-emitting wavelength and wide energy band gap; and blue light-emitting materials are difficult to inject due to their special Molecular structure, carrier mobility is also relatively poor, coupled with the visual function, the luminous efficiency and lifetime of blue light materials are much lower than those of red light and green light

Blue light performance has become an unavoidable short board affecting OLED display

At present, fluorescent materials with TTA (triple-triple annihilation) effect, due to the annihilation effect of electrons in the triplet state, increase the total amount of singlet electrons, and the theoretical internal quantum efficiency can reach 62.5%, which has also been obtained in the field of display. Extensive attention, the demand for blue light-emitting materials with excellent performance in the OLED display field provides opportunities and challenges for the development and design of fluorescent materials with TTA properties

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