Carbazole-fluorene copolymer blue-light materials with spatial structure

Abstract

The invention discloses carbazole-fluorene copolymer blue-light materials with a spatial structure. The general molecular structural formula of the polymers is the molecular formula 4 in the description; the number-average molecular weight of the polymers is 3,000 to 8,000; the polymerization dispersion is 1.01 to 1.1; seen from appearance, the polymers are white or yellowish powder solid; 5 percent thermolysis temperature is 300 to 450 DEG C; in the ultraviolet irradiation, the polymers turn blue; and the photoluminescence efficiency of the copolymer blue-light materials is 0.7 to 0.9, whilethe luminous efficiency of 9,10-diphenylanthrancene in cyclohexane is 0.9.

Description

technical field [0001] The invention belongs to the field of functional materials. Using the electrophilic substitution reaction of heterocycles, a carbazole-fluorene copolymerized blue light material with spatial structure was prepared. Background technique [0002] Organic electroluminescent materials are one of the research hotspots in the field of optoelectronic information functional materials. Among them, polyfluorene has high photothermal stability, and the fluorescence quantum efficiency of solid fluorene is as high as 60% to 80%, and the band gap energy is greater than 2.90eV. It has become the most important blue light material and is the new generation of flat panel display technology. One of the core components and white light primary color materials [1] . Although polyfluorene has unique advantages as a light-emitting material, it also has the following disadvantages: (1) The LUMO and HOMO of polyfluorene do not match the work functions of the anode and catho...

AI Technical Summary

Problems solved by technology

Although polyfluorene has unique advantages as a light-emitting material, it also has the following disadvantages: (1) The LUMO and HOMO of polyfluorene do not match the work functions of the anode and cathode of OLED, which makes the injection of holes and electrons difficult and ineffective. balance, so that the starting voltage is higher and the luminous efficiency is reduced; (2) polyfluorene is easy to form aggregated state or excimer association, so that the thermal stability of the spectrum is deteriorated, and there will be a red shift peak, which affects the light emission of the device. Saturated color purity and stability of luminous color, but also reduces luminous efficiency

[0005] The above reaction belongs to the Suziki polymerization reaction, the synthesized molecular structure is linear or branched, and fluorene is conjugated with carbazole. One unfavorable factor is: due to the electron-rich characteristics of carbazole, the polyfluorene molecular chain can be effectively improved in carbazole. At the same time, it also affects the conduction properties of the fluorene chain

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