Synthesis And Characterization Of Organic Electroluminescent Materials Based On 1,4-p-Carbazolyl-Benzene

Organic electroluminescent diodes as a new generation of light-emitting devices, in the late 20 th Century to date, with more mature technology research, have developed a large number of high-performance, high color purity, long life organic electroluminescent materials and light emitting material cooperating materials. Others will continue to come out. Organic red and green light-emitting material has a mature development. But in the short-wavelength emission of blue, near-ultraviolet or ultraviolet organic light emitting materials and devices have become the art of the neck portion in OLED's development. For the realization of full color, high efficiency and commercialization of industrial process, there is an urgent need to seek the ideal and shorter wavelength blue light emitting material.Carbazole molecule with special rigid structure has the stability of a large conjugated system, a high carrier mobility and an excellent thermal properties. With these good photophysical and electrochemical properties, its light wavelength is about from blue to dark blue region. According to the above Carbazole's excellent properties, the content of this paper is to use carbazole and benzene by the Suzuki coupling reaction principle to react and try to introduce different electron-withdrawing and electron donating functional groups in order to modify the molecular structure.While taking advantages of red spectroscopy, NMR, MS, UV-visible spectroscopy, fluorescence spectroscopy, cyclic voltammetry, thermogravimetry and differential thermal test, we study the electrical properties, photophysical properties and thermal properties of this type of molecular structures. In addition, with the comparison of different functional groups effect on the molecular structure, physical and chemical properties. Eventually we will find a rational law and thus obtain an optimal molecular structure.After characterization and determination of the compound molecular structure physical and chemical properties, the light emission wavelength of target compound is located near ultraviolet region of 390 ? 460nm; the band gap at about 2.8 ? 3.0e V; the highest fluorescence quantum efficiency of 72%; the glass transition temperature of 108 ?. When the compound is used as the emitting layer in a suitable structure device with an emission peak at 400 nm to 410 nm and the emission spectrum has a certain stability, which remained high color purity and short-wavelength characteristics. In the series of compounds obtained relatively introducing different functional groups. As a result, the electron donor –CH3 can effectively shorten the emission peak and improve color purity of the light-emitting device. But the electron-withdrawing group-CN has a red-shift emission wavelength. The molecular structure of this type compounds are appropriate organic light emitting material with an ideal wide gap. And we also proved that the structure type compounds are suitable for near UV or deep blue light organic electroluminescent material.