Synthesis And Optical-electrical Properties Of New Organic Electroluminescent Materials And Devices

Since C. W. Tang reported low-voltage driven high-luminance OED for first time in 1987. Organic light-emitting devices (OLED) becomes the international cutting-edge project and the focus of international competition which need the cooperation and research of many intercrossed branch of science.In order to have better performance, it is essential to develop novel structural polymeric materials with balanced transport of both injected electrons and holes. By changing or modifying the structures of organic semiconductor materials can easily adjust the energy level and charge transporation. The dissertation is divided into five chapters.1. Two novel copolymers composed of fluorene and phenothiazine derivates were synthesized by Wittig reaction. Copolymers of thiophene-co-phenothiazine were prepared by Wittig reaction.The photo-physical, electroluminescence and electrochemical properties of the resulting polymers were analyzed by UV-vis, PL , EL and EC.2. Single layer structure devices with the configuration of ITO/Polymers/Ca/Al were fabricated. The peak value of EL for P1, P2 was 552 nm and 544 nm,respectively. The CV results demonstrated that introduction of phenothiazine moiety into polyfluorenes can enhance electron affinity (Ea) and lower the ionic potential (Ip). EL results revealed that all these two copolymers emit green light with the maximum brightness of 20 cd/m2(16 V)and 12.5 cd/m2(15 V), respectively. The device of P3 with a single layer structure of ITO/Polymer/Ca/Al emits red light with the maximum brightness of 50 cd/m2(17V).3. Preparation of soluble SWNTs(s-SWNTs). SWNTs were purified and cutted, and then reacted with cetylamine(HAD).The resulting s-SWNTs was obtained and characterized by SEM, Raman and FTIR.4. The effect of s-SWNTs properties on the double layers polymer light emitting devices(PLED) were studied. Using s-SWNTs/host polymer composite as hole transport layer,double layer structure devices with the configuration of ITO/PVK: s-SWNTs/Zn(BTZ)2/Mg:Ag/Ag were fabricated. Influence of s-SWNTs on the injection and transport of hole of PLED was studied in detail.5. Novel phosphorescent material Ir(Ⅲ) complexes based on phenothiazine was prepared. And according to the literature, a reasonable explanation was proposed for the target compound.