Preparation And Properties Of Organic Electroluminescent Materials And Films

Organic electroluminescence(OEL) is light-emitting phenomenon arising from luminescent materials in which electricity is transformed into light when turned appropriate voltage on. The advantages of organic materials over inorganic materials are higher fluorescence efficiency, wider selection of emission colors and easer to fabricate large size films. So organic electroluminescent devices (OELDs) are regarded as "The flat panel display in 21 century". OELDs have become a fascinating area of research in recent years. In this paper, the structure of OELDs, EL theories, fabrication of thin films are studied. Organic dyes and polymer with fluorescence are found and synthesized. Different groups of OEL films and OELDs are prepared. The relationship among component, structure and properties of organic films of materials and devices are studied.Many organic composition with conjugate structure can be used as OEL materials. 8-hydroxylquinoline aluminium(Alq3) is one of the best OEL materials with good film-formation and thermal, excellent electron-transporting ability. But Alq3 was used in OELDs by vacuum evaporation mostly because of its poor dissolubility, and easily recrystallized from the OELDs so that the OELDs' stability decreased. To overcome the defects of Alq3, the polymer of 8-hydroxylquinoline with polyether and its metallic complexes have been designed and synthesized. Their chemical structures and properties were investigated by IR, DSC-TG, UV-vis and PL.The characteristics of films are important to OELDs' luminosity fluorescence efficiency of OELDs. To achieve good OELDs, excellent films are needed. In this paper, organic small molecules and polymer films were prepared via electrostatic self-assembled method and spin-coating method. The characteristics of films are examined by UV-vis, PL, XPS, Raman and so on. And some theories are investigated with respect to organic molecules and polyionic deposition on solid surface and the photoelectric characteristics of organic ultrothin films.We analysize the structure and properties of OEL materials and used them as OEL or carrier-transporting materials in OELDs with ITO as anode and Al as cathode. The results of OEL were achieved. The influential factors are discussed.