| Organic electroluminescence has made great progress with the development of organic thin film science and technology. Organic electroluminescent devices, which are also called organic light emitting diodes (OLEDs), are fabricated with organic electroluminescent materials between a metal cathode and a transparent anode, and emit light under a certain voltage applied on electrodes. OLEDs are of growing interest in various display application because of their active lighting, lower power, gently weight, higher quantum yield and lower cost than other flat panel displays.The desirable aim of OLEDs'research is dynamic display with various colors, in which three basic colors must be needed (red, green and blue). Up to now, some materials with photoelectric properties which can generate green and red light have been found, but excellent materials which can emit blue light are rare. This is because the high energy gap, which blue light materials have, prevents the injection of electrons from cathode. Therefore, there will be a contradiction between the high energy gap and the injection of electrons, which limit the developments of the materials with blue-light emitting. It is still a challenge to prepare excellent blue-light emitting materials not only in basic theory but also in application of devices.Organic metal complex has high fluorescence quantum yield as organic compound and excellent stability as inorganic compound. It is believed the most promising candidate for application in luminescent materials. The select of organic ligand is very important due to luminescent properties of the complex depend on properties of the ligand. A novel blue-light emitting organic compound 2-(2-pyridyl)-benzimidazole was selected and several complexes with Cd(â…¡) and Zn(â…¡) were synthesized and both the solid and liquid fluorescence spectra show they are blue-light emitting materials with the high melt point which indicated they are suitable luminescent materials.
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