Novel Zinc Complex with an Ethylenediamine Schiff Base for High-Luminance Blue Fluorescent OLED Applications

To explore the photophysical properties of coordination compounds with bright blue fluorescence, an azomethin–zinc complex was synthesized and characterized by various techniques (elemental analysis, thermogravimetry, and IR–mass-spectroscopy). The crystal structure was determined by X-ray diffraction analysis. Through thermal characterization, this complex was proved to have good thermal stability. Photoluminescence spectra were recorded, both in solution and in the solid state, and the complexes showed noteworthy photoluminescence with a maximum in the blue region. The results of time-dependent density functional theory calculations indicated that the origin of luminescence for the title complex is a combination of monomer and excimer emissions. The light emission performance of the zinc complex in organic light emitting diodes was investigated, and the results indicated superior electroluminescence properties as a blue fluorescent light source (max. brightness 17 000 cd/m2, max. EQE = 5%).