Synthesis and Characterization of New Thienopyrazine-cored Dendrimer for Non-Doped Organic Red Light-Emitting Diodes

A new thieno-[3,4-b]-pyrazine-cored dendrimer with polyphenyls dendrons (D2TP) was designed and synthesized for application as red emitter in non-doped organic light-emitting diodes (OLEDs). The bulky dendritic arms enable this molecule to possess significant molecular weight and good solubility in common organic solvents. As a result, D2TP is suitable for solution processing methods such as spin coating to make thin films and devices. In addition, these large dendrons provide site-isolation effect on the planar emissive core to prevent fluorescence quenching or intermolecular interaction. The photophysical and electrochemical properties of D2TP were investigated in its dilute solutions. D2TP was used as non-doped emitter to fabricate OLEDs by spin coating method and saturated red electroluminescence was obtained.