ORGANIC ELECTROLUMINESCENCE DEVICE BASED ON AN ELECTRODEPOSITED POLY(3-SUBSTITUTED THIOPHENE) FILM

An electrochemically deposited composite film of poly(3-substituted th iophen) and insulating nitrile butadiene rubber (NBR) was used as the emission layer of a polymer electroluminescence (EL) device. The compo site film on an ITO substrate was uniform, and by using this film curr ent leakage was prevented. The device with the composite film as the E L emission layer shows rectification properties, the emitted color dep ending on the substituent of thiophen units. By coating with NBR after the electrodeposition of a poly(3-substituted thiophen) film, EL char acteristics were improved compared with the device with NBR coating pe rformed before electropolymerization. Moreover, by using electropolyme rized poly(3-n-octylthiophen) film as a hole transporting layer, the l uminance of an organic EL device with a poly(N-vinylcarbazole) dip-coa ting layer was remarkably enhanced. The addition of the hole transport ing layer reduced the turn-on bias voltage and increased the emission intensity to 700 ed m(-2).