Multilayer thin films of poly(3-[2-(carboxymethoxy)ethyl]thiophene) and its luminescence properties

We synthesized carboxylic acid group pendant poly(3-alkylthiophene) and prepared multilayer self-assembled films by the use of ionic interaction between charged molecules. The prepared multilayer thin films were optically transparent high quality films and showed emission maximum at 592 nm that was identical to the emission of the cast film. About 2.5 fold enhancement in emission efficiency was observed for the self-assembled film which indicated that less excimer quenching occurred. The light emitting devices were made from both multilayer film and cast film. The device made from the multilayer film had electroluminescence maximum at 602 nm which was shifted about 10 nm to the longer wavelength than that from the cast film.