Thin-films of poly-triarylamines for electro-optic applications

Abstract

We observed that a new anionic triarylamine copolymer, which is easily accessable by radical polymerization can be used for the preparation of thin semiconducting organic films in two extremely different ways: One is the LBL assembly from solution with a cationic polyelectrolyte as counter system; the other is direct vacuum deposition, whereby the polymer degrades to oligomers, but keeps the functional groups intact as proved by UV/Vis, NMR spectroscopy and cyclic voltammetry. The fabricated films are used in light emitting devices as hole transporting layers showing excellent properties. External EL quantum efficiency (eta(ext)) and luminous efficiency-current density (J) characteristics of PLED device were studied.