Novel cross-linkable hole-transport monomer for use in organic light emitting diodes

Thin films of a cross-linkable hole-conducting monomeric triarylamine were investigated. The rate of photocross-linking and the overall polymerization yield were measured using real-time FT-IR spectroscopy. The electrical properties were characterized in a typical diode configuration using indium tin oxide and aluminum as the contacts. The current passed through the devices was found to be limited by the injection of holes into the semi-conducting polymer layer by tunneling. Cross-linked layers withstood about 20 times higher currents than non-cross-linked layers before dielectric breakdown occurred.