Patterned emission from polymeric light-emitting device realized by photo-irradiation in air

Emission characteristics of polymer light-emitting devices (PLED) with a co nfiguration of indium-tin-oxide/poly(3-dodecylthiophene)/semitransparent-Al changed drastically upon photo-irradiation in air. After photo-irradiation to PLED, current passing through the device decreased by about one order o f magnitude and emission disappeared within several minutes. Patterned emis sion from PLED utilizing this effect was also demonstrated. The observed mo dification should originate from slight photo-oxidation at the polymer/Al i nterface and/or the polymer layer. The optical patterning method mentioned here can be applied onto the completed devices, in contrast to other method s such as ink-jet printing technology, in which the patterning of the polym er must be carried out before deposition of the metal electrode. (C) 2000 E lsevier Science S.A. All rights reserved.