Fibrillar, Textured Electron Transport Polymer Layers for Enhanced Performance of Polymer LEDs

Organic light emitting devices are an emerging technology which promises a radically new approach to the manufacture of a wide range of flat displays--from simple alphanumeric displays to high information content flat panel displays. Over the past four years, UNIAX has conducted a research and development program to develop such devices based on organic polymer active layers. The simplest element of this type of device consists of a layer of electroluminescent polymer "sandwiched" between a pair of metal electrodes. When a voltage is applied between the electrodes, charge carriers are injected into the polymer layer (electrons on one side and holes on the opposite side). These oppositely charged carriers meet within the layer and recombine, resulting in the emission of light. The present proposal outlines an effort to develop fibrillar, textured electron transport polymer layers from polyquinoline for enhanced electron injection. The effort is based on the high surface area and local field enhancement advantages for hole injection previously demonstrated with textured polyaniline layers. By enhancing both the electron and the hole injection, we anticipate better devices with improved power efficiency and lower operating voltage.