Screen printable electrode for light emitting polymer device

摘要

A screen printed light emitting polymer device is fabricated by depositing an electroluminescent polymer layer between a transparent electrode and an air stable screen printed top electrode. Screen printing a conductive electrode on top of a light emitting polymer layer typically results in a short circuit because metal conductive particles poke through the polymer layer. We have found three ways to prevent this. One is to screen print an organic conductor on top of the light emitting polymer layer so that metal conductive particles cannot penetrate to the transparent electrode. Another way is to decrease the particle size in the conductive metal paste in addition to using a solvent that does not soften the light emitting polymer layer being printed on. A third way is to print a sol-gel conductive layer where the conductive metal particles precipitate after the layer is printed. In addition, additives to the screen printed top electrode can be used to improve device efficiency.