Patterned multiple color polymer light-emitting diodes

Multicolor Light-emitting patterns are desirable for full-color displays. W e report here a simple method to fabricate patterned polymer light-emitting diodes with multiple colors on one substrate with unpatterned electrodes. This method takes advantage of the concept that light emission can be confi ned in a certain layer of a multilayer LED device and different color emiss ions can be obtained through dye doping. By patterning the dye-doped emissi on layer, we can obtain desired color patterns with unpatterned electrodes. Light-emitting color logos and dots with different colors from the backgro und are demonstrated. (C) 1999 Elsevier Science S.A. All rights reserved.