Polymer electroluminescent diodes with ring microcavity structure

Cylindrical microcavity structures, such as microrings of pi-conjugated conducting polymers, poly(2, 5-dialkoxy-p-phenylene vinylene) (ROPPV), on optical fibers, were fabricated for an optically pumped laser and a light emitting diode (LED). Extremely low excitation threshold for lasing has been demonstrated with the microring structure. Microring LEDs with cylindrical geometry of Al/pi-conjugated conducting polymers, ROPPV, /ITO on optical fibers of 125 mu m external diameter have been fabricated for the first time and orange electroluminescence has been observed upon application of an electric field. These results suggest the future possibility of electrically pumped conducting polymer laser diodes.