Observation of the intrinsic metallic state in conducting polypyrrole by infrared reflectance spectra

Summary form only given. Optical reflectance spectra were measured for polypyrrole doped with PF/sub6/ ( PPy(PF/sub 6/) ) at temperatures from 10 to 300 K. The optical spectra at low temperatues are dominated by the onset of new plasma edge at 0.2eV together with the existing plasma edge at 1.8eV. The oscillator strength responsible for the new plasma edge can be described by the simple Drude model, indicating the delocalized electronic states in PPy(PF/sub 6/), whereas the intraband excitations associated with 1.8eV plasma edge are influenced substantially by disorder. The analysis indicates that the charge dynamics involved in the new plasma edge are inherently different from most of the intraband excitations in infrared region and attributed to the intrinsic metallic state in this system.