| The electrical properties of polyacetylene ionomers are reported with the purpose of understanding the fundamental mixed ionic-electronic conducting properties of these materials and using this knowledge to understand the electrical properties of interfaces between undoped and doped polymers. The polymers used within this thesis were poly[(2-cyclooctatetraenylethyl)trimethylammonium trifluoromethanesulfonate] (PC) and poly(tetramethylammonium 2-cyclooctatetraenylethanesulfonate) (PA).; Both polymers were insulators when undoped and became conductive upon electrochemical doping. PC could be n-doped and p-doped, while PA could only be p-doped. A macromolecular electrolyte, (tetrabutylammonium polystyrenesulfonate), was used to make the internally compensated forms of n-doped PC and p-doped PA without the incorporation of small ions, as well as prevent the oxidation of PC and prevent the overoxidation of PA. When doped, the current-voltage behavior of each polymer was found to depend on the environment of the polymer and the ion polarization at the electrode interfaces.; The steady-state electrical properties of the undoped polymers were also found to depend on the effects of ion polarization. However, due to the different free ion densities, the electrical properties of each material were very dissimilar. In PC, at low applied bias, the electrical properties were dominated by unipolar hole transport, while for bias greater than 1.5 V, substantial doping at the electrode interfaces occurred promoting bipolar carrier injection and increasing the film's conductivity. In P A, the hole transport was determined by the different free ion density and potential profiles for bias less than and greater than 0.7 V. Using proposed models, the carrier and ion mobilities were calculated for each material.; Using the knowledge gathered from the study of the individual materials and the techniques developed within this thesis, interfaces were fabricated between the two undoped polymers, between p-doped PA and undoped PC, between n-doped PC and undoped PA, and, finally, between p-doped PA and n -doped PC. The conjugated polymer pn junction is the first known of its kind. All of the interfaces were investigated using current-voltage measurements and various chemical analysis techniques. Various models were used to describe the different observed electrical behavior of each interface.; This dissertation contains both my previously published and my co-authored materials. |
