Conducting polymer: silver interface, morphology and properties

Polymers having conjugated double bond system in the backbone structure are electronically conducting. Incorporation of certain side groups to such backbone gives introduce unique new properties or alter the initial properties of the polymer. Consequently conducting polymers with unique and tailored properties are valuable new materials of the future engineering. Electrical properties of the interface between conducting polymer and metal is of vital importance to the application potential of the polymer in the electronics. In present study we discuss the electrical properties of the heterojunction composed of conductive polymer pressed nanoparticles and silver thin layer. The contacts were deposited by vacuum evaporation from bulk silver plate or dry silver nanoparticles. In this study the new conjugated polymer poly(4-(thien-3-ylmethoxy)butane-1-sulfonic acid)—PTMBSA—was used as the organic semiconductor. The syntheses of PTMBSA and silver nanoparticles are discussed. In order to evaluate the morphology of PTMBSA pellets with electrodes scanning electron microscopy (SEM) was applied. The important information on the electrical properties of the system were obtained from the measurements of the current–voltage characteristics revealing significant qualitative difference of investigated heterojunctions. It was found that the contact of silver and PTMBSA has electrical properties varying in time. For about 100 h after preparation, intrinsic conductivity of the sandwich specimen has been gradually increasing.