Polymeric Nanocomposites of Te and Bi2Te3 Nanowires in PEDOT:PSS: Synthesis and Electrical Transport Studies

Thin films containing Te and Bi2Te3 nanowires in the polymer PEDOT:PSS were made by drop casting and characterized by scanning electron microscopy, Raman spectroscopy and x-ray photoelectron spectroscopy. Scanning electron microscopy images revealed that the morphology and aspect ratio of the Te nanowires depends on the ratio of PEDOT to PSS used in the synthesis. Electrical conductivity measurements on the Te thin films were measured from 77-300 K and the results were fit to the variable-range hopping model. The results suggest that the improved conductivity of the Te nanocomposites can largely be explained by conducting PEDOT:PSS segments between the Te nanowires. Adding dimethyl sulfoxide increases the electrical conductivity of the composites, but to a much more significant effect in the case of Bi2Te3 films. Overall the results underscore the importance of nanoscale connections on the electrical conduction pathways in these polymeric thin films.