Evaluating SWCNT assembly properties from the temperature dependence of electrical resistivity

We developed a theoretical model to describe the electrical resistivity in films and fibers made of single-walled carbon nanotubes (SWCNTs). The proposed model considers the formation of randomly oriented bundles of metallic and semiconducting nanotubes and takes into account the influence of temperature, while separating contributions of SWCNTs and their junctions to the total resistivity. To verify the model, we applied a powerful experimental tool – measurements of the temperature dependence of electrical resistivity of the investigated macroscopic SWCNT assemblies (pristine and doped SWCNT fibers). This allowed us to estimate various parameters of the material, such as the average length of SWCNT bundles, the acoustic phonon scattering length, and the bundle contact resistance, which are difficult to evaluate experimentally for entangled SWCNTs. The study highlights the importance of understanding the relationship between structural characteristics and electrical properties in SWCNT assemblies. The findings provide insights into optimizing the conductivity of these materials and offer a quick estimation method of the SWCNT network properties based on varying temperature measurements for future fiber and film-based applications.