Statistic Analysis of Nanoscale Tunneling Electrical Contacts Based on Transmission Line Model

This study investigates the influence of contact resistances between carbon nanotubes (CNTs) on electron transport and electrical conductivity of carbon nanofibers (CNFs), which profoundly impacts the performance of CNT thin film field effect transistors (FETs) [S. B. Fairchild, et al., Nanotechnology 26, 105706 (2015)]. A self-consistent contact model is employed, integrating a transmission line model with tunneling current [S. Banerjee, et al., Sci Rep 9, 14484 (2019)] to calculate the plethora of parallel CNT-CNT contacts within individual fibers. A statistical analysis is conducted, using Gaussian distributions to account for variations in contact lengths, gap distances, and single CNT aspect ratios, producing data on CNT-CNT contact resistance and the overall resistance of CNT fiber. By scaling our model to a macroscopic level, we've achieved significant alignment with experimental results [D. Tsentalovich, et al., ACS Appl. Mater. Interfaces, 9, 36189 (2017)]. Findings suggest that while increasing overlap length diminishes individual CNT-CNT contact resistance, it paradoxically increases macroscopic CNT fiber resistance, given a constant CNF mass density. Similarly, greater gap distance also increases both individual and fiber resistance. This research provides a tool for exploring CNT fiber electrical properties, promoting advancement in low-dimensional material-based electronic circuit development.