Conductivity-based approach to estimate average bundle length in randomly oriented network of single-walled carbon nanotubes

In this paper, we report a method to estimate the average length of bundles in a randomly oriented network of single-walled carbon nanotubes (SWCNTs) by analyzing the dependence of its sheet resistance on the distance between contacts. We propose an analytical model to verify the method and find the model's limitations using Monte Carlo simulations. Then, we apply the proposed approach to experimental results acquired from 95% (at 550 nm wavelength) transparent SWCNT films. The proposed method to estimate the average SWCNT bundle length can be used in situ and does not require any specific sample preparation step that can distort the SWCNT network.