In percolating networks of mixed metallic and semiconducting CNTs, there is a tradeoff between high on-current (dense networks) and high on/off ratio (sparse networks in which the metallic CNT fraction is not percolating). Experiments on devices in a transistor configuration and Monte Carlo simulations were performed to determine the scaling behavior of device resistivity as a function of channel length (L) for CNT density p in the range 0.04 - 1.29 CNT/{\mu}m^2 in the on- and off-states. Optimized devices with field-effect mobility up to 50 cm^2/Vs at on/off ratio > 10^3 were obtained at W = 50 {\mu}m, L > 70 {\mu}m for p = 0.54 - 0.81 CNTs/{\mu}m^2.
@article{arxiv.1004.4009,
title = {Optimizing Transistor Performance of Percolating Carbon Nanotube Networks},
author = {V. K. Sangwan and A. Behnam and V. W. Ballarotto and M. S. Fuhrer and A. Ural and E. D. Williams},
journal= {arXiv preprint arXiv:1004.4009},
year = {2015}
}