Impedance dependence on frequency Z(f) for films of different SWCNT densities corresponding to different colors. The highest impedance corresponds to the lowest density. We can define the cutoff frequency (f0), at which Z decreases abruptly: f0 increases when increasing the SWCNT density on the substrate, while resistance decreases, as does the low-frequency impedance.
Ferrer-Anglada et al. Nanoscale Research Letters 2012 7:571 doi:10.1186/1556-276X-7-571