Fractional and chaotic electrical signatures exhibited by random carbon nanotube networks

Abstract

Electrical and nonlinear optical properties exhibited by single-wall carbon nanotubes in thin film form were experimentally and numerically analyzed. A vectorial two-wave mixing technique confirmed an inhomogeneous third-order nonlinear optical response dependent on the orientation of the sample explored by nanosecond pulses at 532 nm wavelength. Electrochemical impedance spectroscopy measurements were lead to evaluate the conductivity and capacitive response. Since electrical and nonlinear optical measurements did not match in comparative 2D regions integrated by the nanotubes, then, the dynamical performance of the nanostructures was studied by using a chaotic electrical modulation. Fractional calculations were carried out for predicting and explaining the electrical and capacitive effects related to different sections of the sample dependent on electrical frequency. The identification of fractional electrical behavior was proposed to determine changes in the density and purity of single-wall nanotubes samples. Potential applications for developing low-dimensional sensors and nonlinear all-optical devices can be contemplated.