Light-induced conductance switching in azobenzene based near-percolated single wall carbon nanotube/polymer composites

Photochromic molecular switches are a class of organic molecules that allow a reversible control over molecular structure, dipole moment, or conductivity with light. Incorporating these chromophores into polymer composites provides the possibility to photoswitch intrinsic properties of these materials. Here we report reversible light-induced conductance switching of near-percolated single wall carbon nanotube/polymethylmethacrylate (SWCNT/PMMA) nanocomposites containing azobenzene derivatives that do not exhibit molecular conductance switching. Stable switching amplitudes up to 28% were achieved near the percolation threshold. The results suggest a Pool-Frenkel type conduction mechanism where the chromophores are an integral part of the conduction path. (C) 2015 Elsevier Ltd. All rights reserved.