• conjugated polymers;
  • electrochromic devices;
  • gels;
  • infrared transmission;
  • P3HT


Thumbnail image of graphical abstract

Poly(3-hexyl thiophene) was used to build a thin-layer, electrically switchable infrared shutter. Electrochromic materials are typically studied in the visible, whereas we focused on P3HT electrochromic behavior in the infrared where morphology changes may have greater impact. Devices were fabricated on ITO-coated silicon and germanium and their performance was characterized in the mid infrared (2–6 µm). Thicker polymer films increased device switching time and did not improve optical contrast. Choice of salt in the electrolyte significantly affects switching dynamics and salt concentrations affect maximum optical contrast. These results are potentially important for the integration of polymer technology into infrared imaging and detection applications.