Effects of Nanostructured Plasmonic Environment on Electrochromic Polymer Switching

Strong modification of local environment associated with plasmonic nanostructures provides possibilities to control various processes, including charge transfer processes and chemical reactions. In this work, we explore the opportunities to enhance electrochromic polymer performance using plasmonic metasurfaces, and study the origin of this enhancement. Electrochromic polyaniline (PANI) films deposited onto gold metasurfaces demonstrate non-monotonnous coloration behavior at low voltages, step-like color-change and much faster saturation in color with the increase in voltage in comparison with polyaniline films deposited on flat gold. The additional small voltage peak in the cyclic voltammogram in nanomesh/PANI cell and the asymmetric and nonlinear I-V characteristics of the sandwich nanomesh/PANI/flat gold structure indicate a possible formation of Schottky-like interface between polyaniline and nanostructured gold, whereas the Ohmic contact is observed for the flat gold-PANI system. The results are discussed in terms of the modified work-function of nanostructured gold, interface charging and threshold-like charge transport. Possibility to engineer optical and charge transport properties of electrochromic materials via nanostructured interfaces can bring niche applications.