Interference color modulation, tunable refractive index, and chiroptical electrochromism in a π-conjugated polymer with cholesteric liquid crystal order

A pi-conjugated polymer film prepared by electrolytic polymerization using a cholesteric liquid crystal (CLC) is demonstrated to have a tunable interference function under electrochemical doping and dedoping. The polymer exhibits a CLC-like periodic structure with a potential-dependent refractive index and optical absorption properties. The interference color of the polymer film can thus be modulated dynamically by appropriate application of a voltage in the +/- 1 V range. This research involves structural chirality and tunable chiroptical properties, doping-dedoping driven tunable refractive index, electrochromism, and interference color modulation for the present polymer. The phenomena demonstrate the possibility of electrochemical photonics. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3126524]