PEDOT preparation: Mix a 5.0 mL of 14.2 wt.% EDOT (3,4-ethylenedioxythiophene) alcoholic solution and 20 mL FeCl3·6H2O (2.0 M) aqueous solution; maintain this under magnetic stirring for 24 h, filter, wash, and dry at 60°C for 12 h.