Figure 6

(a) TE property of the reduced films as a function of acid/PHZ ratio. (b) UV–Vis–NIR spectra of pristine PEDOT and reduced PEDOT with acid/PHZ ratio varied from 1.4–0. ‘0’, ‘.+’ and ‘++’ stand for neutral state, polaron state and bipolaron state, respectively. (c) Changing in color of the reduced film. PEDOT, poly(3,4-ethylenedioxythiophene); TE, thermoelectric.