Fig. 2: Electrochromic and electrochemical performances of n-PBDF EC electrodes.
a Spectroelectrochemical analysis of n-PBDF film electrode (d ~ 90 nm) across an applied potential of −0.3 V to +1.0 V vs. Ag/AgCl (with 0.1 V step) (inset: photo images of the EC electrode, scale bar: 4 mm). b Progression of absorbance (i.e., optical density) in colored/bleached states of various n-PBDF films against charge density. c Transmittance and optical contrast (derived from exponential decay subtraction at colored and bleached states) of films as a function of thickness, measured at λ = 750 nm. Scatter plot of lightness (d) and color difference and chroma for colored states of n-PBDF films (e), both as functions of thickness, based on CIE L*a*b* color coordinate. f Composite coloration efficiencies and switching times for n-PBDF films across four different film thicknesses, calculated at a 95% optical contrast change at λ = 750 nm. g b values of the n-PBDF films, derived from anodic and cathodic peak current ratios in cyclic voltammograms (scan rates from 2 to 100 mV s−1). h Overlay of Nyquist plots of n-PBDF films from EIS measurement in the frequency range of 100 kHz to 0.1 Hz with fitting (inset: high frequency region). i Parameters analyzed from the fitted Nyquist plots using an equivalent circuit model (inset): diffusion resistance and diffusion coefficients.
