PHENOMENOLOGICAL ANALYSIS OF THE OPTOELECTROCHEMICAL BEHAVIOR OF ELECTROCHROMIC INTERCALATION DEVICES

A set of phenomenological analysis tools have been developed for the c haracterization of the optoelectrochemical behavior of electrochromic intercalation devices. Both step current and step potential excitation s are considered. Great simplification is afforded by working with the passed charge as the primary independent variable; consideration is a lso given, however, to the transmission or built-in device potential a s independent variables. It is shown that quasi-static intercalation e fficiency curves, generated from step current measurements, can elucid ate the intercalation site-energy distribution; these curves are also compared to dynamic intercalation efficiency curves obtained from step potential measurements. Quasi-static and dynamic optical efficiencies are also considered and compared. The scaling properties of some of t he phenomenological parameters may be used to generate master curves w hich unify sets of data obtained under a variety of conditions (applie d voltages, imposed currents, film thicknesses, etc.). Quantitative pr edictions can be made of device behavior under conditions not probed e xperimentally.