EIS measurements in molecular electronics

Overview & Synopsis

Although electrochemical impedance spectroscopy (EIS) has already demonstrated its reliability in electrochemistry and organic semiconductors as a tool for tracking charge-carrier transport, its potential in molecular electronics has not yet been fully realized. In this emerging field, where DC-based measurements often obscure key physical processes, EIS provides an indispensable frequency-resolved perspective capable of disentangling interfacial, dielectric, and molecular contributions. The aim of this review is to revisit prior studies and highlight how impedance measurements reveal information that remains hidden or ambiguous in static J-V analysis-ranging from contact resistance and dielectric response to polarization dynamics and environment-induced effects. By surveying the current state of the art, we underscore the unique diagnostic power of EIS and outline the challenges that must be overcome for it to become a standard metrological tool in molecular electronics.