Impedance Spectroscopy Revisited

Abstract Impedance spectroscopy has been widely used in characterizing the electronic properties of semiconductors. Its application in the perovskite photovoltaic research is a natural extension of the well‐established methodology in the new semiconducting material. However, it turns out that the published results are sometimes very strange, difficult to interpret, or the interpretations contradict each other. It is now clear that most of these troubles stem from the dominating influence of ionic contributions. Herein, some of the published data are reviewed and the possible problems are identified, which can be reconciled by taking into account the explicit contribution of the ionic behavior.