Spectroscopy: Impedance spectroscopy and mobility spectra

This article describes impedance spectroscopy and its relationship to dielectric properties (IS/DS). Impedance spectroscopy is generally interpreted in terms of equivalent circuits that can represent different electrical paths present in a material or device. Details about the simplest equivalent circuit models that can be used to interpret results is presented as well as suggestions on how to maximize the information that one can obtain from the ac measurements. IS/DS is often used to determine the conductivity of many materials and devices and therefore it is important to be able to separate effects caused by surface phenomena from bulk processes.