Ionic conduction and relaxation mechanisms in three-dimensional CsPbCl3 perovskite

Abstract

Ionic conduction and relaxation for the cubic phase of three-dimensional CsPbCl3 perovskite with a mean crystal size of 500 nm, synthesized via a facile solution based method, have been investigated in wide temperature and frequency ranges by dielectric spectroscopic measurements. Dielectric data have been analyzed in terms of the complex impedance spectroscopy, AC conductivity and the complex electric modulus by using Maxwell–Wagner equivalent circuit model, universal power law, Havrilliak–Negami, and Kohlrausch–Williams–Watts models to explore the fundamental aspects of the ionic transport and relaxation mechanism in CsPbCl3 perovskite. Nyquist plots indicate the individual grain and grain boundary contributions to the total impedance. The temperature dependence of the DC conductivity and the relaxation time obtained from the analysis was observed to follow the Arrhenius behavior. The activation energy for the DC conductivity was found to be ∼0.25 eV, which was very close to that for the relaxation time. The scaling of the AC conductivity and the electric modulus spectra at different temperatures indicates the validity of the time-temperature superposition principle, i.e., common ionic conduction and relaxation mechanisms at different temperatures in CsPbCl3 perovskite.