Interpretation of dielectric behavior and polaron hopping in lead-free antimony-based double perovskite.

Lately, double perovskite materials have become well-known in the commercialization area owing to their potential use in optoelectronic applications. Here, double perovskite CsAgSbCl single crystals (SCs) with cubic crystal structure and 3̄ space group were successfully synthesized the slow cooling technique. This paper investigates the dielectric relaxation and charge transfer mechanism within CsAgSbCl using electrochemical impedance spectroscopy (EIS) in the 273-393 K temperature range under light. The dielectric response in CsAgSbCl has been explained by the space charge polarization and the ionic motion. The '() study at different temperatures shows a remarkable frequency transition at which d'/d changes from a positive to a negative coefficient. Based on Stevels approach, the density of traps diminishes with the temperature increase, which improved conduction. However, this approach proves the polaronic conduction in CsAgSbCl. 0.42 and 0.21 eV are the binding () and polaron hopping () energy values, respectively. Contrary to free-charge carrier motion, polaron hopping was proposed as the principal conduction process since the ambient-temperature thermal energy was lower than . Moreover, the analysis of ''() and -''() as a function of temperature shows the thermally-activated relaxation from the non-Debye to Debye type model in CsAgSbCl. This scientific research offers an essential understanding of the dielectric relaxation behavior, which is required for improving dielectric switches. Also, this paper provides a deep insight into the conduction mechanism within double perovskite materials.