Potassium tin chloride (K₂SnCl₆) as a lead-free perovskite: anti-solvent synthesis, structural characterization, and charge transport properties

Abstract

Potassium tin chloride (K₂SnCl₆) was synthesized using a facile antisolvent method at room temperature. X-ray diffraction (XRD) confirmed its single-phase cubic perovskite structure with the <i>Fm</i>3̄<i>m</i> space group. Raman spectroscopy and scanning electron microscopy (SEM) further validated the structural and morphological properties. Electrical properties were Studied through impedance spectroscopy (10 Hz-5 MHz, 313-423 K), revealing thermally activated charge transport. The conduction behavior was modeled using an equivalent electrical circuit, with AC conductivity adhering to Jonscher's universal power law and exhibiting frequency-dependent dispersion. Electric modulus analysis indicated a non-Debye relaxation process. The correlated barriers hopping (CBH) model was identified as the most suitable representation of the charge-transport mechanism. Activation energies for DC conductivity and electric modulus were determined to be 0.17 ± 0.04 eV and 0.197 ± 0.07 eV, respectively, showing consistency between conduction and relaxation processes. These findings highlight the promising dielectric and ionic conductivity properties of K₂SnCl₆, positioning it as a potential lead-free material for energy storage applications. This study provides a foundation for future research aimed at optimizing its performance and exploring its use in solid-state energy storage devices.