Exploring the optical and electrical properties of CsSnBr for optoelectronic technologies.

In this study, we report the structural, optical, and electrical properties of lead-free CsSnBr perovskite synthesized via melt growth. UV-Vis absorption and Tauc plot analysis reveal a direct optical band gap of 1.75 eV. Photoluminescence and time-resolved PL measurements confirm efficient radiative recombination and reveal carrier lifetimes on the nanosecond scale. Impedance spectroscopy and dielectric analysis across 300-400 K show non-Debye relaxation and support a small-polaron hopping conduction mechanism, with activation energies consistent with frequency-dependent conductivity. A unique correlation is established between the optical carrier dynamics and low-frequency electrical behavior. These findings contribute to a deeper understanding of charge transport in CsSnBr and support its potential use in lead-free optoelectronic applications such as photodetectors and solar energy conversion.