Photoluminescence enhancement and electrical properties of Sn2+-doped Cs2ZnCl4 for optoelectronic applications.

This study investigates the structural, optical, dielectric, and electrical properties of Sn2+-doped Cs2ZnCl4 crystals. Structural analysis using X-ray diffraction (XRD) confirms lattice expansion resulting from Sn2+ incorporation, while preserving the orthorhombic phase. Optical studies reveal enhanced UV-vis absorption and photoluminescence (PL), with blue emission centered at 445 nm attributed to Sn2+ transitions (3P1 → 1S0). Dielectric measurements show high permittivity at low frequencies, influenced by space charge polarization and thermally activated relaxation processes. The Cole-Cole plot highlights the contributions of both grains and grain boundaries. Electrical conductivity follows Jonscher's universal power law, shifting from small polaron hopping to overlapping large polaron tunneling (OLPT) as a result of Sn2+ doping. These findings suggest potential applications in energy storage, optoelectronics, and electronic devices.