Characterization of Cs2AgInCl6: Bridging Optical and Electrical Properties for Advanced Optoelectronic Applications

Lead-free double perovskites, such as Cs₂AgInCl₆, represent a promising class of materials for optoelectronic applications due to their favorable properties and environmental sustainability. This work focuses on the synthesis and comprehensive characterization of Cs₂AgInCl₆, employing a range of techniques including X-ray diffraction (XRD) for structural verification, thermogravimetric analysis (TGA) to assess thermal stability, and UV–visible absorption measurements to determine the optical bandgap energy of 3.32 eV. Additionally, we explore photoluminescence (PL) and decay measurements to elucidate the luminescent properties of the compound. Complex impedance measurements are performed under both blue and red light to investigate the electrical behavior, revealing two distinct conduction mechanisms: the overlapping large–polaron tunneling (OLPT) and nonoverlapping small–polaron tunneling (NSPT). We analyze the implications of our findings on the current–voltage (I–V) behavior and trap density, further supported by Raman spectroscopy under both illumination conditions. The combined insights from optical and electrical characterizations highlight the potential of Cs₂AgInCl₆ in optical applications, paving the way for its use in advanced optoelectronic devices.