Investigation of optical and electronic characteristics of Bʹ site arranged Cs2NaB′Cl5 (B′= Ni, Mn, Fe) double perovskite: A theoretical and experimental study.

This study delves into the exploration of B′ site arranged Cs 2 NaB′Cl 5 perovskites (B′ = Ni, Mn, Fe) as prospective alternatives to lead-based perovskites, given the environmental concerns associated with lead toxicity and material instability. Structural analysis using X-ray diffraction revealed a stable tetragonal crystal structure with the P4/mmm space group. Electronic properties, assessed via density functional theory (DFT) calculations, identified these materials as p-type semiconductors with tunable band gaps, and this finding supported by optical experimental data. Thermogravimetric analysis (TGA) demonstrated decomposition temperatures up to 750 °C, with Cs 2 NaMnCl 5 exhibiting superior thermal stability. Field emission scanning electron microscopy (FESEM) unveiled distinct morphologies influenced by the transition metal in the B′ site, while elemental analysis confirmed material purity. The optical analysis revealed strong light absorption in the visible spectrum, highlighting the potential of these materials for sustainable energy conversion applications. Overall, this research contributes valuable insights into the environmental-friendly potential of B′ site arranged Cs 2 NaB′Cl 5 perovskites in photoelectrochemical and solar cell application. [Display omitted] • Theoretical and experimental studies were carried out for Cs 2 Na B′ Cl 5. • Band structure was stimulated using DFT. • Cs 2 Na B′ Cl 5 (B′ = Ni, Mn, Fe) was synthesized using a simple solution method. • Band gaps of the Cs 2 Na B′ Cl 5 (B′ = Ni, Mn, Fe) were found to be 1.6–2 eV. • Dielectric constants, extinction coefficient, and refractive index are conferred. [ABSTRACT FROM AUTHOR]