Lead-Free Solid State Mechanochemical Synthesis of Cs2NaBi1–xFexCl6 Double Perovskite: Reduces Band Gap and Enhances Optical Properties

• DOI: 10.1021/acs.inorgchem.2c04149
• Publication Date: 2023-03-15T16:30:10Z
• Authors: Rohini Udavant; Sachin Thawarkar; Sachin Rondiya; Ankita Shelke; Rahul Aher; Thalasseril G. Aj...; Russell W. Cross; Nelson Y. Dzade; Sandesh Jadkar

Efficient and stable lead-free halide double perovskites (DPs) have attracted great attention for the future generation of electronic devices. Herein, we developed a doping approach to incorporate Fe3+ ions into Cs2NaBiCl6 crystal unit reveal crystallographic optoelectronic study Cs2NaBi1-xFexCl6 perovskite. We report simple solid-state mechanochemical method that has solvent-free, one-step, green chemistry synthesis phosphor. The analysis powder X-ray diffraction (XRD) data determines contraction lattice due incorporation cations, this effect is well supported by photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, nuclear magnetic resonance (ss-NMR). band gap reduced with increasing Fe content owing strong overlap Fe-3d orbitals Cl-3p shift valence maxima (VBM) toward higher energies, as confirmed ultraviolet (UPS) density functional theory (DFT) analyses. Photoluminescence (PL) studies phosphors exhibit large Stokes shift, broadband emission, increased PL intensity more than ten times 15% phosphor enhancement in average decay lifetimes (up 38 ns) compared pristine DP. These results indicate transition dark self-trapping excitons (STEs) bright STEs enhances yellow emission. XRD, UV, thermo-gravimetric (TGA) Cs2NaB1-xFexCl6 DPs good structural thermal stabilities. Our findings cations constructive strategy enhance significantly properties these phosphors.