<p>Over the years, lead-free double perovskites have become increasingly popular, as they provide a nontoxic and more stable alternative to lead-based perovskites. Effective solar energy conversion, brilliant light emission, and sensitive photodetection are just a few of the valuable applications for lead-free double perovskites that have been recently demonstrated. The current study produced a homogeneous precursor solution using hydrobromic acid (HBr) for the first time, and synthesized a lead-free double perovskite, Na₂AgBiBr₆, using the solution-state reaction techniques. The crystal structure, morphology, band structure, optical properties, and stability of the Na₂AgBiBr₆ double perovskites were systematically investigated. The synthesis of the Na₂AgBiBr₆ double perovskite was verified using x-ray diffraction (XRD), which also demonstrated its remarkable structural stability. Investigations utilizing x-ray photoelectron spectroscopy (XPS) confirmed the formation of the Na₂AgBiBr₆ double perovskite. Elemental mapping, scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDX) were used to examine the morphology and elemental composition. EDX analysis confirmed that the synthesized sample contained Na, Bi, Ag, and Br. The Na₂AgBiBr₆ exhibited a direct bandgap of 2.358&#xa0;eV and an indirect bandgap of 2.227&#xa0;eV, according to the ultraviolet–visible (UV–Vis) absorption spectra. Thermogravimetric analysis and differential scanning calorimetry (TGA-DSC) demonstrated that the Na₂AgBiBr₆ double perovskite has exceptional thermal stability. The findings of this work indicate that the lead-free and environmentally benign Na₂AgBiBr₆ double perovskite exhibits great potential for photovoltaic and optoelectronic applications in the future.</p>