Facile Synthesis and Structural, Morphological, and Optical Properties of Lead‐Free Layered Ruddlesden–Popper EA ₂ CuCl ₄ Hybrid Perovskite

ABSTRACT The development of new, low‐cost, and environmentally friendly materials for solar energy conversion remains a significant challenge in materials science. In this work, we report the of lead‐free EA 2 CuCl 4 perovskite‐layered microstructures with a nanocrystalline nature via a facile and green antisolvent engineering method using isopropanol. Structural analysis by x‐ray diffraction (XRD) confirmed the formation of the orthorhombic phase (space group Pbca) with high crystallinity. Nanocrystalline features were substantiated through Williamson–Hall (WH) analysis and the Debye–Scherrer (DS) approximation. Scanning electron microscopy revealed a layered sheet morphology with lateral dimensions in the micrometer range, while energy‐dispersive x‐ray spectroscopy (EDX) confirmed uniform elemental distribution and purity. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) indicated that the material remains thermally stable up to 200°C, with a total mass loss occurring around 518°C. Optical characterization showed a bandgap of 2.21 eV and distinct absorption features making the material well suited as a wide‐bandgap top absorber for green solar cell applications. This work presents a sustainable pathway for synthesizing copper‐based perovskites and paves the way for further research into their integration into photovoltaic devices, with potential improvements in device efficiency and long‐term stability.