Synthesis and Characterization of Multiphase Silver‐Doped Magnesium Oxide Nanoparticles: For Optoelectronic Applications

The study investigates the structural, optical, and dielectric properties of silver‐doped magnesium oxide (Ag–MgO) nanoparticles synthesized via the sol–gel method. MgO, known for its wide band gap and excellent dielectric properties, has been doped with varying concentrations of silver to enhance its electrical and optical functionalities. X‐ray diffraction, field emission scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy confirm multiphase formation consisting of metallic Ag and ceramic MgO, along with nonuniform grain distributions. Transmission electron microscopy further reveals morphological changes from spherical to spinel‐shaped nanoparticles with Ag doping. Optical studies reveal a narrowing of the band gap and increased Urbach energy with rising Ag content, indicating enhanced structural disorder. Photoluminescence intensity decreases with higher Ag doping, while emissions that center at 429 and 461 nm confirm oxygen vacancy defects. Dielectric studies demonstrate that silver doping significantly enhances the dielectric constant and alternating current conductivity, attributing to increased charge carrier density and defect states. This investigation elucidates the potential of Ag–MgO nanoparticles for advanced electronic and optical applications, presenting a detailed characterization of their multiphase structure and exploring their dielectric behavior.