Enhanced Nonlinear Optical Response of Er-Doped Ferric Vanadate Nanostructures for Optical Limiting Applications

The development of reliable optical limiters (OL) is an important step toward protecting biological and electronic components from high-intensity laser irradiation. This study examines the characteristics of ferric vanadate (FeVO4) nanostructures and their modification via the incorporation of erbium ions, focusing on their structural, morphological, linear, and nonlinear optical properties. X-ray diffraction confirms the phase formation of the synthesized nanomaterial, while Raman and Fourier-transform infrared spectroscopy examined the distinctive vibrational modes related to it. Major morphological changes are identified by high-resolution scanning electron microscopy and high-resolution transmission electron microscopy analysis, indicating the transition from a nearly spherical to polyhedral structure with the incorporation of Er3+ ions. The X-ray photoelectron spectroscopy technique confirmed the oxidation states of Er, Fe, V, and O in Er-doped FeVO4 nanostructures. TGA analysis validated the thermal stability of the materials. UV–vis and photoluminescence analysis were performed to characterize linear optical behavior, while nonlinear optical properties were qualitatively investigated using the open-aperture Z-scan approach. The reverse saturable absorption dominated the absorption mechanism, indicating strong nonlinear absorption dynamics in the ferric vanadate nanostructures. The incorporation of Er3+ ions in the host lattice rendered a 2.5 times more efficient two-photon absorption coefficient and a 2.4 times decrease in the optical limiting threshold. This ability, along with other properties, further supports the extraordinary potential of Er:FeVO4 nanostructures. Significantly, this is the first comprehensive study of Er-doped FeVO4 nanostructures focusing on nonlinear optical properties and optical limiting behavior under laser irradiation. These results suggest that Er:FeVO4 is a potential candidate for OL against high-intensity laser radiation and also a diversity of optoelectronic devices.