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 (FeVO 4 ) 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 Er 3+ ions. The X-ray photoelectron spectroscopy technique confirmed the oxidation states of Er, Fe, V, and O in Er-doped FeVO 4 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 Er 3+ 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:FeVO 4 nanostructures. Significantly, this is the first comprehensive study of Er-doped FeVO 4 nanostructures focusing on nonlinear optical properties and optical limiting behavior under laser irradiation. These results suggest that Er:FeVO 4 is a potential candidate for OL against high-intensity laser radiation and also a diversity of optoelectronic devices.