Nickel-doped VS4 nanostructures as a promising candidate for nonlinear optical limiter application

Abstract

Nonlinear optics plays a pivotal role in modern photonics, supporting a wide range of applications, including frequency conversion and the creation of ultrafast light pulses. Integrating two-dimensional (2D) materials with nonlinear optical systems opens new avenues for exploring the interaction of fundamental excitons, such as electrons, excitons, and photons, within low-dimensional platforms. This synergy holds promise for advancing future photonics and quantum technologies. Ni-doped VS₄ with a nanosheet-like structure is prepared using the hydrothermal method. X-ray diffraction (XRD) analysis confirms the monoclinic phase. Raman spectroscopy confirms the different vibrational bands corresponding to vanadium and sulfur. Field-emission scanning electron microscopy (FESEM) images confirm the nanosheet-like structure. Energy-dispersive X-ray spectroscopy confirms the presence of all the elements. X-ray photoelectron spectroscopy (XPS) data confirm the presence of different oxidation states. UV-VIS-NIR spectroscopy data give insights into the band gap of the material. The nonlinear effect is confirmed by the Z-scan approach. The nonlinear absorption coefficient (β) and nonlinear refractive index (n₂) are calculated using the open aperture (OA) and closed aperture curves (CA), respectively. The results demonstrate the optical limiting properties of emerging 2D materials. This intensity-dependent nonlinear optical study highlights their immense potential for future photonic and optoelectronic applications.