Optical nonlinearity of Gd-doped VSe₂ nanoflowers for photonic device applications

The nonlinear optical characteristics of semiconductor nanoparticles play an important role in optoelectronic devices. In this regard, we study the linear and nonlinear optical properties, along with the electrical, structural, and morphological properties of Gd-doped VSe₂ nanoflowers. Herein, we successfully synthesized V_1- Gd Se₂ (x = 0, 0.1, 0.2, and 0.3) nanoflowers using a simple hydrothermal technique. Structural analysis shows the pure VSe₂ phase and peak shifting due to the doping of Gd. The prepared samples show a nano flower-like morphology, which is uniformly distributed throughout the sample. EDX analysis confirms all the constituents and doped elements in the prepared samples. In the optical analysis, the Kubelka-Munk equation is used to calculate the bandgap values, which show high bandgap values of 2.6-3.6 eV for the prepared samples. The electrical measurement shows a higher conducting ability for the VSe₂ sample. The nonlinear optical Z-scan investigation showed that the RSA behavior and peak-valley pattern had negative n ₂ values, indicating a self-defocusing effect. Here, VSe₂ exhibits better nonlinear properties. The third-order nonlinear optical NLO susceptibility χ ⁽³⁾ values indicate that the VSe₂ material could be used for future NLO applications.