Nonlinear optical and power limiting characteristics of noble metal decorated reduced graphene oxide and Ti3C2 MXene

Owing to their pronounced light-matter interactions, two-dimensional layered (2D) nanostructures (NSs) have emerged as promising candidates for optoelectronic applications. This study primarily investigates the impact of decorating noble metal NSs (Ag, Au) integrated with 2D layered materials, including reduced graphene oxide (rGO) and delaminated Ti₃C₂ MXene. A simple co-reduction technique was employed to decorate rGO with Ag and Au nanoparticles (NPs), whereas a self-reduction method was used to decorate the surface with Ag and Au NPs onto the Ti₃C₂ MXene. A combination of characterization techniques was employed to analyze the structural, morphological, and linear optical properties of the prepared samples. The nonlinear optical (NLO) properties of these materials were studied with Z-scan measurements with a diode-pumped solid-state laser operating in continuous-wave (CW) mode at a wavelength of 532 nm. Open-aperture Z-scan data indicated the presence of reverse saturable absorption (RSA) behavior in all the samples investigated. Closed-aperture analysis revealed self-defocusing effects, suggesting the potential of these materials for various optoelectronic device applications. The experimental observations were further supported by Finite-Difference Time Domain (FDTD) simulations, which unveil photothermal effects in driving their NLO response. This eventually induces localized surface plasmon resonance (LSPR) led enhanced electric field localization and increased power absorption. This localized heating driven thermo-optic effects were, significantly contributing to the observed enhancement in the NLO properties of these nanocomposites compared to their pristine counterparts.