Enhanced nonlinear optical limiting in Mn_1.25Fe_0.7P_0.44Si_0.56Sn_0.2/rGO nanocomposites via two-photon absorption

The development of high-performance optical limiting materials remains a significant challenge, and this work addresses it by creating integrated inorganic-organic composite materials via hybrid synthesis approaches. A novel manganese-iron-phosphorus-silicon-tin (Mn_1.25Fe_0.7P_0.44Si_0.56Sn_0.2, MnFePSiSn) alloy/graphene oxide (GO) nanocomposite was synthesized by combining laser ablation in liquid for MnFePSiSn nanoparticles with hydrothermal processing (120 °C, 12 h) for integration of MnFePSiSn/rGO for advanced optical limiting applications.Z-scan measurements under 532 nm laser irradiation demonstrate that the resulting MnFePSiSn/rGO nanocomposite exhibits remarkably enhanced optical limiting performance compared to its individual components. Specifically, the nanocomposite possesses an optical limiting threshold that is not only lower than that of pristine MnFePSiSn but also 1/50 that of pristine GO. At an incident intensity of 47.96 GW cm^-2, the composite shows a significantly deeper valley in itsZ-scan trace, attributable to facilitated electron transfer within the hybrid structure that substantially strengthens the two-photon absorption process. This study provides a facile and effective strategy for developing highly efficient optical limiting nanomaterials with ultralow thresholds, showcasing great potential for high-performance laser protection devices.