Broadband laser protection and enhanced nonlinear optical response of samarium-metal-organic framework-based...

The broadband nonlinear optical (NLO) properties of Sm-MOF, Sm-MOF/BN, and Sm-MOF/rGO hybrids have been investigated. These hybrids were synthesized by combining chemically prepared boron nitride (BN) and reduced graphene oxide (rGO) with Sm-MOF crystals, utilizing slow diffusion-driven methods and ultrasonication. The synthesized Sm-MOF/rGO hybrid exhibits high two-photon/three-photon absorption (2PA/3PA) and functions as an efficient optical limiter due to the synergistic effects between the Sm-MOF hybrid and the BN and rGO nanosheets. The hybrid makes electronic transitions more selective, thus altering the band gap to achieve efficient NLO properties in the visible (600 nm) region and thus, excitation shows 2PA (10^-8 m W^-1), and the IR (700-1000 nm) region shows 3PA (10^-20 m³ W^-2). The textural techniques revealed the morphology of the Sm-MOF/rGO hybrids, with a surface area of 276 m² g^-1, as shown by the Brunauer-Emmett-Teller (BET) results. The parameters of the NLO reveal a substantial relationship between the surface area and pore size for both the onset values of optical limiting and the nonlinear optical absorption. Better electron transport results from the Sm-MOF/rGO nanocomposite shows enhanced conductivity compared to bare materials and other composites. By combining metal-organic networks with inorganic molecules as electron acceptors and employing π-electron delocalisation, this finding may pave the way for further improvements and enhancements in the NLO performance of MOF-based materials.