In-plane stiffness of silicene nanoribbons: A tight-binding model calibrated with DFT

Silicene nanoribbons (SiNRs) are quasi-one-dimensional structures whose electronic and mechanical properties make them promising for silicon-compatible nanoelectronics and flexible devices. Experimental studies have shown that silicene nanoribbons can be synthesized on Ag substrates, but their intrinsic mechanical behavior is still understood mainly through theoretical approaches. In this paper, the in-plane stiffness of both armchair and zigzag SiNRs is examined using a tight-binding model (TB) calibrated against density functional theory (DFT) reference band structures. The TB model incorporates strain effects on the hopping integrals through an exponential scaling law, reproducing the reference energy–strain relation. The TB parametrization reproduces the DFT band dispersion near the Fermi level and captures the strain dependence required to obtain the strain–energy curves. From this comparison, the in-plane stiffness is extracted as a function of ribbon width and edge orientation. The results show that zigzag ribbons are stiffer than armchair ribbons and that stiffness decreases with increasing ribbon width, approaching the limit of extended silicene sheets. The extracted stiffness values ([Formula: see text]–0.35[Formula: see text]TPa[Formula: see text][Formula: see text][Formula: see text]Å(29–35[Formula: see text]N/m) for armchair SiNRs and [Formula: see text]–0.73[Formula: see text]TPa[Formula: see text][Formula: see text][Formula: see text]Å(61–73[Formula: see text]N/m) for zigzag SiNRs) are consistent with previous first-principles studies, confirming the reliability of the approach. These results illustrate how edge geometry and quantum confinement affect the mechanical response of silicene nanostructures and provide useful insight into their potential use in nanoscale device applications.