Strain-modulated superconductivity of monolayer Tc₂B₂

Abstract Two-dimensional (2D) superconductors have attracted significant research interest due to their promising potential applications in optoelectronic and microelectronic devices. Herein, we employ first-principles calculations to predicted a new 2D conventional superconductor, Tc 2 B 2 , demonstrating its stable structural configuration. Remarkably, under biaxial strain, the superconducting transition temperature ( T c ) of Tc 2 B 2 demonstrates a significant enhancement, achieving 19.5 K under 3% compressive strain and 9.2 K under 11% tensile strain. Our study reveals that strain-induced modifications in Fermi surface topology significantly enhance the Fermi surface nesting effect, which amplifies electron–phonon coupling interactions and consequently elevates T c . Additionally, the presence of the Lifshitz transition results in a more pronounced rise in T c under compressive strain compared to tensile strain. These insights offer important theoretical guidance for designing 2D superconductors with high- T c through strain modulation.