Designing 2D Wide Bandgap Semiconductor B12X2H6 (X=O, S) Based on Aromatic Icosahedral B12

Constructing two-dimensional (2D) novel materials using superatoms as building blocks is currently a highly promising research field. In this study, by employing an oxidation strategy and based on first-principles calculations, we successfully predicted two types of 2D borides, namely B₁₂X₂H₆ (X=O, S), with icosahedral B₁₂ serving as their core structural unit. Ab initio molecular dynamics simulations demonstrated that these two borides exhibit exceptionally high structural stability, retaining their original structural characteristics even under extreme temperature conditions as high as 2200 K. Electronic structure calculations revealed that B₁₂O₂H₆ and B₁₂S₂H₆ are both wide-bandgap indirect semiconductors, with bandgap widths reaching 4.92 eV and 5.25 eV, respectively. Analysis via deformation potential theory showed that the phonon-limited carrier mobilities of B₁₂X₂H₆ can reach up to 1469 cm²V^-1s^-1 (for B₁₂O₂H₆) and 635 cm²V^-1s^-1 (for B₁₂S₂H₆). Notably, the surfaces of B₁₂X₂H₆ demonstrate excellent migration performance for alkali metal ions, with migration barriers as low as 0.15 eV (for B₁₂O₂H₆) and 0.033 eV (for B₁₂S₂H₆). This study not only expands the family of 2D materials based on B₁₂ superatoms but also provides a solid theoretical foundation for the potential application of B₁₂X₂H₆ in the field of low-dimensional materials.