Metallic BSi3 Silicene and Its One-Dimensional Derivatives: Unusual Nanomaterials with Planar Aromatic D6h Six-Membered Silicon Rings

Achieving two-dimensional (2D) aromatic compounds with planar cyclic six-membered silicon rings (c-Si 6 ) is a grand challenge. By means of density functional theory (DFT) computations, we predicted that c-BSi 3 silicene, the global minimum of the BSi 3 monolayer, contains planar aromatic D 6 h c-Si 6 . In c-BSi 3 silicene, the strong π–p conjugation between c-Si 6 and B atoms is responsible for the planar geometry of the aromatic D 6 h c-Si 6, which is in stark contrast to the conventional bonding motifs of silicon (sp 3 -bonding). Interestingly, the 2D c-BSi 3 silicene and its one-dimensional (1D) derivatives (c-BSi 3 nanotubes and nanoribbons) are metallic, regardless of the charity, tube diameter, or ribbon width, and the metallic behavior of c-BSi 3 silicene is very robust to mechanical strain and surface chemical functionalization. The high stabilities of these systems strongly suggest the feasibility for their experimental realizations.