Strong band hybridization between silicene and Ag(1 1 1) substrate

By using first-principles calculations, we systematically investigated several observed phases of silicene on Ag(1 1 1) substrates ((2×2)silicene/(View the MathML source)Ag(1 1 1), (View the MathML source)silicene/(View the MathML source)Ag(1 1 1), (View the MathML source)silicene/(View the MathML source)Ag(1 1 1)) and their electronic structures. We find that the original Dirac cone of silicene is about 1.5–1.7 eV deeply below the Fermi level and severely destroyed by the band hybridization between silicene and Ag in all the examined phases. Thus, silicene synthesized on Ag(1 1 1) substrates could not preserve its excellent electronic property and new method is needed to develop in synthesizing silicene with its Dirac cone surviving.