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

By using first-principles calculations, we systematically investigated several observed phases of silicene on Ag(1 1 1) substrates ((2×2)silicene/(7×7)Ag(1 1 1), (7×7)silicene/(23×23)Ag(1 1 1), (7×7)silicene/(13×13)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.