Strong band hybridization between silicene and Ag(111) substrate

By using first-principles calculations, we systematically investigated several observed phases of silicene on Ag(111) substrates ((2 x 2)silicene/(root 7 x root 7)Ag(111), (root 7 x root 7)silicene/(2 root 3 x 2 root 3)Ag(1 11), (root 7 x root 7)silicene/(root 13 x root 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. (C) 2013 Elsevier B.V. All rights reserved.