Silicene on substrates: A theoretical perspective

Zhong Hong-Xia^a),^c)†, Quhe Ru-Ge^a),^d),^e),^f)†, Wang Yang-Yang^a),^g)†, Shi Jun-Jie^a), Lü Jing†‡^a),^b)

(a) Top and side views of the atomic structure of silicene and graphene, where red and yellow atoms represent the two sublattices of Si atoms separated vertically by 0.62 Å, and the grey spheres represent carbon atoms in the graphene layer at a separation of 3.3 Å from the lower silicon layer. The lattice vectors a _Si and a _G of the (1×1) unit cell of silicene and graphene, respectively, have a relative rotational angle of 10.9° between them; (b) The first Brillouin zones of the combined system (orange), 1×1 silicene (white), and 1×1 graphene (purple). Band structures of silicene and graphene: (c) the projected states on Si are highlighted; (d) the projected states on C are highlighted; and (e) the projected bands in panels (c) and (d) are combined. The substrate-induced gaps are about 26 meV for Si ( Γ ) and 2 meV for graphene ( K ), respectively (Reproduced with permission from Ref. [ 27 ]. Copyright 2013 American Physical Society).