Fabrication and properties of silicene and silicene–graphene layered structures on Ir (111)

Meng Lei^a),^b), Wang Ye-Liang†^b), Zhang Li-Zhi^b), Du Shi-Xuan^b), Gao Hong-Jun‡^b)

LEED patterns and the corresponding schematic diagrams of the Ir (111) surface before and after silicon deposition. (a) The six bright spots originating from the six-fold symmetry of the Ir (111) substrate. (b) Sketch of the diffraction spots shown in panel (a), where the reciprocal vectors are indicated by white arrows. (c) Outer six bright spots (highlighted by the dashed circles), and the additional diffraction spots due to the silicon adlayer. (d) LEED pattern of the silicon superstructure obtained with lower incident electron beam energy. (e) Sketch of the diffraction spots shown in panel (c), where the reciprocal vectors of each group of spots are indicated by white, red, and blue arrows respectively. (f) Schematic diagram of the diffraction spots in real space. These data reveal a superstructure of the silicon layer [lattice vectors ( a ₁, b ₁) or ( a ₂, b ₂)] with respect to the Ir (111) lattice [lattice vectors ( a ₀, b ₀)]. Panels (a), (c), and (d) are obtained at 55 eV, 47 eV, and 29 eV, respectively.^{[ 73 ]}