Figure 1
From: Understanding the origin of band gap formation in graphene on metals: graphene on Cu/Ir(111)
STM images of graphene on Ir(111) and pseudomorphic Cu/Ir(111).
(a) 3D view of the STM image of graphene/Ir(111) (scanning parameters: 120 × 56 nm2, UT = +0.3 V, IT = 1.6 nA). Upper and lower insets show the LEED image (Ep = 93 eV) and atomically resolved STM image (scanning parameters: 4.5 × 4.5 nm2, UT = +0.5 V, IT = 10 nA) of this system. (b) 3D view of the STM image of graphene/Cu/Ir(111) (scanning parameters: 175 × 82 nm2, UT = +0.3 V, IT = 1.6 nA). Upper and lower insets show the LEED image (Ep = 90eV) and an STM image of two graphene domains (scanning parameters: 60 × 24 nm2, UT = +0.3 V, IT = 1.6 nA). (c) and (d) present atomically resolved images of the graphene/Cu/Ir(111) system obtained at UT = +0.3 V and UT = −0.3 V(top)/−0.9 (bottom), respectively (scanning parameters: 10.1 × 10.1 nm2, IT = 1.6 nA for both images). (e) Top and side views of the graphene/metal(111) structure. In case of Ir(111) all layers consist of the same atoms, whereas for the Cu/Ir(111) pseudomorphic system the metal (S) is the copper layer. In the top view, the circle, triangle, rhombus and rectangular denote the ATOP, HCP, FCC and BRIDGE positions for the carbon atoms, respectively. The big white rhombus marks the unit cell of the graphene/metal(111) system.
