Fabrication of large-scale graphene/2D-germanium heterostructure by intercalation
Guo Hui1, Wang Xueyan1, Bao De-Liang1, Lu Hong-Liang1, Zhang Yu-Yang1, 2, Li Geng1, 2, Wang Ye-Liang1, Du Shi-Xuan1, 2, †, Gao Hong-Jun1, 2
       

STM characterizations for sample before and after Ge intercalation. (a) A large-scale STM image ( U = − 1.54 V and I = 0.05 nA) of the as-fabricated graphene on Ir(111). The unit cell of the graphene Moiré structure is labeled by dash rhombus. (b) An atomically resolved STM image ( U = − 0.05 V and I = 0.3 nA) showing honeycomb lattices of the graphene. (c) A large scale STM image ( U = − 1.5 V and I = 0.1 nA) of the sample after germanium intercalation. The dash rhombus labels the weak graphene Moiré pattern. A new structure with a periodicity of 0.54 nm is visible. (d) An atomic resolved STM image ( U = − 0.01 V and I = 20 nA) of the Ge intercalated graphene.