Impact of germanium substrate orientation on morphological and structural properties of graphene grown by CVD method

摘要

In this paper we study graphene synthesized on undoped (001), (110), and (111) Ge substrates, and show how the surface orientation and reconstruction affect its morphological and structural properties. The article presents the first attempt to explain the impact of germanium surface reconstruction on the shape and the density of graphene nuclei as well as on the material's stress and doping levels. Our findings suggest that graphene obtained on Ge(001) is the most uniform, with low doping (1.5 x 10(12) cm(-2)) and low strain level ( - 0.1%). Graphene on Ge(110) appears to be highly compressed ( - 0.5%) while graphene on Ge(111) exhibits doping reaching 5 x 10(13) cm(-2). These results help to better understand the dynamics of graphene growth on germanium and indicate Ge(001), in terms of its structural properties, as the most promising orientation for the future CMOS applications.