摘要
Epitaxial growth on transition metal surfaces is an effective way to prepare large-area and high-quality graphene.However,the strong interaction between graphene and metal substrates suppresses the intrinsic excellent properties of graphene and the conductive metal substrates also hinder its applications in electronics.Here we demonstrate the decoupling of graphene from metal substrates by germanium oxide intercalation.Germanium is firstly intercalated into the interface between graphene and Ir(111) substrate.Then oxygen is subsequently intercalated,leading to the formation of a GeO_(x) layer,which is confirmed by x-ray photoelectron spectroscopy.Low-energy electron diffraction and scanning tunneling microscopy studies show intact carbon lattice of graphene after the GeO_(x) intercalation.Raman characterizations reveal that the intercalated layer effectively decouples graphene from the Ir substrate.The transport measurements demonstrate that the GeO_(x) layer can act as a tunneling barrier in the fabricated large-area high-quality vertical graphene/GeO_(x)/Ir heterostructure.
基金
Project supported by the National Key Research&Development Program of China(Grant Nos.2019YFA0308500,2016YFA0202300,and 2018YFA0305800)
the National Natural Science Foundation of China(Grant Nos.61888102,61925111,and 21661132006)
the Strategic Priority Research Program of Chinese Academy of Sciences(Grant Nos.XDB30000000 and XDB28000000)
the CAS Key Laboratory of Vacuum Physics。
