Weak localization behavior observed in graphene grown on germanium substrate

Yinbo Sun,Miao Zhang,Zengfeng Di,Xiaoming Xie,Linxi Dong,Gaofeng Wang,Xi Wang,Tao Hu

doi:10.1063/1.5021875

Abstract

Two dimensional electron systems (2DES) usually show the weak localization behavior in consequence of electron interaction in the limited dimension. Distinct from other 2DES, the monolayer graphene, due to the chirality, exhibits unique weak localization behavior sensitive to not only inelastic but also elastic carrier scattering. Grain boundaries, which usually exist in monolayer graphene, are apparently related to the elastic carrier scattering process, thus affecting the weak localization behavior. However, their effect is scarcely studied due to the lack of an ideal platform. Here, a complementary system consisting of both single-crystalline graphene grown on Ge (110) and poly-crystalline graphene grown on Ge (111) is constructed. From the comparison of magnetoresistivity measurements, the weak localization effect is found to be greatly enhanced for the poly-crystalline graphene on Ge(111) compared to the single-crystalline graphene on Ge(110). The degraded transport performance in graphene/Ge(111) is due to the presence of grain boundary in poly-crystalline graphene, which results in the enhanced elastic intervalley scattering. In addition, the inelastic scattering originating from the strong electron-electron interaction at low temperature also contributes to weak localization of poly-crystalline graphene/Ge(111).

Highlights

Weak localization (WL) is the positive quantum correction to the resistivity of disordered two dimensional system at low temperature, which occurs as electrons are coherently backscattered on a closed trajectory.[1]
Weak localization behavior observed in graphene grown on germanium substrate Yinbo Sun,[1,2] Miao Zhang,[1] Linxi Dong,[3] Gaofeng Wang,[3] Xiaoming Xie,[1,4] Xi Wang,[1] Tao Hu,1,4,a and Zengfeng Di1,a 1State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China 2University of Chinese Academy of Sciences, Beijing 100049, China 3Key Laboratory of RF Circuits and System of Ministry of Education, Electronic and Information College of Hangzhou Dianzi University, Hangzhou 310018, China 4CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai 200050, China (Received 9 January 2018; accepted 2 April 2018; published online 16 April 2018)
Those unique scattering mechanisms have been extensively studied on various graphene such as the exfoliated graphene flake,[7,11,12] the transferred poly-crystalline graphene[10] and the epitaxial graphene grown on the SiC,[13] which suggest that the WL in graphene can be aCorresponding authors: thu@mail.sim.ac.cn and zfdi@mail.sim.ac.cn

Summary

Introduction

Weak localization (WL) is the positive quantum correction to the resistivity of disordered two dimensional system at low temperature, which occurs as electrons are coherently backscattered on a closed trajectory.[1]. Weak localization behavior observed in graphene grown on germanium substrate Yinbo Sun,[1,2] Miao Zhang,[1] Linxi Dong,[3] Gaofeng Wang,[3] Xiaoming Xie,[1,4] Xi Wang,[1] Tao Hu,1,4,a and Zengfeng Di1,a 1State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China 2University of Chinese Academy of Sciences, Beijing 100049, China 3Key Laboratory of RF Circuits and System of Ministry of Education, Electronic and Information College of Hangzhou Dianzi University, Hangzhou 310018, China 4CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai 200050, China (Received 9 January 2018; accepted 2 April 2018; published online 16 April 2018)

Results

Conclusion