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Nano Research

Article Title

Fabrication and manipulation of nanosized graphene homojunction with atomically-controlled boundaries

Authors

Hui Chen, Institute of Physics and University of Chinese Academy of Sciences, Beijing 100190, China;CAS Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100049, China
De-Liang Bao, Institute of Physics and University of Chinese Academy of Sciences, Beijing 100190, China;CAS Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100049, China
Dongfei Wang, Institute of Physics and University of Chinese Academy of Sciences, Beijing 100190, China;CAS Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100049, China
Yande Que, Institute of Physics and University of Chinese Academy of Sciences, Beijing 100190, China
Wende Xiao, Institute of Physics and University of Chinese Academy of Sciences, Beijing 100190, China
Yu-Yang Zhang, Institute of Physics and University of Chinese Academy of Sciences, Beijing 100190, China;CAS Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100049, China
Jiatao Sun, Institute of Physics and University of Chinese Academy of Sciences, Beijing 100190, China;CAS Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100049, China
Shixuan Du, Institute of Physics and University of Chinese Academy of Sciences, Beijing 100190, China;CAS Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100049, China
Hong-Jun Gao, Institute of Physics and University of Chinese Academy of Sciences, Beijing 100190, China;CAS Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100049, China

Keywords

homojunction, graphene nanoislands, manipulations, grain boundaries, twisted stacking

Abstract

Controlling the atomic configurations of structural defects in graphene nanostructures is crucial for achieving desired functionalities. Here, we report the controlled fabrication of high-quality single-crystal and bicrystal graphene nanoislands (GNI) through a unique top-down etching and post-annealing procedure on a graphite surface. Low-temperature scanning tunneling microscopy (STM) combined with density functional theory calculations reveal that most of grain boundaries (GBs) formed on the bicrystal GNIs are 5-7-5-7 GBs. Two nanodomains separated by a 5-7-5-7 GB are AB stacking and twisted stacking with respect to the underlying graphite substrate and exhibit distinct electronic properties, forming a graphene homojunction. In addition, we construct homojunctions with alternative AB/twisted stacking nanodomains separated by parallel 5-7-5-7 GBs. Remarkably, the stacking orders of homojunctions are manipulated from AB/twist into twist/twist type through a STM tip. The controllable fabrication and manipulation of graphene homojunctions with 5-7-5-7 GBs and distinct stacking orders open an avenue for the construction of GBs-based devices in valleytronics and twistronics.

Publisher

Tsinghua University Press

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