Premium
Critical Annealing Temperature for Stacking Orientation of Bilayer Graphene
Author(s) -
Zhu Zhenwei,
Zhan Linjie,
Shih TienMo,
Wan Wen,
Lu Jie,
Huang Junjie,
Guo Shengshi,
Zhou Yinghui,
Cai Weiwei
Publication year - 2018
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201802498
Subject(s) - stacking , graphene , annealing (glass) , materials science , bilayer graphene , raman spectroscopy , bilayer , condensed matter physics , chemical vapor deposition , fabrication , nanotechnology , chemical physics , crystallography , composite material , chemistry , optics , membrane , medicine , biochemistry , physics , alternative medicine , organic chemistry , pathology
It is rarely reported that stacking orientations of bilayer graphene (BLG) can be manipulated by the annealing process. Most investigators have painstakingly fabricated this BLG by chemical vapor deposition growth or mechanical means. Here, it is discovered that, at ≈600 °C, called the critical annealing temperature (CAT), most stacking orientations collapse into strongly coupled or AB‐stacked states. This phenomenon is governed (i) macroscopically by the stress generation and release in top graphene domains, evolving from mild ripples to sharp billows in certain local areas, and (ii) microscopically by the principle of minimal potential obeyed by carbon atoms that have acquired sufficient thermal energy at CAT. Conspicuously, evolutions of stacking orientations in Raman mappings under various annealing temperatures are observed. Furthermore, MoS 2 synthesized on BLG is used to directly observe crystal orientations of top and bottom graphene layers. The finding of CAT provides a guide for the fabrication of strongly coupled or AB‐stacked BLG, and can be applied to aligning other 2D heterostructures.