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Isothermal growth and stacking evolution in highly uniform AB-stacked bilayer graphene
preprintsubmitted on 26.12.2019, 08:36 and posted on 31.12.2019, 20:35 by Pablo Solís-Fernández, Yuri Terao, Kenji Kawahara, Kosuke Nagashio, Yung-Chang Lin, Keisuke Yamamoto, Hiroshi Nakashima, Hiroki Hibino, Kazu Suenaga, Hiroki Ago
Controlling the stacking order in bilayer graphene (BLG) allows realising unique physical properties. In particular, the possibility of tuning the band gap in AB-stacked BLG (AB-BLG) has a great technological importance for electronic and optoelectronics applications. Most of current methods to produce AB-BLG suffer from inhomogeneous layer thickness and/or coexistence with twisted BLG. Here, we demonstrate a method to synthesise highly pure large-area AB-BLG by chemical vapour deposition (CVD) using Cu-Ni films. Increasing the reaction time resulted in a gradual increase of the AB stacking, with the BLG eventually free from twist regions for the longer times (99.4 % of BLG has AB stacking), due to catalyst-assisted continuous BLG reconstruction driven by carbon dissolution-segregation processes. The band gap opening was confirmed by the electrical measurements. The concept of the continuous reconstruction to achieve highly pure AB-BLG offers a new strategy to control the stacking order of catalytically grown two-dimensional materials.