Growth of twisted bilayered graphene

Wei-Yen Woon^1*, Che-Men Chu¹

¹Department of Physics, National Central University, Jhongli district, Taoyuan City, Taiwan

* Presenter:Wei-Yen Woon, email:wywoon@phy.ncu.edu.tw

Multilayered graphene is grown through chemical vapor deposition. It is found that many multiple graphene grains can be formed under a milli-meter sized first layer graphene grain under a high hydrogen/methane ratio condition [1]. The distribution of the twist angle between the first and second layers is investigated through micro-Raman mapping. Through measuring the height, width,and symmetry of the 2D band, the ratio between 2D to G band, and the R' side-band, we are able to unambiguously identify the twist angles and categorize into five types. Besides the most abundant Bernal-stacking or large angle (> 15°) twist angle configurations, there are some bilayer regions that contain specific twist angles (5~8°, 8~13°, and 14°) . The distribution of the twist angles is closely correlated to the grain to grain distance between the underneath second layer grains, and local hydrogen termination conditions.

Reference:
1. Nucleation and growth kinetics of multi-layered graphene on copper substrate, Chia-Chun Chan, Wen-Liang Chung, Wei-Yen Woon
Carbon 135 (2018) 118-124

Keywords: graphene, Chemical vapor deposition, twist angle