Self‐Assembly Growth of Twisted Bilayer Graphene on Liquid Cu

Abstract

Twisted bilayer graphene (tBLG) possesses various novel physical properties. Most of tBLG are fabricated by using artificial methods of stacking or folding single‐layer graphene. Chemical vapor deposition (CVD) has been verified that it holds great potential for preparation of large‐size high‐quality graphene. Therefore, it is significant for preparing tBLG in situ by using CVD technology. In this work, a novel approach is developed to directly prepare tBLGs on liquid Cu substrate. When the growth temperature exceeds a certain critical value, the state of aligned high‐quality single‐layer graphene domains grown on liquid Cu will be broken. Then, tBLG with twisted double‐layer regions is prepared in situ by rotating and intercalating between graphene domains. Experimental observations suggest that the liquid phase of Cu substrate and gas flow play a crucial role for the formation of tBLGs. These results demonstrate that the liquid Cu is an ideal potential substrate for preparing tBLGs with a full range of twisted angles and studying the formation mechanism of layer‐stacked materials.

In Situ Growth of High‐Quality Single‐Crystal Twisted Bilayer Graphene on Liquid Copper

“…It is evident that the edges of graphene domains grown on liquid Cu substrates resulting from 127 µm solid foils overlapped with each other, forming bilayer regions with different twist angles, similar to the previous report. [ 33 ] Cu foil of varying thickness exhibited distinct mass and demonstrated good wettability on W substrates post‐melting. [ 23 ] Using thicker Cu foil not only enhanced the catalytic effect but also resulted in greater curvatures on W substrates after melting compared to thinner Cu foils.…”

Atomic engineering of two-dimensional materials via liquid metals

“…Xue et al presented an intriguing study focused on the direct preparation of twisted bilayer graphene (tBLG), 261 which is known for its unique and novel physical properties, [262][263][264] using CVD technology on a liquid Cu substrate. While most tBLG is typically fabricated using artificial methods of folding or stacking single-layer graphene, this research proposes a novel approach to achieve tBLG formation in situ.…”

‘Magic’ of twisted multi-layered graphene and 2D nano-heterostructures

“…Another method is the process of electrochemical intercalation which involves the insertion of foreign atoms or molecules between the layers of graphene to create a twisted BLG structure. This method relies on the intercalation of small molecules or ions into a graphene lattice, followed by thermal or chemical treatments to induce a twist [86]. In alignment with the earlier method of fabricating twisted BLG, chemical functionalization involves modifying one or both layers of graphene with functional groups or molecules, leading to a change in the interlayer coupling and resulting in a twisted structure [87].…”