Influence of numerous Moir?e superlattices on transport properties of twisted multilayer graphene

Band structure engineering by changing the parameters of Moire = superlattices enables creation of materials with outstanding properties for twistronics, straintronics and quantum nanoelectronics applications. Herein, twisted multilayer graphene (tMLG) with various combinations of twist angles (0) and numerous Moire = superlattices was synthesized. The strong dependence of the transport properties of tMLG on the structural characteristics was demonstrated using synchrotron-based core-level spectroscopy methods combined with micro-Raman spectroscopy. It has been shown that tMLG with a large content of the twisted phase with the twist angles between the adjacent graphene layers of 0 = 26-30 degrees over the entire tMLG thickness is characterized by a perfect structure of the single layer graphene (SLG) and extraordinary transport characteristics. At low temperatures, the asymmetry of charge carriers and atypical temperature dependence of average carrier mobility m were observed. In such tMLG, m was higher than 105 cm2V-1s-1. Decrease in the content of the twisted phase with 0 = 26-30 degrees, as well as increase in the contents of other twist angles and AB-stacked phase (0 = 0 degrees), leads to a significant decrease in m. Hence, tMLGs are a better choice for the nanoelectronics industry because, having outstanding transport properties, they are, contrary to SLG, insensitive to the specific features of process procedures.

Automated summary

Band structure engineering through changing the parameters of Moire superlattices can create materials with outstanding properties. This study demonstrated the strong dependence of the transport properties of twisted multilayer graphene (tMLG) on its structural characteristics. tMLG with a large content of the twisted phase was found to have perfect structure and extraordinary transport characteristics, while changes in the content of the twisted phase led to a significant decrease in transport properties. Therefore, tMLG is a better choice for the nanoelectronics industry.