Control of rotation angles of multilayer graphene on SiC (000(1)over-bar) by substrate off-direction and angle

Graphene on SiC (000 (1) over bar) tends to grow in multiple layers and does not have a single orientation relation with the SiC substrate. It has been considered impossible to control the rotation angle of multilayer graphene on SiC (000 (1) over bar). In this study, we grew graphene on off-axis SiC substrates with various off angles from 0 degrees to 8 degrees and investigated their in-plane rotation and electronic structures systematically. As the off angle toward the [11 (2) over bar0](SiC) direction increased, graphene rotated by 30 degrees with respect to SiC became less dominant and instead, graphene rotated by 30 +/- 2.5 degrees appeared. We also found that the uniformity of the graphene rotation angle was relatively high on SiC substrates with a small off angle toward the [1 (1) over bar 00](SiC) direction. Our results suggest that the step-terrace structure defined by the substrate off-direction and angle plays an important role in the controllability of the rotation angle of graphene.

Automated summary

The rotation angle of multilayer graphene on SiC (000 (1) over bar) can be controlled by changing the off angle of the SiC substrate. Graphene rotated by 30 degrees with respect to SiC becomes less dominant as the off angle towards the [11 (2) over bar0](SiC) direction increases, and instead, graphene rotated by 30 +/- 2.5 degrees appears. It was also found that the uniformity of the graphene rotation angle is relatively high on SiC substrates with a small off angle towards the [1 (1) over bar 00](SiC) direction.