Large-area epitaxial growth of curvature-stabilized ABC trilayer graphene
Zhaoli Gao, Sheng Wang, Joel Berry, Qicheng Zhang, Julian Gebhardt, William M. Parkin, J. Ávila, Hemian Yi, Kai Chen, Sebastian Hurtado-Parra, Marija Drndić, Andrew M. Rappe, David J. Srolovitz, James M. Kikkawa, Zhengtang Luo, M. C. Asensio, Feng Wang, A. T. Charlie Johnson
Abstract
The properties of van der Waals (vdW) materials often vary dramatically with the atomic stacking order between layers, but this order can be difficult to control. Trilayer graphene (TLG) stacks in either a semimetallic ABA or a semiconducting ABC configuration with a gate-tunable band gap, but the latter has only been produced by exfoliation. Here we present a chemical vapor deposition approach to TLG growth that yields greatly enhanced fraction and size of ABC domains. The key insight is that substrate curvature can stabilize ABC domains. Controllable ABC yields ~59% were achieved by tailoring substrate curvature levels. ABC fractions remained high after transfer to device substrates, as confirmed by transport measurements revealing the expected tunable ABC band gap. Substrate topography engineering provides a path to large-scale synthesis of epitaxial ABC-TLG and other vdW materials.