In the field of van der Waals heterostructures, the twist angle between stacked two-dimensional (2D) layers has been identified to be of utmost importance for the properties of the heterostructures. In this context, we previously reported the growth of a single layer of unconventionally oriented epitaxial graphene that forms in a surfactant atmosphere [F. C. Bocquet, et al., Phys. Rev. Lett. 125, 106102 (2020)]. The resulting G-R0∘ layer is aligned with the SiC lattice, and hence represents an important milestone towards high quality twisted bilayer graphene (tBLG), a frequently investigated model system in this field. Here, we focus on the surface structures obtained in the same surfactant atmosphere, but at lower preparation temperatures at which a boron nitride template layer forms on SiC(0001). In a comprehensive study based on complementary experimental and theoretical techniques, we find -- in contrast to the literature -- that this template layer is a hexagonal BxNy layer, but not high-quality hBN. It is aligned with the SiC lattice and gradually replaced by low-quality graphene in the 0∘ orientation of the BxNy template layer upon annealing.
@article{arxiv.2203.00985,
title = {Boron nitride on SiC(0001)},
author = {You-Ron Lin and Markus Franke and Shayan Parhizkar and Miriam Raths and Victor Wen-zhe Yu and Tien-Lin Lee and Serguei Soubatch and Volker Blum and F. Stefan Tautz and Christian Kumpf and François C. Bocquet},
journal= {arXiv preprint arXiv:2203.00985},
year = {2022}
}