Scalable High-Mobility Graphene/hBN Heterostructures

Graphene-hexagonal boron nitride (hBN) scalable heterostructures are pivotal for the development of graphene-based high-tech applications. In this work, we demonstrate the realization of high-quality graphene-hBN heterostructures entirely obtained with scalable approaches. hBN continuous films were grown via ion beam-assisted physical vapor deposition directly on commercially available $SiO_2/Si$ and used as receiving substrates for graphene single-crystal matrixes grown by chemical vapor deposition on copper. The structural, chemical, and electronic properties of the heterostructure were investigated by atomic force microscopy, Raman spectroscopy, and electrical transport measurements. We demonstrate graphene carrier mobilities exceeding $10,000 cm^2/Vs$ in ambient conditions, 30% higher than those directly measured on $SiO_{2}/Si$. We prove the scalability of our approach by measuring more than 100 transfer length method devices over a centimeter scale, which present an average carrier mobility of $7500 \pm 850 cm^{2}/Vs$. The reported high-quality all-scalable heterostructures are of relevance for the development of graphene-based high-performing electronic and optoelectronic applications

Progress in epitaxial growth of stanene

With the rise of graphene, other elemental 2D materials have received a massive increase in interest in recent years. However, while theoretical models of free-standing materials predict exotic properties, often outshining those of graphene, the experimental field struggles with the synthesis of such materials. Epitaxial growth has become the main method used in experiments, as the consensus in the scientific community is that such materials require a stabilizing support. In this context, a substrate material suitable for supporting a 2D layer while preserving its topological properties is a key factor in the process. In this review article, our focus is directed to substrates for an elemental topological 2D material from group IV - stanene. We present the current state of the experimental field and give an outlook on future possibilities investigated in density functional theory (DFT) calculations