Sapphire substrates for large-area 2D transition metal dichalcogenides synthesis: A brief review

Two-dimensional transition metal dichalcogenides (TMDs) have attracted significant attention owing to their unique physical properties, such as strong spin-orbit coupling, giant magnetoresistance, and high carrier mobility. To study their fundamentals and develop high-performance electronic devices, high-quality large-area TMD films are inevitably required. Recently, sapphire substrate has emerged as a promising wafer-scale growth platform for synthesizing TMDs via chemical vapor deposition. In this brief review, we address the synthesis of both polycrystalline and single-crystalline TMDs on c-plane and miscut sapphire substrates. In addition, posttreatment processes are investigated, including H2-treatement and oxidation, to achieve a well-defined surface structure and enhance the reproducibility of single-crystalline TMD synthesis. We conclude by offering a summary and insights into future research directions.