Barrier-assisted vapor phase CVD of large-area MoS monolayers with high spatial homogeneity.

Atomically thin molybdenum disulphide (MoS) is a direct band gap semiconductor with negatively charged trions and stable excitons in striking contrast to the wonder material graphene. While large-area growth of MoS can be readily achieved by gas-phase chemical vapor deposition (CVD), growth of continuous MoS atomic layers with good homogeneity is indeed one of the major challenges in vapor-phase CVD involving all-solid precursors. In this study, we demonstrate the growth of large-area continuous single crystal MoS monolayers on -plane sapphire by carefully positioning the substrate using a facile staircase-like barrier.