Two-step growth of 4-inch multilayer MoS₂ wafers

Abstract Molybdenum disulfide (MoS 2 ) is an emerging two-dimensional (2D) semiconductor and has great potential for high-end applications beyond the traditional silicon-based electronics. Compared to the monolayers, multilayer MoS 2 has improved electron mobility and current density, and therefore provides a more promising platform in terms of thin-film transistors, flexible electronic devices, etc. However, the synthesis of large-area, high-quality multilayer MoS 2 films with controlled layer number remains a challenge. Here, we develop a two-step oxygen-assisted chemical vapor deposition (OA-CVD) methodology for the synthesis of 4-inch MoS 2 films from monolayer to trilayer on sapphire substrates. The influence of critical growth parameters on the growth of multilayer MoS 2 is systematically explored, such as the evaporation temperature of MoO 3 and the flow rate of O 2 . Flexible field-effect transistor (FET) devices fabricated from bilayer/trilayer MoS 2 show substantial improvements in mobility compared with flexible FETs based on monolayer films.