Detailed study on MOCVD of wafer-scale MoS2 monolayers: From nucleation to coalescence

Abstract Metal–organic chemical vapour deposition (MOCVD) has become one of the most promising techniques for large-scale fabrication 2D transition metal dichalcogenide (TMDC) materials. Despite efforts devoted to development MOCVD TMDC monolayers, whole picture growth process not been fully unveiled yet. In this work, we employ a commercial AIXTRON CCS tool MoS 2 on sapphire using standard precursors and H as carrier gas. Adsorption diffusion Mo adatoms substrate are found be decisive nucleation. By lowering temperature from 650 450 °C, uniform distribution nuclei terraces is achieved. Full coalescence monolayers with limited bilayer formation (~ 15%) then realized at 700 °C. This study highlights importance understanding details film mechanisms developing multi-stage processes films. Graphical abstract