Large Area Growth and Characterization of Monolayer MoS$_{2}$

Two-dimensional transition metal dichalcogenides have garnered extensive attention due to their direct band gap with great potential in semiconductor application complementing graphene. While most of the experiments were carried out on either exfoliated films or CVD grown crystals, sample size are restricted in hundreds of micrometers. Synthesis of large-area samples were less successful. Here, we report the growth of cm$^{2}$-scale molybdenum disulfide (MoS$_{2})$ monolayer with a facile method by sulfurizing molybdenum trioxide film on sapphire substrates. Uniformity and quality of the monolayer films were verified by Raman, PL mapping and PL efficiency. A quasi- molten phase of the precursor in the initial stage of the reaction is found to be crucial for the monolayer growth.