Wafer-scale synthesis of thickness-controllable MoS2 films via solution-processing using a dimethylformamide/n-butylamine/2-aminoethanol solvent system

Abstract

The wafer-scale synthesis of two-dimensional molybdenum disulfide (MoS₂) films, with high layer-controllability and uniformity, remains a significant challenge in the fields of nano and optoelectronics. Here, we report the highly thickness controllable growth of uniform MoS₂ thin films on the wafer-scale via a spin-coating route. Formulation of a dimethylformamide-based MoS₂ precursor solution mixed with additional amine- and amino alcohol-based solvents (n-butylamine and 2-aminoethanol) allowed for the formation of a uniform coating of MoS₂ thin films over a 2 inch wafer-scale SiO₂/Si substrate. In addition, facile control of the average number of stacking layers is demonstrated by simply manipulating the concentration of the precursor solution. Various characterization results reveal that the synthesized MoS₂ film has wafer-scale homogeneity with excellent crystalline quality and a stoichiometric chemical composition. To further demonstrate possible device applications, a mostly penta-layered MoS₂ thin film was integrated into a top-gated field-effect transistor as the channel layer and we also successfully transferred our films onto transparent/flexible substrates.