Wafer Scale Synthesis and High Resolution Structural Characterization of Atomically Thin MoS2 Layers

Synthesis of atomically thin MoS 2 layers and its derivatives with large‐area uniformity is an essential step to exploit the advanced properties of MoS 2 for their possible applications in electronic and optoelectronic devices. In this work, a facile method is reported for the continuous synthesis of atomically thin MoS 2 layers at wafer scale through thermolysis of a spin coated‐ammonium tetrathiomolybdate film. The thickness and surface morphology of the sheets are characterized by atomic force microscopy. The optical properties are studied by UV–Visible absorption, Raman and photoluminescence spectroscopies. The compositional analysis of the layers is done by X‐ray photo­emission spectroscopy. The atomic structure and morphology of the grains in the polycrystalline MoS 2 atomic layers are examined by high‐angle annular dark‐field scanning transmission electron microscopy. The electron mobilities of the sheets are evaluated using back‐gate field‐effect transistor configuration. The results indicate that this facile method is a promising approach to synthesize MoS 2 thin films at the wafer scale and can also be applied to synthesis of WS 2 and hybrid MoS 2 ‐WS 2 thin layers.