Controlled synthesis and optical properties of polycrystalline molybdenum disulfide atomic layers grown by chemical vapor deposition

We report a scalable growth of mono to few-layer molybdenum disulfide (MoS₂) atomic layers on different substrates by chemical vapor deposition (CVD). The effects of the source material (sulfur and MoO₃ powder) and the growth temperature were systematically optimized for the growth of both highly crystalline and large area MoS₂. The deposited film thickness could be precisely controlled by varying the growth temperatures, and this was confirmed by Raman and AFM results. The monolayer, bilayer, and multilayer MoS₂ could be obtained at 650 °C, 700 °C, and 750-800 °C, respectively. The mobility value of ∼0.89 cm²/V s and current on/off ratio in the order of ∼10⁴ was estimated for monolayer MoS₂. The mobility value increased to ∼7.6 cm²/V s for the bilayer MoS₂. Our results pave the way for the controlled synthesis of high-quality transition metal dichalcogenide materials, which are an attractive option for applications in electronic and optoelectronic devices.