Direct CVD Synthesis of MoS₂ Monolayers on Glass by Carbothermal Reduction

Chemical vapor deposition (CVD) synthesis for two-dimensional (2D) transition-metal dichalcogenides (TMDCs) is fundamentally important for realizing high-quality single crystals of TMDCs for future electronic and optoelectronic device applications. However, CVD synthesis of TMDCs generally requires a high synthetic temperature (>700 °C), which limits the choice of growth substrates and their broad applications. In this work, we present direct CVD synthesis of 2D MoS₂ on glass. The CVD growth temperature was significantly decreased to 500 °C by employing carbothermal reduction, which uses carbon as the catalyst for reducing the thermal decomposition temperature of MoO₃ precursors. MoS₂ single crystals grown on glass showed no observable degradation in electrical, optical, and structural properties compared to MoS₂ grown at high temperatures. The MoS₂ grown on glass exhibited field effect mobility around 7.6 cm² V^-1 s^-1 and a high ON/OFF ratio of up to 10⁷, photoresponsivity up to 40 A/W, and stable and repeatable photocurrent. These findings demonstrate a promising strategy in the CVD growth of 2D materials and the design of their flexible and transparent devices.