CVD Synthesis of MoS(2) Using a Direct MoO(2) Precursor: A Study on the Effects of Growth Temperature on Precursor Diffusion and Morphology Evolutions

In this study, the influence of growth temperature variation on the synthesis of MoS(2) using a direct MoO(2) precursor was investigated. The research showed that the growth temperature had a strong impact on the resulting morphologies. Below 650 °C, no nucleation or growth of MoS(2) occurred. The optimal growth temperature for producing continuous MoS(2) films without intermediate-state formation was approximately 760 °C. However, when the growth temperatures exceeded 800 °C, a transition from pure MoS(2) to predominantly intermediate states was observed. This was attributed to enhanced diffusion of the precursor at higher temperatures, which reduced the local S:Mo ratio. The diffusion equation was analyzed, showing how the diffusion coefficient, diffusion length, and concentration gradients varied with temperature, consistent with the experimental observations. This study also investigated the impact of increasing the MoO(2) precursor amount, resulting in the formation of multilayer MoS(2) domains at the outermost growth zones. These findings provide valuable insights into the growth criteria for the effective synthesis of clean and large-area MoS(2), thereby facilitating its application in semiconductors and related industries.