Atomistic modeling and study of the interaction between differently oriented monolayer MoS2 on different substrates during chemical vapor deposition

Shiddartha Paul


The large-area high-quality synthesis of two-dimensional (2D) materials, specifically transition metal dichalcogenides (TMD) with controlled lattice orientations, is a major barrier to their industrial applications. Controlling the orientation of as-grown TMDs is critical for preventing the formation of grain boundaries and reaching their maximum mechanical and optoelectronic performance. We investigated the role of a substrate on the formation and coalescence of 2D materials using a reactive molecular dynamics method. We considered MoS2 as our model and studied its random and epitaxial growth on silica and Sapphire substrates, respectively. We revealed the role of the substrate’s energy landscape on the orientation of as-grown TMDs and showed a reduction in the binding energy by amorphization. Our results indicate that 0° rotated MoS2 is the most favorable configuration on a sapphire substrate, which is consistent with the experimental reports. The findings and insight on the role of the substrate on the growth of TMDs provided here, paves the way for the high-quality synthesis of TMDs for high performance electronic and optoelectronic devices.