Effect of the Substrate on MoS₂ Monolayer Morphology: An Integrated Computational and Experimental Study

Abstract

Synthesis of two-dimensional materials, specifically transition metal dichalcogenides (TMDs), 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, thus reaching their maximum mechanical and optoelectronic performance. Here, we investigated the role of the substrate’s crystallinity in the growth orientation of 2D materials using reactive molecular dynamics (MD) simulations and verified with experimental growth using the chemical vapor deposition (CVD) technique. We considered MoS2 as our model material and investigated its growth on crystalline and amorphous silica and sapphire substrates. We revealed the role of the substrate’s energy landscape on the orientation of as-grown TMDs, where the presence of monolayer–substrate energy barriers perpendicular to the streamlines hinder the detachment of precursor nuclei from the substrate. We show that MoS2 monolayers with controlled orientations could not be grown on the SiO2 substrate and revealed that amorphization of the substrate changes the intensity and equilibrium distance of monolayer–substrate interactions. Our simulations indicate that 0° rotated MoS2 is the most favorable configuration on a sapphire substrate, consistent with our experimental results. The experimentally validated computational results and insight presented in this study pave the way for the high-quality synthesis of TMDs for high-performance electronic and optoelectronic devices.

Tenth-Order Multiphoton Excitation and Saturable Second Harmonic Generation in Polyoxometalate-Exfoliated Molybdenum Disulfide

“…Previously described synthesis protocols were used to prepare redox-exfoliated MoS 2 , and MOCVD MoS 2 . , H-bn flakes in solution were purchased from 2D Semiconductors. Solution phase samples were drop cast onto a glass coverslip for measurement.…”

Large-area single-crystal TMD growth modulated by sapphire substrates

“…4h and i). 69 Kinetic Monte Carlo (KMC) simulation method has also been used to model the dynamic evolution of TMDs with respect to the substrate. Nie et al used KMC to study the van der Waals epitaxy process of TMDs and discussed how the growth parameters affect the uniform nucleation, growth rate, domain shape and thickness.…”

A Modified Embedded-Atom Method Potential for a Quaternary Fe-Cr-Si-Mo Solid Solution Alloy

“…Efficient computational tools have been developed to perform simulations within timespans not accessible to experimental studies [ 22 , 23 ]. We may refer to large-scale continuum simulations [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ], phase-field simulations for capturing the microstructure [ 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ], MD simulations to capture the atomistic mechanisms [ 2 , 47 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 ], and multiscale simulations to capture the broad spectrum of materials and processes response [ 24 , 25 , 46 ,…”