From molecular precursors to MoS2 monolayers: nanoscale mechanism of organometallic chemical vapor deposition
Authorship
This Chem. Mater. study is authored by Ghorai and Govind Rajan (IISc); Adri van Duin is not a co-author. It is included in the corpus as adjacent 2D CVD theory.
Summary¶
IISc authors Ghorai and Govind Rajan use density-functional theory to propose a stepwise organometallic CVD (OM-CVD) mechanism for monolayer 2H–MoS₂ from Mo(CO)₆ and H₂S on amorphous SiO₂. The pathway follows precursor decomposition (decarbonylation toward Mo(CO)₃ fragments), sulfidation, transient 1T metallic Mo–S clusters, and eventual 2H semiconducting flake growth. The study contrasts Mo-zigzag vs S-zigzag edge propagation and relates edge termination to triangular vs hexagonal island morphologies observed experimentally. The DFT narrative is intended as a mechanistic hypothesis generator for CVD practitioners: it connects gas-phase precursor chemistry to surface cluster isomerism that precedes extended TMD lattices. Downstream ReaxFF or kinetic Monte Carlo projects should treat these static pathways as starting points that may require refitting barriers when coverage, electric fields, or alloying impurities depart from the idealized SiO₂ substrate models used here.
Methods¶
Static DFT on amorphous SiO₂ (C)¶
DFT (functional/basis per Chem. Mater.) for Mo(CO)\(_6\) + H\(_2\)S OM-CVD pathway: decarbonylation, sulfidation, Mo–S cluster isomerism, edge propagation (Mo-zigzag vs S-zigzag) on a-SiO\(_2\).
Thermodynamics and kinetics¶
H\(_2\) elimination highlighted as rate-limiting for the featured sequence; compare edge-mediated growth modes in the article.
Static QM / DFT (OM-CVD on a-SiO\(_2\)). Density functional theory with PBE or the hybrid/meta-GGA level named in Chem. Mater.; DFT+D-type vdW treatment if used. Plane-wave+PAW (or the paper’s localized basis description) and k-point/Brillouin sampling for slab+molecule models. Structures follow NEB/climbing-image (or as stated) reaction pathways for decarbonylation/sulfidation; properties include formation energies, barriers, and edge-mediated kinetics arguments. N/A—molecular-dynamics production in this work (this is a static QM study per tags); N/A—ReaxFF in this paper—see ## Limitations.
Findings¶
Precursor cracking feeds 1T metallic Mo–S clusters that convert toward 2H MoS₂, with edge kinetics and H removal controlling shape and growth rate in the model. Cluster formation energies on SiO₂ favor multi-Mo nuclei, consistent with experimental nucleation trends discussed in the paper.
Comparisons, sensitivity, corpus note. Compares model nucleation/morphology to CVD experiments cited in the paper; sensitivity to edge termination and H-transfer kinetics is a theme. IISc work—not a van Duin-authored page.
Limitations¶
DFT provides 0 K static pathways; ReaxFF is not used here. Real CVD involves gas-phase transport, coverage fluctuations, and substrate heterogeneity beyond a single amorphous SiO₂ model. Microkinetic extrapolation from few elementary steps can miss surface carbon contamination and chamber-specific impurities highlighted experimentally in MoS₂ growth literature. Readers should cite Chem. Mater. metadata from the publisher page for volume/issue/pages rather than relying on filename-only paths in papers/Others/. Preprint-style filenames in papers/Others/ are not authoritative bibliographic identifiers by themselves; always prefer publisher metadata.
Relevance to group¶
Provides QM reference mechanisms for MoS₂ OM-CVD useful alongside ReaxFF TMD and 2D growth reviews (e.g., [[2020momeni-npj-computat-multiscale-computational]]) even though Adri van Duin is not an author. The page flags IISc authorship explicitly to avoid incorrect group attribution in retrieval snippets.
Citations and evidence anchors¶
- DOI:
10.1021/acs.chemmater.3c02675— Chem. Mater.;papers/Others/ghorai-govind-rajan-2024-from-molecular-precursors-to-mos2-monolayers-nanoscale-mechanism-of-organometallic-chemical.pdf; extractnormalized/extracts/2024ghorai-chem-mater-0-molecular-precursors_p1-2.txt.