Influence of monolayer MoS2 grain boundaries on MoS2 cluster nucleation during layer-by-layer growth of bilayer MoS2

Release Time:2025-10-16  Hits:

• Date:2025-10-16
• Title of Paper:Influence of monolayer MoS2 grain boundaries on MoS2 cluster nucleation during layer-by-layer growth of bilayer MoS2
• Journal:Appl. Surf. Sci.
• Summary:Bilayer transition-metal dichalcogenides (TMDs) have promising applications in photoelectronic devices due to their unique physical and chemical properties. Grain boundaries (GBs) are an inevitable defect in the synthesis of TMDs, which will affect the nucleation behavior of the next-layer material, thereby altering the materials’ properties and their applications as devices. However, it remains unclear how the GBs of monolayer MoS2 regulate the nucleation of the next-layer MoS2 clusters. Here, we present a statistical analysis of the crystallographic orientation of MoS2 grown on GBs via chemical vapor deposition, and calculate the energy landscape between MoS2 cluster molecule and underlying MoS2 containing GBs. Our results reveal that the interlayer energy strongly depends on the size, termination edge type and nucleation position of MoS2 cluster. Additionally, the regulatory effect of GBs on MoS2 clusters is notably effective within ∼4 Å but negligible outside. Theoretically, the most favorable stacking configurations at GBs are bilayer MoS2 with 0° and small deflection angles (defined as the angle deviating from the regulation of perfect lattice), consistent with our experimental results. Our work clarifies the nucleation mechanism of MoS2 on GBs, which is scientifically important for optimizing the controlled growth of TMDs.
  Highlights
  1. Atomic structure of TL-MoS2/BL-MoS2 containing GBs was characterized by STEM.
  2. Within 4 Å, GBs exhibit significant regulatory effects on MoS2 clusters.
  3. 0° or small deflection angle is the most stable stacking at GBs for MoS2 clusters.
  4. A facile method to predict the orientation of the underlying MoS2 is demonstrated.
• Co-author:L. N. Chen, Z. F. Cheng, S. D. He, Z. P. Wu, X. D. Zhang, Z. W. Ren, D. H. Zong, K. L. Deng and M. G. Xia*
• Volume:715
• Page Number:164549
• Translation or Not:No
• Date of Publication:2025-09-03