Structure, stability, and electronic and optical properties of TMDC-coinage metal composites: vertical atomically thin self-assembly of Au clusters.

Composites of metal clusters supported on transition metal dichalcogenides (TMDCs) often provide promising opportunities for applications in nanoelectronics, catalysis, sensing, etc. In the present investigation, a systematic attempt has been made to unveil the structure and stability of coinage M 6 clusters supported on TMDC (MoS 2 and WS 2 ) monolayers. The more prominent objective is to explore potential candidates that stabilize the two-dimensional (2D) M 6 clusters on their surface. Periodic energy decomposition analysis (pEDA) was carried out to probe the various interaction energy (IE) components that govern the stability of the M 6 clusters in the composites. Attention has also been devoted to unravelling the electronic and optical properties of these TMDCs/M 6 composites. Moreover, ab initio molecular dynamics (AIMD) simulations were performed to scrutinize the dynamic behaviour of Au cluster on WS 2 monolayer. The results reveal that the coinage M 6 clusters form energetically more stable composites on MoS 2 than WS 2 monolayer. It is worth mentioning that WS 2 promotes the stability of 2D M 6 clusters. Inclusion of dispersion correction marginally altered the geometries of the TMDCs/M 6 composites but its impact on the IE values was significant. AIMD simulation explicitly emphasizes that the WS 2 surface preferentially facilitates the vertical 2D self-assembling of Au atoms and, interestingly, the planarity is mostly retained during the course of simulations. The adsorption of coinage M 6 clusters substantially influences the electronic and optical properties of the TMDCs. HSE06 calculation confirms that the decrease in energy gap is more pronounced in MoS 2 /M 6 composites. The outcomes of this study render fundamental insights into the various TMDCs/M 6 composites that would certainly be worthwhile probing for diverse practical applications.