Au@MoS₂ Core-Shell Heterostructures with Strong Light-Matter Interactions

There are emerging opportunities to harness diverse and complex geometric architectures based on nominal two-dimensional atomically layered structures. Herein we report synthesis and properties of a new core-shell heterostructure, termed Au@MoS₂, where the Au nanoparticle is snugly and contiguously encapsulated by few shells of MoS₂ atomic layers. The heterostructures were synthesized by direct growth of multilayer fullerene-like MoS₂ shell on Au nanoparticle cores. The Au@MoS₂ heterostructures exhibit interesting light-matter interactions due to the structural curvature of MoS₂ shell and the plasmonic effect from the underlying Au nanoparticle core. We observed significantly enhanced Raman scattering and photoluminescence emission on these heterostructures. We attribute these enhancements to the surface plasmon-induced electric field, which simulations show to mainly localize within the MoS₂ shell. We also found potential evidence for the charge transfer-induced doping effect on the MoS₂ shell. The DFT calculations further reveal that the structural curvature of MoS₂ shell results in a modification of its electronic structure, which may facilitate the charge transfer from MoS₂ to Au. Such Au@MoS₂ core-shell heterostructures have the potential for future optoelectronic devices, optical imaging, and other energy-environmental applications.