Plasmon-enhanced broadband absorption of MoS-based structure using Au nanoparticles.

The light absorption of a hybrid novel MoS-based nanostructure is theoretically investigated by using the finite-difference time-domain (FDTD) simulations, and high-efficiency broadband absorption is achieved in the visible wavelength region. The enhancement of localized electromagnetic field owing to that localized surface plasmon resonances (LSPRs) supported by Au nanoparticles (NPs) can be used to enhance the absorption of MoS, and the localized absorption of monolayer MoS are remarkably enhanced up from about 18.3% and 4.6% to about 55.2% and 84.8% at the resonant wavelengths of 467.7 nm and 557.8 nm, respectively. Furthermore, the effects of radii of Au NPs, period of Au NPs array, Au@Si NPs core-shell ratios, period numbers of the distributed Bragg mirror (DBR), and incident angle on the absorption of the proposed nanostructure have been systematically investigated. The similar design idea to enhance the light-MoS interaction can also be applied to other transition-metal dichalcogenides (TMDCs). This work will contribute to the design of TMDCs-based nanophotonic and optoelectronic devices.