Strain and interface engineering of MoS2 nanosheets decorated with Ag nanoparticles and its light-matter coupling in photoexcitation

Abstract

The interfacial stress and electron transfer of metal decorates transition metal dichalcogenides (TMDs) are very important for the novel two-dimensional (2D) semiconductor optoelectronic device technology in the future. Herein, strain and interface engineering of molybdenum disulfide (MoS2) nanosheets decorated with Ag nanoparticles (Ag/MoS2) for controlled charge transfer and electron excitation-relaxation is presented. The effect of strong random scattering on the transport and electron localization phenomena of MoS2 is experimentally investigated. Exploring the charge fast transfer channel constructed by the plasma structure and the separated excited states of Ag, as well as explains the regulating mechanism of the optical absorption for TMDs in time domain. The finite-difference time-domain near-light field is used to simulate the effect of Ag content on the electromagnetic field distribution of MoS2, and then the modification of MoS2 is determined by controlling Ag content. Whilst, we can reveal the excellent light material interaction effect and ultrafast electron transfer mechanism of heterojunction surface contact sites. The E12g peak undergoes splitting, which originates from the lattice mismatch between Ag particles with plasma structure and MoS2, confirming the strong interfacial stress effect between them. On the basis of interfacial stress as well as the effective charge transfer, the Ag/MoS2 composites exhibit excellent excitation and emission behaviors. The local surface plasmon resonance effect of Ag nanoparticles is expected to adjust of nonlinear optical for TMDs. Specifically, we will regulate the ultrafast laser photon induced nonlinear absorption behavior by adjusting the Ag content and contact mode. The local strain generation on the Ag/TMDs boundary provides a new method for the design of new heterogeneous materials, and will be of great significance to investigate the contact physical behavior and application between metals decorates two-dimensional semiconductors.