Plasmon Triggered, Enhanced Light-Matter Interactions in Au-MoS2 Coupled System with Superior Photosensitivity

Enhanced light-matter interactions by integrating plasmonic Au nanostructures as a light harvester on twodimensional (2D) MoS2 carrier sink layers are reported, leading to broadband optical absorption and significantly enhanced Raman scattering intensity. The calculations of electronic band structure using density functional theory analysis and optical simulations elucidate the metal induced doping in MoS2 and the enhancement of electromagnetic field through localized surface plasmon resonance at the Au/MoS2 interface by forming a number of hot spots, corroborating the spectroscopic results. The ultrafast timedomain results reveal a 200-fold enhancement in the carriers' lifetime for nanohybrids, as compared to the control sample, which is attributed to the efficient transfer of hot electrons from Au to MoS2. Fabricated metal-semiconductor-metal photodetectors using hybrid nanostructures exhibit a 20-fold enhancement of photoresponsivity (similar to 1.5 A/W at 640 nm) as compared to pristine MoS2 and a remarkably high peak detectivity (similar to 4.75 x 10(13) Jones at 3 V), which are promising for broadband and multicolor photodetection, making them attractive for large area 2D materials-based nanophotonic devices.

Automated summary

Integrating plasmonic Au nanostructures as a light harvester on two-dimensional MoS2 layers enhances light-matter interactions, leading to increased optical absorption and Raman scattering intensity. The metal-induced doping in MoS2 and enhancement of electromagnetic field through localized surface plasmon resonance at the Au/MoS2 interface are confirmed, with the hybrid nanostructures showing significantly improved carrier lifetime and photodetection performance. Fabricated metal-semiconductor-metal photodetectors exhibit promising broadband and multicolor photodetection capabilities for large area 2D materials-based nanophotonic devices.