Plasmon Triggered, Enhanced Light–Matter Interactions in Au–MoS<sub>2</sub> Coupled System with Superior Photosensitivity
Subhrajit Mukherjee, Rup Kumar Chowdhury, Debjani Karmakar, Meher Wan, Chacko Jacob, Soumen Das, S. K. Ray
Abstract
Enhanced light–matter interactions by integrating plasmonic Au nanostructures as a light harvester on two-dimensional (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 time-domain 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 (∼1.5 A/W at 640 nm) as compared to pristine MoS2 and a remarkably high peak detectivity (∼4.75 × 1013 Jones at 3 V), which are promising for broadband and multicolor photodetection, making them attractive for large area 2D materials-based nanophotonic devices.