Enhanced Photoelectric Response in MoS ₂ /Graphene Heterostructures via Surface Plasmon Resonance

Although two-dimensional materials such as molybdenum disulfide (MoS2) and graphene (Gr) possess excellent electronic properties, their weak light absorption limits their applications in photodetectors. This study introduces an effective strategy to significantly enhance the photoresponse of MoS2/Gr heterostructures by utilizing the localized surface plasmon resonance of Au nanoparticles (Au NPs). The optimized device exhibited a remarkable responsivity of 44.8 A/W, a specific detectivity of 1.05 × 1012 Jones, and a fast self-powered response of 8.42 ms at 447 nm, representing an enhancement of nearly 2 orders of magnitude compared to the pristine device. The enhancement is attributed to the strong near-field effects and efficient hot electron injection enabled by the Au NPs. The finite-difference time-domain (FDTD) simulations further confirm the broad electric field enhancement across the visible spectrum. These findings offer valuable insights for developing high-performance two-dimensional optoelectronic devices.