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

Although two-dimensional materials such as molybdenum disulfide (MoS 2 ) 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 MoS 2 /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 × 10 12 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.