Plasmon-Enhanced Visible and Near-Infrared Photodetection with Gold Nanorods UCNPs/MoS₂ Hybrid Device

The near-infrared photodetection of monolayer MoS₂ can be achieved using upconverted nanoparticles (UCNPs). Herein, we demonstrated that gold nanorods (Au NRs) further enhanced the near-infrared photoresponsivity of a hybrid device via the surface plasmon enhancement of the localized field. We synthesized a three-layer device comprising Au NRs, UCNPs (NaYF₄:Yb³⁺, Er³⁺), and monolayer MoS₂, and examined its photoelectric characteristics using laser irradiation with varying power densities at 980 nm, the excitation wavelength of UCNPs. Compared with a device without Au NRs, the photoelectric response of the three-layer device was greatly improved at 5 V bias, and photoresponsivity was increased at visible wavelengths (450, 532, and 635 nm). This study contributes to the knowledge of two-dimensional materials for the development of hybrid photoelectronic devices.