High-Performance Ultraviolet MoS2 Photodetector Based on the Plasmonic Effect

Ultraviolet (UV) photodetectors are critical for applications ranging from environmental monitoring to biomedical imaging. While MoS₂ offers exceptional carrier mobility and layer-tunable bandgaps for UV-sensitive band alignment, its intrinsically weak UV absorption limits practical performance. Herein, we address this limitation by integrating gold nanoparticles (Au NPs) with MoS₂ to fabricate photodetectors, where the periodic Au NPs array induces plasmonic effect to enhance light-matter interaction. Finite-difference time-domain (FDTD) simulations confirm that the plasmonic effect significantly boosts light absorption via strong local field enhancement at nanogaps. Therefore, we fabricated MoS₂ photodetectors enhanced by the Au-nanoparticle-on-substrate structure (Anss). Under 395 nm UV illumination, the detectivity (D∗) and Responsivity (R) of the MoS₂/Anss device reached 1.40 × 1011 Jones and 2.31 A/W, respectively, representing enhancements by a factor of 12.97 and 15.4 compared to devices without Au nanoparticles. It is clear from the enhanced responsivity that the Au nanoparticle-modified design provides superior performance in UV detection applications.