High-Performance Near-Infrared Photodetector Based on Ag NPs/MoS 2 QDs/SWCNTs/Al 2 O 3 / InP Heterostructure for Optical Communication

Near-infrared (NIR) photodetectors have emerged as critical components in optoelectronic systems. However, conventional bulk semiconductor photodetectors are limited by lattice mismatch and inappropriate band alignment. This work proposes a near-infrared (NIR) photodetector based on Ag NPs/MoS2QDs/SWCNTs/Al2O3/InP structure. The light absorption is enhanced by the localized surface plasmon resonance (LSPR) effect from Ag NPs and the quantum confinement effect from MoS2QDs. An Al₂O₃ thin film serves as a passivation layer to suppress dark current. The device achieves a responsivity as high as 414.5 mA/W at 1 V and a detectivity of 4.07 × 1010Jones at 0.05 V. The device also responds rapidly, exhibiting a rise time of 2.4 μs and a fall time of 36 μs. Furthermore, successful optical transmission experiments have been conducted using this photodetector.