Cladded Surface-Plasmon-Enhanced BP Photodetector Based on the Damage-Free Metal–Semiconductor Interface

Surface plasmon is promising for applications in 2-D semiconductor photodetector due to their great potential to improve light absorption of 2-D semiconductor, where the poor light absorption of 2-D semiconductor limits the performance of 2-D photodetector to some extent. However, high-energy deposition processes of metal surface plasmon damage the surface crystal lattice of 2-D semiconductor, which hampers the current transport in 2-D semiconductor. Here, we report the cladded surface-plasmon-enhanced black-phosphorus (BP) photodetector with damage-free metal-semiconductor interface. Without the adverse effect of the direct deposition process for metal surface plasmon, the cladded surface-plasmon-enhanced BP photodetector exhibits a superior photoresponse enhancement by up to 1000%, which exceeds other conventional surface-plasmon-enhanced 2-D semiconductor photodetectors. Our results provide guidelines to design advanced surface-plasmon-enhanced 2-D semiconductor photodetector for practical application.