Plasmon-enhanced photodetection in nanostructures

Photodetection, which converts light into electric current, has significant importance in modern physics. For the graphene photodetector, the performance is mainly limited by its low external quantum efficiency, mainly due to its poor light absorption properties. While for the semiconductor photodetector, photocurrent generation is limited to photon energies above the band gap of the semiconductor. When a metallic nanostructure is introduced, on the one hand, the plasmon oscillations lead to a dramatic enhancement of the local electric field around graphene, resulting in a significant performance improvement of the graphene photodetector; on the other hand, hot electrons from plasmon decay can transfer across the Schottky barrier at the metal-semiconductor interface, resulting in a photocurrent, which is no longer limited to photon energies greater than the band gap of the semiconductor, but rather to photon energies above the Schottky barrier height. Here, we review typical plasmonic nanostructures for the enhancement of photodetection in graphene and other semiconductor materials.National Science Foundation of China [61422501, 11374023]; National Basic Research Program of China (973 Program) [2015CB932403]; Beijing Natural Science Foundation [L140007]; National Excellent Doctoral Dissertation of PR China [201420]SCI(E)EIREVIEWzhyfang@pku.edu.cn4325-336