Planar hot-electron photodetector utilizing high refractive index MoS2 in Fabry-Perot perfect absorber

Abstract

Hot electron photodetection (HEPD) excited by surface plasmon can circumvent bandgap limitations, opening pathways for additional energy harvesting. However, the costly and time-consuming lithography has long been a barrier for large-area and mass production of HEPD. In this paper, we proposed a planar and electron beam lithography-free hot electron photodetector based on the Fabry-Perot (F-P) resonance composed of Au/MoS2/Au cavity. The hot electron photodetector has a nanoscale thickness, high spectral tunability, and multicolour photoresponse in the near-infrared region due to the increased round-trip phase shift by using high refractive index MoS2. We predict that the photoresponsivity can achieve up to 23.6 mA W-1 when double cavities are integrated with the F-P cavity. The proposed hot electron photodetector that has a nanoscale thickness and planar stacking is a perfect candidate for large-area and mass production of HEPD.