Planar hot-electron photodetector utilizing high refractive index MoS <sub>2</sub> in Fabry–Pérot perfect absorber
Yisong Zhu, Peng Yu, Eric Ashalley, Tianji Liu, Feng Lin, Haining Ji, Junichi Takahara, Alexander O. Govorov, Zhiming Wang
Abstract
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–Pérot (F–P) resonance composed of Au/MoS 2 /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 MoS 2 . 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.