Plasmon-induced hot electrons emission enhanced by Fabry–Perot cavity resonance on SOI

In this investigation, we report an Au/Si hot electron infrared detector fabricated on an SOI substrate. The simulation and experimental results show that Fabry–Perot cavity resonance on the SOI substrate and the surface plasmons excited by the Au nanostructures enhance the photo absorption in Au. Spectral response peaks of the hot electron photocurrent occur in the infrared band at a photon energy much smaller than the bandgap energy of Si. A maximum photocurrent was obtained at an annealing time of 90 s of the nanostructured Au film, and the SEM image showed the formation of a connected semi-island structure during the annealing. This hot electron device paves the way for extending infrared detection wavelength of SOI based detectors.