Plasmonic cuboid array embedded in silicon for polarization-insensitive hot electron photodetection

The design of a Schottky diode with periodic gold cuboid array embedded in silicon substrate is proposed for hot electron photodetection application. The optical characteristics are influenced by the Fabry-Pérot resonance and the guided-mode resonance. The Fabry-Pérot resonance is optimized via the height of cuboids and the wavelength is tuned via the width of cuboids over the C-band. A near-unity peak absorption and the corresponding peak responsivity of 1.4 mA/W can be achieved for nonpolarized light. The designs provide a solution to improve performance of silicon-based hot electron photodetection in the C-band with relatively simple fabrication process.