Hot Electrons in Microscale Thin-Film Schottky Barriers for Enhancing Near-Infrared Detection

Metallic microstructures composed from Au thin films were designed and fabricated to enhance the near-infrared detection of photodetectors based on GaAs. The devices showed significant increase in the photocurrent and the spectral response due to the generation of hot electrons in the Au thin films and their injection into the semiconductor. Enhancement in the order of 120% was achieved in the photocurrent after applying an array of Au thin films with a thickness of 10 nm. Furthermore, a photocurrent-sweep using red laser showed an increase in the photocurrent of the device, as the laser was swept over the Au thin film. The effect of adding Ti adhesive layer on damping the photocurrent enhancement was further studied by varying the thickness of Ti between 0 and 4 nm.