GaAs photodetectors prepared by high-energy and high-dose nitrogen implantation

The authors report on the fabrication and characterization of photodetectors based on nitrogen-ion-implanted GaAs and the annealing dynamics in these devices. An energy of 400 keV was used to implant N ions in a GaAs substrate at an ion concentration of 1 1016 cm−2. Dark current measurements as well as measurements under illumination show that the material properties rapidly change during the annealing process. Photodetectors based on nitrogen-implanted GaAs materials with annealing temperatures up to 400 °C exhibit a subpicosecond carrier lifetime up to 0.6 ps. These properties make nitrogen-ion-implanted GaAs an ideal material for ultrafast photodetectors, as alternative to low-temperature-grown GaAs.