Abstract
The ultrafast carrier dynamics of furnace-annealed GaAs:As near bandgap is investigated by time-resolved reflectivity measurement with temporal resolution of ≅200 fs. The samples are prepared by implanting GaAs with 200 keV arsenic ions at a dose of 10 16 ions/cm 2 and then furnace-annealed Ex-situ at Ta between 200 and 800 °C for 30 mins. As Ta increased from 200 to 800 °C, the carrier lifetimes of GaAs:As is extended from ≈0.4 to 4.6 ps. This is consistent with structure and electrical characterization of GaAs:As that showed the ultrahigh densities defect states in the samples annealed at these temperatures.