Ultrafast carrier trapping in oxygen- and aluminum-implanted GaAs

Summary form only given. By using a pump-probe photoreflectance technique, we have measured the free carrier lifetime of O- and O-Al-implanted GaAs as a function of O and Al implant concentration and annealing temperature. We have studied the effects of O and O-Al implantation on the lifetime of semi-insulating (SI) GaAs. We have shown that the O-implanted GaAs exhibits ultrafast carrier lifetimes, and that these results are consistent with the O-doped MOVPE grown samples. We observed faster trapping times as the O impurity concentration is increased, with trapping time is as fast as 200 fs.