Room-temperature self-annealing of heavy-ion-irradiated InGaAs/GaAs quantum wells

The long-term stability of defects with the ageing of heavy-ion-irradiated and post-irradiated-annealed InGaAs/GaAs compound semiconductor quantum wells is reported using the time-resolved upconversion technique of luminescence lifetimes. The defects created by Ni⁺-heavy-ion irradiation are found to be thermally unstable. The ageing tests prove that a substantial amount of defects are removed by self-annealing in about a month of time even at room temperature through a slow diffusion process, resulting in a dynamically stable sample but with a twofold increment in lifetimes. If the sample is annealed upon Ni⁺ irradiation, the defects are removed immediately, yielding stable and much longer relaxation times independent of the ageing process. These results may be useful in designing devices with an active region as ion-irradiated semiconductor quantum wells.