Focused-ion-beam Implantation in Strained InGaAs-GaAs Quantum Wells

Photoluminescence spectroscopy (PL) is used to monitor the degree of focused ion beam induced interdiffusion in InGaAs–GaAs quantum wells using 100 keV Ga+ and Si+ ions. The observed transition energy shifts are consistent with the effects of channeling of the incident ions near normal incidence. PL decay times obtained from pulsed excitation experiments at higher dose rates indicate incomplete annealing of defects in the quantum wells resulting in an enhanced nonradiative decay rate. If Si+ ions are implanted instead of Ga+ ions we find a red shift of the PL peak positions at very low doses owing to a doping effect in the quantum wells.