Influence of electron irradiation and postannealing on photoluminescence of GaInNAs/GaAs quantum wells

We investigated the effects of 7-MeV electron irradiation (2/spl times/10/sup 13/ and 2/spl times/10/sup 16/ cm/sup -2/ doses) and postannealing on photoluminescence (PL) from 1.3-/spl mu/m GaInNAs/GaAs multiple quantum wells (QWs) grown by molecular-beam epitaxy. A small enhancement (27%) in PL intensity is found for the lower dose whereas a noticeable deterioration in PL intensity is seen for the higher dose. When annealed at 650 /spl deg/C for 1 min the sample irradiated to the dose of 2/spl times/10/sup 13/ cm/sup -2/ underwent a similar enhancement and blue-shift in PL as the nonirradiated sample. In contrast, a much strong PL is observed for the sample irradiated to the dose of 2/spl times/10/sup 16/ cm/sup -2/ as compared to the nonirradiated sample. This irradiation-promoted enhancement in PL is accompanied by a small additional blue-shift as well as by small changes in x-ray diffraction rocking curves, which indicate small changes in quantum-well alloy composition or structure.