Abstract
Double quantum wells of CdTe in CdMnTe were implanted with argon ions to create vacancies and interstitials. This destroyed the photoluminescence (PL) emission from the top well and reduced the intensity from the bottom well. Pulsed radiation from an excimer laser emitting at
308
nm
, with a full width at half maximum pulse lengths of
26
ns
, was used to anneal the implantation damage and restore the luminescence. An optimum fluence close to
50
mJ
cm
−
2
exists for laser annealing, with the best results being obtained if single pulses are employed. Prior irradiation at lower fluences prevents full recovery of the luminescence when the higher fluence pulse is applied, and irradiation at lower fluences on unimplanted material causes a reduction in the luminescence from the top well. These results are interpreted in terms of vacancy creation and annihilation during the laser pulse. Calculations of the total number of vacancies created suggest that annihilation of the Te vacancies is the limiting step in the recovery of the PL in implanted material. It is proposed that loss of material from the surface, amounting to less than a monolayer, leads to the effective diffusion of vacancies into the solid.