Low-energy As+ implantation, followed by rapid thermal annealing, was used to modify the exciton transition energies of quantum wells. Various structures were irradiated using an energy which was sufficiently low that the disordered region was spatially separated from the quantum wells. After rapid thermal annealing, the exciton energies exhibited large increases which depended upon the quantum-well width and the implantation fluence. There was no appreciable increase in the peak line-widths. The observed energy shifts were attributed to modifications of the shapes of the quantum wells, due to enhanced Ga and Al interdiffusion at hetero-interfaces in irradiated areas. The results were consistent with a model which was based upon an enhanced intermixing of Al and Ga atoms, in the depth of the material, due to the diffusion of vacancies which were generated near to the surface.

B.Elman, E.S.Koteles, P.Melman, C.A.Armiento: Journal of Applied Physics, 1989, 66[5], 2104-7