Multiple quantum well structures, with the same well thickness but differing AlxGa1-xAs compositions (with x = 0.1, 0.2, 0.45, or 1), were grown by using molecular beam epitaxy. After Zn diffusion at 575C (1 to 16h), the structures were studied by means of the transmission electron microscopy of cleaved wedges, secondary electron imaging in a scanning electron microscope, and by means of secondary ion mass spectroscopy. The results showed that totally and partially disordered regions always lay beyond the Zn diffusion front. The extent of partial disordering depended upon the value of x. As x increased, the disordering rate increased due to an increase in Zn diffusivity. The effect of a high Zn concentration was investigated by monitoring the photoluminescence and Raman scattering. Analysis of the photoluminescence spectra of structures which had been diffused for various times, and of the photoluminescence spectra from various depths below the sample surface, made it possible to describe the physical processes which occurred during Zn diffusion. Column-III vacancies were created at the sample surface and diffused into the bulk of the sample, where they were filled by other defects. By using X-ray diffraction techniques, an expansion of the lattice constant in the region beyond the Zn diffusion front was detected. This was attributed to a supersaturation of column-III interstitials. During the incorporation of Zn into the crystal lattice, column-III interstitials were generated. These were suggested to be responsible for the enhancement of Al-Ga interdiffusion. An important role was played by the electric field at the p-n junction that was formed by Zn diffusion. That is, the negatively charged column-III vacancies and the positively charged column-III interstitials were confined to the n and p sides of the p-n junction, respectively. These results provided evidence for a self-interstitial mechanism of Zn diffusion-induced disordering in these multiple quantum well structures.Self-Interstitial Mechanism for Zn Diffusion-Induced Disordering of GaAs/AlxGa1-xAs (x = 0.1-1) Multiple Quantum-Well Structures.  N.H.Ky, J.D.Ganière, M.Gailhanou, B.Blanchard, L.Pavesi, G.Burri, D.Araújo, F.K.Reinhart: Journal of Applied Physics, 1993, 73[8], 3769-81