Single quantum-well structures were studied in various II-VI semiconductor materials that were based upon CdTe. In particular, structures were investigated in which the intermixing of column-II elements could be induced as well as permitting interdiffusion within the column-VI sub-lattice. The diffusion was induced by rapid thermal annealing for 60s at various temperatures. The resultant blue shift of the characteristic emission spectrum was analyzed by means of photoluminescence spectroscopy. It was observed that there was a significant difference in the diffusion behaviors. In all of the CdTe-based systems almost complete interdiffusion within the column-II sub-lattice could be obtained. For all CdTe-based quantum wells, activation energies for the interdiffusion process were derived from a simple Fickian diffusion model. This was equal to 2.1eV for (Cd,Hg)Te/(Cd,Hg)Te (figure 6).

D.Tönnies, G.Bacher, A.Forchel, A.Waag, T.Litz, D.Hommel, C.Becker, G.Landwehr, M.Heuken, M.Scholl: Journal of Crystal Growth, 1994, 138, 362-6

Figure 6

Interdiffusivity in (Cd,Hg)Te/(Cd,Hg)Te