Disordering of Ga1−xAlxAs-GaAs quantum well structures by donor sulfur diffusion

We show here, for the first time, that disordering (alloy mixing) on group III sublattice of GaAlAs-GaAs quantum well (QW) structures can be accomplished by the introduction of a group V site substitutional donor impurity. This is achieved by performing donor sulfur diffusions at 850 °C (for varied durations 1 to 14 h) under open-tube conditions in molecular beam epitaxy as well as metalorganic chemical vapor deposition grown GaAlAs-GaAs QW structures. Using simple photoluminescence measurements at room temperature, we provide relevant evidence that the degree of alloy mixing (and so the resulting Al composition) is dependent on the diffused S concentration.