POSTGROWTH TAILORING OF THE OPTICAL-PROPERTIES OF GAAS ALGAAS QUANTUM-WELL STRUCTURES

In this paper we describe a method for performing post-growth bandgap engineering in the GaAs/AlGaAs quantum well system. The method used is impurity-free vacancy diffusion. Using both single and multiple quantum well data we show that this allows blue shifts in the optical properties, while retaining both their distinctive excitonic and electrical characteristics. The electrical response is modelled and no comparative degradation of the quantum confined Stark effect is predicted, and this is confirmed experimentally. Possible applications of this technique are mentioned.