INTERFACE ROUGHNESS AND THE OPTICAL-PROPERTIES OF QUANTUM-WELLS

We investigate the effects of roughness at heterointerfaces in the ele ctronic properties of quantum well structures. AlAs/GaAs/AlAs quantum wells were considered in which one of the interfaces is planar and the other has a shape given by an arbitrary function Z(x, y). Adopting a real-space tight-binding supercell approach to describe the electronic properties of these structures, the energy and oscillator strength of the first optical transition are calculated as a function of the inte rface parameters. For different shape functions Z(x, y) leading to int erface oscillations of comparable wavelengths, we show that the interf ace roughness may be taken as the sole relevant parameter affecting th e studied electronic properties. (C) 1997 Elsevier Science Ltd.