The origin of room temperature luminescence in Si–Ge quantum wells: The case for an interface localization model

Abstract

Photoluminescence from a Gem–Sin–Gem structure has recently been demonstrated at room temperature by Gail et al. [Appl. Phys. Lett. 66, 2978 (1995)]. Experimental measurements have shown that this luminescence is associated with the fourfold degenerate conduction minima which lie in the plane of the interface. In this letter, we report full-scale microscopic calculations on both perfect and imperfect structures of this type which demonstrate that these results cannot be explained either by a ‘‘zone-folding’’ or an alloy scattering model. We propose an alternative mechanism which links the luminescence to anomalous localization at the heterointerfaces.