Fabrication and optical properties of Si/CaF2(111) multi-quantum wells

Abstract
We have synthesized, by molecular beam epitaxy, Si/CaF2(111) multi‐quantum wells which are photoluminescent at room temperature after ageing in air. In this article, we report on the structural properties and on a detailed optical study of these heterostructures. The photoluminescence spectra for various confinements and the temperature dependence of the lifetimes as a function of emission wavelength are described in comparison with the corresponding characteristics of porous silicon and hydrogenated amorphous silicon. A model based on quantum confinement is proposed to explain the experimental data.