FABRICATION AND OPTICAL-PROPERTIES OF SI CAF2(111) MULTIQUANTUM WELLS/

We have synthesized, by molecular beam epitaxy, Si/CaF2(111) multi-qua ntum wells which are photoluminescent at room temperature after ageing in air. In this article, we report on the structural properties and o n a detailed optical study of these heterostructures. The photolumines cence 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 a nd hydrogenated amorphous silicon. A model based on quantum confinemen t is proposed to explain the experimental data. (C) 1996 American Inst itute of Physics.