11 March 1996 Si/CaF2 superlattices: a silicon light-emitting nanostructure
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Proceedings Volume 2777, ALT'95 International Symposium on Advanced Materials for Optics and Optoelectronics; (1996) https://doi.org/10.1117/12.232223
Event: ALT '95 International Conference: Advanced Materials for Optics and Optoelectronics, 1995, Prague, Czech Republic
One promising approach for the development of silicon-based-light-emitting devices is the epitaxial growth of Si nanostructures. In this context, we propose the lattice matched system CaF2/Si/CaF2 as a prototype of a well controlled and ordered Si-based system with known microscopic structure. We present here a combined theoretical and experimental investigation of ultra-thin silicon (111) layers embedded in CaF2. Our all electron calculation predicts the band gap opening and the presence of confined and interface states leading to a quasi-direct band gap. We have synthesized, by molecular beam epitaxy, Si/CaF2 multilayers which efficiently photoluminesce at room temperature. The photoluminescence spectra show a strong resemblance to those of porous silicon. There is a critical dependence of the photoluminescence efficiency on the thickness of the Si layers and a blue shift for decreasing Si layers thickness. Our results allow us to conclude unambiguously that quantum confinement is a necessary condition for visible luminescence in our Si-based structures.
© (1996) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Stefano Ossicini, A. Fasolino, Fausto Bernardini, F. Arnaud d'Avitaya, L. Vervoort, F. Bassani, "Si/CaF2 superlattices: a silicon light-emitting nanostructure", Proc. SPIE 2777, ALT'95 International Symposium on Advanced Materials for Optics and Optoelectronics, (11 March 1996); doi: 10.1117/12.232223; https://doi.org/10.1117/12.232223


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