Grains of porous silicon embedded in SiO2: Studies of optical gain and electroluminescence

Katerina Luterova 1Jan Valenta 2Josef Bursik 3Vojtech Kresalek 4Bernd Honerlage 5Ivan Pelant 1Katerina Dohnalova 1

1. Czech Academy of Sciences, Institute of Physics, Cukrovarnicka 10, Prague 16253, Czech Republic
2. Charles University, Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Ke Karlovu 3, Prague 121 16, Czech Republic
3. Czech Academy of Sciences, Institute of Inorganic Chemistry, Rez near Prague 250 68, Czech Republic
4. T. Bata University, Institute of Information Technology, Mostni 5139, Zlin 760 01, Czech Republic
5. Institut de Physique et Chimie des Materiaux de Strasbourg, UMR7504, CNRS - ULP, 23, rue du Loess, BP 43, Strasbourg CEDEX 2 67034, France


Recent reports on experimental observation of optical gain in silicon nanostructures in the visible region, performed at several laboratories all over the world, have triggered an extraordinary surge of interest in silicon lasing. However, attempts aimed at reproducing the red stimulated emission from "standard" silicon nanocrystals (sized 3-5 nm) at some other laboratories either failed or did not come to definite conclusions. Therefore, more detailed measurements of optical gain in a wider variety of samples containing Si nanocrystals are required in order to unravel whether or not the observation of optical gain is an intrinsic property of Si nanocrystals, etc.
We have performed a detailed study of optical gain in layers of densely packed Si nanocrystals using variable stripe length (VSL) method in combination with shifting excitation spot (SES) method. In selected samples we have observed a distinct difference in behaviour between VSL and SES curves, indicating the occurence of positive optical gain of ~24 cm-1. Preliminary reports on transport and electroluminescence measurements in thin films of SiO2 doped with porous silicon grains, prepared by spin-coating technique, will also be discussed.


Presentation: oral at E-MRS Fall Meeting 2003, Symposium F, by Katerina Dohnalova
See On-line Journal of E-MRS Fall Meeting 2003

Submitted: 2003-04-29 12:25
Revised:   2009-06-08 12:55