Since the demonstration of optical gain in silicon nanocrystals, in the last few years several
papers appeared in the literature reporting gain measurements in silicon nanocrystals
embedded in a silica matrix produced by different techniques. However, it is still unclear
which are the structural, physical and chemical factors that contribute to enhance
photoluminescence and gain in this type of samples. In particular, the presence and the role
of nitrogen in the SiO2 matrix are in fact supposed to be essential factors in understanding …