Photoluminescent porous silicon films were prepared and their microstructure investigations showed a double scale
porosity, the walls of the micropores being formed by a nanowires network. The temperature dependence of both the
electrical transport and photoluminescence processes in these films, as well as the spectral distribution of the
photoluminescence, were measured. The results prove a clear correlation between the two processes. A simple quantum
confiiement model was proposed for the calculation of the electronic energy in nanocrystalline silicon. The model
explains the observed experimental behavior of both the electrical transport and the photoluminescence and justifies their
correlation. Its quantitative predictions are in excellent agreement with the microstructure investigations. The model can
be applied to a wide class of materials.
Nanocrystalline silicon is studied with a view to obtaining a new photonic material. Non-equilibrium electronic processes in such materials play a significant role. We have studied trapping phenomena in nanocrystalline porous silicon and nanocrystalline silicon-based Multi-Quantum Wells structures by means of Optical Charging Spectroscopy method, which is a very good and sensitive method. We have also analyzed the modeling of the processes that occur during our measurements. This modeling allows us to separate the relative contribution of the different types of discharge currents that can appear: ohmic conduction currents of either equilibrium or non-equilibrium carriers, displacement currents, diffusion currents and tunneling currents through insulating layers (in Multi-Quantum Wells structures). It also allows us to increase the accuracy of the determination of the experimental trap parameters and to determine parameters that are not directly measurable. The model can be applied to other nanocrystalline semiconductors and can be easily generalized for other high resistivity materials.