Quantum confinement effect on the electrical transport and photoluminescence processes in nanocrystalline porous silicon

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 confinement 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.