Ballistic regime and photoluminescence excitation in Si wires and dots

This article presents the experimental results supporting the role of the ballistic effect in strong "red" photoluminescence (PL) of silicon low-dimensional structures: wires and dots. The peculiarities of the PL and PL excitation spectra in dependence on the morphology of porous silicon layers and the size of Si nano-crystallites have been investigated. The porous silicon layers with different morphology were created by the variation of preparation regimes. The size of Si nano-crystallites is estimated using the atomic force microscopy and Raman scattering methods. The mechanisms of PL and PL excitation in Si low-dimensional structures are discussed as well.