Abstract
AbstractThe dielectric function of porous silicon layers depends strongly on the electronic properties of the nanostructure of the silicon skeleton. In this paper we discuss the main effects, as determined from spectroscopic ellipsometric measurements of the dielectric function of porous layers formed on p-doped material. Finite-size effects and the high inner surface area of the nanostructure lead to relaxation of k-momentum conservation as defined for infinite crystals and therefore to a broadening of the features in <ε> arising from interband critical points. In addition a small threshold energy shift is observed when the percolation of the structure is reduced. However, this shift is too small to explain red photoluminescence as a consequence of a pseudo-direct gap whose energy is blue-shifted by confinement.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
