Gas permeability of porous silicon nanostructures.

The gas (air and hydrogen) flow through porous silicon ( PS ) nanostructures is studied. Being well described by Darcy's law, the gas flow measurements allow us to deduce PS permeability values, which are measured to be 10(-16) - 10(-15) m(2), corresponding to the 50-70% porosity range. A strong porosity dependence of the PS intrinsic permeability is found to be in good agreement with Kozeny's model.