Effect of LiBr pore-filling on morphological, optical and electrical properties of porous silicon membrane

This study describes the developmental properties of PS membrane derived from the pore-filling with aqueous LiBr solutions. A complete process is described and the effect of pore-filling with Lithium bromide (LiBr) on PS membrane structural, optical and electrical properties is investigated. The microstructural and surface morphology of the elaborated samples were characterized mainly by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The AFM shows an increase of the nanoparticles dimension compared to the initial dimension of the PS membranes nanostructure. This result shows that LiBr covers the nanoparticles of PS membranes, which was confirmed by photoluminescence study. A modification of PS membranes morphology accompanied with significant decrease of reflectivity. The rise of the conductivity is significant after pore-filling with LiBr solution. The conductivities of porous silicon membrane are 0.021 S/cm before pore-filling and 0.019 S/cm after pore-filling with LiBr solution. This suggests the choice of LiBr as filler to improve the electrical conductivity of porous silicon membrane.

► PEMFC based on porous silicon.
► PS membrane pore-filling with LiBr solution.
► Characterization of PS membrane before and after pore-filling.