LiBr passivation effect of porous nanocrystalline hydrogenated silicon

Nanocrystalline hydrogenated silicon (nc-Si:H) films were deposited on a p-type silicon substrate by plasma enhanced chemical vapor deposition (PECVD), using SiH4 and H2 as reactive gases. Porous (nc-Si:H) layers were afterward obtained and immersed in a lithium bromide (LiBr) aqueous solution in order to enhance their optical and electrical properties for a potential solar cells application. A decrease in the reflectivity to about 9% for Li/porous nc-Si:H layer deposited at 75 sccm against an increase in the minority carrier lifetime were obtained. We correlate these results to the change in crystalline characteristics and chemical composition of the layers in order to understand the effect of LiBr coating on nc-Si:H Through optical and electrical characterization we have demonstrated the possibility of using such LiBr treatment to improve the properties of porous nc-Si:H.