In this paper, we will report the enhancement of the conversion efficiency of multicrystalline silicon solar cells after coating the front surface with a porous silicon layer treated with vanadium oxide. The incorporation of vanadium oxide into the porous silicon (PS) structure, followed by a thermal treatment under oxygen ambient, leads to an important decrease of the surface reflectivity, a significant enhancement of the effective minority carrier lifetime (tau(eff)) and a significant enhancement of the photoluminescence (PL) of the PS structure. We Obtained a noticeable increase of (tau(eff)) from 3.11 mu s to 134.74 mu s and the surface recombination velocity (S-eff) have decreased from 8441 cm s(-1) to 195 cm s(-1). The reflectivity spectra of obtained films, performed in the 300-1200 nm wavelength range, show an important decrease of the average reflectivity from 40% to 5%. We notice a significant improvement of the internal quantum efficiency (IQE) in the used multicrystalline silicon substrates. Results are analyzed and compared to those carried out on a reference (untreated) sample. The electrical properties of the treated silicon solar cells were improved noticeably as regard to the reference (untreated) sample. (C) 2013 Elsevier B.V. All rights reserved.