This study deals with external electric field influence on polycrystalline silicon solar cell behavior. We study an n-p-p+ solar cell under electric field resulting from a polarization and under constant multispectral illumination. Taking into account this electric field, we establish news expressions of continuity equation, photocurrent density and back surface recombination velocity. On the basis of these equations, we studied electric field effect on charge carrier’s distribution in the bulk of the base, on photocurrent behaviour and on the charge carrier’s recombination at the rear zone of the base.