The production of electricity based on the conversion of the sunlight by photovoltaic cells containing crystalline silicon is the way most used on the technological and industrial level Consequently, the development of the terrestrial applications for the energy production requires high-output cells and low cost.The aim of our work is to present a comparative study between both theoretical and experimental models of a solar cell based silicon type PHYWE (connecting four cells in series of 80 mm diameter) to improve photovoltaic performance.This study led to the determination of the parameters of the cell starting from the current-voltage characteristic, the influence of luminous flow on this characteristic as well as the effect of the incidental photons on the solar cell. We justify the interest to use the model with two exponential for the optimization of the output by underlining the insufficiency of the model to one exponential.