摘要： The main of our work is to establish a model which enables us to predicate an improvement for solar cells e?ciencies elaborated by hetero-structures compounds; we focused our optimization by simulation on an n-c-AlGaAs/p-c-GaAs solar cell with back surface ?eld (BSF), which is a p/p+ (Low-High) junction. This junction creates a potential barrier which avoid speedy recombination of minor careers (electron in the base), however all the main parameters which have large impact on the short circuit current density, on the open circuit voltage, on the ?ll factor and on the conversion e?ciency were discussed in this work. Generally the electrical conversion is function of the acceptor and donor doping concentrations, of the cell emitter and the base thicknesses, of the surface recombination velocity at front and back contacts and of careers live times (for electrons and holes). The e?ects of the discontinuities occurring in the energies bands clause to the interface were taken into consideration too. Under A.M 1.5 illumination, our calculations results reveal an e?ciency of 23.80% for the optimum parameters (Nd = 5 × 1018 cm?3, Na = 5 × 1017 cm?3, JSC = 25.77 mA/cm2, VOC = 0.985 V, Sf = 104 cm/s and Sb = 108cm/s). It seems that this simulated device can be used in cell concentrations utilities and, it presents an e?ciency of 29.28% under 100 A.M 1.5. Finally, based on these attempts, the n-c-AlGaAs/ p-c-GaAs structure is suggested as promising solar cell applications and the actual model is intended to be extended to multilayer solar cells.