Technique de détermination de l'épaisseur optimum de la base appliquée à une photopile n+ /p / p + au silicium sous éclairement monochromatique de courtes longueurs d'onde

An n/p/p+ silicon solar cell under monochromatic illumination with short wavelength is studied in steady state. Photogenerated minority carrier's density in the base is obtained by solving the diffusion equation with boundary conditions at the surfaces of both the junction and the back. The photocurrent density is calculated and represented as function of junction surface recombination velocity for different absorption coefficient values in the short wavelength range. Then at short-circuit current condition given for large junction recombination values, the back-surface recombination expression is derived as silicon absorption coefficient dependent. As a result, compared with the intrinsic recombination velocity, optimum thickness is extracted for given absorption coefficient corresponding to short wavelength illumination and modeled in mathematic relationship.