EFFECTS OF TEMPERATURE ON THE SHORT CIRCUIT CURRENT OF A SILICON SOLAR CELL, WHILE TAKING INTO ACCOUNT THE EXCITONS

We have studied the temperature’s effects on the short circuit current of a silicon solar cell .For this, we have considered Green’s theoretical model which considers excitons as charge carriers. In this study, we have defined two effective diffusion lengths L1 and L2, and a coefficient b, characteristic of coupling electron- exciton. The electrons are weakly bound excitons for small values of b, so that the coupling is very strong for high values of this coefficient. Furthermore, this study has allowed us to define an optimal temperature T0 at about 450 K, corresponding to the maximum value of the photocurrent. Moreover, the temperature has two contrasted effects on the short-circuit current depending on whether its value be lower or higher than the optimal temperature: The shortcircuit current increases for temperature inferior to T0 and decreases for temperature superior to T0.It is also important to point out that the temperature has no effect on the effective diffusion lengths L1 and L2 when the coupling electron-exciton is weak. However L1 decreases according to the temperature for a strong coupling.