Transferability of the Light-Soaking Benefits on Silicon Heterojunction Cells to Module

We investigate the effect of light soaking and forward electric bias treatment on silicon heterojunction solar cells and modules and, in particular, the influence of the thermal treatment occurring during lamination. A substantial performance increase is observed after electric bias or light soaking, which is shown to be potentially partly reset by the lamination process. This reset is reproduced by annealing the cells with the same thermal budget. A second treatment after lamination again improves performances, and a similar final performance is reached independently of the prelamination treatment. Therefore, a single treatment after lamination enables maximal module output with no benefit from a cell pretreatment. Whereas the cells react overall better to forward bias, the modules show a slightly better response to light soaking.