UV-induced degradation in multicrystalline PERC cell and module

The reliability of the long-term operation of multicrystalline silicon (mc-Si) modules is very important due to its large market share. However, mc-Si modules show significant degradation over time, when exposed to sunlight. In this paper, the changes in the electrical characteristics, before and after ultraviolet-induced degradation (UV-ID), were monitored in mc-Si passivated-emitter-rear-contact (PERC) cells. We first demonstrate that UV light causes the formation of defects in the bulk of solar cells, rather than destroying the surface passivation. An advanced hydrogen passivation process is performed to inhibit the bulk degradation and it is found that UV-ID is effectively suppressed on either the cell or the module.