Impact of Deposition of ITO on Tunnel Oxide Passivating Poly-Si Contact

In this study, we investigate the impact of the deposition of indium tin oxide (ITO) via DC magnetron sputtering on tunnel oxide passivating poly-Si contacts. Before ITO deposition to the tunnel SiOxpassivating n+poly-Si rear-contact on the cell structure with an SiNx/Al2O3passivating boron emitter, the implied open-circuit voltage (iVoc) and implied fill factor (iFF) were measured to be 694±10 mV and 83±0.6%, respectively. After ITO sputtering and curing annealing, the iVocand iFF were almost fully recovered, resulting in the iVoc of 685±11 mV and iFF of 81.9±0.8%. The characteristic of fully recovered effective lifetime is attributed to unique sputtering conditions employing a very low power density at room temperature and curing.