Investigating the benefits of multi busbars for industrial Al-BSF silicon solar cells

This paper reports on the modeled and experimental results of industrial aluminum back surface field (Al-BSF) silicon solar cells with different number of busbars (three-, four- and five) for cost-effective metallization. It is found that by keeping the same metal grid coverage, solar cells with four- and five-busbar designs give higher fill factor (FF) and conversion efficiency than the-state-of-the-art three-busbar. This is attributed to decreased gridline resistance as the number of busbars increases from three to four, and four to five. The experimental I-V data shows an increase in cell efficiency by 0.18%_absolute and 0.34%_absolute with four- and five-busbar cells, respectively, compared to the three-busbar counterpart. This suggests that four- and five-busbar designs having finer gridlines will lead to >20% Al-BSF cell.