Assessing the impact of multi-busbars on metallization cost and efficiency of solar cells with digital inkjet-printed gridlines

The cost of solar electricity can be reduced through the use of less silver ink. This can be achieved by alternative printing technology - the inkjet-printing. In this paper we report on a two-diode model for the gridline design optimization of a 19.2% efficiency inkjet-printed silicon solar cell. The model showed that, the multi-busbar design has less dependence on gridline height in contrast with the conventional design, and is beneficial in cost savings and efficiency enhancement. The cell efficiency increases as the number of busbar increases with optimized busbar width. The optimal finger height for a 5-busbar design is ~20 μm but >50 μm for the 3-busbar. Finally, for both 3-and 5-busbar designs, the maximum efficiencies are obtained with 97 fingers at metallization cost of 1.35⊄/Wp and 1.32⊄/Wp, respectively.