The optical loss, electrical loss and recombination loss should be reduced in order to fabricate high-efficiency crystalline silicon solar cells. One of several methods to reduce these loss is to improve the front electrode in solar cell. Resistance of the front electrode is the highest proportion of the ingredients of the series resistance in crystalline silicon solar cell. While resistance of the front electrode is decreased with larger area, it induces the optical loss, causing the conversion efficiency drop. Therefore the front electrode with high aspect ratio increasing its height and decreasing is necessary for high-efficiency solar cell in considering shadowing loss and resistance of front electrode.
In this paper, we studied the front electrode formation by the screen printing method in varying its shadowing loss and electrode resistance with diverse grid pattern designs. And we used the screen printing method to form the high aspect ratio electrode by multiple printing. Screen printing is the straightforward technology to establish the electrodes in silicon solar cell fabrication.
When the shadowing loss of the front electrode decreased, the short-circuit current and fill factor were increased due to more area to absorb light. But in case the finger spacing was too large, the fill factor and efficiency were decreased caused by the ability decline of the electrode to collect the electron. The several printed front electrodes with Ag paste on silicon wafer showed the significantly increased height and slightly widen finger. As a result, the resistance of the front electrode was decreased with multiple printing even if it slightly increased the shadowing loss. We showed the improved electrical characteristics for c-Si solar cell with repeatedly printed front electrode by 0.5%. It lays a foundation for high efficiency solar cell with high aspect ratio electrode using screen printing.