New Cell Metallization Patterns for Heterojunction Solar Cells Interconnected by the Smart Wire Connection Technology

The success and expansion of the Photovoltaic's electricity production is largely based on the capacity to reduce solar panels cost ($/Wp), increase module energy yield and reliability. The booming of the PV industry in the last ten years was mainly based in the success to continually reduce the solar panel production costs: improve processes, reduce raw materials usage and economies of scale. However, in the same period, the cell and module technologies used didn't change much. Reduce further the solar cell panel cost ($/Wp) become harder and harder with conventional crystalline silicon PV technology. Hopefully, alternative cells and module technologies are now ready for large volume production to bring down price of the photovoltaic energy. The combination of two revolutionary cell and module concepts: heterojunction solar cells and Smart Wire Connection Technology module technology are leading technologies for the next generation of PV modules. These two concepts combine high module power (>300 Wp based on 60 cells module) and a cell production cost as low as 13 c$/Wp. This paper presents some of the latest cell metallization improvements of heterojunction solar cells dedicated to SWCT technology. On the front side, the use of interrupted front fingers instead of continuous fingers was explored. This new pattern reduces front finger shading and increases module power. In the cell back side, a new pattern with fingers screen printed at 45 degrees to the cell edge was introduced. This special orientation of fingers allows to economize ribbons used to interconnect strings in modules.