Industrial solar cells are transitioning from PERC to TOPCon technology. The bifacial TOPCon structure can break through the traditional front-side diffusion limitations. The polyZEBRA technology integrates the bipolar TOPCon structure on the back of the cell to completely eliminate the front-side parasitic absorption. At the same time, it adopts low-cost processes (laser patterning and screen printing) to achieve cost-effectiveness that is competitive with the bifacial contact TOPCon technology. The cell efficiency is increased from 23.0% to 24.0%, achieving an absolute increase of 1%.

The process flow of polyZEBRA solar cells

The manufacturing process of polyZEBRA solar cells

Key process features

Bipolar TOPCon structure: n-type and p-type TOPCon structures are integrated on the back to avoid light absorption loss caused by front-side metallization.

Low-cost process: Industrial low-cost processes such as laser patterning and screen printing are used to ensure the economic feasibility of the technology.

Passivation optimization: The combination of AlOx/SiNx passivation layer and tunneling oxide layer significantly reduces surface recombination loss and improves the open circuit voltage (Voc) and fill factor (FF) of the solar cell.