A 22.3% Efficient p-Type Back Junction Solar Cell with an Al-Printed Front-Side Grid and a Passivating n(+)-Type Polysilicon on Oxide Contact at the Rear Side

The fabrication of a silicon solar cell on 6 in. pseudo-square p-type Czochralski grown silicon wafers featuring poly-Si-based passivating contacts for electrons at the cell rear side and screen-printed aluminum fingers at the front side is demonstrated. The undiffused front surface is passivated with an Al2O3/SiNx stack, and the rear surface is covered with a thin oxide/n(+)-poly-Si/Al2O3/SiNx layer system, contacted by screen-printed silver fingers. A loss analysis shows that the recombination losses at the metal contacts on both cell sides dominate the total energy losses. A voltage of 700 mV as the highest open-circuit voltage from a batch of seven cells is achieved, and the best cell efficiency is 22.3%, independently confirmed.