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.

This article reports the recent progress of p-type back junction solar cells featuring an aluminum front grid and an n þ-type passivating polysilicon on oxide (POLO) contact at the cell rear side. The best cell has an efficiency of 22.6% and an open-circuit voltage of 716 mV, independently confirmed by Institute for Solar Energy Research Hamelin (ISFH) CalTeC. The cell area is 244.5 cm 2. The increase in the SiN x capping layer thickness at the cell rear side reduces the deterioration of passivation quality of the POLO contact by screen-printed silver. This increases the open-circuit voltage by 22 mV compared with cells with a thinner nitride layer thickness. The investigation with scanning electron microscopy shows that the damage of the POLO contacts underneath the screen-printed metal contacts is avoided by increasing the SiN x capping layer thickness. A contact resistivity of 2 mΩ cm 2 is measured using the transfer length method.

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