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

Abstract

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.