Influence of the Front Surface Passivation Quality on Large Area n-Type Silicon Solar Cells with Al-Alloyed Rear Emitter

Efficiencies of large area n-type silicon solar cells with a screen printed rear side aluminum-alloyed emitter are mainly limited by their front surface recombination velocity. The front surface therefore has to be passivated by an effective passivation layer combined with a front surface field (FSF).In this work we investigate the influence of the front surface passivation quality and the base resistivity for a selective FSF n-type solar cell. The potential of this solar cell concept is assessed by PC1D simulations and QSSPC measurements. Furthermore we present solar cell results of all screen printed large area n-type Cz-Si solar cells with an aluminum rear emitter and a selective etch-back FSF passivated by a PECVD-SiNx or a SiO2/SiNx stack. The applied processing sequence is based on industrially available processing equipment and results in an independently confirmed cell efficiency of 19.4% on a 6” solar cell.