Optimizing the geometry of local aluminum-alloyed contacts to fully screen-printed silicon solar cells

The performance optimization of solar cells comprising a locally contacted rear surface is a trade-off between rear surface recombination losses and resistive losses. Considering local aluminum (Al)-alloyed contacts formed by screen-printing an additional challenge arises from the impact of the processing conditions on the contact properties. The aim of this work is the development of a guideline to find the optimum contact geometry based on analytical models and experimentally verified parameterizations. Our study reveals equal performance of point and line rear contact layouts and an optimum metallization fraction of around 20 % on 2 Ωcm p-type Czochralski grown (Cz) Si.