Comparison of Analytical and Numerical Models for the Optimization of c-Si Solar Cells' Front Metallization

Progress in metallization techniques and emitter formation technologies needs fast and reliable tools for the optimization of the metallization pattern of crystalline silicon solar cells. We present and compare three models and discuss their validity and accuracy for different emitter sheet, finger and contact resistances, and finger widths. All models yield a similar optimal number of metallization fingers for a 156 mm x 156 mm large solar cell and broad plateaus concerning the dependence of the conversion efficiency on the finger spacing, but they differ concerning the absolute value of the fill factor and the dependence of the open-circuit voltage on the number of fingers.