Simulation based Development of Industrial PERC Cell Production beyond 20.5% Efficiency

In this work we present our approach to realize an industrial process that allows cell efficiencies up to and above 21%. Based on a loss analysis we systematically investigate the feasible options to improve the efficiency with device simulations and production experiments. Subsequently we perform sensitivity analyses particularly for various silicon wafer materials to ensure stable process capability. Our best prototype process with optimized front and rear side passivation and enhanced laser contact patterning has demonstrated a maximum efficiency of 20.9% with a very high VOC of 670 mV on high-lifetime mono material. We were able to assemble 60-cell based modules with more than 305Wp.