By Tobias Fellmeth, Fraunhofer ISE; Matthieu Ebert, Crystalline Photovoltaic Modules Group, Fraunhofe ISE; Raphael Efinger, Research Scientist, Fraunhofer ISE; Ingrid Hädrich, Head of the Module Efficiency and New Concepts Team, Fraunhofer ISE; Florian Clement, Head of Group, MWT solar cells/printing technology, Fraunhofer ISE; Ulrich Eitner, Module Development, Fraunhofe ISE; Daniel Biro, Head of Group, Thermal, PVD and Printing Technology, Fraunhofer ISE
The combination of metal-wrap-through technology with a unit cell design, referred to as AP-MWT architecture, is proposed for the purpose of operating under low and concentrated irradiance. On the illuminated side, the negative polarity is electrically separated by using an emitter window surrounding the perimeter of each unit cell. The final functioning silicon-based device consists of an arbitrary amount of unit cells with perimeter dimensions ranging from 1cm x 2.25cm to 14cm x 13.5cm. The Czochralski-based bulk material, as well as the assembly approach, conforms with state-of-the-art industrially feasible technologies. For irradiances corresponding to 1 and 10 suns, median efficiencies of 19.8% and 20.9% and top efficiencies of 20.2% and 21.0% have been achieved. Thanks to the flexibility in size, interconnection and irradiance, awide range of current-voltage ratios are covered, providing customized solutions beyond the conventional flat-panel market.