A holistic approach for a large area (>1 cm2) mechanically stacked two terminal tandem perovskite/silicon heterojunction with efficiencies above 30 %

Among the various architectures proposed to produce both four-terminal and two-terminal Perovskite/silicon tandem solar cells, the two-terminal (2T) mechanically stacked tandem configuration combines the simplicity of an independent fabrication and optimization of perovskite and silicon sub cells with a reduced system complexity associated with the 2T architecture. To improve the performance of the 2T mechanically stacked tandem several material and fabrication aspects need to be addressed and combined in a synergetic way. A holistic approach able to improve the photovoltaic performance working on the energy gap tunability, the perovskite thickness and composition, the defect passivation and the device architecture is demonstrated. This technique allows to raise the achievable Power Conversion Efficiency reaching in the best case 31 % (30 % stabilized and 28.32 % on average) on active areas larger than 1 cm2.