Solution-processed chalcopyrite-perovskite tandem solar cells in bandgap-matched two- and four-terminal architectures

Abstract

Solution-processed chalcopyrite and perovskite devices of various bandgaps are combined in four- and two-terminal mechanically stacked tandem architectures. The excellent low-light performance of Cu(In,Ga)(S,Se)2 and low-bandgap CuIn(S,Se)2 cells and the high efficiency of novel NIR-transparent inverted perovskite cells with C60/bis-C60/ITO as electron transport layers, enabled stabilized two- and four- terminal tandem efficiencies up to 18.5% and 18.8%, respectively, which represents a new record for tandem devices with solution-processed chalcopyrite and perovskite absorbers.