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 represent a new record for tandem devices with solution-processed chalcopyrite and perovskite absorbers.