Abstract
Photovoltaics based on organic–inorganic as well as all inorganic semiconducting perovskites have emerged as a high performing technology at a lower cost. Intense research carried out in this regard over the last decade has resulted in single junction power conversion efficiencies that now exceed 25%. Furthermore, combining wide-bandgap perovskites with other narrow-bandgap absorbers such as silicon has enabled efficiencies exceeding 24%. Such tandem architectures provide the possibility of increasing the power conversion efficiency with either a little increase in cost or even at a lower cost. In this review, we discuss the emerging tandem concepts that incorporate perovskites in at least one sub-cell and can also be printed on roll-to-roll manufacturing lines. Initially, we discuss the progress in the field of perovskite/silicon tandem architectures followed by a discussion on perovskite/copper indium gallium selenide tandem devices. Then, recent progress in all-perovskite tandem devices is discussed. This is then followed by developments combining perovskites and organic bulk heterojunction absorbers. Subsequently, we discuss roll-to-roll and sheet-to-sheet printing techniques that can be used for scaled-up manufacturing of the above tandem architectures, which is then followed by reported work on perovskites that have utilised these printing techniques. Finally, we discuss prospects and future directions focusing on material stability and elimination of toxic solvents that are typically used in lab-scale perovskite solar cell fabrication processes and on less well investigated applications such as energy harvesting in space.