Monolithic perovskite/organic tandem solar cells: Developments, prospects, and challenges

Monolithic perovskite solar cells (PSCs) and small-bandgap organic photovoltaics (OPVs) integrated perovskite/organic tandem devices and binary perovskite/bulk-heterojunction (BHJ) devices have recently attracted tremendous attention due to their upgraded light-harvesting range and theoretical efficiency potential. However, compared with the ideal integrated condition, tandem devices usually exhibit obviously reduced current density (J_sc) and open-circuit voltage (V_oc), which results in compromised power conversion efficiency (PCE). Moreover, the champion PCE of perovskite/organic tandem devices is still lower than that of the best reported single-junction PSCs. Therefore, relieving their J_sc and J_sc losses is vital to develop high-performance perovskite/organic tandem devices. Besides, several perovskite/BHJ devices are emerging. This paper presents a systematic overview of developing perovskite/organic tandem devices. Particularly, this is the first study to have comprehensively summarized the factors affecting perovskite/organic tandem device efficiency loss, as well as the modulating strategies. Meanwhile, the development of perovskite/BHJ devices is also discussed. Finally, the prospects and development challenges of perovskite/organic tandem devices in the near future are presented. © 2021 The Authors. Nano Select published by Wiley-VCH GmbH