Synergistic electrical and light management enables efficient monolithic inorganic perovskite/organic tandem solar cells with over 24% efficiency

Abstract

Monolithic perovskite/organic tandem solar cells (TSCs) have attracted increasing attention on account of their high efficiency and beneficially compatible solution processibility. However, the severe recombination loss restricts the efficiency improvement of perovskite/organic TSCs. Herein, a synergistic electrical and light management strategy via optimizing the interface contact in the front wide band gap (WBG) inorganic perovskite subcell and regulating the donor/acceptor ratio in the rear narrow band gap (NBG) organic subcell was developed to maximize the voltage output in TSCs. Compared with the commonly used SnO₂ electron transport layer (ETL), Cl@MZO ETL exhibits a better energy level, reduced leakage current and strengthened carrier extraction in the front WBG subcell. Through elaborate regulation of the donor/acceptor ratio, the rear organic subcell delivers improved morphology and absorption configuration, thus resulting in a favorable current balance for TSCs. The fabricated inorganic perovskite/organic TSCs exhibit a remarkable power conversion efficiency (PCE) of 24.07% with an ultrahigh open-circuit voltage of 2.15 V. Moreover, the unencapsulated TSCs present excellent stability under air conditions.