Perovskite-organic tandem solar cells with superior reverse-bias stability

Abstract

The industrial deployment of thin-film solar cells faces challenges under reverse bias, particularly concerning perovskite materials with poor reverse-bias stability. Meanwhile, the reverse-bias characteristics of organic solar cells (OSCs) remain underexplored. This study first elucidates the mechanism that reverse tunnelling in OSCs, fundamentally dominated by deep trap state within a bulk heterojunction, triggering reversible/irreversible breakdowns under reverse bias. Building on this, we demonstrated high-performance OSCs with superior irreversible breakdown voltage exceeding –35 V by modulating the deep trap state through suppressing an isolated acceptor cluster in the donor–acceptor intermix region. Moreover, through strategically shielding perovskite by OSC with suppressed reverse tunnelling, n–i–p perovskite–organic tandem solar cells maintain over 90% of the initial efficiency when subjected to –40 V. These tandem devices retain 90% and 97% of the initial efficiency after stressing at –20 V for 12 h and –4.5 V for 2,000 h, respectively, outperforming all existing thin-film solar technologies. The exceptional reverse-bias stability under shadowing conditions was further demonstrated in scalable perovskite–organic tandem solar cell minimodules.