One-stone-for-two-birds strategy to attain >25% perovskite solar cells with marvelous stability

Abstract Even though the perovskite solar cell (PSC) has been so popular for its skyrocketing power conversion efficiency (PCE), its further development is still roadblocked by its overall performance, in particular long-term stability, large-area fabrication and stable module efficiency. In essence, the soft component and ionic–electronic nature of metal halide perovskites usually chaperonage large number of anion vacancy defects that act as recombination centers to decrease both the photovoltaic efficiency and operational stability. Herein, we report a one-stone-for-many-birds strategy in which both anion-fixation and associated undercoordinated-Pb passivation are achieved by using a single amidino-based ligand, namely 3-amidinopyridine (3AP), for metal-halide perovskite to overcome above challenges. The resultant devices attain a power conversion efficiency as high as 25.3% (certified at 24.8%) with substantially improved stability. Moreover, the device without encapsulation retained 92% of its initial efficiency after 5000 h exposure in ambient and 90% of its initial efficiency after 200 h of operation at the maximum power point under simulated AM1.5G illumination. It is expected this one-stone-for-many-birds strategy will benefit large-area fabrication that desires for simplicity.