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Combining Efficiency and Stability in Mixed Tin–Lead Perovskite Solar Cells by Capping Grains with an Ultrathin 2D Layer
Author(s) -
Wei Mingyang,
Xiao Ke,
Walters Grant,
Lin Renxing,
Zhao Yongbiao,
Saidaminov Makhsud I.,
Todorović Petar,
Johnston Andrew,
Huang Ziru,
Chen Haijie,
Li Aidong,
Zhu Jia,
Yang Zhenyu,
Wang YaKun,
Proppe Andrew H.,
Kelley Shana O.,
Hou Yi,
Voznyy Oleksandr,
Tan Hairen,
Sargent Edward H.
Publication year - 2020
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201907058
Subject(s) - materials science , perovskite (structure) , energy conversion efficiency , passivation , tin , halide , tandem , optoelectronics , band gap , layer (electronics) , grain size , grain boundary , nanotechnology , chemical engineering , inorganic chemistry , composite material , metallurgy , microstructure , chemistry , engineering
The development of narrow‐bandgap ( E g ≈ 1.2 eV) mixed tin–lead (Sn–Pb) halide perovskites enables all‐perovskite tandem solar cells. Whereas pure‐lead halide perovskite solar cells (PSCs) have advanced simultaneously in efficiency and stability, achieving this crucial combination remains a challenge in Sn–Pb PSCs. Here, Sn–Pb perovskite grains are anchored with ultrathin layered perovskites to overcome the efficiency‐stability tradeoff. Defect passivation is achieved both on the perovskite film surface and at grain boundaries, an approach implemented by directly introducing phenethylammonium ligands in the antisolvent. This improves device operational stability and also avoids the excess formation of layered perovskites that would otherwise hinder charge transport. Sn–Pb PSCs with fill factors of 79% and a certified power conversion efficiency (PCE) of 18.95% are reported—among the highest for Sn–Pb PSCs. Using this approach, a 200‐fold enhancement in device operating lifetime is achieved relative to the nonpassivated Sn–Pb PSCs under full AM1.5G illumination, and a 200 h diurnal operating time without efficiency drop is achieved under filtered AM1.5G illumination.