Lv Shaoshen, Gao Weiyin, Xing Gang, Chao Lingfeng, Song Lin, Li Mingjie, Fu Li, Chen Yonghua, Ran Chenxin
Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, Xi'an 710072, China.
Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon 999077, Hong Kong, China.
ACS Appl Mater Interfaces. 2022 Sep 28;14(38):43362-43371. doi: 10.1021/acsami.2c12539. Epub 2022 Sep 16.
Owing to narrow band gap and low toxicity, tin-lead (Sn-Pb) hybrid perovskites have shown great potential in photovoltaic applications, and the highest power conversion efficiency (PCE) of Sn-Pb perovskite solar cells (PSCs) has recently reached 23.6%. However, it is still challenging to prepare Sn-Pb films in open-air condition due to the Sn oxidation of the precursor solution under this condition. In this work, we report the stabilizing of the Sn-Pb perovskite precursor solution by using ionic liquid methylammonium acetate (MAAc) as the solvent, which enables the fabrication of Sn-Pb films in air. MAAc is found to coordinate with the Sn-Pb precursor via abundant hydrogen bonding, which stabilizes the colloids and protects the Sn stability in the precursor solution in air. Therefore, the durability of the Sn-Pb precursor solution based on the MAAc solvent is greatly improved, which enables the fabrication of efficient PSCs and achieves a champion PCE of ∼16% with robust device stability. Moreover, due to the chemical interactions of MAAc with Sn-Pb perovskites, the Pb leakage is also suppressed in the MAAc-based Sn-Pb PSCs. This work demonstrates a feasible strategy for reliable fabrication of Sn-Pb PSCs, which could also be applied in many other optoelectronic devices.
由于具有窄带隙和低毒性，锡铅（Sn-Pb）混合钙钛矿在光伏应用中展现出巨大潜力，且锡铅钙钛矿太阳能电池（PSC）的最高功率转换效率（PCE）最近已达到23.6%。然而，在露天条件下制备Sn-Pb薄膜仍具有挑战性，因为在此条件下前驱体溶液中的Sn会发生氧化。在这项工作中，我们报道了通过使用离子液体乙酸甲铵（MAAc）作为溶剂来稳定Sn-Pb钙钛矿前驱体溶液，这使得能够在空气中制备Sn-Pb薄膜。发现MAAc通过大量氢键与Sn-Pb前驱体配位，从而稳定胶体并保护前驱体溶液在空气中的Sn稳定性。因此，基于MAAc溶剂的Sn-Pb前驱体溶液的耐久性得到极大提高，这使得能够制备高效的PSC，并实现了约16%的最佳PCE以及稳健的器件稳定性。此外，由于MAAc与Sn-Pb钙钛矿之间的化学相互作用，基于MAAc的Sn-Pb PSC中的Pb泄漏也得到了抑制。这项工作展示了一种可靠制备Sn-Pb PSC的可行策略，该策略也可应用于许多其他光电器件。
