Pu Wei, Li Bo, Liu Yang, Huang Yu, Yue Hanyu, Zhang Meng, Tian Jianjun
College of Materials and Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi, 710055, China.
Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083, China.
Small. 2024 Dec;20(50):e2407706. doi: 10.1002/smll.202407706. Epub 2024 Oct 13.
Solution-processing is the primary method for fabricating high-efficiency perovskite solar cells (PSCs), where solvent choice critically influences film formation and quality. Although additives can optimize film formation dynamics by balancing nucleation and growth of perovskite, they can also induce heterogeneous nucleation due to competitive coordination and varying crystallization kinetics, leading to compositional heterogeneity and structural disorders. Herein, a perovskite precursor solution is developed using acetonitrile (ACN) as a weak coordination host solvent instead of the traditional N,N-dimethylformamide (DMF). The ACN-based perovskite precursor solution reduces heterogeneous nucleation typically caused by the competitive coordination effect of DMF, and cuts costs by half compared to DMF-based precursor solutions. This approach promotes a single crystallization pathway via a dimethyl sulfoxide-solvated intermediate phase to α-FAPbI, which extends the anti-solvent operation window, and enhances the crystallinity of perovskite films, and reduces defect states. The power conversion efficiencies (PCE) of 23.62% and 20.13% is achieved for the PSC and minimodule, respectively. The PSC retains over 97% of its initial efficiency after 800 h of continuous illumination under maximum power point tracking (MPPT). These findings provide valuable insights into solvent interactions in perovskite film formation and offer a cost-effective strategy for improving the device's performance and stability.
溶液处理是制备高效钙钛矿太阳能电池（PSC）的主要方法，其中溶剂的选择对薄膜的形成和质量起着关键作用。尽管添加剂可以通过平衡钙钛矿的成核和生长来优化薄膜形成动力学，但由于竞争性配位和不同的结晶动力学，它们也会引发异质成核，导致成分不均匀和结构无序。在此，开发了一种以乙腈（ACN）作为弱配位主体溶剂的钙钛矿前驱体溶液，以替代传统的N，N-二甲基甲酰胺（DMF）。基于ACN的钙钛矿前驱体溶液减少了通常由DMF的竞争性配位效应引起的异质成核，并且与基于DMF的前驱体溶液相比成本降低了一半。这种方法通过二甲基亚砜溶剂化的中间相促进单一结晶途径生成α-FAPbI，从而扩大了反溶剂操作窗口，提高了钙钛矿薄膜的结晶度，并减少了缺陷态。PSC和微型模块的功率转换效率（PCE）分别达到了23.62%和20.13%。在最大功率点跟踪（MPPT）下连续光照800小时后，PSC仍保持其初始效率的97%以上。这些发现为钙钛矿薄膜形成过程中的溶剂相互作用提供了有价值的见解，并为提高器件性能和稳定性提供了一种经济有效的策略。
