Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Shanghai Key Laboratory of Functional Materials Chemistry, Feringa Nobel Prize Scientist Joint Research Center, Institute of Fine Chemicals, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, 200237, China.
State Key Laboratory of Integrated Optoelectronics, Key Laboratory of Automobile Materials of Ministry of Education, School of Materials Science and Engineering, Jilin Provincial International Cooperation Key Laboratory of High-Efficiency Clean Energy Materials, Jilin University, Changchun, 130012, China.
Adv Mater. 2023 Jun;35(26):e2301871. doi: 10.1002/adma.202301871. Epub 2023 May 12.
Halide diffusion across the charge-transporting layer followed by a reaction with metal electrode represents a critical factor limiting the long-term stability of perovskite solar cells (PSCs). In this work, a supramolecular strategy with surface anion complexation is reported for enhancing the light and thermal stability of perovskite films, as well as devices. Calix[4]pyrrole (C[4]P) is demonstrated as a unique anion-binding agent for stabilizing the structure of perovskite by anchoring surface halides, which increases the activation energy for halide migration, thus effectively suppressing the halide-metal electrode reactions. The C[4]P-stabilized perovskite films preserve their initial morphology after ageing at 85 °C or under 1 sun illumination in humid air over 50 h, significantly outperforming the control samples. This strategy radically tackles the halide outward-diffusion issue without sacrificing charge extraction. Inverted-structured PSCs based on C[4]P modified formamidinium-cesium perovskite exhibit a champion power conversion efficiency of over 23%. The lifespans of unsealed PSCs are unprecedentedly prolonged from dozens of hours to over 2000 h under operation (ISOS-L-1) and 85 °C ageing (ISOS-D-2). When subjected to a harsher protocol of ISOS-L-2 with both light and thermal stresses, the C[4]P-based PSCs maintain 87% of original efficiency after ageing for 500 h.
空穴传输层中的卤化物扩散随后与金属电极反应，这是限制钙钛矿太阳能电池（PSCs）长期稳定性的关键因素。在这项工作中，报道了一种超分子策略，通过表面阴离子络合来提高钙钛矿薄膜以及器件的稳定性。研究表明，杯[4]吡咯（C[4]P）是一种独特的阴离子结合剂，通过锚定表面卤化物来稳定钙钛矿的结构，增加卤化物迁移的活化能，从而有效抑制卤化物-金属电极反应。C[4]P 稳定的钙钛矿薄膜在 85°C 老化或在潮湿空气中 1 个太阳光照射下 50 小时后，仍能保持其初始形态，明显优于对照样品。该策略从根本上解决了卤化物向外扩散的问题，而不会牺牲电荷提取。基于 C[4]P 修饰的甲脒碘化铯钙钛矿的倒置结构 PSCS 表现出超过 23%的冠军功率转换效率。未封装的 PSCS 的寿命从数十小时延长到超过 2000 小时，在操作（ISOS-L-1）和 85°C 老化（ISOS-D-2）下。当在更苛刻的 ISOS-L-2 协议下同时受到光和热应力的影响时，C[4]P 基 PSCS 在老化 500 小时后仍保持 87%的原始效率。
