The stability of perovskite‐based tandem solar cells (TSCs) is the last major scientific/technical challenge to be overcome before commercialization. Understanding the impact of mobile ions on the TSC performance is key to minimizing degradation. Here, a comprehensive study that combines an experimental analysis of ionic losses in Si/perovskite and all‐perovskite TSCs using scan‐rate‐dependent current–voltage (J–V) measurements with drift‐diffusion simulations is presented. The findings demonstrate that mobile ions have a significant influence on the tandem cell performance lowering the ion‐freeze power conversion efficiency from >31% for Si/perovskite and >30% for all‐perovskite tandems to ≈28% in steady‐state. Moreover, the ions cause a substantial hysteresis in Si/perovskite TSCs at high scan speeds (400 s−1), and significantly influence the performance degradation of both devices through internal field screening. Additionally, for all‐perovskite tandems, subcell‐dominated J–V characterization reveals more pronounced ionic losses in the wide‐bandgap subcell during aging, which is attributed to its tendency for halide segregation. This work provides valuable insights into ionic losses in perovskite‐based TSCs which helps to separate ion migration‐related degradation modes from other degradation mechanisms and guides targeted interventions for enhanced subcell efficiency and stability.

中文翻译：

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离子迁移对钙钛矿基叠层太阳能电池性能和稳定性的影响


基于钙钛矿的叠层太阳能电池 （TSC） 的稳定性是商业化前需要克服的最后一个重大科学/技术挑战。了解移动离子对 TSC 性能的影响是最大限度地减少降解的关键。在这里，提出了一项综合研究，该研究使用扫描速率依赖性电流-电压 （J-V） 测量和漂移扩散模拟对 Si/钙钛矿和全钙钛矿 TSC 中的离子损耗进行实验分析。研究结果表明，移动离子对串联电池的性能有显着影响，将硅/钙钛矿的离子冻结功率转换效率从 >31% 和全钙钛矿串联的 >30% 降低到稳态下的 ≈28%。此外，离子在高扫描速度 （400 s-1） 下会导致 Si/钙钛矿 TSC 出现相当大的滞后，并通过内部场筛选显着影响两种器件的性能下降。此外，对于全钙钛矿串联，亚细胞主导的 J-V 表征揭示了衰老过程中宽带隙亚细胞中更明显的离子损失，这归因于其卤化物偏析的趋势。这项工作为基于钙钛矿的 TSC 中的离子损失提供了有价值的见解，有助于将离子迁移相关的降解模式与其他降解机制区分开来，并指导有针对性的干预措施以提高亚电池的效率和稳定性。