近日，南开大学刘永胜团队报道了在钙钛矿太阳能电池的埋藏界面上自发形成二维钙钛矿，提高晶化均匀性和缺陷钝化。2025年11月24日出版的《自然—光子学》杂志发表了这项成果。
实现钙钛矿薄膜顶部与埋藏界面的均匀结晶对于充分发挥其光伏潜力至关重要，但仍是未解决的难题。特别是埋藏界面相较于顶部表面结晶质量较差，导致晶体质量欠佳且缺陷密度升高。
研究组提出一种一步法策略，通过在钙钛矿前驱体溶液中引入有机阳离子卤化物盐，诱导埋藏界面处自发形成近相纯二维钙钛矿。单晶结构分析突显了分子工程在促进埋藏二维钙钛矿相自发形成中的关键作用。有机间隔物的低偶极矩与平面刚性结构促使其在钙钛矿晶界聚集，随后迁移至薄膜底部界面。该二维钙钛矿层同时实现了埋藏界面的均匀结晶与高效缺陷钝化，最终获得26.31%的功率转换效率（认证26.02%）。未封装器件在连续光照1000小时后仍保持初始功率转换效率的95%。
附：英文原文
Title: Spontaneous 2D perovskite formation at the buried interface of perovskite solar cells enhances crystallization uniformity and defect passivation
Author: Gao, Yuping, Liu, Hang, Song, Zonglong, Chen, Yu, Yang, Liu, Hu, Ziyang, Zou, Yu, Chen, Yongsheng, Liu, Yongsheng
Issue&Volume: 2025-11-24
Abstract: Achieving uniform crystallization across both top and buried interfaces in perovskite films is crucial for unlocking their full photovoltaic potential, yet remains an unresolved challenge. The buried interface, in particular, suffers from poor crystallization relative to the top surface, resulting in suboptimal crystal quality and increased defect densities. Here we propose a one-step strategy to induce the spontaneous formation of near-phase-pure two-dimensional perovskites at the buried interface via the introduction of organic cation halide salts in the perovskite precursor solution. Single-crystal structure analysis highlights the pivotal role of molecular engineering in facilitating the spontaneous formation of buried two-dimensional perovskite phases. The low dipole moments and planar rigidity structures of organic spacers promote their aggregation at perovskite grain boundaries, followed by their migration to the film’s bottom interface. The two-dimensional perovskite layer simultaneously promotes uniform crystallization and efficient defect passivation at the buried interface, leading to a power conversion efficiency of 26.31% (certified 26.02%). Unencapsulated devices retain 95% of their initial power conversion efficiency after 1,000hours of continuous illumination.
DOI: 10.1038/s41566-025-01797-9
Source: https://www.nature.com/articles/s41566-025-01797-9