苏州大学李耀文团队研究了分子“推力器”程序调节钙钛矿-膜生长动力学，用于高效稳定的钙钛矿太阳能电池。这一研究成果发表在2024年12月17日出版的国际学术期刊《德国应用化学》上。

据悉，碘化铅（PbI₂）与碘化甲脒（FAI）之间的快速反应，使得制备高质量的碘化甲脒铅（FAPbI₃）薄膜变得复杂。传统的方法，如添加非挥发性小分子添加剂来减缓反应，通常会导致埋藏的界面空洞和分子扩散，从而影响设备操作的稳定性。

在这项研究中，该课题组引入了一种分子“推力器”——一种具有三个羰基和一个C-I键的超价态碘(III)化合物——具有配位和解离能力，可编程调节钙钛矿膜生长动力学。最初，三个羰基与PbI₂配合以减缓碘化甲脒（FAI）与PbI₂之间的反应，防止δ相的形成。

随着温度的升高，C-I键解离，促进钙钛矿生长，解离产物碘苯会促进溶剂挥发，从而避免了界面上埋藏的空隙。另一种产物，具有8个孤对电子的卡宾类化合物，充分钝化了欠配位的Pb²⁺缺陷，并在晶界上锚定而没有扩散。因此，所得的FAPbI₃薄膜具有高质量的相纯度，致密的形貌和减少的缺陷。

显然，0.062和1.004-cm²的pero-SCs的功率转换效率（PCE）分别高达26.06%（经认证为25.79%）和24.65%。这种方法还可以控制塑料衬底上钙钛矿膜的生长，从而产生具有25.12% PCE的柔性pero-SCs。

附：英文原文

Title: Program‐Modulated Kinetics of Perovskite‐Film Growth by Molecular "Thruster" for High‐Efficiency and Stable Perovskite Solar Cells

Author: Chuanshuai Han, Yeyong Wu, Guiying Xu, Xiaoxiao Wu, Jiacheng Xu, Tingting Xu, Shihao Huang, Yunxiu Shen, Zhiyun Cao, Weijie Chen, Xiaoping Xu, Yaowen Li

Issue&Volume: 2024-12-17

Abstract: The rapid reaction between lead iodide (PbI2) and formamidinium iodide (FAI) complicates the fabrication of high-quality formamidinium lead iodide (FAPbI3) films. Conventional methods, such as using nonvolatile small molecular additives to slow the reaction, often result in buried interfacial voids and molecule diffusion, compromising the devices' operational stability. In this study, we introduced a molecular “thruster”—a hypervalent iodine (III) compound with three carbonyl groups and a C––I bond—that possesses coordination and dissociation abilities, enabling programed modulation of perovskite-film growth kinetics. Initially, the three carbonyl groups coordinate with PbI2 to slow the reaction between FAI and PbI2, preventing δ-phase formation. As temperature rises, the C––I bond dissociates, promoting perovskite growth and the dissociated product iodobenzene will promote solvent volatilization, thus avoiding buried interfacial voids. Another product, a carbene compound with eight lone pair electrons sufficiently passivate the undercoordinated Pb2+ defects and anchors at grain boundaries without diffusion. Consequently, the resultant FAPbI3 film displays high-quality with enhanced phase purity, compact morphology, and reduced defects. Evidently, 0.062- and 1.004-cm2 pero-SCs achieve power conversion efficiencies (PCEs) of up to 26.06% (25.79% certified) and 24.65%, respectively. This approach also controls perovskite-film growth on plastic substrates, resulting in flexible pero-SCs with an impressive PCE of 25.12%.

DOI: 10.1002/anie.202419726

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202419726