Han Chuanshuai, Wu Yeyong, Xu Guiying, Wu Xiaoxiao, Xu Jiacheng, Xu Tingting, Huang Shihao, Shen Yunxiu, Cao Zhiyun, Chen Weijie, Xu Xiaoping, Li Yaowen
Laboratory of Advanced Optoelectronic Materials, Suzhou Key Laboratory of Novel Semiconductor-optoelectronics Materials and Devices, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.
Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China.
Angew Chem Int Ed Engl. 2025 Feb 10;64(7):e202419726. doi: 10.1002/anie.202419726. Epub 2025 Jan 7.
The rapid reaction between lead iodide (PbI) and formamidinium iodide (FAI) complicates the fabrication of high-quality formamidinium lead iodide (FAPbI) 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 PbI to slow the reaction between FAI and PbI, 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 Pb defects and anchors at grain boundaries without diffusion. Consequently, the resultant FAPbI film displays high-quality with enhanced phase purity, compact morphology, and reduced defects. Evidently, 0.062- and 1.004-cm 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 %.
碘化铅（PbI）与碘化甲脒（FAI）之间的快速反应使高质量的甲脒碘化铅（FAPbI）薄膜的制备变得复杂。传统方法，如使用非挥发性小分子添加剂来减缓反应，常常会导致掩埋的界面空隙和分子扩散，从而损害器件的运行稳定性。在本研究中，我们引入了一种分子“推进器”——一种具有三个羰基和一个C-I键的高价碘（III）化合物，它具有配位和解离能力，能够对钙钛矿薄膜的生长动力学进行编程调制。最初，三个羰基与PbI配位，减缓FAI与PbI之间的反应，防止δ相形成。随着温度升高，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，从而避免掩埋的界面空隙。另一种产物，一种具有八个孤对电子的卡宾化合物，能够充分钝化配位不足的Pb缺陷并锚定在晶界处而不扩散。因此，所得的FAPbI薄膜具有高质量，具有增强的相纯度、致密的形态和减少的缺陷。显然，0.062平方厘米和1.004平方厘米的钙钛矿太阳能电池（pero-SCs）的功率转换效率（PCE）分别高达26.06%（认证值为25.79%）和24.65%。这种方法还能控制塑料基板上钙钛矿薄膜的生长，从而得到柔性pero-SCs，其PCE高达25.12%。
