Su Jian, Liu Qiwei, Hu Tao, Zhang Xianwei, Sun Nan, Jiang Sai, Gu Ding, Qiu Jianhua, Zhang Han, Zhou Ziyao
Changzhou University, Wang Zheng School of Microelectronics, School of Integrated Circuits Industry, Changzhou 213164, China.
Changzhou University, The Materials and Electronics Research Center (MERC), School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou 213164, China.
J Phys Chem Lett. 2025 Sep 11;16(36):9381-9390. doi: 10.1021/acs.jpclett.5c02124. Epub 2025 Sep 1.
The buried interfacial nonradiative recombination and carrier transport losses in perovskite solar cells, particularly caused by oxygen and iodide vacancy defects at the SnO/perovskite interface, critically limit their efficiency and stability. Herein, we propose a bifunctional passivation strategy using guanidinium phosphate (GAP), which spatially separates phosphate and guanidine groups to synergistically anchor SnO and perovskite interfaces. We systematically demonstrate the multifunctional synergistic roles of GAP molecules at the SnO/perovskite buried interface, where phosphate groups establish robust coordination bonds with the SnO surface to passivate oxygen vacancy defects while optimizing interfacial energy level alignment. At the same time, guanidinium cations suppress the formation of iodine vacancies in the perovskite through electrostatic interactions, induce oriented crystallization, and reduce grain boundary defect density. Additionally, GAP is a bridging molecule that fills interfacial voids, enhancing interfacial bonding strength and improving carrier transport efficiency across the interface. Based on this strategy, the champion device achieves a power conversion efficiency of 24.12% with negligible hysteresis. The unencapsulated devices retain more than 90% of their initial efficiency after 2000 h of aging under a 25% relative humidity. This work establishes a novel paradigm for designing multifunctional molecular passivators, advancing perovskite optoelectronics toward high efficiency and operational stability.
钙钛矿太阳能电池中埋藏的界面非辐射复合和载流子传输损耗，特别是由SnO/钙钛矿界面处的氧和碘空位缺陷引起的，严重限制了它们的效率和稳定性。在此，我们提出了一种使用磷酸胍（GAP）的双功能钝化策略，该策略在空间上分离磷酸根和胍基团，以协同锚定SnO和钙钛矿界面。我们系统地证明了GAP分子在SnO/钙钛矿埋藏界面处的多功能协同作用，其中磷酸基团与SnO表面形成强配位键以钝化氧空位缺陷，同时优化界面能级排列。与此同时，胍阳离子通过静电相互作用抑制钙钛矿中碘空位的形成，诱导定向结晶，并降低晶界缺陷密度。此外，GAP是一种桥连分子，可填充界面空隙，增强界面结合强度并提高跨界面的载流子传输效率。基于此策略，冠军器件实现了24.12%的功率转换效率，滞后可忽略不计。未封装的器件在25%相对湿度下老化2000小时后，仍保留其初始效率的90%以上。这项工作建立了一种设计多功能分子钝化剂的新范式，推动钙钛矿光电器件向高效率和运行稳定性发展。
