Liu Chou, Yang Tinghuan, Cai Weilun, Wang Yajie, Chen Xin, Wang Shumei, Huang Wenliang, Du Yachao, Wu Nan, Wang Zhichao, Yang Yang, Feng Jiangshan, Niu Tianqi, Ding Zicheng, Zhao Kui
Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China.
Adv Mater. 2024 Jun;36(24):e2311562. doi: 10.1002/adma.202311562. Epub 2024 Mar 28.
A robust perovskite-buried interface is pivotal for achieving high-performance flexible indoor photovoltaics as it significantly influences charge transport and extraction efficiency. Herein, a molecular bridge strategy is introduced utilizing sodium 2-cyanoacetate (SZC) additive at the perovskite-buried interface to simultaneously achieve in situ passivation of interfacial defects and bottom-up crystallization modulation, resulting in high-performance flexible indoor photovoltaic applications. Supported by both theoretical calculations and experimental evidences, it illustrates how SZCs serve as molecular bridges, establishing robust bonds between SnO transport layer and perovskite, mitigating oxygen vacancy defects and under-coordinated Pb defects at interface during flexible fabrication. This, in turn, enhances interfacial energy level alignment and facilitates efficient carrier transport. Moreover, this in situ investigation of perovskite crystallization dynamics reveals bottom-up crystallization modulation, extending perovskite growth at the buried interface and influencing subsequent surface recrystallization. This results in larger crystalline grains and improved lattice strain of the perovskite during flexible fabrication. Finally, the optimized flexible solar cells achieve an impressive efficiency exceeding 41% at 1000 lux, with a fill factor as high as 84.32%. The concept of the molecular bridge represents a significant advancement in enhancing the performance of perovskite-based flexible indoor photovoltaics for the upcoming era of Internet of Things (IoT).
坚固的钙钛矿掩埋界面对于实现高性能柔性室内光伏至关重要，因为它会显著影响电荷传输和提取效率。在此，引入了一种分子桥策略，在钙钛矿掩埋界面处使用2-氰基乙酸钠（SZC）添加剂，以同时实现界面缺陷的原位钝化和自下而上的结晶调制，从而实现高性能柔性室内光伏应用。在理论计算和实验证据的支持下，该研究说明了SZC如何作为分子桥，在SnO传输层和钙钛矿之间建立牢固的键，在柔性制造过程中减轻界面处的氧空位缺陷和配位不足的Pb缺陷。这反过来又增强了界面能级对齐并促进了高效的载流子传输。此外，对钙钛矿结晶动力学的这种原位研究揭示了自下而上的结晶调制，扩展了掩埋界面处的钙钛矿生长并影响随后的表面再结晶。这导致在柔性制造过程中钙钛矿的晶粒更大且晶格应变得到改善。最后，优化后的柔性太阳能电池在1000勒克斯光照下实现了超过41%的令人印象深刻的效率，填充因子高达84.32%。分子桥的概念代表了在为即将到来的物联网（IoT）时代提高基于钙钛矿的柔性室内光伏性能方面的重大进展。
