Stable Formamidinium-Based Perovskite Solar Cells via In Situ Grain Encapsulation
Stable Formamidinium-Based Perovskite Solar Cells via In Situ Grain Encapsulation
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通过原位晶粒封装实现稳定的甲脒基钙钛矿太阳能电池
DOI：
10.1002/aenm.201800232
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发表时间：
2018-08-06
影响因子：
27.8
通讯作者：
Zhu, Rui
中科院分区：
文献类型：
--
作者：
Liu, Tanghao;Zhou, Yuanyuan;Zhu, Rui
基于甲脒（FA）的碘化铅钙钛矿已成为主流钙钛矿太阳能电池（PSC）中最有前途的光吸收材料。然而，它们遭受环境大气中的相不稳定性问题，这阻碍了在高效率和稳定性的背景下实现基于FA的PSC的全部潜力。在本文中，原硅酸四乙酯水解过程与FA基钙钛矿的溶液结晶相结合，形成具有由原位形成的纳米级无定形二氧化硅层封装的单独钙钛矿晶粒的新膜结构。二氧化硅不仅保护钙钛矿晶粒免于降解，而且还增强钙钛矿膜的电荷载流子动力学。的基本机制进行了讨论，使用联合实验理论的方法。通过这种原位颗粒包封方法，PSC显示出接近20%的效率，在环境条件下储存1000小时后具有令人印象深刻的97%保留率。
Formamidinium (FA)-based lead iodide perovskites have emerged as the most promising light-absorber materials in the prevailing perovskite solar cells (PSCs). However, they suffer from the phase-instability issue in the ambient atmosphere, which is holding back the realization of the full potential of FA-based PSCs in the context of high efficiency and stability. Herein, the tetraethylorthosilicate hydrolysis process is integrated with the solution crystallization of FA-based perovskites, forming a new film structure with individual perovskite grains encapsulated by amorphous silica layers that are in situ formed at the nanoscale. The silica not only protects perovskite grains from the degradation but also enhances the charge-carrier dynamics of perovskite films. The underlying mechanism is discussed using a joint experiment-theory approach. Through this in situ grain encapsulation method, PSCs show an efficiency close to 20% with an impressive 97% retention after 1000-h storage under ambient conditions.