Sheng Wangping, He Jiacheng, Yang Jia, Cai Qianqian, Xiao Shuqin, Zhong Yang, Tan Licheng, Chen Yiwang
College of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC), Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.
Peking University Yangtze Delta Insititute of Optoelectronics, Nantong, 226010, China.
Adv Mater. 2023 Aug;35(33):e2301852. doi: 10.1002/adma.202301852. Epub 2023 May 28.
The two-step sequential deposition process is demonstrated as a reliable technology for the fabrication of efficient perovskite solar cells (PVSCs). However, the complete conversion of dense PbI to perovskite in planar PVSCs is tough without mesoporous titanium dioxide as support. Herein, multifunctional capsules consisting of zeolitic imidazolate framework-8 (ZIF-8) encapsulant and formamidinium iodide (FAI) are introduced between tin oxide (SnO ) and lead iodide (PbI ) layer. Intriguingly, the capsule dopant interlayer benefits the formation of porous PbI film due to the porous nanostructure of ZIF-8 that is favorable for the subsequent intercalation reaction. Furthermore, the constituent of the perovskite precursor in ZIF-8 pores can convert into the crystal nuclei of perovskite by reacting with PbI first, thereby promoting further perovskite crystallization. Significantly, the incorporation of ZIF-8 can enhance the resistance of perovskite against UV illumination due to down-conversion effect. Consequently, the modified device achieves a champion power conversion efficiency (PCE) of 24.08% and displays enhanced UV stability, which can sustain 83% of its original PCE under 365 nm UV illumination for 300 h. Moreover, the unencapsulated device maintains 90% of initial PCE after 1500 h storage in dark ambient conditions with a relative humidity range of 50%-70%.
两步顺序沉积工艺被证明是一种用于制造高效钙钛矿太阳能电池（PVSCs）的可靠技术。然而，在没有介孔二氧化钛作为支撑的情况下，平面PVSCs中致密的PbI完全转化为钙钛矿是困难的。在此，由沸石咪唑酯骨架-8（ZIF-8）封装剂和碘化甲脒（FAI）组成的多功能胶囊被引入到氧化锡（SnO）和碘化铅（PbI）层之间。有趣的是，由于ZIF-8的多孔纳米结构有利于随后的插层反应，胶囊掺杂剂中间层有利于形成多孔PbI薄膜。此外，ZIF-8孔中钙钛矿前驱体的成分可先与PbI反应转化为钙钛矿的晶核，从而促进钙钛矿的进一步结晶。值得注意的是，由于下转换效应，ZIF-8的掺入可以提高钙钛矿对紫外线照射的抗性。因此，改性器件实现了24.08%的最佳功率转换效率（PCE），并显示出增强的紫外线稳定性，在365nm紫外线照射下300小时可保持其原始PCE的83%。此外，未封装的器件在相对湿度范围为50%-70%的黑暗环境条件下储存1500小时后，仍保持初始PCE的90%。
