Efficient, Hysteresis-Free, and Stable Perovskite Solar Cells with ZnO as Electron-Transport Layer: Effect of Surface Passivation
Efficient, Hysteresis-Free, and Stable Perovskite Solar Cells with ZnO as Electron-Transport Layer: Effect of Surface Passivation
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DOI：
10.1002/adma.201705596
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发表时间：
2018-03-15
影响因子：
29.4
通讯作者：
Zheng, Nanfeng
中科院分区：
文献类型：
--
作者：
Cao, Jing;Wu, Binghui;Zheng, Nanfeng
近年来，钙钛矿太阳能电池（PSCs）的功率转换效率从3.8%上升到22.1%。ZnO是一种优良的电子传输材料。然而，ZnO和有机金属卤化物钙钛矿之间的差的化学相容性使得使用ZnO作为电子传输层获得高效和稳定的PSC具有高度挑战性。它是在这项工作中证明，ZnO的表面钝化的MgO和质子化乙醇胺（EA）的薄层容易使ZnO作为一个非常有前途的电子传输材料，用于创建无杂质，高效，稳定的PSC。系统的研究表明：MgO抑制了界面电荷复合，提高了电池性能和稳定性;质子化EA促进了电子从钙钛矿到ZnO的有效传输，进一步消除了PSC的滞后现象; ZnO与钙钛矿相容，很好地解决了ZnO/钙钛矿界面的不稳定性。所有这些发现，与最好的效率高达21.1%，并没有滞后的PSC成功地制造。当使用石墨烯进一步包封细胞时，获得了在空气中稳定超过300小时的PSC。
The power conversion efficiency of perovskite solar cells (PSCs) has ascended from 3.8% to 22.1% in recent years. ZnO has been well-documented as an excellent electron-transport material. However, the poor chemical compatibility between ZnO and organo-metal halide perovskite makes it highly challenging to obtain highly efficient and stable PSCs using ZnO as the electron-transport layer. It is demonstrated in this work that the surface passivation of ZnO by a thin layer of MgO and protonated ethanolamine (EA) readily makes ZnO as a very promising electron-transporting material for creating hysteresis-free, efficient, and stable PSCs. Systematic studies in this work reveal several important roles of the modification: (i) MgO inhibits the interfacial charge recombination, and thus enhances cell performance and stability; (ii) the protonated EA promotes the effective electron transport from perovskite to ZnO, further fully eliminating PSCs hysteresis; (iii) the modification makes ZnO compatible with perovskite, nicely resolving the instability of ZnO/perovskite interface. With all these findings, PSCs with the best efficiency up to 21.1% and no hysteresis are successfully fabricated. PSCs stable in air for more than 300 h are achieved when graphene is used to further encapsulate the cells.