Efficient,Hysteresis‐Free,and Stable Perovskite Solar Cells with ZnO as Electron‐Transport Layer: Effect of Surface Passivation |
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| Authors: | Jing Cao Binghui Wu Ruihao Chen Youyunqi Wu Yong Hui Bing‐Wei Mao Nanfeng Zheng |
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| Affiliation: | 1. State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, and Engineering Research Center for Nano‐Preparation Technology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China;2. Pen‐Tung Sah Institute of Micro‐Nano Science and Technology, Xiamen University, Xiamen, China |
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| Abstract: | ![]()
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. |
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| Keywords: | electron‐transport layer hysteresis‐free interface engineering perovskite solar cells ZnO |
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