Reducing Hysteresis and Enhancing Performance of Perovskite Solar Cells Using Low-Temperature Processed Y-Doped SnO₂ Nanosheets as Electron Selective Layers

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• 作者：Guang Yang ; Hongwei Lei ; Hong Tao ; Xiaolu Zheng ; Junjie Ma ; Qin Liu ; Weijun Ke ; Zhiliang Chen ; Liangbin Xiong ; Pingli Qin ; Zhao Chen ; Minchao Qin ; Xinhui Lu ; Yanfa Yan and Guojia Fang
• 刊名：Small
• 出版年：2017
• 出版时间：January 11, 2017
• 年：2017
• 卷：13
• 期：2
• 全文大小：1731K
• ISSN：1613-6829

文摘

Despite the rapid increase of efficiency, perovskite solar cells (PSCs) still face some challenges, one of which is the current–voltage hysteresis. Herein, it is reported that yttrium-doped tin dioxide (Y-SnO₂) electron selective layer (ESL) synthesized by an in situ hydrothermal growth process at 95 °C can significantly reduce the hysteresis and improve the performance of PSCs. Comparison studies reveal two main effects of Y doping of SnO₂ ESLs: (1) it promotes the formation of well-aligned and more homogeneous distribution of SnO₂ nanosheet arrays (NSAs), which allows better perovskite infiltration, better contacts of perovskite with SnO₂ nanosheets, and improves electron transfer from perovskite to ESL; (2) it enlarges the band gap and upshifts the band energy levels, resulting in better energy level alignment with perovskite and reduced charge recombination at NSA/perovskite interfaces. As a result, PSCs using Y-SnO₂ NSA ESLs exhibit much less hysteresis and better performance compared with the cells using pristine SnO₂ NSA ESLs. The champion cell using Y-SnO₂ NSA ESL achieves a photovoltaic conversion efficiency of 17.29% (16.97%) when measured under reverse (forward) voltage scanning and a steady-state efficiency of 16.25%. The results suggest that low-temperature hydrothermal-synthesized Y-SnO₂ NSA is a promising ESL for fabricating efficient and hysteresis-less PSC.