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Understanding and Eliminating Hysteresis for Highly Efficient Planar Perovskite Solar Cells |
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| Authors: | Changlei Wang Chuanxiao Xiao Yue Yu Dewei Zhao Rasha A. Awni Corey R. Grice Kiran Ghimire Iordania Constantinou Weiqiang Liao Alexander J. Cimaroli Pei Liu Jing Chen Nikolas J. Podraza Chun‐Sheng Jiang Mowafak M. Al‐Jassim Xingzhong Zhao Yanfa Yan |
| Affiliation: | 1. Department of Physics and Astronomy and Wright Center for Photovoltaics Innovation and Commercialization, University of Toledo, Toledo, OH, USA;2. Key Laboratory of Artificial Micro‐ and Nano‐structures of Ministry of Education of China, School of Physics and Technology, Wuhan University, Wuhan, China;3. Chemical and Materials Science Center, National Renewable Energy Laboratory, Golden, CO, USA;4. Zentrum für Molekulare Biologie der Universit?t Heidelberg (ZMBH), University of Heidelberg, Heidelberg, Germany;5. School of Electronic Science and Engineering, Southeast University, Nanjing, China |
| Abstract: | Through detailed device characterization using cross‐sectional Kelvin probe force microscopy (KPFM) and trap density of states measurements, we identify that the J–V hysteresis seen in planar organic–inorganic hybrid perovskite solar cells (PVSCs) using SnO2 electron selective layers (ESLs) synthesized by low‐temperature plasma‐enhanced atomic‐layer deposition (PEALD) method is mainly caused by the imbalanced charge transportation between the ESL/perovskite and the hole selective layer/perovskite interfaces. We find that this charge transportation imbalance is originated from the poor electrical conductivity of the low‐temperature PEALD SnO2 ESL. We further discover that a facile low‐temperature thermal annealing of SnO2 ESLs can effectively improve the electrical mobility of low‐temperature PEALD SnO2 ESLs and consequently significantly reduce or even eliminate the J–V hysteresis. With the reduction of J–V hysteresis and optimization of deposition process, planar PVSCs with stabilized output powers up to 20.3% are achieved. The results of this study provide insights for further enhancing the efficiency of planar PVSCs. |
| Keywords: | hysteresis Kelvin probe force microscopy perovskite solar cells post annealing |