Critical Role of Removing Impurities in Nickel Oxide on High-Efficiency and Long-Term Stability of Inverted Perovskite Solar Cells

Shuangjie Wang; Yuke Li; Jiabao Yang; Tong Wang; Bowen Yang; Qi Cao; Xingyu Pu; Lioz Etgar; Jian Han; Junsong Zhao; Xuanhua Li; Anders Hagfeldt

doi:10.1002/anie.202116534

Critical Role of Removing Impurities in Nickel Oxide on High-Efficiency and Long-Term Stability of Inverted Perovskite Solar Cells

Angew Chem Int Ed Engl. 2022 Apr 25;61(18):e202116534. doi: 10.1002/anie.202116534. Epub 2022 Mar 4.

Authors

Shuangjie Wang¹, Yuke Li², Jiabao Yang¹, Tong Wang¹, Bowen Yang³, Qi Cao¹, Xingyu Pu¹, Lioz Etgar⁴, Jian Han¹, Junsong Zhao¹, Xuanhua Li¹, Anders Hagfeldt⁵

Affiliations

¹ State key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University, 710000 Shaanxi, Xi'an, China.
² Department Department of Chemistry and Centre for Scientific Modeling and Computation, Chinese University of Hong Kong, 999077, Shatin, Hong Kong, P.R. China.
³ Department of Chemistry-Ångström Laboratory, Uppsala University, 75120, Uppsala, Sweden.
⁴ Institute of Chemistry, Casali Center for Applied Chemistry, The Hebrew University of Jerusalem, 91904, Jerusalem, Israel.
⁵ Laboratory of Photomolecular Science, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Ecole Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland.

PMID: 35174939
DOI: 10.1002/anie.202116534

Abstract

The performance enhancement of inverted perovskite solar cells applying nickel oxide (NiO_x ) as the hole transport layer (HTL) has been limited by impurity ions (such as nitrate ions). Herein, we have proposed a strategy to obtain high-quality NiO_x nanoparticles via an ionic liquid-assisted synthesis method (NiO_x -IL). Experimental and theoretical results illustrate that the cation of the ionic liquid can inhibit the adsorption of impurity ions on nickel hydroxide through a strong hydrogen bond and low adsorption energy, thereby obtaining NiO_x -IL HTL with high conductivity and strong hole-extraction ability. Importantly, the removal of impurity ions can effectively suppress the redox reaction between the NiO_x film and the perovskite film, thus slowing down the deterioration of device performance. Consequently, the modified inverted device shows a striking efficiency exceeding 22.62 %, and superior stability maintaining 92 % efficiency at a maximum power point tracking under one sun illumination for 1000 h.

Keywords: Hole Transport Layer; Interfacial Redox Reaction; Nickel Oxide; Perovskite Solar Cells.

Abstract

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