Engineering the passivation routes of perovskite films towards high performance solar cells

Liangzheng Zhu; Shendong Xu; Guozhen Liu; Long Liu; Han Zhou; Zhiqiang Ai; Xu Pan; Fapei Zhang

doi:10.1039/d3sc06746g

Engineering the passivation routes of perovskite films towards high performance solar cells

Chem Sci. 2024 Mar 13;15(15):5642-5652. doi: 10.1039/d3sc06746g. eCollection 2024 Apr 17.

Authors

Liangzheng Zhu^{1

2}, Shendong Xu^{2

3}, Guozhen Liu², Long Liu^{1

3}, Han Zhou^{1

3}, Zhiqiang Ai^{1

3}, Xu Pan², Fapei Zhang^{1

2}

Affiliations

¹ Anhui Key Laboratory of Low-Energy Quantum Materials and Devices, High Magnetic Field Laboratory, Hefei Institutes of Physical Science, Chinese Academy of Sciences Hefei 230031 P. R. China fzhang@hmfl.ac.cn.
² Key Laboratory of Photovoltaic and Energy Conservation Materials, Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences Hefei 230031 P. R. China xpan@rntek.cas.cn.
³ University of Science and Technology of China Hefei 230026 P. R. China.

Abstract

Passivation treatment is an effective method to suppress various defects in perovskite solar cells (PSCs), such as cation vacancies, under-coordinated Pb²⁺ or I^-, and Pb-I antisite defects. A thorough understanding of the diversified impacts of different defect passivation methods (DPMs) on the device performance will be beneficial for making wise DPM choices. Herein, we choose a hydrophobic Lewis acid tris(pentafluorophenyl)borane (BCF), which can dissolve in both the perovskite precursor and anti-solvent, as the passivation additive. BCF treatment can immobilize organic cations via forming hydrogen bonds. Three kinds of DPMs based on BCF are applied to modify perovskite films in this work. It is found that the best DPM with BCF dissolved in anti-solvent can not only passivate multiple defects in perovskite, but also inhibit δ phase perovskite and improve the stability of devices. Meanwhile, DPM with BCF dissolved in both the perovskite precursor and anti-solvent can cause cracks and voids in perovskite films and deteriorate device performance, which should be avoided in practical applications. As a result, PSCs based on optimal DPMs of BCF present an increased efficiency of 22.86% with negligible hysteresis as well as improved overall stability. This work indicates that the selection and optimization of DPMs have an equally important influence on the photovoltaic performance of PSCs as the selection of passivation additives.