High-Light-Tolerance PbI2 Boosting the Stability and Efficiency of Perovskite Solar Cells

Li Chen; Jingde Chen; Chenyue Wang; Hao Ren; Yu-Xin Luo; Kong-Chao Shen; Yanqing Li; Fei Song; Xingyu Gao; Jian-Xin Tang

doi:10.1021/acsami.1c02929

High-Light-Tolerance PbI₂ Boosting the Stability and Efficiency of Perovskite Solar Cells

ACS Appl Mater Interfaces. 2021 Jun 2;13(21):24692-24701. doi: 10.1021/acsami.1c02929. Epub 2021 May 19.

Authors

Li Chen^{1

2}, Jingde Chen¹, Chenyue Wang², Hao Ren¹, Yu-Xin Luo¹, Kong-Chao Shen¹, Yanqing Li³, Fei Song², Xingyu Gao², Jian-Xin Tang^{1

4}

Affiliations

¹ Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou 215123, China.
² Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, and Shanghai Synchrotron Radiation Facility, Zhangjiang Laboratory, Chinese Academy of Sciences, Shanghai 201204, China.
³ School of Physics and Electronic Science, Ministry of Education Nanophotonics and Advanced Instrument Engineering Research Center, East China Normal University, Shanghai 200062, China.
⁴ Macao Institute of Materials Science and Engineering (MIMSE), Macau University of Science and Technology, Taipa, Macau SAR 999078, China.

PMID: 34008958
DOI: 10.1021/acsami.1c02929

Abstract

Excess lead iodide (PbI₂) plays a crucial role in passivating the defects of perovskite films and boosting the power conversion efficiency (PCE) of perovskite solar cells (PSCs). However, the photolysis of PbI₂ is easily triggered by light illumination, which accelerates the decomposition of perovskite materials and weakens the long-term stability of PSCs. Herein, the high light tolerance of lead iodide (PbI₂) is reported by introducing an electron-donor molecule, namely, 2-thiophenecarboxamide (2-TCAm), to strengthen the [PbX₆]^4- frame. Characterization reveals that the retarded decomposition of PbI₂ is attributed to the interactions between Pb²⁺ and the organic functional groups in 2-TCAm as well as the optimized distribution of PbI₂. The crystallization and morphology of 2-TCAm-doped perovskite films are improved simultaneously. The 2-TCAm-based PSCs achieve a 16.8% increase in PCE and nearly 12 times increase in the lifetime as compared to the reference device. The demonstrated method provides insight into the stability of PbI₂ and its influence on PSCs.

Keywords: lead iodide; light tolerance; perovskite solar cells; photolysis; stability.