Unraveling abnormal buried interface anion defect passivation mechanisms depending on cation-induced steric hindrance for efficient and stable perovskite solar cells

He，Dongmei1; Li，Ru1; Liu，Baibai1; Zhou，Qian1; Yang，Hua2; Yu，Xuemeng3; Gong，Shaokuan3; Chen，Xihan3; Xu，Baomin4; Yang，Shangfeng5; Chen，Jiangzhao1

2023-05-01

10.1016/j.jechem.2023.01.043

Journal of Energy Chemistry   Impact Factor & Quartile

2095-4956

Although ionic liquids (ILs) have been widely employed to heal the defects in perovskite solar cells (PSCs), the corresponding defect passivation mechanisms are not thoroughly understood up to now. Herein, we first reveal an abnormal buried interface anion defect passivation mechanism depending on cation-induced steric hindrance. The IL molecules containing the same anion ([BF]) and different sizes of imidazolium cations induced by substituent size are used to manipulate buried interface. It was revealed what passivated interfacial defects is mainly anions instead of cations. Theoretical and experimental results demonstrate that the large-sized cations can weaken the ionic bond strength between anions and cations, and facilitate the interaction between anions and SnO as well as perovskites, which is conducive to interfacial defect passivation and ameliorating interfacial contact. It can be concluded that interfacial chemical interaction strength and defect passivation effect are positively correlated with the size of cations. The discovery breaks conventional thinking that large-sized modification molecules would weaken their chemical interaction with perovskite. Compared with the control device (21.54%), the device based on 1,3-Bis(1-adamantyl)-imidazolium tetrafluoroborate (BAIMBF) with maximum size cations achieves a significantly enhanced efficiency of 23.61% along with much increased moisture, thermal and light stabilities.

Anion defect passivation mechanism Buried interface Cation-induced steric hindrance Ionic liquid Perovskite solar cells

SCI

English

Others

Support Plan for Overseas Students[cx2020003] ; Fundamental Research Funds for the Central Universities["2020CDJ-LHZZ-074","2021CDJQY-022"] ; Natural Science Foundation of Chongqing[cstc2020jcyj-msxmX0629]

Chemistry ; Energy & Fuels ; Engineering

Chemistry, Applied ; Chemistry, Physical ; Energy & Fuels ; Engineering, Chemical

WOS:000939776400001

ELSEVIER

2-s2.0-85148036653

Scopus

1.Key Laboratory of Optoelectronic Technology & Systems (Ministry of Education),College of Optoelectronic Engineering,Chongqing University,Chongqing,400044,China
2.Institute of High Energy Physics,Chinese Academy of Sciences (CAS),Beijing,100049,China
3.SUSTech Energy Institute for Carbon Neutrality,Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China
4.Department of Materials Science and Engineering,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China
5.CAS Key Laboratory of Materials for Energy Conversion,Department of Materials Science and Engineering,University of Science and Technology of China,Hefei,Anhui,230026,China

He，Dongmei,Li，Ru,Liu，Baibai,et al. Unraveling abnormal buried interface anion defect passivation mechanisms depending on cation-induced steric hindrance for efficient and stable perovskite solar cells[J]. Journal of Energy Chemistry,2023,80:1-9.

He，Dongmei.,Li，Ru.,Liu，Baibai.,Zhou，Qian.,Yang，Hua.,...&Chen，Jiangzhao.(2023).Unraveling abnormal buried interface anion defect passivation mechanisms depending on cation-induced steric hindrance for efficient and stable perovskite solar cells.Journal of Energy Chemistry,80,1-9.

He，Dongmei,et al."Unraveling abnormal buried interface anion defect passivation mechanisms depending on cation-induced steric hindrance for efficient and stable perovskite solar cells".Journal of Energy Chemistry 80(2023):1-9.