Manipulate energy transport via fluorinated spacers towards record-efficiency 2D Dion-Jacobson CsPbI3 solar cells

Yutian Lei; Zhenhua Li; Haoxu Wang; Qian Wang; Guoqiang Peng; Youkui Xu; Haihua Zhang; Gang Wang; Liming Ding; Zhiwen Jin

doi:10.1016/j.scib.2022.05.019

Manipulate energy transport via fluorinated spacers towards record-efficiency 2D Dion-Jacobson CsPbI₃ solar cells

Sci Bull (Beijing). 2022 Jul 15;67(13):1352-1361. doi: 10.1016/j.scib.2022.05.019. Epub 2022 May 27.

Authors

Yutian Lei¹, Zhenhua Li², Haoxu Wang³, Qian Wang¹, Guoqiang Peng¹, Youkui Xu¹, Haihua Zhang⁴, Gang Wang⁵, Liming Ding⁶, Zhiwen Jin⁷

Affiliations

¹ School of Physical Science and Technology & Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, China.
² School of Physical Science and Technology & Lanzhou Center for Theoretical Physics & Key Laboratory of Theoretical Physics of Gansu Province, Lanzhou University, Lanzhou 730000, China.
³ Delft University of Technology, Photovoltaic Materials and Devices Group, Delft 2628CD, the Netherlands.
⁴ Institute of Molecular Plus, Tianjin University, Tianjin 300072, China.
⁵ Department of Microelectronic Science and Engineering, School of Physical Science and Technology, Ningbo University, Ningbo 315211, China.
⁶ Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190, China.
⁷ School of Physical Science and Technology & Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, China. Electronic address: jinzw@lzu.edu.cn.

PMID: 36546268
DOI: 10.1016/j.scib.2022.05.019

Abstract

Two-dimensional (2D) Dion-Jacobson (D-J)-type cesium lead iodide CsPbI₃ perform remarkably in terms of stability. However, the complex interactions between spacer and inorganic layers limit its excellent progress in perovskite solar cells (PSCs). Herein, starting from the considerable structural diversity of organic spacers, we engineer 2D CsPbI₃ with fine-tuning functionalities. Specifically, for the first time we embedded fluorinated aromatic cations in 2D D-J CsPbI₃, and successfully applied it into construction of high-performance PSCs. Compared with constitutive 1,4-diaminobenzene (PDA), the fluorinated 2-fluorobenzene-1,4-diamine (F-PDA) component greatly expands the dipole moment from 0.59D to 3.47D, which reduces the exciton binding energy of the system. A theoretical study shows that the spacer layer and inorganic plane are more enriched with charge accumulation in (F-PDA)Cs_n-₁Pb_nI₃_n+₁. The results show that (F-PDA)Cs_n-₁Pb_nI₃_n+₁ demonstrates more significant charge transfer between organic and inorganic layers than (PDA)Cs_n-₁Pb_nI₃_n+₁, and it is confirmed in the femtosecond transient absorption experiment. Moreover, the interactions of the fluorinated spacer with the [PbI₆]⁴^- plane effectively manipulate the crystallization quality, and thus the ion migration and defect formation of target 2D CsPbI₃ are inhibited. As a result, we obtained a record power conversion efficiency (PCE) beyond 15% for 2D D-J (F-PDA)Cs₃Pb₄I₁₃ (n = 4) PSCs with significantly improved environmental stability compared with the three-dimensional (3D) counterparts.

Keywords: Dion-Jacobson CsPbI(3); Energy transport; Fluorinated spacers; Interaction.