Bulky ammonium iodide and in-situ formed 2D Ruddlesden-Popper layer enhances the stability and efficiency of perovskite solar cells

Yitian Du; Jihuai Wu; Guodong Li; Xiaobing Wang; Zeyu Song; Chunyan Deng; Qi Chen; Yu Zou; Weihai Sun; Zhang Lan

doi:10.1016/j.jcis.2022.01.103

Bulky ammonium iodide and in-situ formed 2D Ruddlesden-Popper layer enhances the stability and efficiency of perovskite solar cells

J Colloid Interface Sci. 2022 May 15:614:247-255. doi: 10.1016/j.jcis.2022.01.103. Epub 2022 Jan 20.

Authors

Yitian Du¹, Jihuai Wu², Guodong Li¹, Xiaobing Wang¹, Zeyu Song¹, Chunyan Deng¹, Qi Chen¹, Yu Zou¹, Weihai Sun¹, Zhang Lan¹

Affiliations

¹ Engineering Research Center of Environment-Friendly Functional Materials, Ministry of Education, Fujian Engineering Research Center of Green Functional Materials, Institute of Materials Physical Chemistry, Huaqiao University, Xiamen 361021, China.
² Engineering Research Center of Environment-Friendly Functional Materials, Ministry of Education, Fujian Engineering Research Center of Green Functional Materials, Institute of Materials Physical Chemistry, Huaqiao University, Xiamen 361021, China. Electronic address: jhwu@hqu.edu.cn.

PMID: 35101672
DOI: 10.1016/j.jcis.2022.01.103

Abstract

The practical applications of perovskite solar cells (PSCs) are limited by the further improvement of their stability and performance. Interface engineering is a promising strategy to solve these pain points. Herein, we design (R)-(-)-1-cyclohexylethylamine iodide (R-CEAI), composed of positively charged hydrophobic R-CEA⁺ and negatively charged I^-, to post-treat the interface of 3D mixed-cation/halide perovskite with assist one of isopropyl alcohol (IPA). R-CEAI treatment not only passivates the defects at surface and grain boundaries of perovskite, but also in-situ grows quasi 2D Ruddlesden-Popper perovskite at the interface between 3D perovskite and hole transport layer, which reduces trap density of states, tunes energy level and alleviates lattice distortion. As a result, R-CEAI treated 2D/3D PSCs yield a champion PCE of 22.52%, with an improved open-circuit voltage of 1.195 V and retain 84.34% of their initial efficiency in long-term stability test, while the pristine device provides a PCE of 19.43% with only 54.30% retention.

Keywords: 2D Ruddlesden-Popper perovskite; 2D/3D perovskite; Ammonium iodide; Interface engineering; Perovskite solar cell.