Synergistic effects of caesium closo-dodecaborate on buried interface for efficient and stable perovskite solar cells

Wenjing Hou; Meiling Yang; Yao Guo; Yuting Ma; Mengna Guo; Yaoming Xiao; Gaoyi Han

doi:10.1016/j.jcis.2023.04.171

Synergistic effects of caesium closo-dodecaborate on buried interface for efficient and stable perovskite solar cells

J Colloid Interface Sci. 2023 Sep:645:472-482. doi: 10.1016/j.jcis.2023.04.171. Epub 2023 May 4.

Authors

Wenjing Hou¹, Meiling Yang², Yao Guo³, Yuting Ma², Mengna Guo², Yaoming Xiao⁴, Gaoyi Han⁵

Affiliations

¹ Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Education Ministry, Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Shanxi University, Taiyuan 030006, PR China. Electronic address: houwenjing@sxu.edu.cn.
² Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Education Ministry, Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Shanxi University, Taiyuan 030006, PR China.
³ School of Materials Science and Engineering, Henan Joint International Research Laboratory of Nanocomposite Sensing Materials, Anyang Institute of Technology, Anyang 455000, PR China. Electronic address: guoyao@ayit.edu.cn.
⁴ College of Chemical Engineering and Materials Science, Quanzhou Normal University, Quanzhou 362000, PR China.
⁵ Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Education Ministry, Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Shanxi University, Taiyuan 030006, PR China. Electronic address: han_gaoyis@sxu.edu.cn.

PMID: 37156156
DOI: 10.1016/j.jcis.2023.04.171

Abstract

The defects and strain of the buried SnO₂/perovskite interface seriously affects the performances of n-i-p type perovskite solar cells. Herein, caesium closo-dodecaborate (B₁₂H₁₂Cs₂) is introduced into buried interface to improve the device performances. B₁₂H₁₂Cs₂ can passivate the bilateral defects of the buried interface, including the oxygen vacancy and uncoordinated Sn²⁺ defects on SnO₂ side and the uncoordinated Pb²⁺ defects on perovskite side. Three-dimensional aromatic B₁₂H₁₂Cs₂ can promote the interface charge transfer and extraction. [B₁₂H₁₂]^2- can enhance the interface connection of buried interface by forming B-H---H-N dihydrogen bond and coordination bonds with metal ions. Meanwhile, the crystal properties of perovskite films can be improved and the buried tensile strain can be released by B₁₂H₁₂Cs₂ due to the matched lattice between B₁₂H₁₂Cs₂ and perovskite. In addition, Cs⁺ can diffuse into perovskite to reduce the hysteresis behavior by inhibiting the I^- migration. Arising from the enhanced connection performances, passivated defects, improved perovskite crystallization, enhanced charge extraction, inhibited ions migration, released tensile strain at buried interface by B₁₂H₁₂Cs₂, the corresponding devices yield a champion power conversion efficiency of 22.10% with enhanced stability. The stability of devices by B₁₂H₁₂Cs₂ modification have been improved, and it can still maintain 72.5% of the original efficiency after 1440 h, while the control devices can only maintain 20% of the original efficiency after aging in air condition of 20-30% RH.

Keywords: B(12)H(12)Cs(2); Buried interface; Interface modification; Perovskite solar cells.