Synchronous regulation of bulk and interfacial defects by an ionic liquid for efficient and stable perovskite solar cells

Bingyu Li, Zhipeng Li, Xiafei Jiang, Zichen Wang, Yi Rao, Chujun Zhang, Mingzhe Zhu, Linbao Zhang, Lirong Wen, Shu Kong So, Yuanyuan Zhou, Shuping Pang*, Zhongmin Zhou*

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

11 Citations (Scopus)

Abstract

Charge recombination at grain-boundary interfaces and charge extraction loss at perovskite-carrier transport layer interfaces are the two main causes for the performance deficiency in perovskite solar cells. Herein we reported the synthesis of an ionic liquid compound 9-bromo-6,7-diphenylpyrido[2,1-a]isoquinolin-5-ium hexafluorophosphate (DPPIQ+PF6), which can synchronously react with perovskites at these two essential interfaces. Specifically, the PF6 anions are incorporated into the perovskite film bulk, immobilizing organic amine ions via hydrogen bonding, while the DPPIQ+ cations are mainly accumulated at the top film surface, binding the [PbI3] through anion-π interactions. Reduced defect density and improved energy level alignment are achieved in the resultant perovskite solar cells. The best-performing DPPIQ+PF6 incorporated device shows a high power conversion efficiency of 23.41% and demonstrates 90% efficiency retention upon maximum-power-point tracking for 1260 h under continuous one-sun-intensity illumination.

Original languageEnglish
Article number154410
JournalApplied Surface Science
Volume603
Early online date2 Aug 2022
DOIs
Publication statusPublished - 30 Nov 2022

Scopus Subject Areas

  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films

User-Defined Keywords

  • Defects
  • Interactions
  • Interface
  • Ionic liquid
  • Perovskite solar cells

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