Importance of Low Humidity and Selection of Halide Ions of Octylammonium Halide in 2D–3D Perovskite Solar Cells Fabricated in Air

Su Yeon Kwon, Byungsoo Kang, Jong Hyeon Won, Chae Young Lee, Kahee Hwang, Hong Hee Kim, Donghee Park, Won Kook Choi, In Soo Kim, Gee Yeong Kim, Yoon Hee Jang, Phillip Lee, Sang Hyuk Im, Taehee Kim

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


Air fabrication of efficient and stable perovskite solar cells with substantial reproducibility is of importance for commercialization of perovskite solar cells. There has been little consensus on which halide is the best selection for thin 2D perovskite layer on 3D perovskite when processing in ambient air. In this work, the influence of humidity and halide ions in alkylammonium halide (OAX)-treated perovskite layer on photovoltaic performance is investigated. The authors find that a combination of high humidity and the presence of chloride ions can induce the deprotonation of methylammonium (MA+) ions. With X-ray diffraction, cross-sectional scanning electron microscope, Fourier-transform infrared spectroscopy, the authors elucidate that the deprotonation reaction in the octylammonium chloride (OACl)-treated perovskite layer makes MA+ ions (CH3NH3+) volatile MA (CH3NH2), which results in void volumes and defects in the bulk of perovskite layer as well as at the interface. The defective perovskite solar cells induced by the deprotonation reaction have the suppressed hole transfer at the interface between the perovskite layer and the hole transport layer, yielding the reduced internal quantum efficiency and JSC. Space charge-limited current analysis reveals that the reduced VOC is caused by the high trap density estimated from VTFL of hole-only devices.

Original languageEnglish
Article number2202249
JournalAdvanced Materials Interfaces
Issue number10
Publication statusPublished - 2023 Apr 4

Bibliographical note

Publisher Copyright:
© 2023 The Authors. Advanced Materials Interfaces published by Wiley-VCH GmbH.


  • charge transfer
  • chloride ions
  • deprotonation
  • humidity
  • perovskite solar cells
  • quantum efficiency
  • recombination

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering


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