Arylammonium-Assisted Reduction of the Open-Circuit Voltage Deficit in Wide-Bandgap Perovskite Solar Cells: The Role of Suppressed Ion Migration

Cong Chen, Zhaoning Song, Chuanxiao Xiao, Rasha Awni, Canglang Yao, Niraj Shrestha, Congwen Li, Sandip Singh Bista, Yi Zhang, Lei Chen, Randy Ellingson, Chun-Sheng Jiang, Mowafak Al-Jassim, Guojia Fang, Yanfa Yan

Research output: Contribution to journalArticlepeer-review

128 Scopus Citations

Abstract

Surface treatment using large alkyl/aryl ammonium cations has demonstrated reduced open-circuit voltage (VOC) deficits in perovskite solar cells (PSCs), but the origin of the improvements has been vaguely attributed to defect passivation. Here, we combine microscopic probing of the local electrical properties, thermal admittance spectroscopic analysis, and first-principles calculations to elucidate the critical role of arylammonium interface layers in suppressing ion migration in wide-bandgap (WBG) PSCs. Our results reveal that arylammonium surface treatment using phenethylammonium iodide increases the activation energy barrier for ion migration on the surface, which suppresses the accumulation of charge defects at surface and grain boundaries, leading to a reduced dark saturation current density in WBG PSCs. With device optimization, our champion 1.73 eV PSC delivers a power conversion efficiency of 19.07% with a VOC of 1.25 V, achieving a VOC deficit of 0.48 V.

Original languageAmerican English
Pages (from-to)2560-2568
Number of pages9
JournalACS Energy Letters
Volume5
Issue number8
DOIs
StatePublished - 14 Aug 2020

Bibliographical note

Publisher Copyright:
© 2020 American Chemical Society.

NREL Publication Number

  • NREL/JA-5K00-78015

Keywords

  • activation energy
  • calculations
  • conversion efficiency
  • energy gap
  • grain boundaries
  • ions
  • open circuit voltage
  • perovskite
  • spectroscopic analysis
  • surface treatment
  • timing circuits

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