Controlled redox of lithium-ion endohedral fullerene for efficient and stable metal electrode-free perovskite solar cells

Research output: Contribution to journalArticle


  • Il Jeon
  • Ahmed Shawky
  • Hao Sheng Lin
  • Seungju Seo
  • Hiroshi Okada
  • Jin Wook Lee
  • Amrita Pal
  • Shaun Tan
  • Anton Anisimov
  • Head of Department Esko Kauppinen

  • Yang Yang
  • Sergei Manzhos
  • Shigeo Maruyama
  • Yutaka Matsuo

Research units

  • University of Tokyo
  • Korea University
  • Central Metallurgical Research & Development Institute
  • Sungkyunkwan University
  • University of California at Los Angeles
  • National University of Singapore
  • Canatu Ltd.
  • Institut national de la recherche scientifique
  • National Institute of Advanced Industrial Science and Technology
  • Nagoya University


High efficiency perovskite solar cells has underpinned the rapid growth of the field. However, their low device stability limits further ad-vancement. Hygroscopic lithium bis(trifluoromethanesulfonyl)imide (Li+TFSI-) and metal electrode are the main causes of the device instability. In this work, the redox reaction between lithium-ion endohedral fullerenes and 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)-9,9′-spirobi-fluorene (spiro-MeOTAD) was controlled to optimize the amount of oxidized spiro-MeOTAD and antioxidizing neutral endohedral fullerenes. Application of this mixture to metal-free carbon nanotube (CNT)-laminated perovskite solar cells resulted in 17.2% efficiency with a stability time of more than 1100 hours under severe condition (temperature = 60ºC, humidity = 70%). Such high performance is attributed to the uninhibited charge flow, no metal-ion migration, and the enhanced anti-oxidizing ac-tivity of the devices.


Original languageEnglish
Pages (from-to)16553-16558
JournalJournal of the American Chemical Society
Issue number42
Early online date1 Jan 2019
Publication statusPublished - 17 Jul 2019
MoE publication typeA1 Journal article-refereed

    Research areas

  • Carbon Nanotube, Endohedral Fullerene, Metallofullerene, Perovskite Solar Cells, Stability of Solar Cells

ID: 37824396