A Eu 3+ -Eu 2+ ion redox shuttle imparts operational durability to Pb-I perovskite solar cells

A redox road to recovery Device longevity is a key issue for organic-inorganic perovskite solar cells. Encapsulation can limit degradation arising from reactions with oxygen and water, but light, electric-field, and thermal stresses can lead to metastable elemental lead and halide atom defects. Wang et al. show that for the lead-iodine system, the introduction of the rare earth europium ion pair Eu 3+ -Eu 2+ can shuttle electrons and recover lead and iodine ions (Pb 2+ and I − ). Devices incorporating this redox shuttle maintained more than 90% of their initial power conversion efficiencies under various aging conditions. Science , this issue p. 265

• SS
  Salt Science Research Foundation
• NN
  National Natural Science Foundation of China

  Awards: BL14B1, 21331001, 21425101, 51722201, 51722201, 51672008, 91733301, 21425101, 21321001, 21371011, 21331001, 91733301, 2017YFA0206701, 51672008, 21621061, 4182026
• CS
  Central South University
• EC
  East China Normal University
• BI
  Beijing Institute of Technology
• NI
  National Institute of Metrology, China
• UO
  University of California, Los Angeles
• NK
  National Key Research and Development Program of China

  Awards: 51672008, 2017YFA0206701, 21621061, 4182026, 51722201, 91733301, 2017YFA0205101