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

• DOI: 10.1126/science.aau5701
• Publication Date: 2019-01-18T00:16:30Z
• Authors: Ligang Wang; Huanping Zhou; Junnan Hu; Bolong Huang; Mingzi Sun; Bowei Dong; Guanghaojie Zheng; Yuan Huang; Yihua Chen; Liang Li; Ziqi Xu; Nengxu Li; Zheng Liu; Qi Chen; Ling-Dong Sun; Chun-Hua Yan
• Keywords: Europium

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, thermal stresses lead metastable elemental halide atom defects. Wang et al. show that the lead-iodine system, introduction of rare earth europium ion pair Eu 3+ -Eu 2+ shuttle electrons recover iodine ions (Pb I − ). Devices incorporating this maintained more than 90% their initial power conversion efficiencies under various aging conditions. Science , p. 265