Phenylalkylammonium passivation enables perovskite light emitting diodes with record high-radiance operational lifetime: the chain length matters

Yuwei Guo, Sofia Apergi, Nan Li, Mengyu Chen, Chunyang Yin, Zhongcheng Yuan, Feng Gao, Fangyan Xie, Geert Brocks, Shuxia Tao, Ni Zhao*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Perovskite light emitting diodes suffer from poor operational stability, exhibiting a rapid decay of external quantum efficiency within minutes to hours after turn-on. To address this issue, we explore surface treatment of perovskite films with phenylalkylammonium iodide molecules of varying alkyl chain lengths. Combining experimental characterization and theoretical modelling, we show that these molecules stabilize the perovskite through suppression of iodide ion migration. The stabilization effect is enhanced with increasing chain length due to the stronger binding of the molecules with the perovskite surface, as well as the increased steric hindrance to reconfiguration for accommodating ion migration. The passivation also reduces the surface defects, resulting in a high radiance and delayed roll-off of external quantum efficiency. Using the optimized passivation molecule, phenylpropylammonium iodide, we achieve devices with an efficiency of 17.5%, a radiance of 1282.8 W sr−1 m−2 and a record T50 half-lifetime of 130 h under 100 mA cm−2.

Original languageEnglish
Article number644
JournalNature communications
Issue number1
Publication statusPublished - 28 Jan 2021

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