Lecithin Capping Ligands Enable Ultrastable Perovskite-Phase CsPbI3Quantum Dots for Rec. 2020 Bright-Red Light-Emitting Diodes

Wasim J. Mir, Ahmed Alamoudi, Jun Yin, Khursand E. Yorov, Partha Maity, Rounak Naphade, Bingyao Shao, Jiayi Wang, Muhammad Naufal Lintangpradipto, Saidkhodzha Nematulloev, Abdul Hamid Emwas, Alessandro Genovese, Omar F. Mohammed*, Osman M. Bakr*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

46 Scopus citations

Abstract

Bright-red light-emitting diodes (LEDs) with a narrow emission line width that emit between 620 and 635 nm are needed to meet the latest industry color standard for wide color gamut displays, Rec. 2020. CsPbI3 perovskite quantum dots (QDs) are one of the few known materials that are ideally suited to meet these criteria. Unfortunately, CsPbI3 perovskite QDs are prone to transform into a non-red-emitting phase and are subject to further degradation mechanisms when their luminescence wavelength is tuned to match that of the Rec. 2020 standard. Here, we show that zwitterionic lecithin ligands can stabilize the perovskite phase of CsPbI3 QDs for long periods in air for at least 6 months compared to a few days for control samples. LEDs fabricated with our ultrastable lecithin-capped CsPbI3 QDs exhibit an external quantum efficiency (EQE) of 7.1% for electroluminescence centered at 634 nm─a record for all-inorganic perovskite nanocrystals in Rec. 2020 red. Our devices achieve a maximum luminance of 1391 cd/m2 at 7.5 V, and their operational half-life is 33 min (T50) at 200 cd/m2─a 10-fold enhancement compared to control samples. Density functional theory results suggest that the surface strain in CsPbI3 QDs capped with the conventional ligands, oleic acid and oleylamine, contributes to the instability of the perovskite structural phase. On the other hand, lecithin binding induces virtually no surface strain and shows a stronger binding tendency for the CsPbI3 surface. Our study highlights the tremendous potential of zwitterionic ligands in stabilizing the perovskite phase and particle size of CsPbI3 QDs for various optoelectronic applications.

Original languageEnglish (US)
Pages (from-to)13302-13310
Number of pages9
JournalJournal of the American Chemical Society
Volume144
Issue number29
DOIs
StatePublished - Jul 27 2022

Bibliographical note

Funding Information:
The authors gratefully acknowledge the financial support provided by King Abdullah University of Science and Technology (KAUST). We also acknowledge the Supercomputing Laboratory at KAUST for their support in providing computational resources.

Publisher Copyright:
© 2022 American Chemical Society.

ASJC Scopus subject areas

  • Catalysis
  • General Chemistry
  • Biochemistry
  • Colloid and Surface Chemistry

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