In-Situ Formed Type i Nanocrystalline Perovskite Film for Highly Efficient Light-Emitting Diode

Jin Wook Lee, Yung Ji Choi, June Mo Yang, Sujin Ham, Sang Kyu Jeon, Jun Yeob Lee, Young Hyun Song, Eun Kyung Ji, Dae Ho Yoon, Seongrok Seo, Hyunjung Shin, Gil Sang Han, Hyun Suk Jung, Dongho Kim, Nam Gyu Park

Research output: Contribution to journalArticlepeer-review

152 Citations (Scopus)


Excellent color purity with a tunable band gap renders organic-inorganic halide perovskite highly capable of performing as light-emitting diodes (LEDs). Perovskite nanocrystals show a photoluminescence quantum yield exceeding 90%, which, however, decreases to lower than 20% upon formation of a thin film. The limited photoluminescence quantum yield of a perovskite thin film has been a formidable obstacle for development of highly efficient perovskite LEDs. Here, we report a method for highly luminescent MAPbBr3 (MA = CH3NH3) nanocrystals formed in situ in a thin film based on nonstoichiometric adduct and solvent-vacuum drying approaches. Excess MABr with respect to PbBr2 in precursor solution plays a critical role in inhibiting crystal growth of MAPbBr3, thereby forming nanocrystals and creating type I band alignment with core MAPbBr3 by embedding MAPbBr3 nanocrystals in the unreacted wider band gap MABr. A solvent-vacuum drying process was developed to preserve nanocrystals in the film, which realizes a fast photoluminescence lifetime of 3.9 ns along with negligible trapping processes. Based on a highly luminescent nanocrystalline MAPbBr3 thin film, a highly efficient green LED with a maximum external quantum efficiency of 8.21% and a current efficiency of 34.46 cd/A was demonstrated.

Original languageEnglish
Pages (from-to)3311-3319
Number of pages9
JournalACS Nano
Issue number3
Publication statusPublished - 2017 Mar 28

Bibliographical note

Publisher Copyright:
© 2017 American Chemical Society.

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)


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