In Situ Preparation of Metal Halide Perovskite Nanocrystal Thin Films for Improved Light-Emitting Devices

Lianfeng Zhao, Yao Wen Yeh, Nhu L. Tran, Fan Wu, Zhengguo Xiao, Ross A. Kerner, Yunhui L. Lin, Gregory D. Scholes, Nan Yao, Barry P. Rand

Research output: Contribution to journalArticlepeer-review

96 Scopus citations

Abstract

Hybrid organic-inorganic halide perovskite semiconductors are attractive candidates for optoelectronic applications, such as photovoltaics, light-emitting diodes, and lasers. Perovskite nanocrystals are of particular interest, where electrons and holes can be confined spatially, promoting radiative recombination. However, nanocrystalline films based on traditional colloidal nanocrystal synthesis strategies suffer from the use of long insulating ligands, low colloidal nanocrystal concentration, and significant aggregation during film formation. Here, we demonstrate a facile method for preparing perovskite nanocrystal films in situ and that the electroluminescence of light-emitting devices can be enhanced up to 40-fold through this nanocrystal film formation strategy. Briefly, the method involves the use of bulky organoammonium halides as additives to confine crystal growth of perovskites during film formation, achieving CH3NH3PbI3 and CH3NH3PbBr3 perovskite nanocrystals with an average crystal size of 5.4 ± 0.8 nm and 6.4 ± 1.3 nm, respectively, as confirmed through transmission electron microscopy measurements. Additive-confined perovskite nanocrystals show significantly improved photoluminescence quantum yield and decay lifetime. Finally, we demonstrate highly efficient CH3NH3PbI3 red/near-infrared LEDs and CH3NH3PbBr3 green LEDs based on this strategy, achieving an external quantum efficiency of 7.9% and 7.0%, respectively, which represent a 40-fold and 23-fold improvement over control devices fabricated without the additives.

Original languageEnglish (US)
Pages (from-to)3957-3964
Number of pages8
JournalACS Nano
Volume11
Issue number4
DOIs
StatePublished - Apr 25 2017

All Science Journal Classification (ASJC) codes

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

Keywords

  • in situ preparation
  • light-emitting diodes
  • nanocrystal synthesis
  • organic-inorganic hybrid perovskites
  • perovskite stability

Fingerprint Dive into the research topics of 'In Situ Preparation of Metal Halide Perovskite Nanocrystal Thin Films for Improved Light-Emitting Devices'. Together they form a unique fingerprint.

Cite this