Photoluminescence Lifetimes Exceeding 8 μs and Quantum Yields Exceeding 30% in Hybrid Perovskite Thin Films by Ligand Passivation

We study the effects of a series of post-deposition ligand treatments on the photoluminescence (PL) of polycrystalline methylammonium lead triiodide perovskite thin films. We show that a variety of Lewis bases can improve the bulk PL quantum efficiency (PLQE) and extend the average PL lifetime, , with large enhancements concentrated at grain boundaries. Notably, we demonstrate thin-film PLQE as high as 35 ± 1% and as long as 8.82 ± 0.03 μs at solar equivalent carrier densities using tri-n-octylphosphine oxide-treated films. Using glow discharge optical emission spectroscopy and nuclear magnetic resonance spectroscopy, we show that the ligands are incorporated primarily at the film surface and are acting as…

• NS
  National Science Foundation

  Awards: 1256082, DGE-1256082, 1542101, ECCS-1542101
• UD
  U.S. Department of Energy

  Awards: SC0013957, DE-SC0013957
• UO
  University of Washington

  Award: ECCS-1542101
• NI
  National Institutes of Health

  Award: DGE-1256082
• CE
  Clean Energy Institute

  Award: ECCS-1542101
• DO
  Division of Graduate Education

  Awards: ECCS-1542101, DGE-1256082
• DO
  Division of Electrical, Communications and Cyber Systems

  Awards: ECCS-1542101, 1542101