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Aboma Mendasa, MSc, PhD. Photo.

Aboma Merdasa

Researcher

Aboma Mendasa, MSc, PhD. Photo.

Enhanced Organo-Metal Halide Perovskite Photoluminescence from Nanosized Defect-Free Crystallites and Emitting Sites

Author

  • Yuxi Tian
  • Aboma Merdasa
  • Eva Unger
  • Mohamed Qenawy
  • Kaibo Zheng
  • Sarah McKibbin
  • Anders Mikkelsen
  • Tönu Pullerits
  • Arkady Yartsev
  • Villy Sundström
  • Ivan Scheblykin
Show all

Summary, in English

Photoluminescence (PL) of organo-metal halide perovskite semiconductors can be enhanced by several orders of magnitude by exposure to visible light. We applied PL microscopy and super-resolution optical imaging to investigate this phenomenon with spatial resolution better than 10 nm using films of CH3NH3PbI3 prepared by the equimolar solution-deposition method, resulting in crystals of different sizes. We found that PL of similar to 100 nm crystals enhances much faster than that of larger, micrometer-sized ones. This crystal-size dependence of the photochemical light passivation of charge traps responsible for PL quenching allowed us to conclude that traps are present in the entire crystal volume rather than at the surface only. Because of this effect, "dark" micrometer-sized perovskite crystals can be converted into highly luminescent smaller ones just by mechanical grinding. Super-resolution optical imaging shows spatial inhomogeneity of the PL intensity within perovskite crystals and the existence of <100 nm-sized localized emitting sites. The possible origin of these sites is discussed.

Department/s

  • Chemical Physics
  • Synchrotron Radiation Research
  • NanoLund: Centre for Nanoscience

Publishing year

2015

Language

English

Pages

4171-4177

Publication/Series

The Journal of Physical Chemistry Letters

Volume

6

Issue

20

Document type

Journal article

Publisher

The American Chemical Society (ACS)

Topic

  • Physical Chemistry
  • Condensed Matter Physics

Status

Published

ISBN/ISSN/Other

  • ISSN: 1948-7185