Emission Enhancement and Intermittency in Polycrystalline Organolead Halide Perovskite Films

Cheng Li, Yu Zhong, Carlos Andres Melo Luna, Thomas Unger, Konstantin Deichsel, Anna Graeser, Juergen Koehler, Anna Koehler, Richard Hildner, Sven Huettner*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

19 Citations (Scopus)
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Abstract

Inorganic-organic halide organometal perovskites have demonstrated very promising performance for opto-electronic applications, such as solar cells, light-emitting diodes, lasers, single-photon sources, etc. However, the little knowledge on the underlying photophysics, especially on a microscopic scale, hampers the further improvement of devices based on this material. In this communication, correlated conventional photoluminescence (PL) characterization and wide-field PL imaging as a function of time are employed to investigate the spatially-and temporally-resolved PL in CH3NH3PbI3-xClx perovskite films. Along with a continuous increase of the PL intensity during light soaking, we also observe PL blinking or PL intermittency behavior in individual grains of these films. Combined with significant suppression of PL blinking in perovskite films coated with a phenyl-C61-butyric acid methyl ester (PCBM) layer, it suggests that this PL intermittency is attributed to Auger recombination induced by photoionized defects/traps or mobile ions within grains. These defects/traps are detrimental for light conversion and can be effectively passivated by the PCBM layer. This finding paves the way to provide a guideline on the further improvement of perovskite opto-electronic devices.

Original languageEnglish
Article number1081
Number of pages12
JournalMolecules
Volume21
Issue number8
DOIs
Publication statusPublished - Aug-2016
Externally publishedYes

Keywords

  • perovskite solar cells
  • photoluminescence
  • intermittency
  • Auger recombination
  • ion migration
  • passivation
  • blinking
  • Methylammonium Lead Halide
  • methylammonium lead iodide
  • ORGANOMETAL TRIHALIDE PEROVSKITE
  • METHYLAMMONIUM LEAD IODIDE
  • SOLAR-CELLS
  • ION MIGRATION
  • TRAP STATES
  • PHOTOLUMINESCENCE
  • LUMINESCENCE

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