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Emission Enhancement and Intermittency in Polycrystalline Organolead Halide Perovskite Films

Cheng Li, Yu Zhong, Carlos Andres Melo Luna, Thomas Unger, Konstantin Deichsel, Anna Gräser, Jürgen Köhler, Anna Köhler, Richard Hildner, Sven Huettner

Molecules. 2016 Aug 18;21(8):1081.

PMID: 27548128

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.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP7720834 Titanium(IV) iodide Titanium(IV) iodide 7720-83-4 Price
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